Danfoss How to design balancing and control solutions for energy efficient hydronic applications in residential and commercial buildings Application guide

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Application guide

Hydronic applications

Commercial

Hydronic applications

How to design

balancing and control solutions for

energy ecient hydronic applications

in residential and commercial buildings

applications with detailed descriptions about the investment, design, construction and control

Residential

Mixing loop

AHU application

AHU heating

AHU application

AHU cooling

hbc.danfoss.com

Chillers applications Boilers applications Hot water

Content structure in this guide

1. Hydronic applications

1.1 Commercial

1.1.1 Variable ow

1.1.2 Constant ow

1.2 Residential

1.2.1 Two-pipe system

1.2.2 One-pipe system

1.2.3 Heating – special application

Typical page shows you:

Chapter

Schematic drawing

2. Mixing loop

3. AHU applications

3.1 AHU applications heating

3.2 AHU applications cooling

4. Chillers applications

5. Boiler applications

6. Hot water applications

Recommendation Type of solution

7. Glossary and abbreviations

8. Control and valve theory

9. Energy eciency analyses

10. Product overview

Application

General system description

Danfoss products

Performance indicators

Application details

Introduction Notes

Return of investment

poor exellent

Design

acceptable

Designing HVAC systems is not that simple. Many factors need to be considered before making the nal decision about the heat- and/or cooling load, which terminal units to use, how to generate heating or cooling and a hundred other things.

This application guide is developed to help you make some of these decisions by showing the consequences of certain choices. For example, it could be tempting to go for the lowest initial cost (CAPEX) but often there would be compromises on other factors, like the energy consumption or the Indoor Air Quality (IAQ). In some projects the CAPEX might be the deciding factor but in another ones it is more about energy eciency or control precision, therefore it diers from project to project. We collected the most important information concerning a particular solution on a single page with clear indications what consequences can be expected when certain choices are made.

The aim of this guide was not to cover each and every application because that would be impossible. Every day, smart designers come up with new solutions that might be relevant only to one specic problem or that is solving new problems. That is what engineers do. The drive for greener, more energy-friendly solutions is creating new challenges every day, so there are always some new applications. In this particular guide we will nd to cover the applications that are the most common.

Danfoss also has many competent people available that can support you with specic challenges or that can support you with calculations. Please contact your local Danfoss oce for support in your native language.

We hope this guide will help you in your daily work.

Each application shown here is analyzed for four aspects:

Return on Investment, Design, Operation/Maintenance, Control

Return of investment

poor exellent

Design

poor exellent

acceptable

All of them are marked as:

Technically and economically optimized solutions as recommended by Danfoss. This solution will result in eciently operating systems.

Depending on the situation and the particularities of the system this will result in a good installation. However, some trade-os are made.

Operation/Maintenance

poor exellent

Control

poor exellent

Recommended

Acceptable

acceptable

This system is not recommended since it will result in expensive and inecient systems or the Indoor Air Quality is not ensured.

Not Recommended

Table of Contents

Content structure in this guide 2

Typical page shows you: 2

Introduction 3

1. Hydronic applications

1.1Hydronic applications – commercial buildings 6

1.1.1 Commercial - Variable ow

1.1.1.1 Variable ow: Pressure Independent Control (PICV) with ON/OFF actuator 8

1.1.1.2 Variable ow: Pressure Independent Control (PICV) with proportional control 9

1.1.1.3 Variable ow: Pressure Independent Control (PICV) with digital actuator 10

1.1.1.4 Variable ow: Flow limitation (with ow limiter) on terminal unit with ON/OFF or modular actuator 11

1.1.1.5 Variable ow: Dierential pressure control with ON/OFF or modulation 12

1.1.1.6 Variable ow: Shell and Core installation for Oces and Shopping malls* 13

1.1.1.7 Variable ow: Manual balancing 14

1.1.1.8 Variable ow: Manual balancing with reverse return 15

1.1.1.9 Variable ow: Four-pipe Changeover (CO6) for radiant heating/cooling panels,

chilled beams, etc. with PICV control valve 16

1.1.1.10 Variable ow: Two-pipe heating/cooling system with central changeover* 17

1.1.2 Commercial - Constant ow

1.1.2.1 Constant ow: 3-way valve with manual balancing (in fan-coil, chilled beam etc. application) 18

1.1.2.2 Constant ow: 3-way valve with ow limiter on terminal units (fan-coil, chilled beam etc. application) 19

1.2 Hydronic applications - residential buildings

1.2.1 Residential - Two pipes system

1.2.1.1 Two-pipe radiator heating system – risers with, thermostatic radiator valves (with presetting) 20

1.2.1.2 Two pipe radiator heating system – risers with, thermostatic radiator valves (without presetting) 21

1.2.1.3 Pressure Independent Control for radiator heating system 22

1.2.1.4 Subordinated risers (staircase, bathroom, etc.) in two- or one-pipe radiator heating system without thermostatic valve 23

1.2.1.5 Δp control for manifold with individual zone/loop control 24

1.2.1.6 Δp control and ow limitation for manifold with central zone control 25

1.2.2 Residential - One pipe system

1.2.2.1 One-pipe radiator heating system renovation with automatic ow limitation

and possible self-acting return temperature limitation 26

1.2.2.2 One-pipe radiator heating system renovation with electronic ow limitation and return temperature control 27

1.2.2.3 One-pipe radiator heating system renovation with manual balancing 28

1.2.2.4 One-pipe horizontal heating systems with thermostatic radiator valves, ow limitation

and return temperature self-acting control 29

1.2.3 Residential - Heating - special application

1.2.3.1 Three-pipe, at station system; Δp controlled heating and local DHW* preparation 30

2. Mixing loop

2.1 Mixing with PICV – manifold with pressure dierence 31

2.2 Injection (constant ow) control with 3-way valve 32

2.3 Mixing with 3-way valve – manifold without pressure dierence 33

3 AHU applications

3.1 AHU applications - heating

3.1.1 Pressure Independent Control (PICV) for cooling 34

3.1.2 3-way valve control for cooling 35

3.2 AHU applications - cooling

3.2.1 Pressure Independent Control (PICV) for heating 36

3.2.2 3-way valve control for heating 37

3.2.3 Keep proper ow temperature in front of AHU in partial load condition 38

4. Chillers applications

4.1 Variable primary ow 39

4.2 Constant primary variable secondary (Step Primary) 40

4.3 Constant primary and variable secondary (Primary Secondary) 41

4.4 Constant primary & secondary (Constant Flow System) 42

4.5 District cooling system 43

5. Boiler applications

5.1 Condensing boiler, variable primary ow 44

5.2 Traditional boilers, variable primary ow 45

5.3 System with manifolds de-couplers 46

6. Domestic hot water

6.1 Thermal balancing in DHW circulation (vertical arrangement) 47

6.2 Thermal balancing in DHW circulation (horizontal loop) 48

6.3 Thermal balancing in DHW circulation with self–acting disinfection 49

6.4 Thermal balancing in DHW circulation with electronic desinfection 50

6.5 DHW* circulation control with manual balancing 51

7. Glossary and abbreviations 54

8. Control and valve theory 56

9. Energy eciency analyses 65

10. Product overview 75

Commercial

Hydronic applications

Residential

Hydronic applications

Mixing loop

Hydronic applications – commercial buildings

Variable flow* systems

1.1.1.1 - 1.1.1.6**

Hydronic applications can be controlled and balanced based on a lot of dierent type of solutions. It is impossible to nd the best one for all.

We have to take into consideration each system and its specic to decide what kind of solution will be the most ecient and suitable.

All applications with control valves are variable ow* systems. Calculation is generally done based on nominal parameters but during operation ow in each part of the system is changing (control valves are working). Flow changes result in pressure changes. That’s why in such case we have to use balancing solution that allows to respond to changes in partial load.

Pressure Independent Control

Notes

AHU application

Chillers applicationsBoilers applicationsHot water

AHU heating

Dierential Pressure Control

AHU cooling

Manual Balancing

The evaluation of systems (Recommended/Acceptable/Not recommended) is principally based on combination of 4 aspects mentioned on page 3 (Return on investment/Design/ Operation-Maintenance/Control) but the most important factors are the system performance and eciency.

On application above the manual balanced system is Not recommended because the static elements are not able to follow the dynamic behaviour of variable ow* system and during partial load condition huge overow occurs on control valves (due to smaller pressure drop on pipe network).

The dierential pressure controlled system performs much better (Acceptable) because the pressure stabilization is closer to control valves and although we still have manual balanced system inside the dp controlled loop, the overow phenomenon mitigated. The eciency of such system depends on location of dierential pressure control valve. The closer it is to control valve, the better it works.

The most ecient (Recommended) system we can have is using PICV (pressure independent control valves). In this case the pressure stabilization is right on the control valve, therefore we have full authority* and we are able to eliminate all unnecessary ow from the system.

*see page 54-55

** applications below

Commercial

Hydronic applications

Hydronic applications – commercial buildings

Variable flow* system: PICV – ON/OFF vs modulating vs smart control

1.1.1.1 - 1.1.1.3**

All these applications base on PICV (Pressure Independent Control Valve) technology. It means the control valve (integrated into the valve body) is independent from pressure uctuation in the system during both full, and partial load conditions. This solution allows us to use dierent types of actuators (control method)

• With ON/OFF control, the actuator has two positions, open and closed

• With modulation control the actuator is able to set any ow between nominal and zero value

• With SMART actuator we can ensure (above modulation control) direct connectivity to BMS (Building Management System) to use advanced functions such as energy allocation, energy management etc.

Controlers

Notes

Hydronic applications

Residential

Mixing loop

AHU application

AHU heating

PICV & ON/OFFPICV &

ControlerControler

modulating

PICV technology allows us to use proportional or end point (based on Δp sensor) pump control

The above mentioned control types strongly aect on overall energy consumption of systems.

While ON/OFF control ensures either 100% or 0 ow during operation, the modulation control enables to minimize the ow rate through on terminal unit according real demand. For example, to the same 50% average energy demand we need around 1/3 of ow rate to modulation control, compared to ON/OFF control. (You can nd more details in chapter 9) The lower ow rate contributes to energy saving* on more levels:

• Less circulation cost (fewer ow needs less electricity)

• Improved chiller/boiler eciency (less ow ensures bigger ΔT in the system)

• Smaller room temperature oscillation* ensures better comfort and denes the room temperature setpoint

PICV &

SMART actuator

T T

AHU application

AHU cooling

Chillers applications Boilers applications Hot water

The SMART control – over the above mentioned benets - enable to reduce the maintenance cost with remote access and predictive maintenance.

*see page 54-55 ** applications below

Commercial

FAN COIL UNITS (FCU)

Hydronic applications

Recommended

1.1.1.1

CoolingHeating

Variable ow: Pressure Independent Control (PICV) with ON/OFF actuator

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

1. Preasure Independent Control Valve (PICV)

2. Room temperature Control (RC)

Balancing of the terminal unit by pressure independent valves. This will ensure the right ow at all system loads, regardless of pressure uctuations. ON/OFF control will cause uctuations in the room temperature. The system will not be operating optimally because the ΔT is not optimized.

PICV-1

CHILLED PANELS

PICV-2

Danfoss products:

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

PICV-1: AB-QM 4.0 + TWA-Q PICV-2: AB-QM 4.0 + AMI-140

Explanation

Return of investment

• Reduction of components by eliminating the need for balancing valves

• Lower installation cost due to simplied installation

• The chillers and boilers operate eciently but not optimally because the ∆T is not optimized

• Handover of the building can easily be done in phases

Design

• Easy selection of valves based only on the ow requirement

• No Kv or authority* calculation is needed, the calculation is based on ow demand

• Perfect balance at all loads

• Proportional pump control is applicable and the pump(s) can be optimized* easily

• Min available ∆p demand on the valve can be taken for calculating the pump head

Operation/Maintenance

• Simplied construction because of a reduction of components

• Set and forget, so no complicated balancing procedures

• Fluctuating room temperature, so some occupant complaints can be expected

• Low operational and upkeep cost, so occupants may experience discomfort

• Good but reduced eciency in chillers, boilers and pumping because of a sub-optimized ∆T in the system

Control

• Temperature uctuations *

• No overows*

• Pressure independent solution, so no pressure changes do not aect control circuits

• Low ∆T syndrome* is unlikely to happen

*see page 54-55

CoolingHeating

FAN COIL UNITS (FCU)

Variable ow: Pressure Independent Control

Hydronic applications

Commercial

Recommended

(PICV) with proportional control

PICV-1

0-10VRC

CHILLED PANELS

PICV-2

Danfoss products:

BMS

1.1.1.2

1. Pressure Independent Control Valve (PICV)

2. Building Management System (BMS) or Room temperature Control (RC)

Temperature control of the terminal unit is ensured with pressure independent valves. This will ensure the right ow at all system loads, regardless of pressure uctuations. The result will be stable* and precise room temperature control to ensure a high ΔT and prevent actuators from hunting.

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

PICV-2: AB-QM 4.0 + AME 110 NLPICV-1: AB-QM 4.0 + ABNM A5

Explanation

Return of investment

• Reduction of components by eliminating the need for balancing valves

• Lower installation cost due to simplied installation

• Signicant energy savings* due to optimal working conditions for all components

• Handover of the building can easily be done in phases

Design

• Easy selection of valves based only on the ow requirement

• No Kv or authority* calculation is needed, ow presetting calculation based on ow demand

• Proportional pump control is applicable. The pump(s) can be optimized easily *

• Suitable for BMS applications to monitor the system and reduce energy usage

Operation/Maintenance

• Simplied construction because of a reduction of components

• Set and forget, so no complicated balancing procedures

• Good control at all loads, so no complaints by occupants

• Low operational and upkeep cost

• High comfort (building classication*) because of precise ow control at all loads

• High eciency in chillers, boilers and pumping because of the optimized ∆T in the system

Control

• Perfect control because of full authority *

• No overows* at partial system loads

• Proportional control minimizes the ow circulation and optimizes the pump head

• Pressure independent solution, so pressure interdependency of the control circuits

• No low ∆T syndrome *

Applicable for all terminal units, included AHU (see page 34, 36)

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

AHU heating

Chillers applications Boilers applications Hot water

AHU applications

*see page 54-55

Commercial

Hydronic applications

Residential

Hydronic applications

Recommended

1.1.1.3

I/O

BMS

CoolingHeating

Variable ow: Pressure Independent Control (PICV) with digital actuator

FAN COIL UNITS (FCU)

I/O

PICV

Mixing loop

AHU cooling

AHU applications

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

1. Pressure Independent Control Valve

(PICV)

2. Building Management System (BMS)

3. Digital or Analogue Input/Output

(I/O)

Temperature control of the terminal unit is ensured with pressure independent valves. This will ensure the right ow at all system loads, regardless of pressure uctuations. The result will be stable and precise room temperature control to ensure a high ΔT and prevent actuators from hunting. The additional features of digital, connected actuators will enable better system monitoring and reduce maintenance cost.

Applicable for all terminal units, included AHU (see page 34, 36)

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

I/O

PICV

Danfoss products:

PICV: AB-QM 4.0 + NovoCon® S.

Explanation

CHILLED PANELS

BMS

Return of investment

• Reduction of components by eliminating the need for balancing valves

• Lower installation cost due to simplied installation

• Signicant energy savings* due to optimal working conditions for all components

• The higher cost for the SMART actuator can be oset by hardware savings like a reduced number of additional IOs

• High occupant satisfaction because of perfect balance and control extended with predictive maintenance and pro-active alarm functions

Design

• Easy selection of valves based only on the ow requirement

• No Kv or authority calculation* is needed, ow presetting calculation based on ow demand

• Proportional pump control is applicable. The pump(s) can be optimized easily *

• Suitable for BMS applications to monitor the system and reduce energy usage

• Wide range of possible connected I/O devices ensures large number of BMS variants

Operation/Maintenance

• The full commissioning procedure can be run through BMS ensuring less complexity and high exibility

• Low operational and upkeep cost because the system health can be monitored and maintained through BMS.

• High comfort (building classication) because of precise ow control at all loads

• High eciency in chillers, boilers and pumping because of the optimized ∆T in the system

• Flexible and expandable control system through BMS connectivity

Control

• No overows at partial system loads

• Perfect control because of full authority *

• Proportional control minimizes the ow circulation and optimizes the pump head

• Pressure independent solution, so pressure changes do not aect control circuits

• No low ∆T syndrome *

*see page 54-55

CoolingHeating

Variable ow: Flow limitation (with ow

Hydronic applications

Commercial

Not Recommended

limiter) on terminal unit with ON/OFF or modular actuator

FAN COIL UNITS (FCU)

CV-1

ON/OFF

CV-2 0-10V

Danfoss products:

CHILLED PANELS

BMS

CV-2: VZ2 + AME130 FL: AB-QMCV-1: RA-HC + TWA-A

1.1.1.4

1. 2-way Control Valve (CV)

2. Flow Limiter (FL)

3. Building Management System (BMS) or Room temperature Control (RC)

Temperature control of the terminal unit is done by conventional motorized control valves (CV) while the hydronic balance in the system is realized by automatic ow limiter (FL). For ON/OFF control this could be an acceptable solution, provided that the pump head is not too high. For modulating control this is not acceptable. The FL will counteract the actions of the CV and fully distort the control characteristic. Therefore, modulation with this solutions is impossible.

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

AHU applications

AHU heating

Explanation

Return of investment

• Relatively high product cost because of 2 valves for all terminal units (one CV + FL)

• Higher installation costs although no manual partner valves* are needed

• Variable speed pump is recommended (proportional pump control is possible)

Design

• Traditional calculation is needed but only the kvs of the control valve. It is not necessary to calculate the authority* since the FL will take away the authority of the CV

• For ON/OFF control it is an acceptable solution (simple design: big kvs of zone valve, ow limiter selected based on ow demand)

• High pump head is needed because of the two valves (additional Δp on ow limiter)

Operation/Maintenance

• Closing force of actuator should be able to close the valve against the pump head at minimum ow

• Most ow limiters have pre-determined ow, no adjustment is possible.

• For ushing cartridges need to be removed from the system and placed back afterwards (emptying and lling the system twice)

• Cartridges have small openings and clog easily

• If modulation is attempted the lifetime of the CV is very short due to hunting at partial system loads

• High energy consumption with modulation control due to higher pump head and overow on terminal units in partial load

Control

• Temperature uctuations due to ON/OFF control, even with modulating actuators*

• No overows*

• No pressure interdependency of the control circuits

• Overow during partial load when modulating because the FL will keep the maximum ow if possible

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

3-point or proportional control

acceptable

Chillers applications Boilers applications Hot water

excellent

ON/OFF control

*see page 54-55

Commercial

Hydronic applications

Acceptable

1.1.1.5

CoolingHeating

Variable ow: Dierential pressure control with ON/OFF or modulation

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

1. Zone Control Valve

(with presetting) (CV)

2. Zone Control Valve

(no presetting) (CV)

3. Manual Balancing Valve (MBV)

4. Δp Controller (DPCV)

5. Partner Valve*

6. Building Management System (BMS)

or Room temperature Control (RC)

1 2

6 6

Temperature control at the terminal unit is done by conventional motorized control valve (CV). Hydronic balance is achieved by dierential pressure controllers (DPCV) on the branches and manual balancing valves (MBV) at the terminal unit. If the CV has a pre-setting option the MBV is redundant.

CV-1

ON/OFF

CV-2 0-10V

Danfoss products:

FAN COIL UNITS (FCU)

DPCV

CHILLED PANELS

MBV

DPCV

BMS

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

It guarantees that, regardless of pressure oscillations in the distribution network, we have the right pressure and ow in the pressure-controlled segment.

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

3-point or proportional control

acceptable

excellent

ON/OFF control

CV-2: VZ2 + AME130 DPCV: ASV-PV+ASV-BD MBV: MSV-BD CV-1: RA-HC +TWA-A

Explanation

Return of investment

• Requires Δp controllers and partner valves*.

