Hoval RoofVent LHW-9, RoofVent LKW-9, RoofVent LHW-10, RoofVent LKW-6, RoofVent LKW-10 Design Handbook

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RoofVent

Design Handbook

Supply and Extract Air Handling Units for Heating and Cooling High Spaces

Safety

RoofVent® LHW

Supply and extract air handling unit with energy recovery for heating high spaces

RoofVent® LKW

Supply and extract air handling unit with energy recovery for heating and cooling high spaces

RoofVent® twin heat

Supply and extract air handling unit with high-capacity energy recovery for heating high spaces

RoofVent® twin cool

Supply and extract air handling unit with high-capacity energy recovery for heating and cooling high spaces

RoofVent® twin pump

Supply and extract air handling unit with reversible heat pump for heating and cooling high spaces

117

RoofVent® condens

Supply and extract air handling unit with gas condensing boiler for heating high spaces

149

RoofVent® direct cool

Supply and extract air handling unit with single-split cooling system for heating and cooling high spaces

175

RoofVent® LH

Supply and extract air handling unit with optimum fresh air rate for heating high spaces

207

RoofVent® LK

Supply and extract air handling unit with optimum fresh air rate for heating and cooling high spaces

235

Options

265

Control systems

287

System design

299

Operation

305

Safety A

1 Symbols _____________________________________ 5

2 Operational Safety ____________________________ 5

3 Information for a User Manual ___________________ 5

Safety

Content

1 Symbols

Caution

This symbol warns against risks of injury. Please heed all instructions designated by this symbol to prevent injuries and/or death.

Attention

This symbol warns against risks of property damage. Please heed the respective instructions to prevent risk of damage to the unit and its functions.

Note

This symbol denotes information about the economic use of the equipment or special tips.

2 Operational Safety

RoofVent® units are state of the art design and are safe to operate. Nevertheless, hazards may emanate from the units if they are used incorrectly or not used as intended. Therefore:

■ Please read the operating instructions before unpacking,

installing, commissioning and before maintaining the equipment.

■ Store the operating instructions so that they are easily

accessible.

■ Observe all appropriate informational and warning signs.

■ Follow the local safety and accident prevention regula-

tions at all times.

■ RoofVent

units may only be installed, operated and main-

tained by authorized, skilled and trained specialists.

Specialists as dened by these operating instructions are

those persons who, based on their training, knowledge and experience as well as their knowledge of the relevant regulations and guidelines, can carry out the work assigned to them and recognize potential hazards.

3 Information for a User Manual

According to the accident prevention regulations of some countries, the operator of equipment must meet certain requirements for the prevention of occupational accidents and instruct the operating personnel as to the hazards that may occur and how to prevent them. This can be done with the help of the user manual. In addition to national regulations for accident prevention and environmental protection, a user manual should also include the most important items of the operating instructions.

Safety

Symbols

RoofVent® LHW

Supply and extract air handling unit with energy recovery for heating high spaces

1 Use ________________________________________ 8

2 Construction and operation______________________ 8

3 Technical data _______________________________ 15

4 Design example ______________________________ 24

5 Options ____________________________________ 26

6 Control systems______________________________ 27

7 Transport and installation ______________________ 28

8 Specication texts ____________________________ 32

RoofVent® LHW

Content

1 Use

1.1 Intended use

RoofVent® LHW units are used to supply fresh air, for the disposal of extract air as well as for heating coupled with energy recovery in high spaces. Also included under intended use are compliance with the installation, commissioning, operating and maintenance provisions (operating manual). Any use beyond this is considered improper use. The manufacturer shall not be held responsible for any damage resulting from such use.

1.2 User group

RoofVent® LHW units may only be installed, operated and serviced by authorised and trained specialist personnel who are familiar with the equipment and aware of the dangers involved. The operating manual is for English-speaking operating engineers and technicians as well as specialists in building, heating and ventilation technology.

1.3 Risks

RoofVent® LHW units are built to correspond to the state of the art and to current safety standards. However, despite all precautionary measures taken, there are still some potential hazards which are not immediately obvious, such as:

■ Dangers when working with the electrical systems

■ During work on the ventilation unit, parts (e.g. tools) may

fall or be dropped.

■ Dangers when working on the roof

■ Damage to devices or components due to lightning

■ Malfunctions as a result of defective parts

■ Hazards from hot water when working on the hot water

supply

■ The ingress of water through the roof unit if the access

panels are not closed correctly

2 Construction and operation

The RoofVent® LHW provides fresh air supply and extract air removal as well as heating for large spaces (production halls,

shopping centres, sports halls, exhibition halls etc.). It fulls

the following functions:

■ Heating (with connection to central hot water supply)

■ Fresh air supply

■ Extract air removal

■ Recirculation

■ Energy recovery

■ Air distribution via Air-Injector

■ Air ltration

A ventilation system consists of several autonomous RoofVent

LHW units and, as a rule, works without supply and extract air ducts. The units are decentrally installed in the roof and are also serviced from roof level.

Thanks to their high output and efcient air distribution,

RoofVent

LHW units have a large operating range. This means that compared with other systems, only few units are necessary to create the required conditions. Three unit sizes, various coil types and a series of accessories make it possible to provide a customised solution for any hall.

2.1 Unit construction

The RoofVent® LHW consists of the following components:

■ Roof unit with energy recovery: self-supporting casing

made of Aluzinc sheet steel, insulated inside (class B1)

■ Filter box: available in three standard lengths per unit size

for adjusting to specic dimensional requirements

■ Heating section:

coil connections possible on each side (usually underneath the extract air grille)

■ Air-Injector:

patented, automatically adjustable vortex air distributor for draught-free air distribution over a large area

The unit is delivered in two sections: roof unit and below-roof unit (see Fig. B1). The components are bolted together and can be dismantled individually.

RoofVent® LHW

Use

2.2 Air distribution with the Air-Injector

The patented air distributor – called the Air-Injector – is the core element. The air discharge angle is set by means of the

adjustable guide vanes. It depends on the air ow rate, the

mounting height and the temperature difference between the supply air and room air. The air is therefore blown into the room vertically downward, conically or horizontally. This ensures that:

■ each RoofVent

LHW ventilates and heats a large oor

area,

■ no draughts occur in the occupied area,

■ the temperature stratication in the room is reduced, thus

saving energy.

Above-roof unit: Roof unit with energy recovery

Below-roof unit:

a Filter box b Heating section c Air-Injector

Fig. B1: Components of the RoofVent® LHW

b c

RoofVent® LHW

Construction and operation

RoofVent® LHW

Use

Actuator Air-Injector: adjusts the supply air discharge direction continuously from vertical to horizontal

Frost controller: prevents the coil freezing

Extract air grille

Extract air lter:

bag lter with differential pressure switch for lter monitoring

ER damper and bypass damper: opposed dampers for regulation of energy recovery, with actuator

Access panel:

access to extract air lter

Weather louvre door:

access to the fresh air lter and to the DigiUnit terminal box

Fresh air lter:

bag lter with differential pressure switch for lter monitoring

Fresh air damper and recirculation damper: opposed dampers for switching between fresh air and recirculation operation, with actuator

Gravity damper: closes the bypass during shutdown and thus prevents heat loss

Exhaust air fan: twin impeller centrifugal fan with maintenance-free drive

Exhaust air grille: access to exhaust air fan

Plate heat exchanger: with bypass for energy recovery control and condensate drain

Access panel: access to supply air fan

Supply air fan: twin impeller centrifugal fan with maintenance-free drive

Access panel: access to heating coil

Heating coil:

LPHW coil consisting of copper tubes with aluminium ns

Fig. B2: Components of the RoofVent® LHW

RoofVent® LHW

Construction and operation

Fresh air inlet through weather louvre door

Filter with differential pressure switch

Fresh air damper with actuator

Plate heat exchanger

Supply air fan

Silencer and diffuser

LPHW heating coil

Frost controller

Supply air sensor

Air-Injector with actuator

Extract air inlet through extract air grille

Extract air sensor

Filter with differential pressure switch

Recirculation damper (opposed to the fresh air damper)

ER/bypass damper with actuator

Gravity damper

Exhaust air fan

Silencer and diffuser

Exhaust air outlet through exhaust air grille

Fig. B3: Operational diagram, RoofVent® LHW

RoofVent® LHW

Construction and operation

2.3 Operating modes

The RoofVent® LHW has the following operating modes:

■ Off

■ Ventilation

■ Ventilation (reduced)

■ Recirculation

■ Recirculation night

■ Exhaust air

■ Supply air

■ Night cooling summer

■ Emergency operation

The DigiNet control system controls these operating modes automatically per control zone, in accordance with the scheduler (exception: emergency operation). In addition, you can:

■ manually switch the operating mode of a control zone,

■ switch each individual RoofVent

unit to the following operating modes: Off,

Recirculation, Exhaust air, Supply air and Emergency operation.

Code

Operating mode Use Diagram Description

OFF Off

The fans are turned off. Frost protection remains active. There is no room temperature control.

If the unit is not needed

Supply air fan ...................Off

Exhaust air fan ................. Off

Energy recovery ...............0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating ............................ Off

VE2 Ventilation

The RoofVent

unit blows fresh air into the room and draws off spent room air. Heating and energy recovery are controlled depending on the heat demand and temperature conditions. The room temperature set value day is active.

During room use

Supply air fan ................... On

Exhaust air fan ................. On

Energy recovery ............... 0 – 100 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating ............................ 0 – 100 %

VE1 Ventilation (reduced)

Like VE2, but with reduced air ow rate

The room temperature set value day is active.

During room use (only for fans with

variable air ow

rate)

REC Recirculation

On/Off operation: In the event of heat demand, the RoofVent

unit draws in room air, warms it and blows it back into the room. The room temperature set value day is active.

For pre-heating

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating ............................ On

*) during heat demand

RECN Recirculation night

Like REC, but with room temperature set value night

During the night and on weekends

RoofVent® LHW

Construction and operation

Code

Operating mode Use Diagram Description

EA Exhaust air

The RoofVent

unit extracts spent room air. There is no room temperature control.

For special cases

Supply air fan ................... Off

Exhaust air fan ................. On

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating ............................ Off

SA Supply air

The RoofVent

unit blows fresh air into the room. Heating is controlled depending on the heat demand and temperature conditions. Spent room air passes through open windows and doors or another system provides extraction. The room temperature set value day is active.

For special cases

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating ............................ 0 – 100 %

NCS Night cooling summer

On/Off operation: If current temperatures allow, the RoofVent

unit blows cool fresh air into the room and extracts warmer room air. The room temperature set value night is active. The unit blows the supply air vertically downwards to achieve the greatest

possible efciency.

For free cooling during the night

Supply air fan ................... On

Exhaust air fan ................. On

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating ............................ Off

*) depending on temperature conditions

– Emergency operation

The RoofVent

unit draws in room air, warms it and blows it back into the room. The heater is switched on via manual control of the mixing valve. There is no room temperature control.

If the DigiNet system is not operating (e.g. before commissioning)

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating ............................ On

This is the code for the respective operating mode in the DigiNet control system (see Part L 'Control systems').

Table B1: Operating modes of the RoofVent

LHW

RoofVent® LHW

Construction and operation

3 Technical data

3.1 Unit type reference

Below-roof unit

LHW - 6 / DN5 / LW + F00 - H.B - D / ...

Unit type

RoofVent

LHW

Unit size

6, 9 or 10

Control

DN5 Design for DigiNet 5 KK Design for non-Hoval control

Roof unit

Roof unit with energy recovery

Filter box

F00 Filter box, short F25 Filter box, medium F50 Filter box, long

Heating section and coil type

H.A Heating section with coil type A H.B Heating section with coil type B H.C Heating section with coil type C

Air-Injector

Options

Table B2: Unit type reference

3.2 Application limits

Extract air temperature max. 50 °C

Extract air relative humidity max. 60 %

Moisture content of extract air max. 12.5 g/kg

Fresh air temperature Min. -30 °C

Heating medium temperature max. 120 °C

Operating pressure max. 800 kPa

Supply air temperature max. 60 °C

Minimum operating time VE2 min. 30 min

Table B3: Application limits of the RoofVent® LHW

RoofVent® LHW

Technical data

3.3 Air flow rate, electrical connections

Unit type LHW-6 LHW-9 LHW-10

Air distribution Nominal air ow rate

Supply air m³/h 5500 8000 8800

Exhaust air m³/h 5500 8000 8800

Floor area reached Max. m² 480 797 915

Energy recovery Heat recovery efciency, dry % 60 63 57

Heat recovery efciency, wet % 68 73 65

Fan characteristics Supply voltage V AC 3 x 400 3 x 400 3 x 400

Permitted voltage tolerance % ± 10 ± 10 ± 10

Frequency Hz 50 50 50

Active power per motor kW 1.8 3.0 4.5

Current consumption A 4.0 6.5 9.9

Set point of thermal relays A 4.6 7.5 11.4

Speed of rotation (nominal) rpm 1440 1435 1450

Actuators Supply voltage V AC 24 24 24

Frequency Hz 50 50 50

Control voltage V DC 2…10 2…10 2…10

Torque Nm 10 10 10

Run time for 90° rotation s 150 150 150

Filter monitoring Factory setting of differential pressure switch Pa 300 300 300

Refers to: RoofVent® LHW with heating coil type B and vertical supply air discharge direction

Table B4: Technical data, RoofVent

LHW

RoofVent® LHW

Technical data

3.4 Sound levels

Unit type LHW-6 LHW-9 LHW-10

Operating mode VE2

REC

VE2

REC

VE2

REC

Position

Sound pressure level (at a distance of 5 m) 1)dB (A) 46 60 58 47 46 52 66 57 49 48 54 68 60 52 51

Total sound power level dB (A) 68 82 80 69 68 74 88 79 71 70 76 90 82 74 73

Octave sound power level 63 Hz dB (A) 51 63 62 48 54 52 69 59 54 56 54 71 62 57 59

125 Hz dB (A) 55 71 70 56 63 63 78 70 60 63 65 80 73 63 66

250 Hz dB (A) 61 76 74 64 63 65 81 71 63 66 67 83 74 66 69

500 Hz dB (A) 61 75 71 61 58 66 81 70 62 61 68 83 73 65 64

1000 Hz dB (A) 65 77 72 63 57 71 81 72 67 60 73 83 75 70 63

2000 Hz dB (A) 57 72 72 60 56 66 80 73 64 58 68 82 76 67 61

4000 Hz dB (A) 49 71 71 57 48 58 76 71 58 50 60 78 74 61 53

8000 Hz dB (A) 36 65 63 49 42 44 70 62 51 41 46 72 65 54 44

with hemispherical radiation in a low-reection environment

outdoors (roof unit)

Table B5: Sound levels, RoofVent

LHW

RoofVent® LHW

Technical data

3.5 Heat output

Note

The performance data listed here applies to the most frequent design conditions. Use the selection program 'HK-Select' to calculate the performance data for other design data. You can download 'HK-Select' free of charge on the Internet.

Fresh air temperature -5 °C -15 °C

LPHW Size Type Q Q

TGHmax

tS∆p

QQTGH

max

tS∆p

°C kW kW m °C kPa l/h kW kW m °C kPa l/h

80/60 LHW-6 A 37 20 16.2 28 8 1569 39 16 18.3 26 8 1663

LHW-6 B 52 36 12.4 36 14 2228 55 33 13.0 34 16 2363

LHW-6 C 80 64 9.5 51 13 3447 85 63 9.6 50 15 3656

60/40 LHW-6 A 23 7 25.0 21 3 984 25 3 25.0 19 4 1079

LHW-6 B 32 16 18.1 26 6 1393 36 13 20.4 24 8 1530

LHW-6 C 51 35 12.6 36 6 2185 56 33 12.9 35 7 2395

80/60

LHW-9

A 59 39 14.7 32 7 2544 62 34 15.7 30 7 2678

LHW-9

B 75 55 12.5 37 10 3235 79 51 12.9 36 11 3407

LHW-9

C 116 96 9.7 52 10 4984 122 94 9.8 51 11 5248

60/40

LHW-9

A 37 16 22.5 24 3 1570 40 12 25.0 22 3 1706

LHW-9

B 46 26 17.8 27 5 1992 51 22 19.4 26 5 2167

LHW-9

C 73 52 12.8 36 5 3119 79 51 13.0 36 5 3385

80/60 LHW-10 A 74 46 23.5 24 10 3173 74 35 23.5 24 10 3173

LHW-10 B 83 55 14.3 35 12 3549 88 49 15.2 33 14 3778

LHW-10 C 129 101 10.8 50 12 5529 137 98 10.9 49 14 5887

60/40 LHW-10 A 50 22 25.0 16 5 2151 50 11 25.0 16 5 2151

LHW-10 B 52 24 21.5 25 6 2231 57 18 25.0 23 7 2465

LHW-10 C 82 54 14.4 35 6 3528 91 52 14.8 34 7 3888

Legend: Type = Type of heating coil

Q = Heat output Q

= Output to cover fabric heat losses

max

= Maximum mounting height

= Supply air temperature

∆p

= Water pressure drop

= Water ow rate

Refers to: Room air 18 °C, extract air 20 °C/40 % rel. humidity

Table B6: Heat output, RoofVent

LHW

Note

The output for coverage of the fabric heat losses (Q

) allows for the ventilation heat requirement

) and the energy recovery output (QER) under the respective air conditions. It is calculated as

follows:

QTG = Q + QER – Q

RoofVent® LHW

Technical data

3.6 Minimum and maximum distances

X/2

Unit type LHW-6 LHW-9

LHW-10

Align the RoofVent® units so that no unit draws in the exhaust air from another unit as fresh air.