• MBVs or pre-settable CV is needed for each terminal unit

• Cooling systems might require big and expensive (anged) Δp controllers

• Good energy eciency because there are only limited overows* in partial load

Design

• Simplied design because the branches are pressure independent

• Kv calculation needed for Δp controller and control valve. An authority* calculation is also needed for modulating control

• Pre-setting calculation for terminal units is necessary for proper water distribution within the branch

• The setting for the Δp controller needs to be calculated

• A variable speed pump is recommended

Operation/Maintenance

• More components to install included impulse tube connection between Δp - and partner valve*

• Simplied commissioning* procedure because of pressure independent branches

• Balancing on the terminal units is still required although simplied by Δp controlled branch

• Phased commissioning is possible (branch by branch)

Control

• Generally acceptable to good controllability

• Pressure uctuations that impact the controllability can occur with long branchesor and/or big Δp on terminal units

• Depending on the size of the branch overows can still result in room temperature uctuations.

• If we use ow limitation on partner valve* connected to Δp controller (not on terminal units), higher overow and room temperature oscillation* are expected

*see page 54-55

CoolingHeating

Variable ow: Shell and Core installation for

Hydronic applications

Commercial

Recommended

Oces and Shopping malls*

PICV-3

VACANT

Danfoss products:

PICV-1

PICV-3

PICV-2

PICV-3

VACANT

FAN COIL UNITS (FCU)

CHILLED PANELS

PICV-1

BMS

1.1.1.6

1. Combined Automatic Balancing Valve as Δp Controller (PICV 1)

2. Combined Automatic Balancing Valve as Flow Controller (PICV 2)

This application is useful specically for situations where the system is built in two phases by dierent contractors. The rst phase is usually the central infrastructure, like boilers, chillers and transport piping, while the second part includes the terminal units and room controls.

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

PICV-2 & PICV3: AB-PM + TWA-QPICV-1: AB-PM+AME435QM

Explanation

Return of investment

• Only one valve needed

• One actuator for zone or ow control

• Variable speed pump is recommended (proportional pump control is possible)

Design

• No kvs and authority* calculation needed.

• Presetting calculation needed only based on ow and Δp demand of loop

• For loop design (later stage of installation) the set parameters are available

Operation/Maintenance

• Reliable solution for shop or oor connection

• Flow setting can be done based on measurements on the test plugs of the valve

• Central distribution is always correctly balanced and independent of any mistakes made in sizing on the occupant ‚s side

• Changes in secondary section of the system do not inuence other shops or oors

• Easy trouble shooting, energy allocation, management, etc. with NovoCon

Control

• Stable pressure dierence for shops or oors

• If only ow limitation is used small overows can happen within the loop during partial load

• Actuator on valve (if applied) ensures either zone control (Δp control application) or ow control (ow control application)

This commonly occurs in shopping malls, where the shops use their own contractor to do the shop’s installation, or Shell & Core oces where the renter of an oce oor ts out his own space, including the HVAC.

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

acceptable

excellent

AHU heating

Chillers applications Boilers applications Hot water

AHU applications

**Two dierent approaches can be chosen:

1. Flow and ΔP limitation. Here the valve limits both the ΔP and the ow.

2. Flow limitation only. This will require additional zone controls and balancing for the terminal units

*see page 54-55

poor

Δp control application

acceptable

excellent

Flow control application

Commercial

FAN COIL UNITS (FCU)

Hydronic applications

Not Recomended

1.1.1.7

CoolingHeating

Variable ow: Manual balancing

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

1. 2-way Control Valve (CV)

2. Manual Balancing Valve (MBV)

3. Partner Valve* (MBV)

4. Building Management System (BMS)

or Room temperature Control (RC)

The terminal units are controlled by conventional motorized control valves and the hydronic balance is achieved by manual balancing valve. Due to the static nature the MBV only ensures hydronic balance in full system load. During partial load under- and overows can be expected in the terminal units, causing excessive energy consumption as well as cold and hot spots in the system.

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

CV-1

MBV-1

Danfoss products:

Explanation

MBV-1

CHILLED PANELS

CV-2 MBV-1

MBV-2

BMS

CV-2: VZ2 + AME130 MBV-1: MSV-BD MBV-2: MSV-F2 CV-1: RA-HC +TWA-A

Return of investment

• Many components are needed: 2 valves per terminal unit and additional branch valves for commissioning*

• Increased installation cost due to many valves

• Complex commissioning procedure is required increasing risk of a delayed.

• Variable speed pump is recommended with constant Δp function

Design

• Precise sizing is required (Kv-value, authority*)

• Authority* calculations are crucial for acceptable modulation

• Constant Δp pump control is recommended because of the proper location for the pressure

• It is impossible to predict system behaviour in partial load

Operation/Maintenance

• Complicated commissioning procedure that can only be executed by qualied sta

• Commissioning process can only be started at the end of the project with full load on the system and sucient access to all balancing valves

• High complaint costs because of balancing issues, noise and inaccurate control during partial load

• Rebalancing needed regularly and in case of changes in the system

• High pumping costs* because of overows during partial load

Control

• Interdependence of circuits creates pressure uctuations, which inuence control stability and accuracy

• The generated overow reduces the system eciency (high pumping cost*, low ΔT syndrome* in cooling system, room temperature oscillation*)

• Failure to create sucient pressure drop on the valve will result in low authority* which will make modulating control impossible

*see page 54-55

CoolingHeating

FAN COIL UNITS (FCU)

Variable ow: Manual balancing

Hydronic applications

Commercial

Not Recommended

with reverse return

CV-1

CV-2

Danfoss products:

Explanation

MBV-1

CV-2: VZ2 + AME130 MBV-2: MSV-F2 MBV-1: MSV-BD CV-1: RA-HC +TWA-A

MBV-1

CHILLED PANELS

MBV-1

MBV-2

BMS

1.1.1.8

4 4

1. 2-way Control Valve (CV)

2. Manual Balancing Valve (MBV)

3. Partner Valve* (MBV)

4. Building Management System (BMS) or Room temperature Control (RC)

In a reverse return system (Tichelmann), the piping is designed in such way that the rst terminal unit on the supply is the last one on the return. The theory is that all terminal units have the same available Δp and therefore are balanced. This system can only be used if the terminal units are the same size and have constant* ow. For other systems this application is unsuitable.

Performance

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

AHU applications

AHU heating

Return of investment

• Due to extra pipe runs the investment is much higher

• More space needed in technical shaft for additional third pipe

• Bigger pump needed because of added resistance of additional piping

• High complaint costs because of the balancing issues, noise and inaccurate control during partial loads

Design

• Complicated piping design

• Precise control valve sizing is required (Kv-values, authority*)

• Authority* calculations are crucial for acceptable modulation

• Constant Δp pump control is recommended, it is impossible to use a Δp sensor

• The system is only balanced during full load conditions

• It is impossible to predict system behaviour in partial load

Operation/Maintenance

• Complicated commissioning* procedure that can only be executed by qualied sta

• Commissioning process can only be started at the end of the project with full load on the system and sucient access to all balancing valves

• Δp sensor does not solve over pumping issues

• Rebalancing needed in case of changes in the system

• Extra high pumping costs* because of third pipeline and overows during partial load

Control

• Interdependence of circuits creates pressure uctuations which inuence control stability and accuracy

• The generated overow reduces the system eciency (high pumping cost*, low ΔT syndrome* in cooling system, room temperature oscillation*)

• Failure in creating sucient pressure drop on the valve will result in low authority which* will make modulating control impossible

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

Chillers applications Boilers applications Hot water

excellent

*see page 54-55

Commercial

Hydronic applications

Recommended

1.1.1.9

CoolingHeating

Variable ow: Four-pipe Changeover (CO6) for radiant heating/cooling panels, chilled beams, etc. with PICV control valve

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

1. 6-way Valve

2. Pressure Independent

Control Valve (PICV)

3. Building Management System (BMS)

This application is useful if you have one heat exchanger that needs to do both heating and cooling. This t well with radiant panel solutions. The application uses a 6-way valve for switching over between heating and cooling and a PICV is used to balance and control the ow.

Danfoss products:

6-way value

FAN COIL UNITS (FCU)

PICV

6-way value

PICV

BMS

6-way valve + PICV: NovoCon ChangeOver6 +AB-QM

CHILLED PANELS

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

Explanation

Return of investment

• Only two valves are needed instead of four. One for changeover* and one for heating/ cooling control

• Very energy ecient thanks to high ∆T and no overows*

• Low commissioning* cost because only the ow needs to be set either on PICV or on BMS when using a digital actuator

• BMS costs are reduced because only one datapoint is needed

Design

• Easy selection of PICV, only the ow is required for sizing

• No Kv or authority* calculations needed

• The Δp on CO6 valve does need to be checked

• Perfect balance and control under all loads ensuring precise room temperature control

Operation/Maintenance

• Simplied construction because of reduction of components and pre-built sets

• One valve controls both cooling and heating

• Low complaint costs because of perfect balance and perfect control at all loads

• No cross ow between heating and cooling

• Low operational and upkeep cost. Flushing, purging, energy allocation and management can all be done through BMS.

Control

• Perfect control because of full authority*

• Individual settings for cooling and heating (ow), so perfect control in both situations

• Precise room temperature control

• Digital actuator ensures further saving with energy measurement and management function

*see page 54-55

CoolingHeating

Variable ow: Two-pipe heating/cooling

Hydronic applications

Commercial

Acceptable

system with central changeover*

FAN COIL UNITS (FCU)

PICV-1

CHILLED PANELS

PICV-2

HEATING

SUPPLY/RETURN

Danfoss products:

PICV-1: AB-QM 4.0 + TWA-Q PICV-2: AB-QM 4.0 + AMI-140

SUPPLY

RETURN

COOLING

1.1.1.10

1. Central Changeover Valve

2. Pressure Independent Control Valve (PICV)

3. Room thermostat (RC)

In this application a central change guarantees that the rooms can be cooled and heated. It is strongly recommended to use a PICV to control the temperature because of the dierent ow requirements for the heating and cooling.

3 3

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

AHU applications

AHU heating

Explanation

Return of investment

• Heavily reduced construction cost due to elimination of a secend set of pipes

• Extra costs if automatic changeover* is required

• Proportional pump control is recommended

Design

• Simple PICV selection according to cooling ow, which is usually the highest

• The change-over valve needs to be selected according to the biggest ow rate (cooling) and a big Kvs is recommend to reduce the pumping cost*

• Dierent ow rates for heating and cooling need to be ensured, either by limiting the actuator stroke or by the ability to remotely set the maximum ow, (digital actuator)

• In most cases a dierent pump head is needed for heating and cooling

Operation/Maintenance

• Simple system setup with few valves, so low maintenance cost

• The seasonal changeover* needs to be managed

• No overow* (if ow can be set for dierent heating/cooling mode)

Control

• Simultaneous heating and cooling in dierent rooms is not possible

• Perfect hydronic balancing and control with PICV

• ON/OFF control results in overows when the ow limitation is not solved for lower ow demand (heating)

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

Chillers applications Boilers applications Hot water

excellent

*see page 54-55

Commercial

Hydronic applications

Not Recommended

1.1.2.1

CoolingHeating

Constant ow: 3-way valve with manual balancing (in fan-coil, chilled beam etc. application)

FAN COIL UNITS (FCU)

MBV-1

CV-1

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

1. 3-way Control Valve (CV)

2. Manual Balancing Valve (MBV)

3. Partner Valve* (MBV)

4. Building Management System (BMS)

or Room temperature Control (RC)

In this application temperature control on the terminal unit is done by using 3-way valves. Manual balancing valves are used to create hydronic balance in the system. This application should be avoided due to its high energy ineciency.

MBV-1

Danfoss products:

CV-2

MBV-1

CHILLED PANELS

MBV-2

BMS

CV-2: VZ3 +AME130 MBV-2: MSV-F2CV-1: VZL3 + TWA-ZL

MBV-1: MSV-BD

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

Explanation

Return of investment

• Many components are needed: a 3-way valve and a balancing valve per terminal unit and additional branch valves for commissioning*

• Extremely high operational cost, very energy inecient

• The ow is close to constant, no variable speed drive applied

• In partial loads very low ΔT in the system, so boilers and chillers run at very low eciency

Design

• Kv calculation is required, as well as an authority calculation* for the 3-way valve in case of modulation

• A by-pass needs to be sized or a balancing valve should be tted. Otherwise big overows in partial loads can occur causing terminal unit starvation and energy ineciencies.

• For the Pump head calculation partial load needs to be considered if overows on the by-pass are expected

Operation/Maintenance

• Commissioning of the system is required

• The hydronic balance at full- and partial load is acceptable

• Huge pump energy consumption due to constant operation

• High energy consumption (low ΔT)

Control

• The water distribution and the available pressure on the terminal units are more or less constant under all loads

• The room temperature control is satisfactory

• An oversized control valve will result in low rangeability and oscillation* with modulation

ON/OFF control

Modulation control

*see page 54-55

CoolingHeating

FAN COIL UNITS (FCU)

Constant ow: 3-way valve with ow limiter

Hydronic applications

Commercial

Not Recommended

on terminal units (fan-coil, chilled beam etc. application)

Danfoss products:

CV-1

CHILLED PANELS

CV-2

BMS

1.1.2.2

1. 3-way Control Valve (CV)

2. Flow Limiter (FL)

3. Building Management System (BMS) or Room temperature Control (RC)

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

CV-2: VZ3 +AMV-130CV-1: VZL3 + TWA-ZL

Explanation

FL: AB-QM

Return of investment

• Many components are needed: a 3-way valve and an automatic ow limiter per terminal unit

• Fairly simple valve setup, no need for a balancing valve in by-pass or other valves for commissioning*

• Extremely high operational cost, very energy inecient

• The ow close to constant, no variable speed drive applied

• In partial loads very low ΔT in the system, so boilers and chillers run at very low eciency

Design

• Kv calculation is required, as well as an authority* calculation for the 3-way valve in case of modulation.

• Sizing and presetting of the ow limiters is based on the nominal ow of terminal unit

• For the Pump head calculation partial load needs to be considered if overows on the by-pass are expected.

Operation/Maintenance

• Commissioning of the system is required

• The hydronic balance at full- and partial load is acceptable

• Huge pump energy consumption due to constant operation

• High energy consumption (low ΔT)

Control

• The water distribution and the available pressure on the terminal units are more or less constant under all loads

• The room temperature control is satisfactory

• An oversized control valve will result in low rangeability and oscillation* with modulation

In this application temperature control on the terminal unit is done by using 3-way valves. Automatic ow limiters are used to create hydronic balance in the system. This application should be avoided due to its high energy ineciency.

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

AHU heating

Chillers applications Boilers applications Hot water

AHU applications

*see page 54-55

ON/OFF control

Modulation control

Commercial

Hydronic applications

Residential

Hydronic applications

Recommended

1.2.1.1

CoolingHeating

Two-pipe radiator heating system – risers with, thermostatic radiator valves (with presetting)

TRV-2

TRV-1

Mixing loop

AHU cooling

AHU applications

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

1. Termostatic Radiator Valve (TRV)

2. Return Locking Valve (RLV)

3. Δp controller (DPCV)

4. Partner valve*

In this application we ensure variable ow* on risers with thermostatic radiator valves. In case of presetting available on TRV, ΔP controller used without ow limitation on the riser.

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

2 2

acceptable

excellent

DPCV

Danfoss products:

TRV-1: RA build in + RA TRV-2: RA-N + RA

Explanation

DPCV

DPCV: ASV-PV+ASV-BD

Return of investment

• Δp controller is more expensive compared to manual balancing

• Commissioning is not needed only Δp setting on Δp controller and ow pre-setting on TRVs

• Variable speed pump is recommended

Design

• Simple calculation method, Δp controlled risers can be calculated as independent loops (you can split the system by risers)

• The presetting calculation of radiators is needed,

• Kv calculation needed for Δp controller and control valve. Authority calculation also needed for proper TRV operation

• The Δp demand of loop should be calculated and set according nominal ow and system resistance

Operation/Maintenance

• Hydraulic regulation is in the bottom of risers and radiator presetting

• No hydronic interference among the risers

• Balancing at full and partial load – good – with TRV presetting

• Good eciency: increased ΔT on riser and variable speed pump ensures energy saving

Control

• The eciency of system good with individual presetting on radiators

• Low pumping costs – the ow rate of risers are limited.

• Maximum ΔT on risers

poor

acceptable

excellent

*see page 54-55

CoolingHeating

TRV

Two pipe radiator heating system – risers

Hydronic applications

Commercial

Acceptable

with, thermostatic radiator valves (without presetting)

RLV-2

DPCV

1.2.1.2

Hydronic applications

Residential

2 2

Mixing loop

1. Termostatic Radiator Valve (TRV)

2. Return Locking Valve (RLV)

3. Δp controller (DPCV)

4. Partner valve*

AHU applications

AHU cooling

Danfoss products:

DPCV: ASV-PV+ASV-BD

Explanation

Return of investment

• Δp controller plus ow limitation is more expensive then manual balancing

• Commissioning* is needed for ow limitation on the bottom of riser plus dp setting on Δp controller

• Variable speed pump is recommended

Design

• Simple calculation method, Δp controlled risers can be calculated as independent loops (you can split the system by risers)

• The presetting calculation of partner valve* for ow limitation is required

• Kv calculation needed for Δp controller and control valve. Authority *checking is also essential to know the control performance of TRV

• The Δp demand of loop should be calculated and set according nominal ow and system resistance

Operation/Maintenance

• Hydronic regulation is at the bottom of risers only

• No hydronic interference among the risers

• Balancing at full and partial load is acceptable

• Acceptable eciency and variable speed pump ensures energy saving*

Control

• The ow limitation at the bottom of riser causes extra pressure drop within the Δp controlled loop therefore higher overow appears during partial load (compared to presetting on TRV )

• Higher pumping costs* – however the ow rate of risers is limited slight oveow occure within the riser during partial load condition

• Acceptable ΔT on risers (lower comparing to presetting on TRV)

In this application we ensure variable* ow on risers with thermostatic radiator valves. No possibility of presetting on TRV, ΔP controller used with ow limitation on the riser with partner valve*.

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

AHU heating

Chillers applications Boilers applications Hot water

AHU applications

*see page 54-55

Commercial

Hydronic applications

Recommended

1.2.1.3

CoolingHeating

Pressure Independent Control for radiator heating system

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

3 4

1. Radiator Dynamic Valve (RDV)

2. Termostatic Radiator Valve (TRV)

3. Return Locking Valve (RLV)

4. Return Locking

Dynamic Valve (RLDV)

In this application Pressure Independent Control Valves used in smaller radiator heating system combined with thermostatic senor (self-acting proportional room temperature control), give us a guarantee that regardless of the pressure oscillation inside the system, we will secure the right ow, allowing the right amount of heat to be delivered to the room. (Traditional radiator or „H” piece connection available).

Danfoss products:

RDV

TRV-1: RA build in + RA

TRV

RLDV

RLDV: RLV-KDVRDV: RA-DV + RA

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

Explanation

Return of investment

• A minimal number of components is needed which means less installation costs

• Low complaint costs because of perfect balance and perfect control at all loads

• Highly energy eciency because of precise ow limitation at all loads

• High eciency of boilers and pumping because of high ∆T in the system

Design

• Easy selection of valves based only on ow requirement

• No Kv or authority* calculation is needed, presetting calculation is based on ow demand

• Perfect balance and control at all loads

• Proportional pump control is recommended, pump speed can be optimized easily

• This solution applicable up to max. 135 l/h ow rate on terminal unit and max 60 kPa pressure dierence across the valve

• Min available Δp on the valve 10 kPa

Operation/Maintenance

• Simplied construction because of reduction of components

• Set and forget, no complicated balancing procedures are needed

• Changes of ow setting do not inuence the other users

• Flow verication is possible on the valve with special tool

Control

• Perfect control because of full authority*

• No overows*

• Fix 2K proportional Xp band

• Fully pressure independent so no interference from pressure uctuations and therefore stable room temperatures*

*see page 54-55

CoolingHeating

Subordinated risers (staircase, bathroom,

Hydronic applications

Commercial

Recommended

etc.) in two- or one-pipe radiator heating system without thermostatic valve

TRV

RLV

PICV +QT

Danfoss products:

TRV: RA-N+RA PICV+QT: AB-QT

1.2.1.4

1. Radiator Valve (without sensor) (RV)

2. Pressure Independent Control Valve (PICV)

3. Temperature Sensor (QT)

In this application we have theoretical constant ow* on subordinated risers and no thermostatic sensor on radiator valve (like staircase, bathroom etc.) For better eciency we ensure variable ow* in case of partial load condition when the return temperature is increasing, with return ow temperature limitation.