The extract air grille must be easily accessible.

Provide a clear space of approx. 1.5 m on the side opposite to the heating coil connections for service and maintenance.

The stream of supply air must be able to spread unobstructed (note position of beams and lamps).

Unit clearance X Min. m 11.0 13.0 14.0

Max. m 22.0 28.0 30.0

Mounting height Y

Min. 1)m 4.0 5.0 5.0

Max.

m 9.0 … 25.0

The minimum height can be reduced by 1 m in each case using the 'Air

outlet box' option (see Section K 'Options').

The maximum height varies depending on the ancillary conditions (for

values, see Table B6).

Table B7: Minimum and maximum distances

RoofVent® LHW

Technical data

3.7 Dimensions and weight

Roof unit LW

Filter box short F00 / medium F25 / long F50

Heating section H

Air-Injector D

Cable feedthroughs for electrical connections

Access panel

Return

Flow

Fig. B4: Dimensional drawing for RoofVent® LHW (dimensions in mm)

RoofVent® LHW

Technical data

Unit type LHW-6 LHW-9 LHW-10

Dimensions of roof unit

A mm 2100 2400 2400

B mm 1080 1380 1380

C mm 1390 1500 1500

D mm 600 675 675

E mm 1092 1392 1392

Dimensions of below-roof unit

Filter box design F00 F25 F50 F00 F25 F50 F00 F25 F50

G mm 940 1190 1440 980 1230 1480 980 1230 1480

S mm 1700 1950 2200 1850 2100 2350 1850 2100 2350

H mm 530 780 1030 530 780 1030 530 780 1030

F mm 980 1240 1240

J mm 410 450 450

K mm 848 1048 1048

M mm 270 300 300

N mm 101 111 111

O mm 767 937 937

P mm 758 882 882

Q mm 490 570 570

R mm 900 1100 1100

V mm 500 630 630

Heating coil data

Coil type ABCABC ABC

Water content l 3.1 3.1 6.2 4.7 4.7 9.4 4.7 4.7 9.4

L " Pipe thr. 1 ¼

(female)

Pipe thr. 1 ½

(female)

Pipe thr. 1 ½

(female)

Weight Roof unit kg 390 560 565

Below-roof unit (with F00) kg 130 130 137 182 182 192 182 182 192

Filter box F00 kg 63 82 82

Heating section kg 30 30 37 44 44 54 44 44 54

Air-Injector kg 37 56 56

Total (with F00) kg 520 520 527 742 742 752 747 747 757

Filter box F25

kg + 11 + 13 + 13

Filter box F50

kg + 22 + 26 + 26

Additional weight compared to the design with lter box F00

Table B8: Dimensions and weights, RoofVent

LHW

RoofVent® LHW

Technical data

3.8 Air flow rate with additional pressure drops

Pressure increase in Pa Exhaust air

LHW-6

0 2

0 4

0 6

0 8

0 0 1

0 2 1

0 4 1

0 6 1

0 8 1

0 0 2

0 2 2

0 4 2

0 0 0 6 0 0 5 5 0 0 0 5 0 0 5 4 0 0 0 4

Supply air

Example: An additional pressure drop of 84 Pa results in a

new air ow rate of

5100 m³/h.

Air ow rate in m³/h

Diagram B1: Air ow rate, RoofVent® LHW-6 with additional pressure drops

Pressure increase in Pa Exhaust air

LHW-9

0 2

0 4

0 6

0 8

0 0 1

0 2 1

0 4 1

0 6 1

0 8 1

0 0 2

0 2 2

0 4 2

0 5 8 0 0 0 8 0 0 5 7 0 0 0 7 0 0 5 6

Supply air

Air ow rate in m³/h

Diagram B2: Air ow rate, RoofVent® LHW-9 with additional pressure drops

RoofVent® LHW

Technical data

Pressure increase in Pa Exhaust air

LHW-10

0 2

0 4

0 6

0 8

0 0 1

0 2 1

0 4 1

0 6 1

0 8 1

0 0 2

0 2 2

0 4 2

0 0 9 0 0 5 8 0 0 8 8 0 0 0 8 0 0 5 7 0 0 0 7

Supply air

Air ow rate in m³/h

Diagram B3: Air ow rate, RoofVent® LHW-10 with additional pressure drops

RoofVent® LHW

Technical data

4 Design example

Design data

■ Required fresh air ow rate or air change rate

■ Hall geometry (length, width, height)

■ Design fresh air temperature

■ Desired room temperature (in the occupied area)

■ Extract air conditions

■ Fabric heat losses (portion to be covered by the

RoofVent

units)

■ Internal heat gains (machines, lighting, etc.)

■ Heating medium

The extract air temperature is generally higher than the temperature in the

occupied area. This is the result of unavoidable temperature stratica-

tion in high spaces, but is reduced to a minimum with the Air-Injector.

A temperature gradient of only 0.2 K per metre height can therefore be

assumed.

Example

Fresh air ow rate ......................................30'000 m³/h

Hall geometry (L x W x H) ......................52 x 45 x 9 m

Design fresh air temp. ......................................... -5 °C

Desired room temperature...................................18 °C

Extract air conditions ............................... 20 °C / 40 %

Fabric heat losses ........................................... 220 kW

Internal heat gains ............................................. 36 kW

Heating medium ................................. LPHW 80/60 °C

Room temperature:..............................................18 °C

Temperature gradient: .................................... 9 · 0.2 K

Extract air temperature: ....................................≈ 20 °C

Required number of units n

req

Based on the air ow rate per unit (see Table B4), select a

trial unit size. (Depending on the results of further calculations, repeat the layout design for another unit size if necessary.)

req

= V

req

/ V

req

= required fresh air ow rate in m³/h

= air ow rate for the selected unit size in m³/h

Approximate selection: Unit size LHW-9

req

= 30'000 / 8'000

req

= 3.75

Select 4 LHW-9s.

Actual fresh air ow rate V (in m³/h)

V = n · V

n = Selected number of units

V = 4 · 8'000 V = 32'000 m³/h

Effective fabric heat losses Q

Teff

(in kW)

Tef f

= QT – Q

QT = fabric heat losses in kW Q

= internal heat gains in kW

Use the following criteria for calculation of internal heat gains (connected loads of machines and lighting): Operating times, diversity, direct heat output through convection, indirect heat output through radiation, etc.

Tef f

= 220 – 36

Tef f

= 184 kW

Necessary output to cover fabric heat losses per unit Q

(in kW)

= Q

Tef f

/ n

= 184 / 4

= 46 kW

RoofVent® LHW

Design example

Selection of coil type

From Table B6, select the required coil type based on the output necessary to cover the fabric heat losses per unit.

Select coil type B with 55 kW heat output to cover the fabric heat losses at LPHW 80/60 °C and fresh air temperature

-5 °C.

Checking the ancillary conditions

■ Maximum mounting height

Select a different coil type or unit size if the actual

mounting height (= distance between the oor and

the bottom edge of the unit) is greater than maximum mounting height H

max

(see Table B6).

■ Maximum oor area reached

Calculate the oor area reached per unit using the

selected number of units. If it exceeds the maximum value listed in Table B4, increase the number of units.

■ Compliance with minimum and maximum distances

Check the resulting distances based on the hall geometry and arrangement of the units, using the information in Table B7.

Actual mounting height = 7.2 m Max. mounting height H

max

= 12.5 m

→ OK

Floor area per unit = 52 · 45 / 4 = 585 m²

Max. oor area reached = 797 m² → OK

Minimum and maximum distances can be complied with when units are arranged symmetrically.

→ OK

Denitive number of units

With a larger number of units, there is more exibility of

operation. However, the costs are also higher. For an optimal solution, compare both the costs and ventilation quality of the system.

Select 4 LHW-9s with heating coil type B. They ensure cost-effective and energy-saving operation.

RoofVent® LHW

Design example

5 Options

RoofVent® LHW units can be adapted to the requirements of the specic project with a series of options.

You will nd a detailed description of all optional components in Section K 'Options' of this handbook.

Option Use

ColdClimate design For installation of the RoofVent

unit in areas where the fresh

air temperatures fall below –30 °C

Explosion-proof design For installation of the RoofVent

unit in explosive areas (Zone

1 and Zone 2)

Oil-proof design When using the RoofVent

unit in applications with high oil

content in the extract air

Hygiene design When using the RoofVent

unit in applications with higher

hygiene requirements (corresponds to VDI 6022)

Fans with variable air ow rate For operation of the unit with variable air ow rate

(supply air and exhaust air)

High-pressure fan, supply air To overcome additional external pressure drop

(e.g. from supply air ducts installed on-site)

High-pressure fan, exhaust air To overcome additional external pressure drop

(e.g. from extract air ducts installed on-site)

Hydraulic assembly diverting system

To facilitate hydraulic installation

Magnetic mixing valve For continuous regulation of the heating coil (ready-to-

connect)

Fresh air silencer For reduction of noise from the weather louvre door

Exhaust air silencer For reduction of noise from the exhaust air grille

Supply air silencer For reduction of noise within the room

Extract air silencer For reduction of noise within the room

Acoustic cowl For reduction of noise within the room

(in the Air-Injector)

Actuators with spring return As additional frost protection (close the fresh air damper and

the ER damper during a power failure)

Air outlet box When using the RoofVent

unit in low-roofed halls

(instead of the Air-Injector)

Drop eliminator To drain condensate from the plate heat exchanger onto the

roof

Design for injection system For installation of the RoofVent

unit with a hydraulic injection

system (integrated pump control)

Table B9: Availability of options for RoofVent® LHW

RoofVent® LHW

Options

6 Control systems

There are basically two possibilities for controlling the RoofVent® LHW:

System Description

Hoval DigiNet We strongly advise that the RoofVent

LHW should be

controlled by Hoval DigiNet. This control system, developed

specically for Hoval indoor climate systems, offers the

following advantages:

■ DigiNet utilises the full potential of the decentralised

systems. It controls each ventilation unit individually, depending on local conditions.

■ DigiNet allows for maximum exibility of operation with

respect to the control zones, unit combinations, operating modes and operating times.

■ DigiNet regulates the air distribution and thus ensures

maximum ventilation efciency.

■ DigiNet regulates the energy recovery output in the plate

heat exchanger.

■ The ready-to-connect units with integrated control compo-

nents are easy to plan and install.

■ Commissioning of the DigiNet is quick and easy thanks

to the plug & play components and pre-addressed control modules.

You can nd a detailed description of the Hoval DigiNet in Part

L 'Control systems' of this handbook.

Non-Hoval system RoofVent

LHWs can also be controlled with non-Hoval systems. However, the non-Hoval system must take the special features of the decentralised systems into account. In the design for non-Hoval control, the RoofVent

LHW comes only with a basic terminal box instead of the DigiUnit terminal box. Additional information can be found in the separate description 'Terminal box unit RoofVent

LHW' (available

on request).

Table B10: Control systems, RoofVent® LHW

RoofVent® LHW

Control systems

7 Transport and installation

7.1 Assembly

Caution

Risk of injury as a result of incorrect handling. Have transport and assembly work carried out by trained

specialists !

RoofVent

LHW units are delivered in 2 sections (roof unit, below-roof unit) on a wooden pallet. Parts which belong together are labelled with the same unit number.

Note

Depending on the optional components, the delivery may consist of multiple parts (such as when a supply air silencer is installed). In this case a forklift truck or a crane is required for assembling the below-roof unit on site.

The following guidelines are important when preparing for assembly:

■ The units are assembled from roof level. A crane or heli-

copter is required.

■ To transport the unit to the roof, 2 hoisting slings are

required (approx. length 6 m). If steel cables or chains are used, the unit corners must be properly protected.

■ Make sure that the roof frames correspond to the speci-

cations in Section M 'System design.'

■ Dene the desired orientation of the units (position of the

coil connections).

■ The units are held in the roof frame by means of their own

weight. Silicone, PU foam or similar is required for sealing.

■ For units with exhaust air silencers, additional attachment

to the roof frame is required.

■ Follow the assembly instructions included.

Fig. B5: RoofVent® roof units are installed from roof level.

7.2 Hydraulic installation

Caution

Risk of injury as a result of incorrect handling. Hydraulic installation must be carried out by trained

specialists only !

The Hoval DigiNet control system is designed for a distributor circuit with separate hydraulic connection of the units; i.e. a mixing valve is installed in front of each unit. The diverting system is used as standard.

Boiler system requirements

■ Adjust the hydraulic system to the control zone divisions.

■ Hydraulically coordinate the pipework for the individual

units within a control zone to ensure even distribution.

■ Starting at a fresh air temperature of 15 °C, the heating

medium (max. 120 °C) must be available at the mixing valve without delay in the required amount and at the required temperature.

■ A ow temperature control which is dependent on the

fresh air temperature is required.

The Hoval DigiNet control system switches the Enable heating on for 1 minute once a week. This prevents the main pump from blocking after a prolonged shutdown.

Pipework requirements

■ Use 3-way mixing valves with linear characteristics and

high quality.

■ The valve authority must be ≥ 0.5.

■ The valve actuator must have a short run time (5 s).

■ The valve actuator must be continuous, i.e. the stroke

changes in proportion to the control voltage (DC 0…10 V).

■ The valve actuator must be designed for emergency

operation with a separate manual control (AC 24 V).

■ Install the valve close to the unit (max. distance 2 m).

Caution

Risk of injury from falling parts. Do not apply any

loads to the coil, e.g. by means of the ow or return !

Note

Use the 'Hydraulic assembly' or 'Magnetic mixing valve' options for quick and easy hydraulic installation.

RoofVent® LHW

Transport and installation

DigiUnit terminal box

novaNet system bus

Power supply

Connection box

Magnetic mixing valve

Collective trouble indicator

Fresh air sensor

Room air sensor

Trouble input heating

Main pump

DigiMaster

Zone control panel

Enable heating

Heating control panel

Fig. B6: Conceptual drawing for hydraulic diverting system

< 2 m

RoofVent® LHW

Transport and installation

7.3 Electrical installation

Caution

Danger from electric current. The electrical installation

must be carried out by a qualied electrician!

■ Comply with all relevant legislation (e.g. EN 60204-1).

■ For long supply lines, select cable cross-sections in

accordance with the technical regulations.

■ Carry out electrical installation in accordance with the

wiring diagram (for wiring within the unit, see Fig. B7).

■ Install the system bus for the control systems separately

from the mains cables.

■ Establish plug connections from the Air-Injector to the lter

box and from the lter box (inside) to the roof unit.

■ Wire the mixing valves to the connection box. (There is a

plug connection for Hoval magnetic mixing valves.)

■ For injection system: Wire the pump to the DigiUnit

terminal box.

■ Make sure there is onsite overload protection equipment

for the mains connection line of the zone control panel (short circuit resistance 10 kA).

DigiUnit terminal box with isolation switch

Cable feedthroughs and plug-in connections

Power supply

Bus cable

Connection box

Fig. B7: Wiring in unit

RoofVent® LHW

Transport and installation

Component Description Voltage Cable

Option

Comment

DigiUnit terminal box

Power supply 3 x 400 V LHW-6: 5 x 4 mm²

LHW-9: 5 x 6 mm² LHW-10: 5 x 10 mm²

novaNet system bus 2 x 0.16 mm² For bus cable specications,

see Section L, chap. 2.4

Heating pump 3 x 400 V 4 x 2.5 mm²

For injection system

Zone control panel 3-phase

Power supply 3 x 400 V 5 x … mm² Depending on options

novaNet system bus 2 x 0.16 mm² For bus cable specications,

see Section L, chap. 2.4

Room air sensor 2 x 1.5 mm² Max. 170 m

Shielded cable

Fresh air sensor 2 x 1.5 mm² Max. 170 m

Enable heating Volt-free

Max. 230 V

3 x 1.5 mm² 2 A max.

Per zone

Trouble input heating 24 V 3 x 1.5 mm² Per zone

Collective trouble indicator Volt-free

Max. 230 V

3 x 1.5 mm² Max. 6 A

Special function on terminal 24 V 3 x 1.5 mm²

Per special function

Power supply for RoofVent

LHW

3 x 400 V LHW-6: 5 x 4 mm²

LHW-9: 5 x 6 mm² LHW-10: 5 x 10 mm²

Per RoofVent® LHW

Main pump 3 x 400 V 4 x 2.5 mm²

Per pump

Humidity sensor 24 V 4 x 1.5 mm²

Max. 170 m

sensor 24 V 4 x 1.5 mm² Max. 170 m

Variant:

Zone control panel 1-phase

Power supply 1 x 230 V 3 x … mm² Depending on options

novaNet system bus 2 x 0.16 mm² For bus cable specications,

see Section L, chap. 2.4

Room air sensor 2 x 1.5 mm² Max. 170 m

Shielded cable

Fresh air sensor 2 x 1.5 mm² Max. 170 m

Enable heating Volt-free

Max. 230 V

3 x 1.5 mm² 2 A max.