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

AHU applications

AHU heating

Explanation

Return of investment

• QT (temperature limiter sensor) is an extra cost (ow limiter is recommended in any case)

• Commissioning of the system is not required only setting of ow on PICV and temperature on QT

• VSD pump is recommended

Design

• Simple calculation is required for riser ow, based on heat demand and ΔT, the size of radiator, convector has to be designed accordingly

• The ow is controlled by return temperature signal

• The presetting calculation of radiator is crucial due to no room temperature controller, the heat emission will depend on ow rate and size of radiator. The presetting calculation is based on ow rate among radiators and pressure drop of pipeline

• Simplied hydraulic calculation (you can split the system by risers)

Operation/Maintenance

• No overheating on riser during partial load condition (strongly recommended for renovation)

• Good balancing at full and partial load - additional energy saving*

• Higher eciency, limited return temperature and variable speed pump ensures energy saving*

Control

• Inner rooms (typically bathrooms) have constant heat demand, to keep constant heat output, with increasing ow temperature, QT reduces the ow rate.

• Less overheating of risers – energy saving*

• ΔT increasement ensures lower heat loss and better heat production eciency

• LOW pumping costs* – the ow rate of subordinated risers are limited and reduced even more with temperature limitation by QT

• Limited eciency of QT control when ow temperature drops. Electronic controller (CCR3+) increases eciency at higher outdoor temperature.

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

Chillers applications Boilers applications Hot water

excellent

*see page 54-55

Commercial

Hydronic applications

Residential

Hydronic applications

Mixing loop

Recommended

1.2.1.5

1. Δp controller (DPCV)

2. Partner valve*

3. Manifold with presettable valves

CoolingHeating

Δp control for manifold with individual zone/loop control

DPCV

AHU cooling

AHU applications

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

In this application we ensure variable ow* in the distribution pipeline and constant dierential pressure on each manifold independently from temporal load and pressure uctuation in the system. Applicable for both radiator and oor heating systems.

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

Danfoss products:

Manifold: FHF + TWA-A

Explanation

DPCV: ASV-PV + ASV-BD

Return of investment

• Beside manifold we need DPCV with partner valve*. Heat meter is often used for individual at connections

• Thermal actuator for zone control (oor heating) or thermostatic sensor (radiator)

• Commissioning is not needed, Δp setting and ow setting on manifold loops only

• With additional investment, the users’ comfort can be increased with individual, time based wired or wireless room temperature control

• Variable speed pump is recommended

Design

• Simple DPCV sizing according kvs calculation and total ow demand of manifold

• Presetting calculation is needed for built in zone valves only

• The presetting of loops, limiting the ow to be ensured no under/overow on connections

Operation/Maintenance

• Reliable, pressure independent solution for individual at/manifold connection

• Partner valve* can have dierent functions like, impulse tube connection, shut o, etc.

• Flow setting can be done accurately via Δp setting on DPCV with heat meter most often used

• NO noise risk thanks for Δp controlled manifolds

• High eciency, especially with individual programmable room control

Control

• Stable pressure dierence for manifolds

• Flow limitation is solved, no overow* or underow per connections

• Thermal actuators (oor heating) ensure manifold or individual time based room temperature zone control (ON/OFF) with suitable room controller

• Thermostatic sensor (radiator) ensures proportional room control with proper Xp band

*see page 54-55

CoolingHeating

Δp control and ow limitation for manifold

Hydronic applications

Commercial

Recommended

with central zone control

Danfoss products:

Manifold: FHF

DPCV

ABV: AB-PM +TWA-Q (optional)

1.2.1.6

1. Δp controller (DPCV)

2. Manifold with presettable valves

In this application we ensure variable ow* in the distribution pipeline and maximum pressure dierence on each manifold independently from temporal load and pressure uctuation in the system. Furthermore, we limit the ow for manifold and able to ensure zone control with adding thermal actuator on DPCV. Applicable for both radiator and oor heating systems.

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

AHU applications

AHU heating

Explanation

Return of investment

• DPCV and impulse tube connection needed only. Heat meter often used for individual at connection

• Thermal actuator for zone control as option (installed on DPCV)

• Individual zone control (oor heating) or thermostatic sensor (radiator) also possible

• Installation time can be reduced with usage of set solution

• Commissioning is not needed, ow setting on DPCV only and presetting of each loop

• Variable speed pump is recommended

Design

• Simple, no kvs and authority* calculation, valve selection based on ow rate and Δp demand of loop

• Presetting calculation is needed for built-in zone valves (if there are)

• The presetting of ow limitation ensures no under/overow on manifold

• Pump head calculation is very simple, min available pressure dierence for DPCV (included the loop Δp) is given

Operation/Maintenance

• Reliable, pressure independent solution for individual at connection

• Partner valve* – if applied - can have dierent functions like, impulse tube connection, shut o, etc.

• No noise risk thanks to Δp controlled manifold

• High eciency, especially with individual programmable room control

Control

• Maximized pressure dierence for manifold

• Flow limitation is solved, no overow* or underow per connections

• ...but slight overow within the loop during partial load

• Thermal actuator ensures zone control (ON/OFF) with suitable room controller

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

Chillers applications Boilers applications Hot water

excellent

*see page 54-55

Commercial

Hydronic applications

Recommended

1.2.2.1

CoolingHeating

One-pipe radiator heating system renovation with automatic ow limitation and possible self-acting return temperature limitation

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

1. Radiator Valve (TRV )

2. Pressure Independent Control Valve

(PICV)

3. Optional - Temperature Sensor (QT)

This application is suitable for renovating of vertical one-pipe radiator heating system. We recommend high capacity thermostatic radiator valve and ow limiter installation on riser. For better eciency we optionally recommend to use return temperature control with QT (Thermostatic Sensor)

Danfoss products:

TRV

PICV

PICV: AB-QM

PICV+QT

PICV+QT: AB-QTTRV: RA-G + RA

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

With QT Without QT

acceptable

excellent

Explanation

Return of investment

• Investment cost are higher (thermostatic radiator valve + ow limiter + QT on risers) compared to manual balancing

• Simple QT installation with low extra cost

• No commissioning* demand only ow setting

• Variable speed pump is recommended (without QT the pump control is not needed)

Design

• „α” (radiator share) calculation with iteration

• Big capacity TRV is needed to increase the „α”

• Radiator size depends on ow temperature changes

• Gravitation eect should be taken into account

• Simple hydronic calculation regarding riser controller, selection based on ow rate but we need to ensure the minimum available pressure on it

• QT setting depends on system conditions

Operation/Maintenance

• System less sensitive for gravitation eect due to ow limitation

• „α” (radiator share) sensitive for installation punctuality

• Real constant ow* without QT, variable ow* with QT

• QT contributes to energy saving* on pumping

• QT ensures more accurate heat cost allocation

Control

• Accurate and simple water distribution among risers

• Improved room temperature control

• The radiator heat emission depends on varying ow temperature

• Heat gain from pipe in the rooms aects the room temperature

• QT eect is limited in case of higher outdoor temperature

*see page 54-55

CoolingHeating

One-pipe radiator heating system renovation

Hydronic applications

Commercial

Recommended

with electronic ow limitation and return temperature control

TRV

PICV

CCR3+

1.2.2.2

1. Radiator Valve (TRV )

2. Pressure Independent Control Valve (PICV)

3. Elecrtonic Controller (CCR3+)

4. Temperature sensor (TS)

CCR3+

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

Danfoss products:

TRV: RA-G + RA

Explanation

PICV: AB-QM+TWA-Q CCR3+

Return of investment

• High investment cost (thermostatic radiator valve + ow limiter with thermal actuator, sensor on risers + CCR3+)

• Electronic wiring is needed, programing CCR3+

• No commissioning* demand only ow setting

• Variable speed pump is recommended

Design

• „α” (radiator share) calculation with iteration

• Big capacity TRV is needed to increase the „α”

• Radiator size depends on ow temperature changes

• Gravitation eect should be taken into account

• Simple hydronic calculation regarding riser controller, selection based on ow rate but we need to ensure the minimum available pressure on it

• Dening of needed return characteristic

Operation/Maintenance

• The system less sensitive for gravitation eect due to ow limitation

• „α” (radiator share) sensitive for installation punctuality

• Programming CCR3+, data logging, remote maintenance and access

• Higher eciency due to improved ΔT, and reduced pipe heat loss

Control

• Accurate and simple water distribution among risers

• Improved room temperature control

• The radiator heat emission depends on varying ow temperature

• Heat gain from pipe in the rooms aects the room temperature

• CCR3+ Weather compensation on return temperature on all individual risers

This application is suitable for renovating of vertical one-pipe radiator heating system. We recommend high capacity thermostatic radiator valve and ow limiter installation on riser. For best eciency we recommend to use CCR3+ (Electronic Controller)

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

AHU heating

Chillers applications Boilers applications Hot water

AHU applications

*see page 54-55

Commercial

Hydronic applications

Not Recommended

1.2.2.3

CoolingHeating

One-pipe radiator heating system renovation with manual balancing

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

1. Radiator Valve (TRV )

2. Manual Balancing Valve (MBV)

This application is suitable for renovating of vertical one-pipe radiator heating system. Many one-pipe system are renovated based on thermostatic radiator valves and manual balancing valves. It is not recommended due to its low eciency.

TRV

MBV

Danfoss products:

MBV: MSV-BDTRV: RA-G +RA

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

Explanation

Return of investment

• Medium investment cost (thermostatic radiator valve + manual balancing)

• Commissioning* is needed

• Complains can occur when not proper commissioning

• Traditional constant speed pump is acceptable

Design

• Dicult sizing of hydronic, presetting calculation of MBV is important

• „α” (radiator share) calculation with iteration

• Big capacity TRV is needed to increase the „α”

• Radiator size depends on ow temperature changes

• Gravitation eect should be taken into account

Operation/Maintenance

• System sensitive for gravitation eect (over/under pumping) during operation

• „α” (radiator share) sensitive for installation accuracy

• Not real constant ow*, the ow rate can vary 70-100% according to the radiator valve operation

• High pumping energy consumption due to „constant” ow

• Inecient system, during partial load (when TRVs are closing) too high inlet temperature into radiators and overall return temperature

Control

• Inaccurate room temperature control

• The radiator heat emission depends on varying ow temperature

• Heat gain from pipe in the rooms aects the room temperature

• Inaccurate heat cost allocation

*see page 54-55

CoolingHeating

One-pipe horizontal heating systems with

Hydronic applications

Commercial

Acceptable

thermostatic radiator valves, ow limitation and return temperature self-acting control

TRV

PICV + QT

TRV

1.2.2.4

1. Radiator Valve (TRV )

2. Pressure Independent Control Valve (PICV)

3. Temperature Sensor (QT)

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

Danfoss products:

TRV: RA-KE +RA

Explanation

PICV+QT: AB-QT

Return of investment

• Investment cost – good (thermostatic radiator valve + ow limiter + QT on risers)

• Less valves than in case of manual balancing, lower installation costs

• Simple QT installation and setting. (Re-set recommended based on operational experience)

• Commissioning* of the system not required (only ow and temperature setting)

• Variable speed pump is recommended

Design

• Traditional radiator connection. „a” (radiator share) eect on radiator selection

• Simplied hydraulic calculation, the loops are pressure independent

• No TRV presetting

• Return temperature setting on sensor of ow limiter according to system features

• Pump head calculation according to nominal ow and dp demand of ow limiter

• Heat metering applicable

Operation/Maintenance

• Minimal length of pipeline

• Higher pump head demand (vs. two pipe), due to minimum Δp on ow limiter, higher pressure loss on pipeline, big Δp on radiator valve if no big Kvs selected

• The heat output of radiator depending on partial load condition due to varying inlet temperature

• Optimization* of pump head is recommended (if variable pump control is available)

Control

• Thermostatic radiator valve has small Xp value

• Flow restriction in loop via QT when return temperature is increasing

• Loop ow demand is varying according to partial load condition

• Hydraulic regulation only at the end of loop, balancing at full and partial load – good

• Room temperature oscillation* occur s

In this application we ensure automatic ow limitation for all heating circuits and limit the return temperature with QT (Thermostatic Sensor) to avoid small ∆T in the loops during partial load. (More ecient in case of lower outdoor temperature.)

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

AHU heating

Chillers applications Boilers applications Hot water

AHU applications

*see page 54-55

Commercial

Hydronic applications

Recommended

1.2.3.1

Heating Cooling Water supply

Three-pipe, at station system; Δp controlled heating and local DHW* preparation

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

FLAT

STATION

1. Δp controller (DPCV)

2. Partner valve*

3. Heating return (primary)

4. Heating ow (primary)

5. Domestic Cold Water (DCW)

6. Heating return (secondary)

7. Heating ow (secondary)

8. Circulation (DHW-C)

9. Domestic Hot Water

10. Domestic Cold Water

In this application we use 3 pipes only (heating ow / return and cold water ), for heating of the ats and instantaneous DHW* preparation locally (at the at). We ensure variable ow*, Δp control for heating system and ow limitation on riser taking into consideration the simultaneous eect

7 6

(primary)

(DHW) (secondary)

(DCW) (secondary)

Danfoss products:

DPCV

FLAT

STATION

FLAT

STATION

DPCV: ASV-PV + MSV-F2

Flat Station: Evoat

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

Performance

Return of investment

poor

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

Explanation

Return of investment

• Investment cost are signicant (at stations, MBV in front of ats + Δp control in risers) but they are worth to be considered taking into account the full investment cost

• Less pipeline and additional equipment (no primary DHW*system), less installation cost

• Commissioning *of MBV and setting of DPCV with ow limitation is needed

• Variable speed pump is recommended (constant pump characteristic)

Design

• Special hydraulic calculation is needed for pipeline: the size of pipeline depends on simultaneous factor

• Presetting calculation for TRVs is needed

• Riser ∆p controller: ∆p setting (at station + pipeline) + ow limitation according simultaneous eect

• The at station is equipped with ∆p controller for heating

• Flat pump characteristic is advantage, fast reaction VSD* needed (due to very fast load changes in the system based on DHW* uctuation)

Operation/Maintenance

• Δp controlled TRV ensures good room temperature control

• Heat losses on primary pipe are low (one hot pipe instead of two)

• Higher pump head demand – high ∆p demand on at station and extra pressure loss on ∆p controller + ow limiter required

• Simple system setup, easy energy metering

• No legionella problem

Control

• Balancing at full and partial load very good

• Energy ecient solution, low heat loss in the system

• High comfort; TRV and/or time control possible

• Pressure independent DHW* preparation, ∆p controlled heating, ow limitation on riser

*see page 54-55

CoolingHeating

Mixing with PICV – manifold

Hydronic applications

Commercial

Recommended

with pressure dierence

controller

Danfoss products:

PUMP

PICV

2.1

1. Preasure Independent Control Valve (PICV)

2. Temperature sensor (TS)

3. Controller

Regardless of pressure uctuations in the system, we have the right ow for the temperature control of the secondary side. The PICV valve ensures the mixed/ controlled ow temperature circulated by the secondary pump. The primary pump ensures the needed pressure dierence up to the mixing points including the Δp demand of PICV.

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

PICV: AB-QM + AME435QM

Explanation

Return of investment

• Minimum number of components - no MBV needed

• Low installation cost

• Primary pumps needed to cover the Δp demand up to mixing points

• MBV is needed on the secondary side if there is no VSD* or pressure stabilization

• Balancing on secondary side is required

• VSD on primary side is recommended

Design

• Easy PICV selection based on ow requirement

• The PICV valve size can be smaller if the secondary temperature is lower than the primary temperature

• Perfect hydronic balance and control at all loads,

• Min available Δp demand on the valve should be taken for primary pump selection

• Proportional primary pump control can be used

Operation/Maintenance

• Simplied construction due to the a reduction of components

• No balancing needed, just setting the ow on the PICV

• Non-return valve is recommended in the by-pass line to prevent back-ow if the secondary pump stops

• Flexible solution; the ow rate setting does not inuence the other mixing loops

• Low operational and upkeep cost

Control

• Full authority* of control valve, precise control of secondary water temperature

• No overows*

• Pressure independent solution, no interference from pressure uctuations in the system

• Linear system response matches with linear PICV characteristic

• Room temperature oscillation* occur s

The individual terminal unit should be controlled according to applications is chapter 1 or 2. One possibility is shown in the drawing.

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

AHU heating

Chillers applications Boilers applications Hot water

AHU applications

*see page 54-55

Commercial

Hydronic applications

Acceptable

2.2

CoolingHeating

Injection (constant ow) control with 3-way valve

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

1. 3 - way Control Valve (CV)

2. Manual Balancing Valve (MBV)

3. Non-Return Valve (N-RV)

4. Temperature Sensor (TS)

5. Controller

The 3-way valve controls the ow to ensure the required temperature on the secondary side. The circulation pump and the MBV on the secondary side are needed to ensure mixing and (usually) a constant ow* through the loop (for example with radiant heating). A 3-way valve and MBV are used in the primary circuit to ensure proper temperature control for the loop and balancing the circuits. It should only be used in case of big temperature dierences between primary and secondary.

Danfoss products:

MBV

controller

N-RV

MBV

CV: VF3 + AME435 MBV: MSV-F2

MBV

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

Explanation

Return of investment

• Very high: 3-way valve + 2xMBV for balancing and control (partner valve* for the pump is needed for the pump head setting)

• More valves result in higher installation cost

• Both MBVs have to be balanced

• No VSD* required on the primary side because of constant ow*

Design

• The 3-way valve has good authority* because of the small pressure drop on the primary network

• The 3-way valve should be sized accordingly to the ow rate of the primary side

• Kv and ow pre-setting calculation of the MBV is essential for the ow setting

• MBV is calculated based on the nominal condition and is valid for all system loads

Operation/Maintenance

• Complicated system setup with many valves and a lot of balancing

• Slight ow changes during partial load due to ideal authority* of the 3-way valve

• Simple balancing of the secondary MBV but complex balancing is needed on the primary side

• A non-return valve is recommended in the by-pass line to prevent back-ow if the secondary pump stops

• In case of a low secondary energy demand the ΔT of the primary circuit will drop

• No possibility of energy saving* on the pump because of constant ow*

Control

• Good control thanks to high authority* of the control valve

• Constant ow, so no pressure oscillation. Therefore there is no interference among loops

• Low ΔT syndrome* in cooling

• Recommended only if the secondary ow temperature is signicantly lower than the primary

*see page 54-55

CoolingHeating

Mixing with 3-way valve – manifold

Hydronic applications

Commercial

Not Recommended

without pressure dierence

MBV

controller

Danfoss products:

MBV

2.3

1. 3 - way Control Valve (CV)

2. Manual Balancing Valve (MBV)

3. De-coupler

4. Temperature Sensor (TS)

5. Controller

The 3-way valve controls the ow temperature on the secondary side. This setup allows dierent ow rates in the primary- and secondary loops. The secondary pump circulates the water through the system included manifolds and de-coupler. Primary pump is located before de-coupler, there is no pressure dierence between manifolds.

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

CV: VF3 + AME435 MBV: MSV-F2

Explanation

Return of investment

• 3-way valve and MBV are needed, more valves results in higher installation cost

• The balancing of the MBV is important

• The secondary side should be equipped with a variable speed drive (variable ow)

• Balancing of the secondary side is needed

• Primary pump control should be done by return temperature if possible, which results in additional controller cost

Design

• Simple 3-way valve sizing (50% of the pump head should drop on the control valve)

• Linear 3-valve and actuator characteristic is needed

• Kv and pre-setting calculation for MBV are essential for compensating Δp dierences between the by-pass line and the manifold loop towards de-coupler

• Secondary pump needs to cover the Δp demand from and to the de-coupler

Operation/Maintenance

• Complicated system setup with several valves and balancing of the MBVs is required

• For stable operation of the 3-way valve the authority* and rangeability need to be taken into consideration

• If the primary pump is not controlled water will be circulated back needlessly during partial load

• Low energy eciency due to low ΔT and high pump head demand on the primary pump

Control

• Good control if the authority* is 50% or higher *

• Very low overows* on the secondary side

• The mixing loops are pressure independent

• Low ΔT syndrome * primary pump is not properly controlled

• The linear system response is combined with a linear 3-way valve characteristic, so temperature is stable control

The individual terminal unit should be controlled according to applications in chapter 1 or 2. One possibility is shown in the drawing.