Per zone

Trouble input heating 24 V 3 x 1.5 mm² Per zone

Collective trouble indicator Volt-free

Max. 230 V

3 x 1.5 mm² Max. 6 A

Special function on terminal 24 V 3 x 1.5 mm²

Per special function

Main pump 1 x 230 V 3 x 1.5 mm²

Per pump

Humidity sensor 24 V 4 x 1.5 mm²

Max. 170 m

sensor 24 V 4 x 1.5 mm² Max. 170 m

Table B11: Cable list

RoofVent® LHW

Transport and installation

8 Specification texts

RoofVent® LHW supply and extract air handling unit, consisting of:

■ Roof unit with energy recovery

■ Filter box

■ Heating section

■ Air-Injector

■ Control systems

All components are wired ready-to-connect.

8.1 Roof unit with energy recovery LW

Self-supporting, weatherproof casing made from Aluzinc

sheet steel, insulated on the inside (re protection class B1), with weather louvre door for easy access to the fresh air lter

and DigiUnit terminal box, access panel with quick-release

fasteners for easy access to the extract air lter, isolation

switch outside for interruption of the high-voltage supply. The roof unit includes:

■ Fresh air lter (bag lter, class G4) with differential pres-

sure switch for lter monitoring

■ Opposed fresh air and recirculation dampers with actuator

■ Plate heat exchanger made of aluminium with bypass,

condensate collecting channel and siphon to the roof, including ER and bypass dampers with actuators to regulate the energy recovery

■ Maintenance-free, direct-drive supply air fan

■ Maintenance-free, direct-drive exhaust air fan

■ DigiUnit terminal box with DigiUnit controller as part of the

Hoval DigiNet control system.

DigiUnit controller DU5

Control module, fully wired to the components of the ventilation unit (fans, actuators, temperature sensors, frost

controller, lter monitoring):

■ Controls the unit, including the air distribution, according

to the specications of the control zone

■ Controls the supply air temperature using cascade control

High-voltage section

■ Mains power terminals

■ Isolation switch (can be operated from the outside)

■ Motor contactor for each fan

■ Fuse for the electronics

■ Transformer for the DigiUnit controller, the mixing valve

and the actuators

■ Relays for emergency operation

■ Connecting terminals for actuators and temperature

sensors

■ Control box heating

Type LW- … /DN5

Nominal air ow rate, supply air/

exhaust air

… m³/h

Heat recovery efciency, dry … %

Active power per motor … kW

Supply voltage 3 x AC 400 V

Frequency 50 Hz

8.2 Filter box F00 / F25 / F50

Casing made from Aluzinc sheet steel with extract air grille

and access panel. The lter box includes:

■ Extract air lter (bag lter class G4) with differential pres-

sure switch for lter monitoring

■ Extract air temperature sensor

■ Sound attenuation body as supply air diffuser

Type F-…

8.3 Heating section H.A / H.B / H.C

Aluzinc sheet steel casing, includes the LPHW heating coil

made of copper tubes and aluminium ns and the frost

controller.

Type H.__-…

Heat output … kW

Heating medium LPHW … / … °C

At air inlet temperature … °C

8.4 Air-Injector D

Casing made from Aluzinc sheet steel with:

■ Vortex air distributor with concentric outlet nozzle, adjust-

able vanes and integrated absorber hood

■ Actuator for automatic adjustment of the air distribution

■ Supply air sensor

■ Electric connection box (includes the terminals for the

heating mixing valve)

Type D -9

Floor area reached … m²

RoofVent® LHW

Specication texts

8.5 Options

ColdClimate design

■ Cold-resistant materials

■ Fans with downtime heating

■ Valve actuators with spring return and additional heating

■ Heating coil type X with water-side frost monitoring

■ Plate heat exchanger with differential pressure switch

Oil-proof design

■ Oil-proof materials

■ Extract air lter class F5

■ Condensate drain from the plate heat exchanger to the

drip tray in the lter box

■ Filter box F25 in oil-tight design with integrated oil/conden-

sate drip tray and drain connection

Hygiene design

■ Fresh air lter class F7

■ Extract air lter class F5

Fans with variable air ow rate VAR

■ Maintenance-free, direct-drive supply air fan with

frequency converter

■ Maintenance-free, direct-drive exhaust air fan with

frequency converter

High-pressure fan supply air HZ

Maintenance-free, direct-drive high-pressure supply air fan

High-pressure fan exhaust air HF

Maintenance-free, direct-drive high-pressure exhaust air fan

Hydraulic assembly diverting system HG

Prefabricated assembly for hydraulic diverting system, consisting of magnetic mixing valve, balancing valve, ball valve, automatic air vent and screw connections for connection to the unit and to the distributor circuit; ready-to-connect mixing valve for connection to the connection box; sized for the respective heating coil and the Hoval DigiNet control system

Magnetic mixing valve ..HV

Continuous regulating valve with magnetic drive, ready for connection to the connection box, sized for the respective heating coil

Fresh air silencer ASD

As an attachment to the weather louvre door, casing consisting of Aluzinc sheet steel with lining of sound attenuation material, for reducing noise from the weather louvre door, insertion attenuation _____ dB

Exhaust air silencer FSD

As an attachment to the exhaust air grille, casing consisting of Aluzinc sheet steel with built in sound attenuation splitters,

for reducing the noise from the exhaust air grille, insertion attenuation _____ dB

Supply air silencer ZSD

As an inserted component in the below-roof unit, casing consisting of Aluzinc sheet steel with built in sound attenuation splitters, for reducing the noise in the room, insertion attenuation _____ dB

Extract air silencer ABSD

As an attachment to the extract air grille, casing consisting of Aluzinc sheet steel with built in sound attenuation splitters, for reducing the noise in the room, insertion attenuation _____ dB

Acoustic cowl AHD

Consisting of an absorber hood of large volume and a screen with a lining of sound attenuation material, insertion attenuation 4 dB

Actuators with spring return SMF

Modulating actuators with safety function in the case of a power failure, mounted and wired on the fresh air damper and ER damper

Air outlet box AK

Consisting of Aluzinc sheet steel, with four adjustable exhaust air grilles (replaces the Air-Injector)

Drop eliminator TA

Consisting of aluminium ns, tted in the extract air ow

on the air inlet side of the plate heat exchanger, to drain condensate onto the roof

Design for injection system ES

Control and high-voltage section for the heating pump integrated into the DigiUnit terminal box

RoofVent® LHW

Specication texts

8.6 Control systems

Digital control system for the energy-optimised operation of decentralised indoor climate systems:

■ System set up according to OSI reference model

■ Onsite connection to the individual control modules using

novaNet system bus in a serial topology

■ Cross-communication with equal priority (peer-to-peer/

multiplier) using novaNet log

■ Fast reaction times due to data transmission on an events

basis

■ Control modules pre-addressed in the factory with

integrated lightning protection and battery-buffered RAM modules

■ No onsite engineering (binding) required

DigiNet operator terminals

DigiMaster DM5 Pre-programmed Plug-&-Play operator terminal with graphic user interface, consisting of a touch panel with colour display, installed in the door of the zone control panel.

■ Monitoring and setting the DigiNet system (operating

modes, temperature values, scheduler, calendar, alarm handling, control parameters)

DigiCom DC5 Package consisting of operating software, novaNet router and connection cables for using the Hoval DigiNet with a PC:

■ Monitoring and setting the DigiNet system (operating

modes, temperature values, scheduler, calendar, alarm handling and forwarding, control parameters)

■ Trend function, data storage and logbook

■ Differentiated password protection

DigiEasy DE5 Additional unit for operating a control zone, for installation at

any location in a triple ush socket box or in the door of the

zone control panel:

■ Display of the current room temperature set value

■ Increase or decrease the set value by up to 5 °C

■ Display and acknowledge alarms

■ Switch the operating mode

Options

■ Window for DigiMaster

■ IP65 framework

■ novaNet socket

■ novaNet router

■ 4 special functions with switch

■ 8 special functions with 2 switches

■ Special function on terminal

■ DigiEasy installation

DigiNet zone control panel

The zone control panel (coated sheet steel, RAL 7035) contains:

■ 1 fresh air sensor

■ 1 transformer 230/24 V

■ 2 circuit breakers for transformer (1-pin)

■ 1 relay

■ 1 safety relay (2-pin, external)

■ Input and output terminals (top)