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

AHU heating

Chillers applications Boilers applications Hot water

AHU applications

*see page 54-55

Commercial

Hydronic applications

Residential

Hydronic applications

Recommended

3.1.1

1. Preasure Independent Control

Valve (PICV)

CoolingHeating

Pressure Independent Control (PICV) for cooling

PICV

Mixing loop

AHU cooling

AHU applications

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

A PICV is used to control the AHU so that regardless of pressure uctuations in the system we secure the right ow. It is applicable if Δp is available for PICV. A by-pass is recommended to be used in front of the PICV (light gray) to ensure proper ow temperature in partial load also, when there is no circulation in AHU at all. Dierent types of by-pass control can be used. (see page 38).

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

MBV

Danfoss products:

PICV: AB-QM + AME345QM

Explanation

Return of investment

• A minimal number of components because there is no MBV on primary side and/or partner valves* are needed. Consequently, there is a low installation cost

• Minimal complaint costs because of perfect balance at all loads

• No balancing* needed

• Energy ecient because of proper ∆T in the system

Design

• Easy selection of valves based only on the ow requirement

• No Kv or authority* calculation is needed. The ow pre-setting calculation is based on the ow demand

• Perfect balance at all loads

• Proportional pump control is recommended.

• Minimum available Δp demand on the valve should be used to select the primary pump

Operation/Maintenance

• Simplied construction because of a reduced number of components

• Set and forget, no complicated balancing procedures are needed for the primary side

• Low operational and upkeep cost

Control

• Perfect control thanks to full authority *

• No overows*

• Pressure independent solution, no interference from pressure uctuations anywhere in the system

• No low ΔT syndrome *

• Stable temperature control without hunting of the valve

*see page 54-55

CoolingHeating

3-way valve control for cooling

Hydronic applications

Commercial

Not Recommended

3.1.2

Hydronic applications

Residential

1 2

MBV-2

MBV-1

Danfoss products:

MBV-1: MSV-F2 CV: VF3 + AME435

Explanation

Return of investment

• Many components are needed: a 3-way valve and 2*MBV, and additional partner valves for commissioning* in bigger system

• Extremely high operational cost, very energy inecient

• The ow is close to constant, no VSD applied

• In partial loads very low ΔT in the system, so chillers run at very low eciency

Design

• Kvs calculation is required, as well as an authority calculation* for the 3-way valve

• Presetting of MBVs crucial for proper system operation and control

• The by-pass MBV needs to be calculated to compensate the pressure drop of terminal unit, otherwise big overows occur in partial loads causing terminal unit starvation and energy ineciency

• High (min. 1:100) control ratio is needed for proper low ow control on 3-way valve

Operation/Maintenance

• Commissioning of the system is required

• The hydronic balance at full and partial load is acceptable

• Huge pump energy consumption due to constant ow operation

• High energy consumption (low ΔT)

Control

• Good control in case of ~50% authority* on 3-way valve

• Constant ow, no pressure oscillation, consequently no interference among AHUs

• Low DT syndrome *

• The room temperature control is satisfactory…

• … but high energy consumption because of low ΔT reduces chiller eciency and constant pumping consumes more electricity

1. 3 - way Control Valve (CV)

2. Manual Balancing Valve (MBV)

Controlling the room temperature based on controlling the supply air to the room is common. This can be done with a 3-way valve. An MBV is needed in the by-pass to compensate for the dierence between the pressure drop of the AHU and the by-pass. Additionally, an MBV is needed in the primary circuit to be able to balance the AHUs. The ow rate on primary side nearly constant all the time

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

Mixing loop

AHU applications

AHU cooling

AHU applications

AHU heating

Chillers applications Boilers applications Hot water

*see page 54-55

Commercial

Hydronic applications

Residential

Hydronic applications

Mixing loop

Recommended

3.2.1

1. Preasure Independent Control

Valve (PICV)

2. Manual Balancing Valve (MBV)

CoolingHeating

Pressure Independent Control (PICV) for heating

MBV

AHU cooling

AHU applications

AHU heating

AHU applications

Chillers applicationsBoilers applicationsHot water

A PICV is used to control the AHU so that regardless of pressure uctuations in the system we secure the right ow. It is applicable if Δp is available for PICV. A circulation pump and an MBV are needed to ensure constant ow* through the coil, therefore freezing of the coil can be avoided. A by-pass is recommended (at last AHU in the circuit) to be used in front of the PICV (light gray) to ensure proper ow temperature in partial load also, when there is no circulation in AHU at all.

Dierent types of by-pass control can be used. (see page 38).

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

PICV

Danfoss products:

MBV: MSV-F2 PICV: AB-QM + AME345QM

Explanation

Return of investment

• Minimal number of components (no MBV on primary side and partner valves* are needed. Consequently, installation cost is low

• Minimal complaint costs because of perfect balance at all loads

• No commissioning* needed (MBV setting only for nominal ow setting on the pump)

• Ecient boiler usage because of proper ∆T in the system

Design

• Easy selection of valves based only on ow requirement

• No Kv or authority* calculation is needed, ow presetting calculation is based on ow demand

• Proportional primary pump control is applicable. Pump without control in secondary side

• Min available Δp demand on the valve should be taken for primary pump selection

• The PICV valve size can be smaller if secondary ow temperature is lower than the primary

• Usage of SMART actuator* ensures peripherical device connection, energy allocation, energy management, etc.

Operation/Maintenance

• Simplied construction thanks to reduction of components

• Set and forget, no complicated balancing procedures are needed for primary side

• Simple setting of MBV on secondary side

• Low operational and upkeep cost

• Secondary pump contributes to frost protection (easily manageable with SMART actuator*)

Control

• Perfect control because of full authority *, no overows*

• Pressure independent solution, no interference from pressure* uctuations anywhere in the system

• Stable* air temperature control in AHU without oscillation

• I/O connections to SMART actuator* can be used for additional control features of AHU

*see page 54-55

CoolingHeating

3-way valve control for heating

Hydronic applications

Commercial

Not Recommended

3.2.2

Hydronic applications

Danfoss products:

MBV

MBV-1: MSV-F2 CV: VF3 + AME435

1. 3 - way Control Valve (CV)

2. Manual Balancing Valve (MBV)

Controlling the room temperature based on controlling the air supplied to the room is common. This can be done with a 3-way valve. A circulation pump and an MBV are needed to ensure constant ow* through the coil, so freezing of the coil can be avoided. Additionally, an MBV is needed in the primary circuit to be able to balance the AHUs.

A by-pass at the furthest unit is recommended to prevent the cooling down of the pipe in low loads.

Dierent types of by-pass control can be used, see application 2.3.1

Residential

Mixing loop

AHU applications

AHU cooling

AHU applications

AHU heating

Explanation

Return of investment

• 3-way valve and 2 MBVs for balancing and control are needed as well as branch valves in bigger system for balancing

• More valves result in higher installation costs

• Both MBVs have to be balanced

• Complaint cost expected due to low authority* of 3-way valve

Design

• Sizing of the 3-way valve should be done according to the ow rate in the secondary side in case of lower ΔT

• Kv and ow pre-setting calculation of the MBVs is essential

• Pre-setting of the primary side MBV is valid at full load only, overows will occur during partial loads

• The secondary pumps do not need a VSD* as they run on full load at all loads

Operation/Maintenance

• Complicated system setup with several valves and a lot of balancing

• Hunting of the 3-way valve can occur, shortening the valve’s lifespan

• Simple setting of the MBV on the secondary side

• Overows reduce the energy eciency

• Commissioning of primary side is crucial

Control

• Bad control ability at low loads

• Overows* can occur depending on the authority* of the 3-way valve

• Not a pressure independent solution, therefore the available pressure widely oscillates on the 3-way valve on the primary side

• Unacceptable temperature control at low loads

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

Chillers applications Boilers applications Hot water

excellent

*see page 54-55

+ heating- cooling

PICV

MBV

PICV

MBV-1

PICV

MBV

PICV

Commercial

Hydronic applications

Residential

Hydronic applications

Mixing loopChillers applicationsBoilers applicationsHot water

Recommended

3.3

solution

1 or 2 or 3

solution

1 or 2 or 3

1. Preasure Independent Control

Valve (PICV)

2. Manual balancing valve (MBV)

CoolingHeating

Keep proper ow temperature in front of AHU in partial load condition

solution 1 solution 2 solution 3

PICV

PICV + QT

BMS

MBV2

PICV: AB-QM 4.0 + NOVOCON S.

AHU cooling

AHU applications

MBV: MSV-BD

Performance

AHU heating

AHU applications

Return of investment

poor acceptable

Design

poor exellent

Operation/Maintenance

poor exellent

Control

poor

PICV+OT: AB-QT

exellent

acceptable

PIVC with BMS connectivity with QT MBV

exellent

AV TA

PICV

AV TA

MBV

In variable ow* installations it is possible that the water in the system has such a low ow speed that it warms up (cooling) or cools down (heating) and it will take a while for the AHU to be able to start cooling or heating. In such cases it is recommended to install a bypass at the furthest unit to maintain the temperature in the system. Dierent types* of by-pass control can be used. The options are:

1)A PICV connected to the BMS system – optional SMART actuator* to reduce hardware demand,

2)Self-acting controls, either a PICV and QT sensor (heating) or an AVTA (cooling),

3)An MBV with a constant ow* setting

Explanation

Return of investment

• Only small valve sizes needed

• Lowering the complexity (going from solution 1-3) reduces cost but also reduces energy eciency

• Balancing* is needed in option 3, for 1 and 2 only setting of the ow or temperature is needed

• Solution 1 requires additional cabling and additional programming in the BMS

Design

• Flow demand calculation is based on heat loss/gain on the related pipe network

• For 1 and 2 a simple valve is selection based on ow rate. For option 3 a full Kv and pre-setting calculation is needed

• For 1 and 2 ow/temperature setting only. For option 3 balancing is needed

• Option 1 and 2 will only allow the minimum ow needed to maintain the temperature. Option 3 will always have ow, independent of the system load.

• The available pressure is dened by the demand for the PICV of the AHU

Operation/Maintenance

• Accurate ow temperature can be controlled independently from the system load

• Some temperature inaccuracy is expected due to the Xp band of the self/acting controller

• Always open by-pass and the ow is changing – in spite of balancing – according to the Δp uctuations caused by partial loads

• Option 1 and 2 are more energy ecient than option 3 due to minimal ow

Control

• 1 and 2 have perfect hydronic balance and control due to pressure independency

• 3 has an unnecessarily high ow through the by-pass during most system loads

• Limited low ΔT syndrome * in appl. 1-2, the ΔT on system 3 is signicantly smaller

• BMS connectivity ensures a stable ow temperature control and the Smart actuator is able to add further functions like a Δp signal for pump optimization*

• Lowest energy consumption

*see page 54-55

CoolingHeating

Variable primary ow

PICV-1

PICV-2

Chiller

Hydronic applications

Commercial

Recommended

4.1

Hydronic applications

Danfoss products:

Residential

∆P

Critical unit

PICV-4

VLT

BMS

PICV-3 PICV-3

For a variable ow* system this is considered the most ecient system for a building’s thermal operation. The chillers can have multiple variable speed compressors.

This system has a variable primary (and secondary) circuit, where there are no secondary pumps. The by-pass is used to control the minimum ow for the chillers in a partial load operation.

The chillers can be staged according to the optimal eciency of chillers at certain load. The appropriate ow through on chillers controlled by dedicated PICVs in chiller loop.

Explanation

Return of investment

• More expensive variable speed chillers are required

• Best return on investment if used in combination with PIBCV on secondary side as well

• By-pass with PICV and ow meter needed for by-pass control

• PICV for ow setting, isolation and control in line with the chillers. An MBV + isolation valve is an alternative solution in such case that chillers are the same size

Design

• PICV selection and ow setting according to the maximum ow demand of the chillers

• By-pass valve is sized according to the chiller’s minimum ow requirement

• A PICV installed in each terminal unit on the secondary side is recommended to maximize eciency

• A VSD* with a Δp sensor on the critical point is mandatory

• Additional pumps can be added to provide operational reliability

Operation/Maintenance

• Simple and transparent construction

• Simple commissioning based only on ow setting. Optimization* of the pump head is recommended

• Isolation (with PICV) is important for the chillers that are not in operation

Control

• Primary pump control based on the Δp signal of the critical unit is recommended to minimize energy use

• The by-pass control ensures the minimum ow needed for chiller operation based on signal of the ow meter

• Small chance on low ΔT syndrome*. Variable speed chillers can handle low ows and therefore the by-pass rarely opens

• Highest eciency compared to other chilled water systems

• Advanced chiller control logic required to maximize the eciency

PICV-1: AB-QM 4.0 + AME 655

PICV-2,3: AB-QM + AME345QM

PICV -Preasure Independent Control Valve

PICV-4: AB-QM 4.0 + AME 110

VLT®HVAC

Drive FC102

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

Flow meter FM: SonoMeterS

excellent

Mixing loop

AHU applications

AHU cooling

AHU applications

AHU heating

Chillers applications

Boilers applications Hot water

*see page 54-55

Commercial

Hydronic applications

Residential

Recommended

4.2

Danfoss products:

CoolingHeating

Constant primary variable secondary (Step Primary)

MBV

Hydronic applications

Mixing loop

AHU cooling

AHU applications

AHU heating

AHU applications

Chillers applications

Boilers applicationsHot water

PICV-1,2: AB-QM + AME345QM

PICV-3: AB-QM 4.0 + AME 110

PICV -Preasure Independent Control Valve

MBV: MSV-F2

Flow meter FM: SonoMeterS

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

PICV-1

Chiller

BMS

*BMS - only for monitoring, no pump control (optional)

This system has a constant primary circuit, a variable secondary circuit and no secondary pumps. The by-pass is used to control the minimum ow for the chillers. For optimal eciency a swing chiller is recommended. The chillers can be staged according to the load variation and constant ow* through the chiller can be maintained by dedicated pump capacity. The appropriate ow through chillers can be ensured by ow meter measurement and control of by-pass. (Secondary side description see applications: 1.1.1.1-1.1.1.3)

Explanation

PICV-2

BMS*

∆P

Critical unit

PICV-3

Return of investment

• Medium investment cost – No secondary pumps needed but the dimension of the by-pass and the control valve is large

• A ow meter is needed for by-pass control

• Motorized isolation valves and MBVs are needed for chiller staging (PIBCV is an alternative solution for ow limitation and isolation)

• Dedicated pumps for each individual chiller are required

Design

• Kvs calculation of isolation and manual balancing valve is required and the pre-setting of the MBVs is important

• The by-pass and valve should be sized according to the ow of the biggest chiller

• The ow meter sizing is based on the nominal ow in the system

• The pump head needs to cover the Δp demand of the entire system

• Pump head adjustment is needed with dierent sizes of chillers

• Pumps can be added based for operational security

Operation/Maintenance

• Installation of the by-pass is needed between the supply and return

• Constant ow* on the chiller is essential for their proper operation

• Balancing of the system is needed

• Isolation of idle chillers is important

• Pumps work at constant speed but due to better chiller staging the energy eciency is better compared with application 4.3

Control

• Chiller and pump operation have to be harmonized

• By-pass control ensures the exact ow demand for the active chillers based on the signal of the ow meter

• Advanced chiller control logic is required to maximize eciency

• Low ΔT syndrome* is possible in partial load due to the by-pass

*see page 54-55

CoolingHeating

Constant primary and variable secondary

Hydronic applications

Commercial

Acceptable

(Primary Secondary)

MBV

Chiller

De-coupler

PICV-1

∆P

Critical unit

PICV-2

4.3

Danfoss products:

PICV-1: AB-QM + AME345QM

Preasure Independent PICV - Control Valve

PICV-2: AB-QM 4.0 + AME 110

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

This system is a variation of a constant primary (constant ow*) system. Variable speed drives are used to control the pumps on the secondary side. By de-coupling the primary and the secondary circuits, the chillers can be staged according to the load variation while keeping a constant ow* on the chillers. (Secondary side description see applications:

1.1.1.1-1.1.1.3)

Explanation

Return of investment

• High investments cost - primary and secondary pumps are required

• Motorized isolation valves and MBVs are needed for the chiller staging (PICV is an alternative solution for ow limitation and isolation)

• Balancing is required

• Constant speed pumps on the primary side and speed-controlled pumps on the secondary side

Design

• Kvs calculation of the isolation and manual balancing valves, pre-setting of the MBVs is important (a low pressure drop on the isolation valve is recommended)

• The pressure drop on the de-coupler should not be more than 10-30 kPa to minimize hydraulic interdependency

• Pump capacities have to correlate to the individual chiller ow demand

• The secondary pump head is often bigger than the primary side one

Operation/Maintenance

• Additional space is required for the pumps on the secondary side

• Commissioning of the system is complex

• Isolation is important for idle chillers

Control

• A hydronic de-coupler prevents interactivity between the primary and secondary circuits

• Secondary pumps should be controlled based on a Δp signal of the critical circuit, to optimize the energy eciency

• Simple chiller control logic

• Low ΔT syndrome* in partial loads due to the de-coupler

• Primary pumps work at a constant speed so no energy saving* is possible

VLT®HVAC

Drive

FC102

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

Manual Balancing Valve

MBV: MSV-F2

excellent

AHU heating

Chillers applications

Boilers applications Hot water

AHU applications

*see page 54-55

Commercial

Hydronic applications

Not Recommended

4.4

CoolingHeating

Constant primary & secondary (Constant Flow System)

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

Danfoss products:

MBV-1: MSV-BD

CV-1: VRB + AME435

3 - way Control Valve Manual Balancing Valve

CV-2: VF3 + AME435

MBV-2: MSV-F2

MBV-2

MBV-1

Chiller

CV-1

This is one of the oldest chiller applications with no variable speed drives for pumps and chillers. The chillers can only handle xed ows, so there are 3-way control valves in the secondary side of the system to maintain a constant ow*. They are controlling the ow through the terminal units to maintain a constant room temperature. (Secondary side description see applications: 1.1.2.1, 2.2 and 3.2.1)

CV-2

MBV-2

AHU heating

AHU applications

Chillers applications

Boilers applicationsHot water

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

Explanation

Return of investment

• Constant ow* chillers are used

• MBVs are needed* for proper water distribution among the chillers. Alternatively, but only if the chillers are the same size, a Tichelman system can be used

• The ow is constant in the manifolded pump station, so there is no option for saving energy by applying VSDs*

Design

• Kv and pre-setting calculation for the chiller MBVs are needed

• Chiller staging is not possible

• The pump selection and operation should be adjusted to the chiller capacity

• The real ow in the system is usually 40-50% bigger than the nominal ow demand in partial load condition

• Pump head calculation according to the entire pressure drop of the system

Operation/Maintenance

• The ow through the chillers must be constant at all times. If not, the chiller’s low ow alarm trips and the chiller ceases operation

• Balancing of the MBVs is crucial to set the ow rate according to the pump operation

• It’s a rigid system. It is not possible to take out or add terminal units during operation

• High pump head demand and high energy consumption

Control

• For chiller operation we need to ensure constant ow*

• The chiller and pump operation must be harmonized

• There is no by-pass in the system therefore we need to keep the nominal ow through the system all the time

• High risk for low ΔT syndrome *

• Low ΔT in the system and constant pump operation result in poor eciency of the chiller

*see page 54-55

CoolingHeating

District cooling system

Hydronic applications

Commercial

Recommended

4.5

MBV

Chiller

Thermal Energy Storage (TES)

VLT

critical circuit

∆P

PICV-1 PICV-2

Danfoss products:

PICV-1: AB-QM + AME345QM

Preasure Independent Control Valve Manual Balancing Valve

PICV-2: AB-QM 4.0 + AME 655

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

Drive

A district cooling system is a large-scale cooling network suitable for feeding several buildings. It contains a Thermal Energy Storage (TES) capable of storing the thermal energy like a rechargeable battery. This application should be used above 35MW cooling capacity. The goal is to increase the power plant’s eciency by attening peak loads. The additional function of the TES is hydronic separation of the primary and secondary side (Secondary side applications similar to applications: 1.1.1.1-1.1.1.3)

Explanation

Return of investment

• Expensive but environmentally friendly solution for providing cooling to complete districts of many buildings

• TES cost needs to be included.