■ 1 wiring diagram of the system

■ 1 DigiZone controller, 1 relay and 1 room air sensor

(included) for each control zone

DigiZone controller DZ5 Control unit for each control zone, integrated in the zone control panel:

■ Processes the following inputs: room and fresh air temper-

ature, trouble heating and special functions (optional)

■ Controls the operating modes according to the scheduler

■ Sets the outputs for the enable heating and the collective

trouble indicator

Options

■ Alarm lamp

■ Socket

■ Control of the main pump

■ 2-pin circuit breakers

■ Power supply for indoor climate units with integrated

DigiUnit controller

■ Integration of indoor climate units without integrated

DigiUnit controller

■ Room temperature average value

■ DigiPlus controller

■ Humidity sensor

■ CO

sensor

■ Base

RoofVent® LHW

Specication texts

RoofVent® LKW

Supply and extract air handling unit with energy recovery for heating and cooling high spaces

1 Use _______________________________________ 36

2 Construction and operation_____________________ 36

3 Technical data _______________________________ 43

4 Design example ______________________________ 52

5 Options ____________________________________ 54

6 Control systems______________________________ 55

7 Transport and installation ______________________ 56

8 Specication texts ____________________________ 60

RoofVent® LKW

Content

1 Use

1.1 Intended use

RoofVent® LKW units are used to supply fresh air and to remove extract air as well as for heating and cooling coupled with energy recovery in high spaces. Also included under intended use are compliance with the installation, commissioning, operating and maintenance provisions (operating manual). Any use beyond this is considered improper use. The manufacturer shall not be held responsible for any damage resulting from such use.

1.2 User group

RoofVent® LKW units may only be installed, operated and serviced by authorised and trained specialists who are familiar with the equipment and aware of the dangers involved. The operating manual is for English-speaking operating engineers and technicians as well as specialists in building, heating and ventilation technology.

1.3 Risks

RoofVent® LKW units are built to correspond to the state of the art and to the latest safety standards. However, despite all precautionary measures taken, there are still some potential hazards which are not immediately obvious, such as:

■ Dangers when working with the electrical systems

■ Parts (e.g. tools) can fall down below when working on the

ventilation unit.

■ Dangers when working on the roof

■ Damage to devices or components due to lightning

■ Malfunctions as a result of defective parts

■ Hazards from hot water when working on the hot water

supply

■ Ingress of water through the roof unit if the access panels

are not closed correctly

2 Construction and operation

The RoofVent® LKW is used for ventilating, heating and cooling large areas (production halls, shopping centres, sports halls, exhibition halls, etc.). It fulls the following functions:

■ Heating (with connection to central hot water supply)

■ Cooling (with connection to chilled water system)

■ Fresh air supply

■ Extract air removal

■ Recirculation

■ Energy recovery

■ Air distribution via Air-Injector

■ Air ltration

A ventilation system consists of several autonomous RoofVent

LKW units and, as a rule, works without supply and extract air ducts. The units are decentrally installed in the roof and are also serviced from roof level.

Thanks to their high output and efcient air distribution,

RoofVent

LKW units have a large operating range. This means that compared with other systems, only few units are necessary to create the required conditions. Three unit sizes, various coil types and a series of accessories make it possible to provide a customised solution for any hall.

2.1 Unit construction

The RoofVent® LKW consists of the following components:

■ Roof unit with energy recovery:

self-supporting casing made of Aluzinc sheet steel, insulated inside (class B1)

■ Filter box:

available in three standard lengths per unit size for adjust-

ment to specic dimensional requirements

■ Heating/cooling section:

coil connections possible on each side (usually underneath the extract air grille)

■ Air-Injector:

patented, automatically adjustable vortex air distributor for draught-free air distribution over a large area

The unit is delivered in two sections: above-roof unit and below-roof unit (see Fig. C1). The components are bolted together and can be dismantled individually.

RoofVent® LKW

Use

2.2 Air distribution with the Air-Injector

The patented air distributor – called the Air-Injector – is the core element. The adjustable vanes are used to set

the air discharge angle. It depends on the air ow rate, the

mounting height and the temperature difference between the supply air and room air. The air is therefore blown into the room vertically downward, conically or horizontally. This ensures that:

■ each RoofVent

LKW ventilates, heats and cools a large

oor area,

■ no draughts occur in the occupied area,

■ the temperature stratication in the room is reduced, thus

saving energy.

Above-roof unit: Roof unit with energy recovery

Below-roof unit:

a Filter box b Heating/cooling section c Air-Injector

Fig. C1: Components of the RoofVent® LKW

RoofVent® LKW

Construction and operation

RoofVent® LKW

Use

Actuator Air-Injector:

adjusts the supply air discharge direction continuously from vertical to horizontal

Condensate connection

Frost controller

Extract air grille

Extract air lter:

bag lter with differential pressure switch for lter monitoring

ER damper and bypass damper:

opposed dampers for regulation of energy recovery, with actuator

Access panel:

access to extract air lter

Weather louvre door:

access to the fresh air lter and to the DigiUnit terminal box

Fresh air lter:

bag lter with differential pressure switch for lter monitoring

Fresh air damper and recirculation damper:

opposed dampers for switching between fresh air and recirculation operation, with actuator

Gravity damper:

closes the bypass during shutdown and thus prevents heat loss

Exhaust air fan:

twin impeller centrifugal fan with maintenance-free drive

Exhaust air grille:

access to exhaust air fan

Plate heat exchanger:

with bypass for energy recovery control and condensate drain

Access panel:

access to supply air fan

Supply air fan:

twin impeller centrifugal fan with maintenance-free drive

Access panel: access to the heating/cooling coil

Heating/cooling coil:

LPHW/LPCW coil consisting of copper tubes with aluminium ns

Condensate separator

Fig. C2: Components of the RoofVent® LKW

RoofVent® LKW

Construction and operation

Fresh air inlet through weather louvre door

Filter with differential pressure switch

Fresh air damper with actuator

Plate heat exchanger

Supply air fan

Silencer and diffuser

Heating/cooling coil LPHW/LPCW

Frost controller

Condensate separator

Supply air sensor

Air-Injector with actuator

Extract air inlet through extract air grille

Extract air sensor

Filter with differential pressure switch

Recirculation damper (opposed to the fresh air damper)

ER/bypass damper with actuator

Gravity damper

Exhaust air fan

Silencer and diffuser

Exhaust air outlet through exhaust air grille

Fig. C3: Operational diagram, RoofVent® LKW

RoofVent® LKW

Construction and operation

2.3 Operating modes

The RoofVent® LKW has the following operating modes:

■ Off

■ Ventilation

■ Ventilation (reduced)

■ Recirculation

■ Recirculation night

■ Exhaust air

■ Supply air

■ Night cooling summer

■ Emergency operation

The DigiNet control system controls these operating modes automatically per control zone, in accordance with the scheduler (exception: emergency operation). In addition, you can:

■ manually switch the operating mode of a control zone,

■ switch each individual RoofVent

unit to the following operating modes: Off,

Recirculation, Exhaust air, Supply air and Emergency operation.

Code

Operating mode Use Diagram Description

OFF Off

The fans are turned off. Frost protection remains active. There is no room temperature control.

If the unit is not needed

Supply air fan ................... Off

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating/cooling ................Off

VE2 Ventilation

The RoofVent

unit blows fresh air into the room and draws off spent room air. Heating/cooling and energy recovery are controlled on the basis of heating/cooling demand and temperature conditions. The room temperature set value day is active.

During room use

Supply air fan ................... On

Exhaust air fan ................. On

Energy recovery ............... 0 – 100 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating/cooling ................0 - 100 %

VE1 Ventilation (reduced)

Like VE2, but with reduced air ow rate

The room temperature set value day is active.

During room use (only for fans with

variable air ow

rate)

REC Recirculation

On/Off operation: When heating or cooling is required, the RoofVent

unit draws in room air, heats or cools it and blows it back into the room. The room temperature set value day is active.

For pre-heating and pre-cooling

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating/cooling ................On

*) during heat or cool demand

RECN Recirculation night

Like REC, but with room temperature set value night

During the night and on weekends

RoofVent® LKW

Construction and operation

Code

Operating mode Use Diagram Description

EA Exhaust air

The RoofVent

unit extracts spent room air. There is no room temperature control.

For special cases

Supply air fan ................... Off

Exhaust air fan ................. On

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating/cooling ................Off

SA Supply air

The RoofVent

unit blows fresh air into the room. Heating/cooling is controlled on the basis of the heating/cooling demand and temperature conditions. Spent room air passes through open windows and doors or another system provides extraction. The room temperature set value day is active.

For special cases

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating/cooling ................0 - 100 %

NCS Night cooling summer

On/Off operation: If current temperatures allow, the RoofVent

unit blows cool fresh air into the room and extracts warmer room air. The room temperature set value night is active. The unit blows the supply air vertically downwards to achieve the greatest

possible efciency.

For free cooling during the night

Supply air fan ................... On

Exhaust air fan ................. On

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating/cooling ................Off

*) depending on temperature conditions

– Emergency operation

The RoofVent

unit draws in room air, warms it and blows it back into the room. The heater is switched on via manual control of the mixing valve. There is no room temperature control.

If the DigiNet system is not operating (e.g. before commissioning)

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating/cooling ................On

This is the code for the respective operating mode in the DigiNet control system (see Part L 'Control systems').

Table C1: Operating modes of the RoofVent

LKW

RoofVent® LKW

Construction and operation

3 Technical data

3.1 Unit type reference

Below-roof unit

LKW - 9 / DN5 / LW + F00 - K.C - D / ...

Unit type

RoofVent

LKW

Unit size

6, 9 or 10

Control

DN5 Design for DigiNet 5 KK Design for non-Hoval control

Roof unit

Roof unit with energy recovery

Filter box

F00 Filter box, short F25 Filter box, medium F50 Filter box, long

Heating/cooling section

K.C Heating/cooling section with coil type C K.D Heating/cooling section with coil type D

Air-Injector

Options

Table C2: Unit type reference

3.2 Application limits

Unit type LKW-6 LKW-9 LKW-10

Extract air temperature max. °C 50 50 50

Extract air relative humidity max. % 60 60 60

Moisture content of extract air

max. g/kg 12.5 12.5 12.5

Fresh air temperature

min. °C -30 -30 -30

Heating medium temperature max. °C 120 120 120

Operating pressure max. kPa 800 800 800

Supply air temperature max. °C 60 60 60

Minimum operating time VE2 min. min 30 30 30

Amount of condensate max. kg/h 60 150 150

Air ow rate min. m³/h 3100 5000 5000

Table C3: Application limits of the RoofVent® LKW

RoofVent® LKW

Technical data

3.3 Air flow rate, electrical connections

Unit type LKW-6 LKW-9 LKW-10

Air distribution Nominal air ow rate

Supply air m³/h 5000 7650 8400

Exhaust air m³/h 5000 7650 8400

Floor area reached Max. m² 426 748 855

Energy recovery Heat recovery efciency, dry % 60 63 57

Heat recovery efciency, wet % 68 73 65

Fan characteristics Supply voltage V AC 3 x 400 3 x 400 3 x 400

Permitted voltage tolerance % ± 10 ± 10 ± 10

Frequency Hz 50 50 50

Active power per motor kW 1.8 3.0 4.5

Current consumption A 4.0 6.5 9.9

Set point of thermal relays A 4.6 7.5 11.4

Speed of rotation (nominal) rpm 1440 1435 1450

Actuators Supply voltage V AC 24 24 24

Frequency Hz 50 50 50

Control voltage V DC 2…10 2…10 2…10

Torque Nm 10 10 10

Run time for 90° rotation s 150 150 150

Filter monitoring Factory setting of differential pressure switch Pa 300 300 300

Refers to: RoofVent® LKW with heating/cooling coil type C and vertical supply air discharge direction

Table C4: Technical data, RoofVent

LKW

3.4 Sound levels

Unit type LKW-6 LKW-9 LKW-10

Operating mode VE2

REC

VE2

REC

VE2

REC

Position

Sound pressure level (at a distance of 5 m) 1)dB (A) 46 60 58 47 46 52 66 57 49 48 54 68 60 52 51

Total sound power level dB (A) 68 82 80 69 68 74 88 79 71 70 76 90 82 74 73

Octave sound power level 63 Hz dB (A) 51 63 62 48 54 52 69 59 54 56 54 71 62 57 59

125 Hz dB (A) 55 71 70 56 63 63 78 70 60 63 65 80 73 63 66

250 Hz dB (A) 61 76 74 64 63 65 81 71 63 66 67 83 74 66 69

500 Hz dB (A) 61 75 71 61 58 66 81 70 62 61 68 83 73 65 64

1000 Hz dB (A) 65 77 72 63 57 71 81 72 67 60 73 83 75 70 63

2000 Hz dB (A) 57 72 72 60 56 66 80 73 64 58 68 82 76 67 61

4000 Hz dB (A) 49 71 71 57 48 58 76 71 58 50 60 78 74 61 53

8000 Hz dB (A) 36 65 63 49 42 44 70 62 51 41 46 72 65 54 44

with hemispherical radiation in a low-reection environment

outdoors (roof unit)

Table C5: Sound levels, RoofVent

LKW

RoofVent® LKW

Technical data

3.5 Heat output

Note

Fresh air temperature -5 °C -15 °C

LPHW Size Type Q Q

TGHmax

tS∆p

QQTGH

max

tS∆p

°C kW kW m °C kPa l/h kW kW m °C kPa l/h

80/60 LKW-6 C 75 60 8.6 52 12 3210 79 59 8.7 51 13 3399

60/40 LKW-6 C 47 33 11.3 36 5 2035 52 32 11.5 36 6 2225

80/60 LKW-9 C 112 93 9.2 53 10 4823 118 91 9.3 52 11 5070

LKW-9D ––––––––––––

60/40 LKW-9 C 70 51 12.1 37 4 3020 76 49 12.4 36 5 3269

LKW-9 D 86 67 10.7 42 5 3680 93 66 10.8 42 6 3977

80/60 LKW-10 C 125 98 10.2 51 12 5347 133 95 10.4 50 13 5684

LKW-10 D 151 124 9.2 60 13 6481 161 124 9.2 60 14 6887

60/40 LKW-10 C 80 53 13.7 36 5 3414 87 50 14.0 35 7 3753

LKW-10 D 98 71 11.9 42 6 4192 107 70 12.0 41 7 4601

Legend: Type = Type of heating/cooling coil

Q = Heat output Q

= Output to cover fabric heat losses

max

= Maximum mounting height

= Supply air temperature

∆p

= Water pressure drop

= Water ow rate

Refers to: Room air 18 °C, extract air 20 °C/40 % rel. humidity

— These operating conditions are not permissible, because the maximum supply air temperature of 60 °C is exceeded.

Table C6: Heat output, RoofVent

LKW

Note

The output for coverage of the fabric heat losses (Q

) allows for the ventilation heat requirement

) and the energy recovery output (QER) under the respective air conditions. It is calculated as

follows:

QTG = Q + QER – Q

RoofVent® LKW

Technical data

3.6 Cooling capacities

Cooling medium temperature

6/12 °C 8/14 °C

rhFSize Type Q

senQtotQTG

tS∆p

mWmCQ

senQtotQTG

tS∆p

mWm

°C % kW kW kW °C kPa l/h kg/h kW kW kW °C kPa l/h kg/h

28 40 LKW-6 C 19 21 13 15 13 3065 3 17 17 11 16 8 2403 0

60 LKW-6 C 18 36 12 15 33 5084 24 16 29 10 17 23 4199 19

32 40 LKW-6 C 24 33 18 16 29 4761 13 22 27 16 17 20 3877 7

60 LKW-6 C – – – – – – – 21 46 14 18 51 6529 35

28 40 LKW-9 C 29 32 20 15 11

4553

4 25 25 16 16 7

3618

LKW-9 D 36 42 27 12 14

6047

10 31 31 22 14 8

4448

60 LKW-9 C 27 54 19 15 28

7753

38 24 45 15 17 20

6396

LKW-9 D 35 70 26 12 35

10067

50 30 59 21 14 25

8405

32 40 LKW-9 C 37 51 28 16 26

7315

20 33 42 24 17 18

5960

LKW-9 D 45 66 36 13 32

9510

30 41 55 31 14 22

7848

60 LKW-9 C 35 79 26 17 57

11375

63 31 70 22 18 44

9979

LKW-9 D 44 102 35 13 69

14630

82 39 90 30 15 54

12941

28 40 LKW-10 C 32 34 21 15 12

4879

3 28 28 17 16 8

3959

LKW-10 D 40 46 29 12 16

6551

9 34 34 23 14 9

4906

60 LKW-10 C 30 58 19 16 32

8339

40 26 48 16 17 23

6891

LKW-10 D 38 76 28 13 41

10953

54 33 64 23 14 29

9157

32 40 LKW-10 C 40 54 29 16 29

7801

21 36 44 26 18 20

6357

LKW-10 D 50 72 39 13 36

10262

32 45 59 34 15 25

8466

60 LKW-10 C 37 85 27 17 64

12183

67 34 75 23 18 50

10691

LKW-10 D 48 111 37 13 79

15866

89 43 98 32 15 63

14036

Legend: tF = Temperature of the fresh air

= Relative humidity of the fresh air Type = Type of cooling coil Q

sen

= Sensible cooling capacity

tot

= Total cooling capacity

= Output for coverage of fabric cooling losses (→ sensible cooling load)

= Supply air temperature

∆p

= Water pressure drop

= Water ow rate

= Amount of condensate

Refers to: ■ At fresh air temperature 28 °C: room air 22 °C, extract air 24 °C/50 % rel. humidity

■ At fresh air temperature 32 °C: room air 26 °C, extract air 28 °C/50 % rel. humidity

— These operating conditions are not permissible, because the maximum condensate quantity of 60 kg/h is exceeded.