• Huge chillers are usually required. Min. 3.5MW per chiller.

• Advanced chiller control logic is required to maximize plant eciency

• Constant speed pump for the primary side and VSD* on the secondary loop

Design

• Kvs calculation of isolation and MBVs, pre-setting of the MBVs is important (a low pressure drop on the isolation valve is recommended)

• The TES also functions as a hydronic de-coupler, it will store ow surplus from the constant primary loop.

• PICVs installed in each energy transfer station are highly recommended to maximize eciency

• A Δp sensor located on critical points to secure proper pump control is recommended

• Chiller and pump operation have to be harmonized

Operation/Maintenance

• Simple and transparent construction

• Constant ow* through the chillers is essential for their proper operation

• Commissioning* is needed to analyze the load pattern over time.

• Isolation is important for idle chillers

Control

• Secondary and tertiary pumps can be connected to critical units with proportional pump control to save energy

• Control of feeding and emptying the TES is important for ensuring the proper cooling energy in peak load and to achieve better eciency

• There is no low ΔT syndrome* while TES is not overcharging

• The primary pumps work at constant speed but due to chiller staging the energy the eciency is good

*see page 54-55

MBV: MSV-F2

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

VLT®HVAC

Drive

FC102

excellent

AHU heating

Chillers applications

Boilers applications Hot water

AHU applications

Commercial

Hydronic applications

Recommended

5.1

CoolingHeating

Condensing boiler, variable primary ow

1. Preasure Independent Control Valve

(PICV)

2. Building Management System (BMS)

3. Temperature Sensor

4. VSD* Pump

Residential

Hydronic applications

AHU applications

Danfoss products:

Mixing loop

AHU cooling

PICV: AB-QM + AME345QM or Novocon M

PICV

Boiler

Condesing

BMS

VSD

This application uses a varied number of condensing boilers. All boiler circuits are equipped with PICV valves that are connected to the BMS system. They ensure proper balancing, staging and control in full- and partial load conditions. Variable speed drives are used for minimizing the pumping cost*. PICV or Δp control on the secondary side is also strongly recommended to minimize energy consumption.

AHU heating

AHU applications

Chillers applicationsHot water

Boilers applications

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

Explanation

Return of investment

• Low - one set of pumps and dedicated PICVs with modulating actatuors for control and isolation of the boilers

• Valves need to be connected to the BMS which controls the ow through each boiler to optimize the energy eciency

• A variable speed drive on the pump is required

Design

• Simple PICV selection based on the ow demand of single boilers

• The pump head also needs to cover the pressure drop of the entire system

• Pump head optimization* by using Δp sensors on the critical unit is recommended

Operation/Maintenance

• Optimization of the return temperature is possible with proportional PICV or Δp control on the secondary side

• Increased ΔT ensures optimal condensing boiler eciency

• Minimized ow through the system so the pumping costs* are low

• The control system should be aligned with internal boiler logic

Control

• Perfect ow control through each boiler to achieve optimum boiler eciency

• Good control of the return temperature due to the lack of a by-pass in the system

• Maximum eciency of the boilers at design and partial load

• Expected variable ow* on secondary side with PICV or Δp control so a VSD* is required

*see page 54-55

CoolingHeating

Traditional boilers, variable primary ow

Hydronic applications

Commercial

Acceptable

5.2

MBV

Boiler

VSD

PICV

1. Isolation Valve (CV)

2. Manula Balancing Valve (MBV)

3. By pass Valve (PICV)

4. Temperature Sensor

5. VSD* Pump

Danfoss products:

CV: VF2 + AME345

Hydronic applications

Residential

Mixing loop

Boiler Controler

AHU applications

MBV: MSV-F2

AHU cooling

This application is used for traditional (non-condensing) boilers. In order to avoid low inlet temperature to the boilers a controlled by-pass (with a PICV) is needed. In this application we use only one set of pumps to circulate ow through both the primary and the secondary system

Explanation

Return of investment

• Medium - one set of pumps, MBVs and isolation valves are required

• Additional by-pass with a PICV is needed to ensure minimum inlet boiler temperature

• Temperature sensor for the control of the by-pass

• Commissioning of the manual balancing valve is required. Alternatively, but only if the boilers are the same size, a Tichelman system can be used

• A variable speed drive for the pump is required to save energy

Design

• Presetting calculation of the MBVs is needed to ensure the nominal ow through all the boilers

• The by-pass valve is sized according to the ow demand of the biggest boiler

• The pump head also needs to cover the pressure drop of the secondary system

• Idle boilers need to be isolated.

• A pressure relief valve is recommended at the end of the system to ensure the minimum ow for the pump

Operation/Maintenance

• Boilers work with variable ow* depending on the system load. Therefore, it’s dicult to maintain stable boiler control

• The plant controller must control the by-pass valve based on the temperature of the return

• Moderate pumping costs*

Control

• Simple control logic based on the expected return ow temperature

• Boiler staging according to the ow temperature and based on the energy demand in the system

• The return temperature can not be optimized which has negative eects, especially on condensing boilers, and reduces the system’s eciency

• With variable ow* on the secondary side with PICV or Δp control, a VSD* is required

PICV: AB-QM + AME345QM

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

AHU heating

Chillers applications Hot water

Boilers applications

AHU applications

*see page 54-55

Commercial

Hydronic applications

Not Recommended

5.3

CoolingHeating

System with manifolds de-couplers

Residential

Hydronic applications

Mixing loop

AHU cooling

AHU applications

1. Isolation Valve (CV)

2. Manula Balancing Valve (MBV)

3. Pump

4. ΔP=0 Manifold

5. De-coupler

Danfoss products:

CV: VF2 + AME435

MBV: MSV-F2

MBV

Boiler

AHU heating

AHU applications

Chillers applicationsHot water

Boilers applications

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

This is the most common constant primary ow boiler plant arrangment (cascade). The primary and secondary systems are hydronically independent. The manifolds are connected with a by-pass that allows water circulation between them.

Explanation

Return of investment

• Pumps are needed both on the primary and the secondary side

• A large by-pass between the manifolds is required

• Commissioning* of the MBVs is required. Alternatively, but only if the boilers are the same size, a Tichelman system can be used

• Motorized isolation valves and MBVs are needed for each boiler. Alternatively, a PICV for ow limitation and isolation can be used

Design

• A pre-setting calculation of the MBVs is needed to ensure the nominal ow for each boiler

• The manifold and by-pass need to be sized properly to prevent interference between the primary and secondary pumps

• Proper sizing of the primary and secondary pumps is crucial to minimize the ow through the by-pass

• Proportional pump control is recommended with a variable ow* on the secondary side

Operation/Maintenance

• Primary pumps don’t require minimum ow protection

• Boiler operation is independent from the secondary system

• Boiler staging should be done according to the heat demand of the secondary system

• In case of non-condensing boliers, an additional by-pass is needed before each boiler to ensure a minimum inlet temperature for the boiler

Control

• Staging of the boilers should be based on the return temperature of the secondary side

• The return temperature could be high which negatively aects condensing boilers and reduces the system’s eciency

• Individual boiler logic according to supply temperature

*see page 54-55

Hot & Cold Water Supply

Thermal balancing

Hydronic applications

Commercial

Recommended

in DHW circulation (vertical arrangement)

TMV

TBV

6.1

1. Termostatic Balancing Valve (TBV)

2. Termostatic Mixing Valve (TMV) ( optional )

3. Domestic Cold Water (DCW)

4. Domestic Hot Water (DHW)

5. Circulation (DHW-C)

Danfoss products:

TMV: TMV-WTBV: MTCV-A

Hydronic applications

Residential

Mixing loop

AHU applications

AHU cooling

In this application we ensure variable ow* in the DHW* circulation pipeline and constant tapping temperature* on either tap independently from the distance from storage tank and temporary hot water usage. Thanks to this we reduce the quantity of circulation water during all periods. Thermal disinfection* is possible with additional equipment. TMV (as optional) ensures maximum tapping temperature preventing scalding.

Explanation

Return of investment

• Low investment MTCV valves only, further hydraulic elements are not needed

• Low installation cost

• No commisioning – temperature setting only

• Variable Speed Drive recommended

Design

• Flow – accoridng to heat loses in pipeline and temperature drops in branches when taps are closed, no kvs and ow presetting calculation is needed

• Temperature setting on valve is based on temperature drop from the last tap to the valve

• Pump head calculation according to nominal ow when no DHW* consumption

Operation/Maintenance

• Minimum temperature losses on pipeline – high energy saving*

• Re-commissioning* is not needed – self-acting temperature control

• Lower maintanance costs due to constant/optimal temperatures in the system (less scalding, corrosion etc.)

• Thermometer can be connected to the valve for inspection and proper thermal commissioning

Control

• Stable tapping temperature* on all risers

• Perfect balancing at full and partial load

• Access to hot water immediately

• Circulated ow quantity minimized, no overow

• Lime scale deposit has no eect control accuracy

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

AHU heating

Chillers applications

Boilers applications

Hot water

AHU applications

*see page 54-55

Commercial

Hydronic applications

Residential

Recommended

6.2

1. Termostatic Balancin Valve (TBV)

Hot & Cold Water Supply

Thermal balancing in DHW circulation (horizontal loop)

Hydronic applications

Mixing loop

AHU cooling

AHU applications

AHU heating

AHU applications

Chillers applicationsBoilers applications

Danfoss products:

TBV: MTCV-A

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

TBV 1

In this application we ensure variable* ow in the DHW* circulation pipeline and constant tapping temperature on either tap independently from the distance from storage tank and temporary hot water usage. Thanks to this we reduce the quantity of circulation water during all periods. Thermal disinfection* is possible with additional equipment

Explanation

Return of investment

• Low investment MTCV valves only, further hydraulic elements are not needed,

• Low installation cost

• No commisioning – temperature setting only

• Variable Speed Drive (VSD*) is recommended

Design

• Flow – accoridng to heat loses in pipeline and temperature drops in branches when taps are closed, no kvs and ow presetting calculation needed

• Temperature setting on valve based on temperature drop from the last tap to the valve

• Pump head calculation according to nominal ow when there is no DHW* consumption

• If MTCV is used in horizontal loops rule of 3l water volume must be applied

Operation/Maintenance

• Minimal temperature losses on a pipeline – high energy saving*

• Re-commissioning* is not needed – self-acting temperature control

• Lower maintenance costs due to constant/optimal temperatures in the system (less scalding, corrosion etc.)

• Thermometre can be connected to a valve for inspection and proper thermal commissioning

Control

• Stable tapping temperature* on all horizontal loops

• Perfect balancing at full and partial load

• Access to hot water immediately

• Circulated ow quantity minimized, no overow*

• Lime scale deposit has no eect on control accuracy

Hot water

*see page 54-55

Hot & Cold Water Supply

Thermal balancing in DHW circulation

Hydronic applications

Commercial

Recommended

with self–acting disinfection

TMV

TBV

6.3

Hydronic applications

1. Termostatic Balancing Valve (TBV)

2. Termostatic Mixing Valve (TMV) ( optional )

3. Domestic Cold Water (DCW)

4. Domestic Hot Water (DHW)

5. Circulation (DHW-C)

Danfoss products:

TMV: TMV-WTBV: MTCV-B

Residential

Mixing loop

AHU applications

AHU cooling

In this application we ensure variable ow* in the DHW* circulation pipeline and constant tapping temperature* on either tap independently from the distance from storage tank and temporary hot water usage. Thanks of this we reduce the quantity of circulation water during all periods. Thermal self-acting disinfection is possible based on special module in MTCV valves.

scalding.

Explanation

TMV (as optional) ensures maximum tapping temperature preventing

Return of investment

• Low investment MTCV with self-acting disinfection module, further hydraulic elements are not needed

• Low installation cost

• No commisioning* – temperature setting only

• Variable Speed Drive (VSD*) is recommended

Design

• Like application 6.1; 6.2

• Pump head verication for desinfection process needed

• During thermal disinfection higher ow temperature is needed (65-70°C)

Operation/Maintenance

• Composite MTCV valve cone ensures longer lifetime

• Thermal disinfection* of the system cannot be guaranteed (pump capacity, heat losses etc) and optimized

• TMV valves are able to limit the tapping temperature* during thermal disinfection*

• Thermometer can be connected to valve for inspection and proper thermal commissioning

Control

• Stable tapping temperature* on all risers/loops

• Acceptable solution for small residential buildings if their own heat source is available

• Perfect balancing at full and partial load

• Circulated ow quantity minimized, no overow*

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

acceptable

excellent

AHU heating

Chillers applications Boilers applications

AHU applications

*see page 54-55

poor

acceptable

excellent

Hot water

Commercial

Hydronic applications

Residential

Recommended

6.4

1. Termostatic Balancing Valve (TBV)

2. Termostatic Mixing Valve (TMV)

( optional )

3. Electronic Controler (CCR2+)

4. Temperature Sensor

Hot & Cold Water Supply

Thermal balancing in DHW circulation with electronic desinfection

TMV

Hydronic applications

Mixing loop

AHU cooling

AHU applications

AHU heating

AHU applications

Chillers applicationsBoilers applications

Danfoss products:

TBV: MTCV-C

TMV: TMV-W

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

CCR2+

excellent

CCR2+

TBV

In this application we ensure variable ow* in the DHW* circulation pipeline and constant tapping temperature* on either tap independently from the distance from storage tank and temporary hot water usage. Thanks to this we reduce the quantity of circulation water in all periods. TMV valves ensure constant tapping temperature* in term of thermal disinfection period too. Thermal disinfection* is controlled by CCR2+ electronic device.

Explanation

TBV

Return of investment

• High, control equipment required -MTCV with actautor and CCR2+ for disinfection control, furthermore (as option) temperature mixing valve

• Higher installation costs – included with wiring cost

• Commissioning of hydronic system is not required

• CCR2+ programming is needed

• Variable Speed Drive (VSD*) is recommended

Design

• Like application 6.1; 6.2

• Excellent engineering – minimal energy consumption

• Thermal disinfection* is solved

• No need for pump verication for disinfection capacity

Operation/Maintenance

• Composite MTCV valve cone ensures longer life time

• Excellent thermal disinfection* of the system –programmable and optimized

• TMV valves are able to limit the tapping temperature* during thermal disinfection*

• Temperature registration is managed by CCR2+

• Automatized disinfaction procces can be programmed

• All data and settings available remotely

Control

• No overow*, ow rate is according to temporary demand

• Minimum required time for disinfection

• Variable speed pump and good boiler eciency ensure energy saving*

• Conectivity with BMS and DHW* automatization modules

Hot water

*see page 54-55

Hot & Cold Water Supply

DHW* circulation control

Hydronic applications

Commercial

Not Recommended

with manual balancing

MBV

2 TMV

MBV

6.5

Hydronic applications

1. Manual Balancing Valve (MBV)

2. Termostatic Mixing Valve (TMV) ( optional )

Danfoss products:

TMV: TMV-W

Residential

Mixing loop

AHU applications

AHU cooling

In this application we ensure constant ow* in the domestic hot water circulation pipeline independently on temporary hot water usage and demand. TMV (as optional) ensures maximum tapping temperature preventing scalding.

Explanation

Return of investment

• Low investment –MBVs , constant speed pump, partner valve* (rarely used)

• Higher installation cost – if partner valves* are used

• Commisioning of the system is required

• No Variable Speed Drive (VSD*) demand

Design

• Traditional calculation: kvs of the manual balancing valve

• Presetting calculation of the valves is needed

• Complicated circulation ow demand is calculated according to heat loss on supply hot water and circulation pipeline

• Pump head calculation according to nominal ow when there is no DHW* consumption

• Circulation pump and MBVs is often oversized

Operation/Maintenance

• High energy losses on pipeline, high energy consumption

• Re-commissioning* of the system is required from time to time

• Lower eciency of boiler due to high return temperature

• Higher service cost due to more lime scale deposit (higher circulation temperature)

• Legionella growth risk

• Big water consumption

Control

• Variable tapping temperature* (depends on distance from DHW* tank)

• Static control doesn’t follow dynamic behaviour of water usage

• Circulated ow quantity independent from real demand, overow most of the time

Performance

Return of investment

poor acceptable

Design

poor

Operation/Maintenance

poor

Control

poor

acceptable

excellent

AHU heating

Chillers applications Boilers applications

Hot water

AHU applications

*see page 54-55

Commercial

Hydronic applications

Residential

Hydronic applications

Mixing loop

Notes

AHU cooling

AHU applications

AHU heating

AHU applications

Chillers applicationsBoilers applications

Hot water

Glossary and abbreviations

Control and valve theory

Energy eciency analyses

Glossary and abbreviationsControl and valve theoryEnergy efficiency analyses

∆p

7.1

Glossary and abbreviations

Traditional calculation: For good control, we have to take two most important control features into consideration; the authority of the control valve and the pressure equivalence before each terminal unit. For this requirement we have to calculate the required kvs value of the control valves and treat the whole hydraulic system like one unit.

Balancing – Flow regulation by means of balancing valves in order to achieve right ow in each circuit of heating or cooling system.

Commissioning: However, we have to calculate the required settings of the manual or automatic balancing valve during the traditional calculation, before we hand the building over to the user. We have to be sure that the ow is according to the required value all over. Therefore, (due to installation imprecision), we have to check the ow on the measuring points and correct this if necessary.

Re-commissioning: From time to time commissioning must be redone. (e.g. in the case of changing the function and size of the room, regulating heat loss and heat gain).

SMART actuator: Digital, high precision stepper actuator with direct connectivity with BMS system, extended with additional special functions to make the installation and operation easier.

Good authority: The authority is a dierential pressure rate which shows the pressure loss of the control valve and is compared to the available dierential pressure ensured by pump or Δp controller (if exists)

a =

∆p

Pumping cost: The expense that we have to pay for pump energy consumption.

Constant ow: The ow in the system or the unit does not change during the whole operational term.

Low ΔT syndrome: This is more signicant for cooling systems. If the required ΔT in the system cannot

be ensured, the eciency of the cooling machine declines dramatically. This symptom can also occur in heating systems.

Return of investment: How fast based on exploitation savings we will have back the whole amount that we have to pay for a certain part of installation.

Pump optimization: In the case of electronic controlled pump usage, the pump head can be reduced to the point where the required ow in the whole system is still ensured, bringing the energy consumption to the minimum.

∆p

Control is better in case of higher authority. The minimum recommended authority is 0,5.

pipes+units

Room temperature oscillation: The real room temperature deviates constantly from the set temperature all the time. The oscillation means the size of this deviation.

No overow: The constant ow through a terminal unit according to the desired ow.

Partner valve: An additional manual balancing valve is required for all branches to achieve commissioning properly. As a partner valve we can describe a valve which allows to connect impulse tube from dierential pressure controller valve (DPCV)

Variable ow: The ow in the system varies continuously according to temporal partial load. It is dependent on external circumstances such as sunshine, internal heat gains, room occupation, etc.

Thermal disinfection: In DHW systems the number of Legionella bacteria increases dramatically around tapping temperature. It causes diseases and from time to time it can lead to death. To avoid this, disinfection is needed periodically. The simplest way to do this is to increase the temperature of the DHW above ~60-65 °C. In this temperature the bacteria will be destroyed.

Variable speed drive (VSD): Circulation pump is equipped with a built-in or external electronic controller, ensuring constant, proportional (or parallel) dierential pressure in the system.

Energy saving: Electrical and /or heat cost reduction.

Change over: In systems where cooling and heating do not function in parallel, the system must be

changed between these operational modes.

Building classication: The rooms are classied according to comfort capability (EU norm). “A” means the highest rank with smallest room temperature oscillation and better comfort.

Stable room temperature: Achievable with proportional self acting or electronic controller. This application avoids any undesirable uctuations of room temperature because of hysteresis of on/o room thermostat.

Tapping temperature: The temperature that appears immediately when the tap is opened.

Partial load: Any load during system operation time that is less than designing load.

DHW: Domestic Hot Water system.

AHU: Air Handling Unit

BMS: Building Management System

PICV: Pressure Independent Balancing Valve

FL: Flow Limiter

DPCV: Δp Control Valve

MBV: Manual Balancing Valve

CO6: Change Over 6-way valve

Energy efficiency analysesControl and valve theoryGlossary and abbreviations

CV: Control Valve

RC: Room temperature Control

FCU: Fan Coil Unit

TRV: Thermostatic Radiator Valve

RLV: Return Locking Valve

TES: Thermal Energy Storage

Signal modulated

to perform error

correction

Control and valve theory

Glossary and abbreviationsControl and valve theoryEnergy efficiency analyses

8.1

Valve authority

The authority of the valve is a measure of how well the control valve (CV) can impose its characteristic on the circuit it is controlling. The higher the resistance in the valve, and therefore the pressure drop across the valve, the better the control valve will be able to control the energy emission of the circuit.

The authority (acv) is usually expressed as the relationship between the dierential pressure across the control valve at 100% load and fully open valve (the minimum value ∆Pmin), and the dierential pressure across the control valves when it is fully closed (∆Pmax). When the valve is closed, the pressure drops in other parts of the system (pipes, chillers and boilers for example) disappear and the total available dierential pressure is applied to control valves. That is the maximum value (∆Pmax).

Formula: acv = ∆Pmin / ∆Pmax

The pressure drops across installation are illustrated in Fig 1

Balancing

Valve

Control

Valve

Terminal

unit

Shut-o

Valve

Fig 1

∆P vmax

*see page 54-55

50%

100%

Balancing

Valve

∆P vmax

Setpoint

Proportional

Integral Time Actuator Valve

Stroke %

Control

Signal

Derivative Time

Control

Valve

Shut-o

Valve

Terminal

unit

Signal Output %

Signal modulated

to perform error

correction

Valve characteristics 8.2

50%

100%

ow [%]

Balancing

Valve

∆P vmax

Setpoint

Proportional

Integral Time Actuator Valve

Stroke %

Control

Signal

Derivative Time

Control

Valve

Shut-o

Valve

Terminal

unit

stroke (lift) [%]

50%

100%

ow [%]

stroke (lift) [%]

Controlled

Variable

Signal modulated

to perform error

correction

1,0 0,7 0,5 0,3 0,2 0,1

Each control valve has its own characteristic, dened by the relation between the lift (stroke) of the valve and the corresponding water ow. This characteristic is dened at a constant dierential pressure across the valve, so with an authority of 100% (see formula). During practical application in an installation, the dierential pressure is however not constant which means that the eective characteristic of the control valve changes. The lower the authority of the valve, the more the characteristic of the valve is distorted. During the design process we have to ensure that the authority of the control valve is as high as possible to minimize deformation of the characteristic.

The most common characteristics are presented below in the graphs:

1. Logarithmic/Equal percentage control valve characteristic (Fig 2)

2. Linear control valve characteristic (Fig 3)

The line designated with 1.0 is the characteristic at an authority of 1 and the other lines represent progressively smaller authorities.

ow [%]

100%

50%

Fig 2

Closed loop control in HVAC system

The word “control” is used in many dierent contexts. We talk of quality control, nancial control, command and control, production control, and so on – terms which cover an enormous range of activities. However all these types of control, if they are to be successful, have certain features in common. One is that they all presuppose the existence of a system whose behavior we wish to inuence, and the freedom to take actions which will force it to behave in some desirable way.

1,0 0,7 0,5 0,3 0,2 0,1

50%

stroke (lift) [%]

100%

Fig 3

ow [%]

100%

50%

stroke (lift) [%]

1,0 0,7 0,5 0,3 0,2 0,1

100%

8.3

Setpoint

Fig 4

*see page 54-55

Error

Controller

Signal

output

Feedback

Plant

Process

Capacity

Output

Energy efficiency analysesControl and valve theoryGlossary and abbreviations

Glossary and abbreviationsControl and valve theoryEnergy efficiency analyses

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

Coli Characteristic Control CharacteristicControl Valve Characteristic

+ =

Coli Characteristic Control Valve CharacteristicControl Valve Characteristic

50%

100%

Setpoint

Proportional

Integral Time Actuator Valve

Load

Coil

Stroke %

Stroke %Control Signal

Danfoss Actuator can be switched from logarythmic to linear or in between

Controlled variable feedback

Control Signal

Control

Signal

Flow %

Capacity %

Derivative Time

Signal Output %

Temperature

22oC Error

Setpoint

16oC 24oC

correction

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

Coli Characteristic Control CharacteristicControl Valve Characteristic

+ =

Flow %

Coli Characteristic Control Valve CharacteristicControl Valve Characteristic

+ + =

nom

50% 100%

CHL(%) 100% 100% 66,6%

11-7 13-7

CWRTR - CWSTD CWRTR - CWSTD

= = =x x

50%

100%

Signal Output %

Temperature

22oC Error

Setpoint

16oC 24oC

Signal modulated

to perform error

correction

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

Coli Characteristic Control CharacteristicControl Valve Characteristic

Coli Characteristic Control Valve CharacteristicControl Valve Characteristic

CHL(%) 100% 100% 66,6%

CWRTR - CWSTD CWRTR - CWSTD

= = =x x

The block diagram above (Fig 4) is a model of continuously modulated control, a feedback controller is used to automatically control a process or operation. The control system compares the value or status of the process variable being controlled with the desired value or setpoint (SP) and applies the dierence as a control signal to bring the process variable output of the plant to the same value as the setpoint.

Signal Output %

100%

Signal modulated

to perform error

correction

50%

Fig 6

Each individual component in the system has its own characteristic. Combining each components correctly with a properly set and tuned controller makes a good control response and eciency of HVAC system.

Fig 7

*see page 54-55

Fig 5

Proportional

Integral Time Actuator Valve

Setpoint

Derivative Time

Stroke %

Control

Signal

Controlled

Variable

Load Disturbance

Overshoot

16oC 24oC

Flow %

Stroke %Control Signal

+ + =

Stroke %

Danfoss Actuator can be switched from logarythmic to linear or in between

Controlled variable feedback

Setting Time

Time

Temperature

Setpoint

22oC

Error

Coil

Capacity %

Flow %

Capacity %

Control Signal

Steady State

Load

The example above is a typical cooling application control response. The load disturbance is conside-

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

Coli Characteristic Control CharacteristicControl Valve Characteristic

+ =

Flow %

red a signicant change either in load or setpoint. (Fig 6)

The goal of a good control system is characterized to achieve the settling time the soonest possible with the lowest maximum deviation during steady state.

Process control demand – Matching the system characteristic

Coli Characteristic Control CharacteristicControl Valve Characteristic

Flow %

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

Fig 8

Every process system has dierent mix of characteristic. The control valve manufacturer has to always meet the design of the coil characteristic. As we can observe in the graphs above, the coil characteristic is logarithmic, hence, it requires an exact opposite characteristic to meet the linear control demand. We expect the control signal of 40% will be attribute an output of 40% capacity. The above control valve authority is equal to 1, which is unrealistic scenario in practice. A conventional control valve will always be changing when dierential pressure changes within the hydronic system. Dierential changes because of load is always varying within the system.

100

90 80 70 60 50

+ =

40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

8.4

Coli Characteristic Control Valve CharacteristicControl Valve Characteristic

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

Fig 9

In reality, the coil can have dierent characteristic. This is very dependent on the thermal energy magnitude in the liquid. For instance in the cooling application, the colder the water, the steeper the coil

100

90 80 70 60 50

+ =

40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

characteristics. Certainly there are also many factors like the energy transfer surface and the speed of the air velocity. Ultimately to meet the exact opposite character, Danfoss has added a adjustable actuator characteristic. The actuator allows exibility to switch from linear to logarithmic characteristic or in between. The feature is called Alpha Value setting. (Fig 9)

Energy efficiency analysesControl and valve theoryGlossary and abbreviations

*see page 54-55

Glossary and abbreviationsControl and valve theoryEnergy efficiency analyses

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

Coli Characteristic Control CharacteristicControl Valve Characteristic

+ =

Flow %

Coli Characteristic Control Valve CharacteristicControl Valve Characteristic

8.5

The “low ΔT syndrome”

Chillers are sized for certain extreme conditions which depend on the climate relevant for that installation. It is important to realize that, in general, that means that the chillers are oversized since these extreme circumstances occur during less than 1% of the operational time. Eectively we can say that the installation is running in partial load for 99% of the time. When the installation is running in partial load, we can experience a phenomenon low ΔT syndrome which can cause very low chiller eciencies and fast on-o switching of the chiller. Additionally the low ΔT syndrome prevents the chillers from running in the so-called Max-Cap mode. During Max-Cap the chiller can put out more than its rated capacity at very high eciencies.

Low ΔT syndrome occurs when the return supply temperature to the chiller is lower than designed. If the installation is designed for a dierential temperature of 6K but the water fed into the chiller is only 3K lower than the chilled water supply setpoint, it is easy to understand the chiller can supply maximally only 50% of its rated capacity. If that is insucient for the situation either the installation will not have enough capacity, or an extra chiller needs to be brought online.

Take this example: when the secondary circuit return water temperature is lower than the design temperature (due to overow problems etc.), chillers cannot be loaded at their maximum capacity. If the chillers in the chilled water plant, designed to cool 13°C chilled water return to 7°C, we receiving a design ow rate at 11°C rather than a design temperature of 13°C, the chiller will be loaded at the ratio of:

CHL(%) 100% 100% 66,6%

CWRTR - CWSTD

= = =x x

CWRTR - CWSTD

11-7 13-7

Where:

• CHL (%) – Percent chiller loading

• CWRTR – Real chilled water return temperature (in our case, 11OC)

• CWSTD – Design chilled water supply temperature (in our case, 7OC)

• CWRTD – Design chilled water return temperature (in our case, 13OC)

In this case, where the low ΔT in the plant (the dierence between return and supply chilled water temperature) has been lowered from 6°C (13°C-7°C) design condition to 4°C (11°C-7°C) , the capacity of the chiller has been reduced by 33,4 %.

In many cases the operating eciency of the chiller can drop 30 to 40 percent when the returning chilled water temperature is lower than the designed. Contrarily when the ΔT is increased, the eciency of the chiller can increase up to 40%.

How to solve

There are several potential causes of low ΔT syndrome:

Using 3-way control valves:

3-way valves by their nature bypass the supply chilled water into the return line during part load conditions, causing the chilled water temperature to be lower than designed. This exacerbates low ΔT problem (presented in application 1.1.12.1; 3.1.2).

The remedy: Do not use 3-way control valves but use a variable ow system with modulating control. If 3-way control valves are unavoidable, application 1.1.2.2. is recommended to limit overows in partial load conditions.

Poor 2-way control valve selection with improper system balance:

An improperly sized 2-way control valve may allow a higher water ow than necessary. The low ΔT syndrome is worse in partial load due to pressure changes in the system, which results in a high overow through the control valves. This phenomenon occurs in particular in systems with faulty hydraulic balance as presented in application 1.1.1.7.

The remedy: 2-way control valves with built in pressure controllers. The pressure control function on the control valves eliminates the overow problem and therefore eliminates low ΔT syndrome.

Other such as:

Improper set-point, control calibration or reduced coil eectiveness.

*see page 54-55

50%

100%

50%

100%

ow [%]

Balancing

Valve

∆P vmax

Setpoint

Proportional

Integral Time Actuator Valve

Stroke %

Stroke %Control Signal

Danfoss Actuator can be switched from logarythmic to linear or in between

Controlled variable feedback

Control

Signal

Flow %

Capacity %

Derivative Time

Control

Valve

Shut-o

Valve

Terminal

unit

stroke (lift) [%]

50%

100%

ow [%]

stroke (lift) [%]

Feedback

Error

Setpoint

Signal

output

Signal Output %

Controller

Plant

Process

Capacity

Output

Controlled

Variable

Setpoint

Load Disturbance

Time

Overshoot

22oC Error

Setpoint

16oC 24

Signal modulated

to perform error

correction

100%

6/12

C 6/9,3

110%

+ + =

1,0 0,7 0,5 0,3 0,2 0,1

∆4K

∆P3=∆P

critica

∆P1=∆P2=∆P3=∆P

critica

Q1= Q2 = Q3

50%

100%

ow [%]

∆P

pump

∆P

Setpoint

Proportional

Integral Time Actuator Valve

Stroke %

Stroke %Control Signal

Danfoss Actuator can be switched from logarythmic to linear or in between

Controlled variable feedback

Control

Signal

Flow %

Derivative Time

stroke (lift) [%]

50%

100%

ow [%]

stroke (lift) [%]

Feedback

Error

MCV

MBV

Setpoint

Signal

output

Controller

Plant

Process

Capacity

Output

Controlled

Variable

Setpoint

Load Disturbance

Overshoot

10%

50%

50% 100% 160%

100%

110%

Heat transfer [%]

+ + =

MCV

MBV

1,0 0,7 0,5 0,3 0,2 0,1

∆4K

∆6K

∆10K

∆18K

∆20K

The “overow phenomenon”

One of the sources of the well-known problems in chilled water systems such as low ΔT syndrome is the overow phenomenon. In this chapter, we will shortly try to explain what it is and what it is caused by.

All systems are designed for nominal conditions (100% load). Designers calculate pump heads based on the combined pressure drop in pipes, terminal units, balancing valves, control valves and other elements in the installation (strainers, water meters etc), assuming the installation is operating at maximum capacity.

Consider a traditional system as presented below, Fig 10.1, based on application 1.1.1.7. It is obvious that the coil and control valve located closer to the pump will have a higher available pressure as compared to the one last in the installation. In this application, unnecessary pressure has to be reduced by manual balancing valves, so the manual balancing valves closer to the pump will be more throttled. The system operates properly only with 100% load.

In Fig 10.2 we see a so-called reverse return system (Tichelman). The idea behind this system is that because the total pipe length for every terminal unit is equal, no balancing is necessary because the available pressure for all units is the same. Please note that if the terminal units require dierent ows you still need to balance the system with balancing valves. In general, we can say that the only proper application of a reverse return system is when we’re talking about a constant ow system (3-way valves) and when all the terminal units are of the same size.

MCV

8.6

∆P

MBV

∆P

Q1= Q2 = Q3

Fig 10.2 Variable ow static FCU control (not recommended system)

MCV

∆P

∆P3=∆P

∆P1=∆P2=∆P3=∆P

critica

MBV

pump

∆P

Fig 10.1 Direct return system

To control ow across each coil, two-way control valves are used. Consider the situation in partial

(not recommended system)

∆P

load (i.e. coils 2 is closed).

MCV

MBV

pump

∆P

100% load

∆P

Partial load

∆P3=∆P

∆P1>∆P2>∆P

critica

Fig 11.1 Partial load - direct return system Fig 11.2 Partial load - revers return system

*see page 54-55

MBV

∆P

100% load

∆P

Partial load

∆P1=∆P2=∆P3=∆P

∆P

∆P3=∆P

∆P

critica

Energy efficiency analysesControl and valve theoryGlossary and abbreviations

50%

Setpoint

Proportional

Integral Time Actuator Valve

Load

Coil

Stroke %

Stroke %Control Signal

Danfoss Actuator can be switched from logarythmic to linear or in between

Controlled variable feedback

Control Signal

Control

Signal

Flow %

Capacity %

Derivative Time

Temperature

Controlled

Variable

Setpoint

Load Disturbance

Time

Overshoot

Setting Time

Steady State

22oC Error

Setpoint

16oC 24oC

correction

50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

+ =

Coli Characteristic Control Valve CharacteristicControl Valve Characteristic

+ + =

∆P

pump

∆P

pump1

∆P

uns

∆P

uns

∆P

1 2 3 pump characterictic

nom

50% 100%

CHL(%) 100% 100% 66,6%

11-7 13-7

CWRTR - CWSTD CWRTR - CWSTD

= = =x x

MCV

MBV

Glossary and abbreviationsControl and valve theoryEnergy efficiency analyses

Due to a lower ow in the system, the pressure drop in the pipe system decreases, providing a higher available pressure in the still open circuits. Since manual balancing valves (MBV) with xed, static, settings were used to balance the system, the system becomes unbalanced. Consequently a higher dierential pressure across the 2-way control valves causes overows across the coils. This phenomenon appears in direct return systems as well as in reverse return systems. This is the reason why these applications are not recommended, as the circuits are pressure dependent.

110%

100%

50%

Heat transfer [%]

10%

∆4K

∆6K

∆10K

6/12

C 6/9,3 oC

∆18K

∆20K

Flow [%]

50% 100% 160%

Fig 12

Terminal unit emission characteristic

The traditional FCU is usually designed for a ΔT of 6 K. The 100% emission is achieved at 100% ow across the unit at a supply temperature of 6ºC and a return 12oC. The overow across the unit has little inuence on the emission. However, another phenomenon is more critical for proper chilled water system functionality. Higher ow across the units has an incredible inuence on heat/cool transfer which means that the return temperature never achieves the designed temperature. Instead of the design temperature of 12ºC, the real temperature is much lower, for example 9,3oC. The consequence of a lower return temperature from the FCU can be low ΔT syndrome.

For variable ow systems it is not recommended to use xed speed pumps as they worsen the overow problem. In Fig 13 this can be seen clearly. The gure represents the pump curve and the dierently colored areas represent the pressure drops in the system. The red area represents the pressure drop across the control valve. If we let the pump follow its natural curve, we see that with a decreasing ow, the dierential pressure will rise. If you compare the dierential pressure at 50% of the load you can see that the available pump head is much higher (P1) than the pump head at full load (P

. All the extra

nom)

pressure will have to be absorbed by the control valve. This will cause overows in the system, as well as a serious deformation of the characteristic of the valve.

*see page 54-55

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

100

90 80 70 60 50 40 30 20 10

10 20 30 40 50 60 70 80 90 100

Coli Characteristic Control CharacteristicControl Valve Characteristic

+ =

Flow %

Coli Characteristic Control Valve CharacteristicControl Valve Characteristic

CHL(%) 100% 100% 66,6%

11-7 13-7

CWRTR - CWSTD CWRTR - CWSTD

= = =x x

nom

Fig 13 Dierent pump characteristic

1 2 3 pump characterictic

50% 100%

Today commonly used Variable Speed Drives (VSD*) with pressure transmitters can modify the pump characteristic in accordance with ow and pressure changes in the water system. The nominal ow at 100% load and the above-mentioned pressure drop in the system determine the pump head which is equal to the nominal pressure, Pnom. We can see that a constant dierential pressure results in a much better situation at partial load, the dierential pressure across the control valve will increase much less than when the natural curve of the pump is followed. Please note however, that the pressure across the control valve will still rise considerably.

Modern pumps come equipped with speed controllers that can modify the pump not only based on the pressure but also on the ow, the so-called proportional control. If the ow is reduced, the dierential pressure is reduced. Theoretically this gives the best results as can be seen at P3 in Fig. 13. Unfortunately, it is unpredictable where in the installation the ow will be reduced so there is no guarantee that the pressure can be reduced as much as can be seen in Fig 13. It is therefore strongly recommended to limit the dierence pressure on P2 level to prevent parts of the installation from starving in certain situations.

The inescapable conclusion is that over- and underow problems cannot be solved by the pump alone. It is therefore strongly recommended to use pressure independent solutions. Pressure independent Balancing and Control Valves (AB-QM) can take care of pressure uctuations in the system and will provide the terminal units always with the right ow, under all loads of the system. We denitely recommend using VSDs* on the pump since that will result in very big savings. As for the control method we recommend to use xed dierential pressure control which will guarantee enough pressure under all circumstances. If proportional control is wanted than the AB-QM can operate under such conditions but we recommend keeping the pressure dierence on P3 level as to a minimum to prevent starving of certain parts of the installation during partial load.

*see page 54-55

Energy efficiency analysesControl and valve theoryGlossary and abbreviations

1 2 3 pump characterictic

nom

50% 100%

CHL(%) 100% 100% 66,6%

11-7 13-7

CWRTR - CWSTD CWRTR - CWSTD

= = =x x

8.7

The “underow phenomenon”

As can be seen from Fig 10.1, the available pressure for the rst circuit is much higher than the pressure of the last circuit. In this application the MBVs should take care of this by throttling the excess ow. So, the last MBV should be opened as much as possible and the other MBVs should be more and more throttled the closer they are to the pump.

MCV

Glossary and abbreviationsControl and valve theoryEnergy efficiency analyses

MBV

∆P

uns

pump

∆P

pump1

∆P

uns

∆P

Fig 14 Direct system with proportional pump control

A very standard application places the dierential pressure sensor controlling the pump at the last terminal unit to minimize pump consumption. We can see what happens when the two middle terminal units are closed. Because the ow in the piping is considerably reduced also the resistance in the system goes down which means that most of the pump head ends up at the end of the installation where the sensor is. This is represented by the red lines in Fig 14. If you look at the rst unit you can see that, even though the pressure on the loop should be the same, it actually gets a much lower dierential pressure and therefore too little ow. This can lead to the confusing situation where the installation is operating without problems on full load and when the load is reduced there are capacity problems close to the pump. Needless to say, putting the pump on proportional control will enhance the problems considerably. The pump senses a 50% drop in the ow and will drop the dierential pressure, accordingly, creating even lower ows in the rst terminal unit and a capacity problem at the last terminal unit as well.

An often-suggested compromise between creating underows and minimizing the pump consumption is to put the sensor at a lenght of two-thirds of the system. This is however still a compromise and there is no guarantee for having the right ow under all circumstances. An easy solution is to mount Pressure Independent Balancing and Control Valves (AB-QM) on every terminal unit and control the pump on constant dierential pressure. That way you will maximize the savings on the pump without any underor overow problems.

*see page 54-55

Energy eciency analyses

riser L(sup.+ret.)=85m Nr branches=15 ∆p cooling=250Pa/m ∆p heating=150Pa/m

source ∆p chiller=90kPa ∆p boiler=40kPa

riser

1 2

Goal:

In this chapter we describe in detail the dierences between 4 hydronic balancing and control solutions for an imaginary hotel building. For the comparison purpose the HVAC system in our hotel building is equipped with a 4-pipe heating/cooling system. For each of the 4 solutions we analyze the energy consumption/eciency. By adding the investment and operational costs, the payback time for each of the solutions is calculated.

• MBV_ON/OFF - 2 way control valve with ON/OFF actuator on Terminal Unit and Manual Balancing Valves on distribution pipe, risers, branches and TU-s.

• DPCV_ON/OFF - 2 way control valve with ON/OFF actuator on Terminal Unit and Dierential Pressure Control Valves on branches

• DPCV_modulation - 2 way control valve with modulating actuator on Terminal Unit and Dierential Pressure Control Valves on branches

• PICV_modulation – Danfoss recommendation -Pressure Independent Control Valve (PICV) with Modulating actuator on (TU). Optional MBV for ow verication on branches

MBV_ON/OFF

DPCV_ON/OFF DPCV_modulating

9.1

Fig 15

PICV_modulating

optional

ON/OFF actuator

ON/OFF

modulating

actuator

CV - Control Valve 2 way

PICV - Pressure Independent Control Valve

DPCV - Dierentiol Presure Control Valve

MBV - Manual Balancing Valve

Energy efficiency analysesControl and valve theoryGlossary and abbreviations

*see page 54-55

9.2

Data:

Building data Volume 57600 m3/h Area total 18000 m2 Nr. Floors 15 Area/Floor 1200 m2

Glossary and abbreviationsControl and valve theoryEnergy efficiency analyses

Cooling demand Capacity Regime Cooling demand / m2 Cooling demand / m3

COOLING SYSTEM DATA Nr risers Nr branches/riser Nr unit/branch Nr unit total Capacity/unit Capacity/branch

Flow/unit Flow/branch Flow/riser Flow/building

Cost of electricity Cooling season Chiller COP

900 kW

7/12oC

50 W/m2

15,6 W/m3

2 15 20

600

1,5 kW

30 kW

258 1/h

5160 1/h

77400 1/h

154800 1/h

0,15 EUR/kWh

150 days

3,5

Heating demand Capacity Regime Cooling demand / m2 Cooling demand / m3

HEATING SYSTEM DATA Nr risers Nr branches/riser Nr unit/branch Nr unit total Capacity/unit Capacity/branch

Flow/unit Flow/branch Flow/riser Flow/building

Cost of electricity Cooling season Chiller COP

630 kW

50/40oC

35 W/m2 11 W/m3

2 15 20

600 1,05 kW 21,0 kW

91 1/h

1820 1/h 27300 1/h 54600 1/h

0,008 EUR/kWh

180 days

Condensing

9.3

System scheme:

riser L(sup.+ret.)=85m Nr branches=15 ∆p cooling=250Pa/m ∆p heating=150Pa/m

source ∆p chiller=90kPa ∆p boiler=40kPa

Fig 16

1 2

riser

branch

distribution pipe L(sup.+ret.)=100m Nr risers=2 ∆p cooling=300Pa/m ∆p heating=200Pa/m

1 2... 20

terminal unit Nr TU=600 ∆p cooling=50kPa

branch L(sup.+ret.)=70m Nr TU=20 ∆p cooling=200Pa/m ∆p heating=150Pa/m

∆p heating=30kPa

Load prole:

Boiler load [%]

Cooling load prole:

900

800

700

600

500

Load duration [hours]

400

300

200

100

10% 10%

Fig 17

Load [%] 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Time [%] 0,40% 5,30% 22,60% 20,80% 19,10% 17,30% 7,80% 3,40% 2,90% 0,40% Capacity [kW] 90 180 270 360 450 540 630 720 810 900 Time [hours] 14 191 814 749 688 623 281 122 104 14 Energy consumpt.

[kWh] Expected cooling energy consump. [kWh/a] 1 533 168,0 Expected electrical energy consumption (COP=3,5) [kWh/a] 438 048,0 Expected energy cost [EUR/a] 65 707,20

14 14

20% 30% 40% 50%

1296 34344 219672 269568 309420 336312 176904 88128 84564 12960

9.4

Annual Load Prole

104122281623688749814191

60% 70% 80% 90% 100%

Cooling load [%]

Heating load prole:

1800

1600

1400

1200

1000

Load duration [hours]

800

600

400

200

12,8% 30,3% 38,8% 47,5% 62,6%

Fig 18

Load [%] 12,8% 30,3% 38,8% 47,5% 62,6% Time [%] 44,9% 19,0% 14,8% 12,1% 9,2% Capacity [kW] 115,2 272,7 349,2 427,5 563,4 Time [hours] 1616 684 533 436 331 Energy consumpt.

[kWh] Expected heating energy consump. [kWh/a] 931 606,9 Expected energy cost [EUR/a] 26 830,28

Annual Load Prole

3314365336841616

Energy efficiency analysesControl and valve theoryGlossary and abbreviations

186209 186527 186054 186219 186598

Glossary and abbreviationsControl and valve theoryEnergy efficiency analyses

ow

head [kPa]

PUMP HEAD

300

250

200

150

100

25%

50% 75% 100%

head [kPa]

FLOW

200

150

100

25%

50% 75% 100%

9.5

Enery consumption

Cooling:

Pump energy consumption

Most suitable pump control will be combined with matching balancing & control solution.

MBV_ON/OFF constant dierential pressure pump control DPCV_ON/OFF proportional pressure, calculated control DPCV_modulation proportional pressure, calculated control PICV_modulation proportional pressure, measured control

Fig 19

head

constant dierential pressure pump control

PUMP HEAD

300

250

200

150

100

head [kPa]

head

H/2

proportional pressure, calculated control

200

150

100

head [kPa]

head

proportional pressure, measured control

FLOW

Fig 20

Fig 21

25%

ENERGY CONSUMPTION

50% 75% 100%

kWh kWh kWh kWh

3 006

6 532

6 398

12 040

25%

2 796

7 841

8 162

50% 75% 100%

1 916

13 550

4 171

5 179

7 040

2 876

3 092

2 982

3 144

25%

50% 75% 100%

MBV_ON/OFF DPCV_ON/OFF DPCV_modulation PICV_modulation

Chiller energy consumption comparison:

Design conditions:

Chiller plant: Variable primary COP: 3.5 kW/kW (100% load) Chilled water Supply temperature (constant): T Chilled water Return temperature (variable): T Design ΔT

Assumption:

If ΔT

if ΔT

< 5K => T

chw

> 5K => T

chw

< 12oC, COP will drop

chw,return

> 12oC, COP will increase

chw,return

chw,supply

chw,return

=5K

chw

=7oC =12oC

19,00 16,00 17,00 15,00 13,00 11,00

9,00 7,00 5,00 3,00

10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Chiller COP

∆Tch w

4,40

4,20

4,00

3,80

3,60

3,40

3,20

3,00

10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Chiller elect. energy consumption

446,02 MWh

438,76 MWh

435,28 MWh

MBV_ON/OFF DPCV_ON/OFF DPCV_modulation PICV_modulation

Fig 22

390,32 MWh

DPCV_modulationDPCV_ON/OFF PICV_modulationMBV_ON/OFF

Energy efficiency analysesControl and valve theoryGlossary and abbreviations

Glossary and abbreviationsControl and valve theoryEnergy efficiency analyses

Additional energy consumption due to room

Temperature control energy consumption comparisson:

Expected room temperature deviation:

MBV_ON/OFF ±1.5oC = 22,5% DPCV_ON/OFF ±1.0oC = 15% DPCV_modulation ±0.5oC = 8% PICV_modulation ±0.0oC = 0%

Each 1oC deviation causes, from 12% up to 18% more energy consumption per the whole cooling system. For calculation 15% per 1oC deviation is taken.

Break-up HVAC energy consumption

Chiller energy consumption presents approx. 55% of whole cooling system energy consumption. Let’s take energy consumption of chiller 390MWh as a reference. Then whole cooling system consumes 710MWh of electrical energy per season.

Fig 23

chiller water

cooling tower

condenser

pump 12%

FCU & AHU 14%

pump 15%

pump 4%

chiller 55%

159,68 MWh

Fig 24

Comparison:

Energy consumption

Pumping 35 774,0 kWh 22 721,0 kWh 21 636,0 kWh 10 594,0 kWh Chiller energy consumption 446 022,2 kWh 438 761,6 kWh 435 275,7 kWh 390 322,6 kWh Add. en. usage temp control 159 676 kWh 106 450,9 kWh 53 225,5 kWh 0,0 kWh SUM 641 472,6 kWh 567 933,5 kWh 510 137,1 kWh 400 916,6 kWh

Energy consumption cost

Pumping 5 366,10 kWh 3 408,15 kWh 3 245 kWh 1 589,1 kWh Chiller energy consumption 66 903,33 kWh 65 814,24 kWh 65 291,35 kWh 58 548,4 kWh Room temp control energy consumption SUM 96 220,89 kWh 85 190,02 kWh 76 520,57 kWh 60 137,50 kWh

Investment

Distribution pipe balancing 2 239,2 € - € - € - € Riser balancing 3 141,8 € - € - € - € Branch balancing/flow verification 6 522,0 € 27 894,0 € 26 874,0 € 6 522,0 € Terminal unit 34 800,0 € 34 800,0 € 53 100,0 € 85 140,0 € Room thermostat 15 000,0 € 15 000,0 € 21 000,0 € 21 000,0 € Remote dp sensor - € - € - € 2 000,0 € SUM 61 703,0 € 77 694,0 € 100 974,0 € 114 662,0 €

Payback time

Energy cost 96 220,89 € 85 190,02 € 76 520,57 € 60 137,50 € Investment 61 7703,00 € 77 694,00 € 100 974,00 € 114 662,00 €

temperature control

106,45 MWh

53,23 MWh

0,00 MWh

DPCV_modulationDPCV_ON/OFF PICV_modulationMBV_ON/OFF

MBV_ON/OFF DPCV_ON/OFF DPCV_MODULATION PICV_MODULATION

23 951,45 kWh 15 967, 64 kWh 7 983,82 kWh - kWh

Payback time vs MBV_on/o 1,45 year 1,99 year 1,47 year Payback time vs DPCV_on/o 2,69 year 1,48 year Payback time vs DPCV_modulation 0,8 year

Heating:

Pump energy consumption

MBV_ON/OFF constant dierential pressure pump control DPCV_ON/OFF proportional pressure, calculated control DPCV_modulation proportional pressure, calculated controlPICV_modulation proportional pressure, measured control

Fig 25

head

ow

constant dierential pressure pump control

PUMP HEAD

200

150

100

head [kPa]

25%

50% 75% 100%

kWh kWh kWh kWh

883,6

1 476,0

1 608,0

2 559,0

814,1

head

H/2

ow

proportional pressure, calculated control

529,3

879,8

1 303,0

1 687,0

2 049,0

2 893,0

1 536,0

Flow m

685,4

750,8

head

ow

proportional pressure, measured control

FLOW

25%

50% 75% 100%

MBV_ON/OFF

702,7

DPCV_ON/OFF DPCV_modulation PICV_modulation

Fig 26

ENERGY CONSUMPTION

25%

50% 75% 100%

Energy efficiency analysesControl and valve theoryGlossary and abbreviations

Boiller energy consumption comparison:

Design conditions:

Glossary and abbreviationsControl and valve theoryEnergy efficiency analyses

Heating water Supply temperature (constant): T

Heating water Return temperature (variable): T

chw,supply

chw,return

=50oC

=40oC

Design ΔThw=10K

Assumption:

If ΔThw < 10K => T

if ΔT

>10K => T

chw

> 40oC, Boiler eciency will drop

hw,return

< 40oC, Boiler eciency will increase

hw,return

Boiller energy consumption

978,24 MWh

941,57 MWh

915,13 MWh

861,68 MWh

DPCV_modulationDPCV_ON/OFF PICV_modulationMBV_ON/OFF

Fig 27

Temperature control energy consumption comparison:

Expected room temperature deviation:

MBV_ON/OFF ±1.5oC = 9.75% DPCV_ON/OFF ±1.0oC = 6,5% DPCV_modulation ±0.5oC = 3,25% PICV_modulation ±0.0oC = 0%

Each 1oC deviation causes, from 5% up to 8% more energy consumption per whole heating system. For calculation 6,5% is taken.

Additional energy consumption due to room

129,689 kWh

Fig 28

temperature control

86,459 kWh

43,230 kWh

0,00 MWh

DPCV_modulationDPCV_ON/OFF PICV_modulationMBV_ON/OFF

Comparison table - 4 pipe (cooling and heating) system:

MBV_ON/OFF DPCV_ON/OFF DPCV_MODULATION PICV_MODULATION

Energy consumption heating

Pumping 7 689,0 kWh 5 711,0 kWh 4 797,0 kWh 2 912,0 kWh

Bolier energy consumption 978 240,0 kWh 941 570,0 kWh 915 130,0 kWh 861 680,0 kWh

Energy usage due to room temp deviation SUM 1 158 847,4 kWh 1 076 969,8 kWh 1 006 386,2 kWh 907 821,6 kWh

Energy cost heating

Pumping 1 153,35 € 856,65 € 719,55 € 436,80 €

Boiler energy consumption 28 171,06 € 27 115,05 € 26 353,64 € 24 814,40 €

Room temp control energy consumption 4 979,65 € 3 734,74 € 2 489,83 € 1 244,91 €

SUM 34 304,06 € 31 706,44 € 29 563,01 € 26 496,11 €

Energy consumption cooling

Pumping 35 774,0 kWh 22 721,0 kWh 21 636,0 kWh 10 594,0 kWh

Chiller energy consumption 446 022,2 kWh 438 761,6 kWh 435 275,7 kWh 390 322,6 kWh

Energy usage due to room temp deviation 6 522,0 kWh 106 450,9 kWh 53 225,5 kWh 0,0 kWh

SUM 61 703,0 kWh 567 933,5 kWh 510 137,1 kWh 400 916,6 kWh

Energy cost cooling

Pump 5 366,10 € 3 408,15 € 3 245,40 € 1 589,10 €

Chiller energy consumption 66 903,33 € 65 814 € 65 291,35 € 58 548,40 €

Room temp control energy consumption 23 951,45 € 15 967,64 € 7 983,82 € - €

SUM 96 220,89 € 85 190 € 76 520 € 60 137,50 €

172 918,4 kWh 129 688,8 kWh 86 459,2 kWh 43 229,6 kWh

9.6

Investment heating

Distribution pipe balancing 919,20 € - € - € - €

Riserbalancing 971,80 € - € - € - €

Branch balancing/ow verication 2 997,00 € 8 019,00 € 8 019,00 € 2 997,00 €

Terminal unit 34 800 € 34 800,00 € 53 100,00 € 85 140,00 €

Room thermostat 1 for cooling & heating 1 for cooling & heating 1 for cooling & heating 1 for cooling & heating

Remote Δp sensors - € - € - € 2 000,00 €

SUM 39 688,00 € 42 819,00 € 61 119,00 € 90 137,00 €

Investment cooling

Distribution pipe balancing 2 239,20 € - € - € - €

Riserbalancing 3 141,80 € - € - € - €

Branch balancing/ow verication 6 522,00 € 27 894,00 € 26 874,00 € 6 522,00 €

Terminal unit 34 800,00 € 34 800,00 € 53 100,00 € 85 140,00 €

Room thermostat 15 000,00 € 15 00,00 € 21 000,00 € 21 00,00 €

Remote Δp sensors - € - € - € 2 000,00 €

SUM 661 703,00 € 77 694,00 € 100 974,00 € 114 662,00 €

Payback time

Energry cost HEATING 34 304,06 € 31 706,44 € 29 563,01 € 26 496,11 €

Energy cost COOLING 96 220,89 € 85 190,02 € 76 520,57 € 60 137,50 €

Investment HEATING 39 688,00 € 42 819,00 € 61 119,00 90 137,00 €

Investment COOLING 61 703,00 € 77 694,00 € 100 974,00 € 114 662,00 €

total 231 915,95 € 237 409,46 € 268 176,58 € 291 432,661 €

Payback time vs MBV_on/o 1,40 year 2,48 year 2,36 year

Payback time vs DPCV_on/o 3,85 year 2,79 year

Payback time vs DPCV_modulation 2,2 year

Energy efficiency analysesControl and valve theoryGlossary and abbreviations

Notes

Product overview

Here you nd a short overview of all the Danfoss products as used in the HVAC applications described.

PICV: Pressure Independent Control Valves PICV without actuators: Automatic Flow Limiter PICV with actuators: Pressure Independent Control Valves with balancing function

Picture Name Description Size (mm)

Pressure independent control

AB-QM

valve, with or without test plug;

size small, combinations for

thermal units

Pressure independent control

valve, with or without test plug;

size medium, combinations for

air handling units

Pressure independent control

valve, with or without test plug;

size large, combinations for

chillers

Pressure independent control

valve, with or without test plug;

size x-large, combinations for

district cooling

15… 32 0.02...4

40… 100 3...59

125… 150 36...190

200...250 80...370

Flow

(m3/h)

Datasheet active link

Comments

Combined with

actuator ensures

high end

ow control – log-

arithmic or linear

characteristic

Combined with

actuator ensures

high end ow con-

trol – logarithmic

characteristic

Combined with

actuator ensures

high end

ow control – log-

arithmic charac-

teristic

Combined with

actuator ensures

high end

ow control

– logarithmic

characteristic

PRODUCTS OVERVIEW

Actuators for AB-QM valves

Picture Name Description useage with

Thermal actuator with 24V

TWA- Q

AMI 140

ABNM

AMV 110/120

and 230V AC/DC power

supply, visual positioning

indicator. Speed 30s/mm

Gear actuator with 24V and

230V AC power supply, posi-

tioning indicator.

Speed 12s/mm

Thermal actuator with 24V

AC/DC power supply, visual

positioning indicator.

Speed 30s/mm

Gear actuator with 24V AC power supply, positioning

indicator. Speed 24/12s/mm

AB-QM

valves size S;

dn 10-32

AB-QM

valves size S;

dn 15-32

AB-QM

valves size S;

dn 15-32

AB-QM

valves size S;

dn 15-32

control

signal

on/o; (PWM)

on-o

0-10V

3-point

Datasheet active link

Comments

IP54, cable lengh

1.2/2/5 m

IP42, cable lengh

1.5/5 m

IP54, cable lengh

1/5/10 m; loga-

ritmic or linear

characteristic

IP42, cable lengh

1.5/5/10 m

logarithmic or

linear characteristic

AME 110/120

NL (X)

NovoCon S

AMV 435

Gear actuator with 24V AC

power supply, positioning

indicator.

Speed 24/12 s/mm

Digital step motor 24V AC/

DC power supply, possible

BMS integration.

Speed 24/12/6/3 s/mm

Gear push-pull actuator with

24V and 230V AC power

supply, hand operation, LED

indication.

Speed 15/7,5 s/mm

AB-QM

valves size S;

dn 15-32

AB-QM

valves size S;

dn 15-32

AB-QM

valves

size M;

dn 40-100

IP42, cable lengh

0-10V;

4-20mA

BACnet;

Modbus;

0-10V;

4-20mA

3-point IP 54, push/pull

1.5/5/10 m

x-signal, logaritmic

or linear characte-

ristic

IP 54, cable lengh

1.5/5/10 m, Daisy-

chain cable length

0.5/1.5/5/10 m,

logaritmic or linear

characteristic

AME 435 QM

NOVOCON M

AME

655/658*

AME 55 QM

NOVOCON L

Gear push-pull actuator with

24V AC/DC power supply,

hand operation, LED indica-

tion. Speed 15/7,5 s/mm

Digital step motor 24V AC/

DC power supply, possible

BMS integration.

Speed 24/12/6/3 s/mm

Gear actuator with 24V AC/

DC power supply,

UL certication.

Speed 6/2(4*)

Gear actuator with 24V AC

power supply, positioning

indicator. Speed 8 s/mm

Digital step motor 24V

AC/DC power supply,

possible BMS integration.

Speed 24/12/6/3 mm

AB-QM

valves

size M;

dn 40-100

AB-QM

valves size M;

dn 40-100

AB-QM

valves size L;

dn 125-150

AB-QM

valves size L;

dn 125-150

AB-QM

valves size L;

dn 125-150

0-10V;

4-20mA

BACnet;

Modbus;

0-10V;

4-20mA

0-10V;

4-20mA;

3-point

0-10V;

4-20mA;

3-point

BACnet;

Modbus;

0-10V;

4-20mA

IP 54, push/pull,

x-signal, logaritmic

or linear charac-

teristic

IP 54, push/pull,

logaritmic or linear

characteristic,

3x Temperature

sensors;

1x Analog Input; 1x

Analog Output

IP 54, push/pull, x-signal, logaritmic or linear character-

istic, safety func-

tions spring up /

spring down

IP 54, push/pull, x-signal, logaritmic

or linear charac-

teristic

IP 54, push/pull, logaritmic or linear

characteristic,

3x Temperature

sensors;

1x Analog Input; 1x

Analog Output;

Spring up / Spring

down

PRODUCTS OVERVIEW

AME 685

NOVOCON XL

Gear actuator with 24V AC/

DC power supply, UL certi-

cation. Speed 6/3 s/mm

Digital step motor 24V AC/

DC power supply, possible

BMS integration.

Speed 24/12/6/3 s/mm

AB-QM

NovoCon

valves size

XL;

dn 200-250

AB-QM

NovoCon

valves size

XL;

dn 200-250

0-10V;

4-20mA;

3-point

BACnet;

Modbus;

0-10V;

4-20mA

IP 54, push/pull, x-signal, logaritmic

or linear charac-

teristic

IP 54, push/pull, logaritmic or linear

characteristic,

3x Temperature

sensors;

1x Analog Input; 1x

Analog Output;

Electronic and selfacting controller for AB-QM; One pipe system accessories

Picture Name Description Size (mm)

setting

range

Datasheet active link

Comments

Return temperature controller,

CCR3+

temperature registration.

Electronic control

Self-acting actuator, return tem-

perature controller.

Proportional control

Change over solution Change over valve

Picture Name Description Size (mm)

ChangeOver

valve 6

Motorized 6-port Ball Valves

for local change over between

heating and cooling

- -

35-50°C,

DN 15-32

15…20 2,4…4,0

45-60°C 65-85°C

Kvs

(m3/h)

Datasheet active link

Programmable temperature control, data storage, TPC/IP, Wi-Fi, BMS

Sensor holder and

heat conductivity

pasta included-

Sensor holder and

heat conductivity

pasta included

Comments

Change over

valve for

heating/cooling

mode changes

in 4 pipe system

with 2 pipe

terminal unit.

Not suitable for

control

PRODUCTS OVERVIEW

Change over actuators

Picture Name Description

Actuator

Change

Over 6

Actuator

NovoCon

Change

Over 6

Actuator

NovoCon

Change Over

6 Energy

Actuator

NovoCon

Change Over

6 Flexible

Rotating actuator, 2-point

control, 24V AC power supply .

Rotating actuator, 2-point con-

trol, power supply via NovoCon.

Rotating actuator, 2-point con-

trol, power supply via NovoCon,

2 temperatire sensor.

Rotating actuator, 2-point con-

trol, power supply via NovoCon,

I/O cable. Speed 120 s/mm

Speed 80 s/mm

Speed 120 s/mm

usage

with

Change-

Over

valve 6

Change

Over

valve 6

Change

Over

valve 6

Change

Over

valve 6

control

signal

0-10V

0-10V by

NovoCon®

0-10V by

NovoCon®

0-10V by

NovoCon®

Datasheet active link

Comments

Connected to

control system to

ensure change over between heating and cooling

Connected to

NovoCon with

plug in cable

Connected to No-

voCon with plug

in cable, with

built in 2*PT1000

temperature

sensors

Connected to No-

voCon with plug

in cable, with

built in I/O cable

for peripherical device connec-

tions

DBV - Dynamic Balancing Valves DPCV - Dierential Pressure Controller

Picture Name Description Size (mm)

Dierential pressure controller

ASV-P

ASV-PV

ASV-M

ASV-I

ASV-BD

in the return pipe with x 10 kPa

pressure setting

Dierential pressure controller

in the return pipe with adjusta-

ble 5-25 or 20-60 kPa pressure

setting

Flow pipe mounting valve,

impuls tube connection, shut

o function,

Flow pipe mounting valve

impuls tube connection,

presetting, measuring

possibility, shut o function

Flow pipe mounting valve

impuls tube connection,

presetting, measuring

possibility, shut o function

15… 40 1,6… 10

15… 50 1,6… 16

15....50 3....40

Kvs

(m3/h)

Datasheet active link

Comments

Integrated shut

o and draining

possibility

Integrated shut

o and draining

possibility, up-

gradeable Δp range

Used with ASV-P

or PV together

mainly for shut of

function

Used with ASV-PV

valve together mainly for ow limitation func-

tion

Used with ASV/P

or PV together,

big capacity,

measurement,

shut of function

PRODUCTS OVERVIEW

ASV-PV

AB-PM

Dierential pressure controller

with adjustable 20-40, 35-75 or

60-100 kPa pressure setting

Pressure Independent Balancing

and Zone Valve

Dierential pressure controller

with adjustable Δp range and

Zone Valve

50… 100 20… 76

10... 32

40…100

0,02...2,4

Δp=10/20Pa

3…14

Δp=

42/60 kPa

Used with MSV-F2

in the w pipe for

shut o ow lim-

iting and impulse

tube connection

Max. w capacity

depends on Δp

demand of con-

trolled loop

Max. ow capa-

city

depends on

Δp demand of

controlled loop,

Δp setting range

40-100 kPa

MBV: Manual Balancing Valves

Picture Name Description Size (mm)

Impulse tube connection,

USV-I

USV-M

MSV-BD

MSV-B

presetting, draining, measuring

possibility,shut o function

Return pipe mounting valve,

shut of function with drain pos-

sibility, normal brass valve body,

upgradeable for Δp controller

with membrane kit

Presetting, with test plug, DZR

valve body, closing and drain

function

Presetting, with test plug, DZR

valve body, closing function

Kvs

(m3/h)

15...50 1,6...16

15...50 2,5...40

Datasheet active link

Comments

Used with ASV-PV

valve together

mainly for w

limitation func-

tion

Upgradeable to

diferential pressu-

re controller (for

DN15- DN40)

Extra large Kvs

valve, unidirectio-

nal construction,

high accuracy

rotary measuring

station

Extra large Kvs

valve, unidirectio-

nal construction,

high accuracy

PRODUCTS OVERVIEW

Presetting, with test plug, DZR,

MSV-O

MSV-S Closing valve, DZR body 15...50 3...40

MSV-F2

PFM 1000

valve body, closing function and

xed orie

Presetting, with test plug, GG-25

valve body, closing function

Measuring device for manual

balancing valve and trouble

shooting

MCV: Zone Valve, Motorised Control Valves

Picture Name Description Size (mm)

Presetting valve (14 sets) on

RA-HC

VZL-2/3/4

zone control or self acting room

tempeature control with ther-

mostatic head

Fan-coil valve on zone control with linear valve characteristic

15...50 0,63...38

15...400 3,1...2585

- -

Kvs

(m3/h)

15...25 2,8...5,5

15...20 0,25...3,5

Datasheet active link

Extra large Kvs

valve, high

accuracy rotary

measuring station

Extra large Kvs

valve,shut

o funtion, high

draining capacity

PN 25 version is

available

Bluetooth com-

munication via Danfoss

smartphone app

(iOs/Android)

Comments

Recommended

application

with central Δp

controller

Short stroke valve

applicable with thermal or gear

actuator

VZ-2/3/4

Fan-coil valve on zone or

3-point, proportional control

with logarithmic valve

characteristic

15...20

0,25.....3,5

(A-AB)

0,25......2,5

(B-AB)

Logarithmic stro-

ke valve – accura-

te control

AMZ 112/113

VRB-2/3

Zone controller ball valve

with high kvs value

Traditional logarithmic-linear

control valve

15...50

15...25

15...50 0,63...40

17...290,

3,8...11,6

With integrated

gear actuator

Internal and

external thread

connection, high

control ratio,

pressure relieved

VF-2/3

Traditional logarithmic-linear

Actuators for MCV valves

Picture Name Description

Thermal actuator with 24V

TWA- A

TWA-ZL

ABNM,

ABNM-Z

AMI 140

AMV/E-H

130,

140

and 230V power supply, visual

positioning indicator.

Thermal actuator with 24V

power supply, visual positioning

indicator. Speed 30 s/mm

Gear actuator with 24V and

230V power supply, positioning

indicator. Speed 12/24 s/mm

Gear actuator with 24V and

230V power supply, hand

operation. Speed 14/15 s/mm

control valve

Speed 30 s/mm

15...150 0,63...320 High control ratio

useage

with

RA-N, RA-

HC; VZL

RA-N, RA-

HC; VZL

VZ; VZL

control

signal

on/o, (PWM)

0-10V

3-point,

0-10V

3-point,

0-10V

Datasheet active link

Comments

Available both,

NC and NO

version, closing,

force 90 N

LOG or LIN stroke

movement, only

NC version is

available closing

force 100 N

Closing force

200N, hand ope-

ration

Closing force 200

N, force switch-o

at stem down

position

PRODUCTS OVERVIEW

AMV/E 435

AMV/E 25

SD/SD

AMV/E 55/56

AMV/E 85/86

AMZ 112/113

Gear push-pull actuator with

24V or 230V power supply. Seed

7/14 s/mm

Gear push-pull actuator spring

UP/DOWN with 24V and 230V

power supply.

Speed 11/15 s/mm

Gear push-pull actuator with

24V or 230V power supply.

Speed 8/4 s/mm

Gear push-pull actuator with

24V or 230V power supply.

Speed 8/3 s/mm

2- piont central heating actu-

ator with 24V or 230V power

supply. Speed 30 s/mm

VRB, VF

AMZ ON/OFF

3-point,

0-10V

3-point,

0-10V

3-point,

0-10V

3-point,

0-10V

230V version

only on 3-point

actuator, built in

antioscillation

algorithm

Spring down:

overheating pro-

tection, spring up:

frost protection

230V version

only on 3-point

actuator

230V version

only on 3-point

actuator

90 ratation; AUX

swich

TRV - Termostatic Radiator Valves; BIV - Built In Valves ; RLV- Return Locking Valves

Picture Name Description size (mm)

Presetting valve (14 sets) on

RA-N

RA-UN

RA-DV

RA-G

zone control or self acting room

tempeature control with ther-

mostatic head

Low Flow Presetting valve (14

sets) on zone control or self

acting room tempeature control

with thermostatic head

Pressure Independent Preset-

ting valve (14 sets) on zone

control or self acting room

tempeature control with ther-

mostatic heade

High capacity valve for 1-pipe

systems

10…25 0,65… 1,4

10…20 0,57

10…20

10...25 2,3…4,58

Kvs

(m3/h)

Max ow

135 l/h

Datasheet active link

Comments

Recommended

application with

central

∆p controller-

Recommended

application with

central

∆p controller

Recommended

application with

central ∆p con-

troller

Recommended

application with

central

∆p between

10-60 kPa Recom-

mended applica-

tion with central

∆p between 10-

60 kPa

Use Optimal 1

tool for best ba-

lancing results

PRODUCTS OVERVIEW

RA-FS

RA-KE

RA-KEW

RA-N

RA-U

Special Bi-directional valve for

UK market, where the spindle

can be turned for opposite

direction

Manifold assemblies for one

pipe system

Integrated normal-ow built in

valve wit 7 steps presetting

Integrated low-ow built in valve wit 7 steps presetting

15 0,73

Radiator

system

20Radia-

tor 15

system

15, 20,

M18, M22,

15 0,74

2,5

0,95

RA-FS valves must only be used with

RAS-C2 or RAS-D

sensors. 15, 10

and 8 mm copper

connections.

Capacity of ma-

nifold assembly.

Bypass through

radiator: 35 %.

∆p max = 30

- 35 kPa.Capa-

city of manifold assembly. Bypass through radiator:

35 %.

∆p max = 30 - 35 kPa.

The integrated

valve, type RA-N,

is designed for

incorporation into

convectors from

dierent radiator

manufacturers

The integrated

valve, type RA-U,

is designed for

incorporation into

convectors from

dierent radiator

manufacturers

RLV-S

RLV

Standard lockshield valve,

nickel-plated

Lockshield Valve with drain-o

feature

10,15,20 1,5…2,2

10,15,20 1,8…3

To be placed at radiator return

side. Presetting is

possible to do at

lockshield

To be placed at radiator return

side. Presetting is

possible to do at

lockshield

Standard H-piece With drain-

RLV-K

RLV-KS

RLV-KDV

-o feature, for 1 and 2-pipe

Standard H-piece with shut-o.

For radiators with Built In Valves

Dynamic H-piece valve, pressure

independent. For radiators with

Sensors for TRV

Picture Name Description

RA 2000

RA 2920

RAE

RAW

Temp. range 7-28oC

Tamperproof. For use in institu-

tions etc. Temp. range 7-28oC

Click connection. White socket.

Temp. range 8-28oC

Click connection. White socket.

Temp. range 8-28oC

systems

Built In Valves

Click connection.

10...20 1,4

10...20 1,3

10...20

Below

type

Gas

Liquid

Max ow

159 l/h

Responce

time

With

built in

sensor=12

min. With

remote

sensor= 8

min.

With

built in

sensor=12

min. With

remote

sensor= 8

min.

With

built in

sensor=22

min. With

remote

sensor=

18 min.

With

built in

sensor=22

min. With

remote

sensor=

18 min.

Datasheet active link

Presetting must

be done at Built In

Valve. Drain func-

tion at H-piece

Presetting must

be done at Built

In Valve. Shut-

-o function at H-piece

Presetting must

be done at Built In

Valve. Drain func-

tion at H-piece

PRODUCTS OVERVIEW

Comments

Positive shut-o

feature,Temperature limitation, Frost protection,

Remote sensor

available, An-

titheft protection

Temperature limi-

tation, Frost pro-

tection, Version

+16ºC, Remote sensor available,

Antitheft protec-

tion

Positive shut-o

feature,Temperature limitation, Frost protection,

Version +16ºC,

Remote sensor

available, An-

titheft protection

Positive shut-o

feature,Temperature limitation, Frost protection,

Version +16ºC,

Remote sensor

available, An-

titheft protection

DHWC: Domestic Hot Water Controllers

Picture Name Description Size [mm]

MTCV-A

MTCV-B

MTCV-C

WITH

CCR2+

Multifunctional thermosta-

tic DHW circulation valve

Multifunctional thermosta-

tic DHW circulation valve

with Self acting temperatu-

re desinfection module

Multifunctional thermosta-

tic DHW circulation valve with disinfection process

controller and temperature

registration electronic, 24V

DC power suplly

15...20 1,5...1,8

Kvs

(m3/h)

Function

Return

temperature

limitation

Return

temperature

limitation and

allow thermic

desinfection

Return

temperature

limitation, electronic

control

for disinfec-

tion

Datasheet active link

Comments

Temp. range

35-60°C,Valve

body RG5, max.

ow tempera-

ture

100°C

Built in by-pass

for start of ther-

mic disinfection

process

Programable

disinfecton

process, data

storage,TPC/IP,

Wi-Fi, BMS

PRODUCTS OVERVIEW

Thermal actuator with

TWA- A

ESMB,

ESM-11

TVM-W Temperature mixing valve 20...25 2,1...3,3

TVM-H

24V power supply, visual

positoning indicator

Temperature sensors - -

Temperature mixing valve

for heating application

- -

20...25 1,9...3,0

ON/OFF

control of

disinfection

Temperature

registration,

start disinfec-

tion

Tapping

temperature

limitation

Temperature

mixing

Available both,

NC and NO

version, closing

force 90 N

PT 1000, more diernt shape

sensors are

available

Built in tempe-

rature sensor,

external thread

Built in tempe-

rature sensor,

external thread

Additional equipment

Picture Name Describtion Outlets (pcs) Pmax (bar)

FHF

Manifolds for water oor

heating system, with individual

shut-o on supply and with

integrated Danfoss pre-setting

valves on return

from 2+2 to

12+12

10 (without

owmeter)

16 (with ow-

meter)

Picture Name Describtion Heat source

EvoFlat systems are compatible

EvoFlat

with virtually any kind of heat

supply infrastructure, and are

independent of the type of

Condensing boiler; Substation;

Biomass; Heat pumps (all heating

source)

energy used.

Picture Name Describtion Size (mm) Kvs m3/h

Thermo- operated water valves

used for proportional regulation

AV TA

of ow quantity, depending

10-25 1,4 …. 5,5

on the setting and the sensor

temperature.

Datasheet active link

Comments

Airvent

on end pieces;

Flow T

- 900C;

MAX

Comments

DHW prepara-

tion;Indepen-

dency on heat

source;

Comments

Self acting;

vMax Δp = 10

bar;

Media tempera-

ture range:

-25 – 130 °C

Ethylene glycol

up to 40%

Picture Name Describtion

ultrasonic, compact energy

Sono

MeterS

meters intended for measuring

energy consumption in heating

and cooling applications for

billing purposes.

Picture Name

datasheet active link

VLT®HVAC

Drive

FC102

Outlets [pcs]

Size (mm)

Nominal ow

(m3/h)

20 … 100 0,6 ... 60

Datasheet active link

Comments

Temperature

range 5 - 130 °C,

PN 16 or 25 bar;

IP65; M-Bus

Notes

Type of Support Explanation

ENERGY SAVING CALCULATION

HYDRONIC ANALYSE

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We help designers to specify projects with an optimal Danfoss solution from cost and energy efficiency aspects.

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detailed hydronic calculations, pump head calculation, Δp sensor allocation, pipe size analyses, domestic hot water system (circulation) calculation

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AB137886464511en-010401 | 2020.07

Danfoss How to design balancing and control solutions for energy efficient hydronic applications in residential and commercial buildings Application guide

Specifications and Main Features

Frequently Asked Questions

User Manual