Table C7: Cooling capacity, RoofVent

LKW

Note

The output for coverage of fabric cooling losses (Q

) allows for the ventilation cooling require-

ment (Q

) and the output of the energy recovery (QER) under the respective air conditions. It is

calculated as follows:

QTG = Q

sen

+ QER – Q

RoofVent® LKW

Technical data

3.7 Minimum and maximum distances

X/2

Unit type LKW-6 LKW-9

LKW-10

Align the RoofVent® units so that no unit draws in the exhaust air from another unit as fresh air.

The extract air grille must be easily accessible.

Provide a clear space of approx. 1.5 m on the side opposite to the coil connections for service and maintenance.

The stream of supply air must be able to spread unobstructed (note position of beams and lamps).

Unit clearance X Min. m 11 13 14

Max. m 21 27 29

Mounting height Y

Min. 1)m 4.0 5.0 5.0

Max.

m 8.6 … 14.0

The minimum height can be reduced by 1 m in each case using the 'Air

outlet box' option (see Section K 'Options').

The maximum height varies depending on the ancillary conditions (for

values, see Table C6).

Table C8: Minimum and maximum distances

RoofVent® LKW

Technical data

3.8 Dimensions and weight

Roof unit LW

Filter box short F00 / medium F25 / long F50

Cable feedthroughs

Access panel

Heating/cooling section K

Air-Injector D

Return

Flow

Condensate connection

Fig. C4: Dimensional drawing for RoofVent® LKW (dimensions in mm)

RoofVent® LKW

Technical data

Unit type LKW-6 LKW-9 LKW-10

Dimensions of roof unit

A mm 2100 2400 2400

B mm 1080 1380 1380

C mm 1390 1500 1500

D mm 600 675 675

E mm 1092 1392 1392

Dimensions of below-roof unit

Filter box design F00 F25 F50 F00 F25 F50 F00 F25 F50

G mm 940 1190 1440 980 1230 1480 980 1230 1480

S mm 2050 2300 2550 2160 2410 2660 2160 2410 2660

H mm 530 780 1030 530 780 1030 530 780 1030

F mm 1000 1240 1240

J mm 410 450 450

K mm 848 1048 1048

M mm 620 610 610

O mm 767 937 937

P mm 758 882 882

Q mm 490 570 570

R mm 900 1100 1100

V mm 500 630 630

W mm 54 53 53

Coil type CCDCD

N mm 123 92 83 92 83

Y mm 78 78 95 78 95

Heating coil data Water content l 6.2 9.4 14.2 9.4 14.2

L " Pipe thr. 1 ¼

(female)

Pipe thr. 1 ½

(female)

Pipe thr. 2

(female)

Pipe thr. 1 ½

(female)

Pipe thr. 2

(female)

Weights Roof unit kg 390 560 560 565 565

Below-roof unit (with F00) kg 170 240 259 240 259

Filter box F00 kg 63 82 82 82 82

Heating/cooling section kg 70 102 121 102 121

Air-Injector kg 37 56 56 56 56

Total (with F00) kg 560 800 819 805 824

Filter box F25

kg + 11 + 13 + 13 + 13 + 13

Filter box F50

kg + 22 + 26 + 26 + 26 + 26

Additional weight compared to the design with lter box F00

Table C9: Dimensions and weights, RoofVent

LKW

RoofVent® LKW

Technical data

3.9 Air flow rate with additional pressure drops

Pressure increase in Pa Exhaust air

LKW-6

0 2

0 4

0 6

0 8

0 0 1

0 2 1

0 4 1

0 6 1

0 8 1

0 0 2

0 2 2

0 4 2

0 0

6 0 0 5 5 0 0 0 5 0 0 5 4 0 0 0 4

Supply air

Example: An additional pressure drop of 42 Pa results in a

new air ow rate of

4800 m³/h.

Air ow rate in m³/h

Diagram C1: Air ow rate, RoofVent® LKW-6 with additional pressure drops

Pressure increase in Pa Exhaust air

LKW-9

0 2

0 4

0 6

0 8

0 0 1

0 2 1

0 4 1

0 6 1

0 8 1

0 0 2

0 2 2

0 4 2

0 0

8 0 0 0 8 0 0 5 7 0 5 6 7 0 0 0 7 0 0 5 6

Supply air

Air ow rate in m³/h

Diagram C2: Air ow rate, RoofVent® LKW-9 with additional pressure drops

RoofVent® LKW

Technical data

Pressure increase in Pa Exhaust air

LKW-10

0 2

0 4

0 6

0 8

0 0 1

0 2 1

0 4 1

0 6 1

0 8 1

0 0 2

0 2 2

4 2

0 0

9 0 0 5 8 0 0 4 8 0 0 0 8 0 0 5 7 0 0 0 7

Supply air

Air ow rate in m³/h

Diagram C3: Air ow rate, RoofVent® LKW-10 with additional pressure drops

RoofVent® LKW

Technical data

4 Design example

Note

The following design example relates to cooling mode. The design rating for heating mode can be performed analogously to the design example above in Section B 'RoofVent

LHW.'

Design data

■ Required fresh air ow rate or air change rate

■ Hall geometry (length, width, height)

■ Design conditions

■ Desired room temperature (in the occupied area)

■ Extract air conditions

■ Cooling load

■ Cooling medium

The extract air temperature is generally higher than the temperature in the

occupied area. This is the result of unavoidable temperature stratica-

tion in high spaces, but is reduced to a minimum with the Air-Injector. A

temperature gradient of only 0.2 K per metre hall height can therefore be

assumed.

Example

Fresh air ow rate ......................................75'000 m³/h

Hall geometry (L x W x H) ....................72 x 60 x 10 m

Design conditions .................................... 32 °C / 40 %

Desired room temperature...................................26 °C

Extract air conditions ................................. 28 °C/50 %

Cooling load..................................................... 200 kW

Cooling medium.................................... LPCW 8/14 °C

Room temperature:..............................................26 °C

Temperature gradient: .................................. 10 · 0.2 K

Extract air temperature: ....................................= 28 °C

Required number of units n

req

Based on the air ow rate per unit (see Table C4), select a

trial unit size. (Depending on the results of further calculations, repeat the layout design for another unit size if necessary.)

req

= V

req

/ V

req

= required fresh air ow rate in m³/h

= air ow rate for the selected unit size in m³/h

Approximate selection: Unit size LKW-10

req

= 75'000 / 8'400

req

= 8.93

Select 9 LKW-10s.

Actual fresh air ow rate V (in m³/h)

V = n · V

n = Selected number of units

V = 9 · 8'400 V = 75'600 m³/h

Necessary output to cover fabric cooling losses (sensible cooling capacity) per unit Q

(in kW)

= Q

Tef f

/ n

= 200 / 9

≈ 22 kW

Selection of coil type

From Table C7, select the required coil type based on the necessary output to cover fabric heat losses per unit.

Note

Note that the total cooling capacity Q

tot

must be used

for dimensioning of the chiller.

Select coil type C with 26 kW capacity to cover fabric cooling losses at LPCW 8/14 °C and a fresh air temperature of 32 °C / 40 %.

RoofVent® LKW

Design example

Checking the ancillary conditions

■ Maximum oor area reached

Calculate the oor area reached per unit using the

selected number of units. If it exceeds the maximum value listed in Table C4, increase the number of units.

■ Compliance with minimum and maximum distances

Check the resulting distances based on the hall geometry and arrangement of the units, using the information in Table C8.

Floor area per unit = 72 · 60 / 10 = 432 m²

Max. oor area reached = 855 m² → OK

Minimum and maximum distances can be complied with when units are arranged symmetrically.

→ OK

Denitive number of units

With a larger number of units, there is more exibility of

operation. However, the costs are also higher. For an optimal solution, compare both the costs and ventilation quality of the system.

Select 9 LKW-10s with coil type C. They guarantee costeffective and energy-saving operation.

RoofVent® LKW

Design example

5 Options

RoofVent® LKW units can be adapted to the requirements of the specic project with a series of options.

You will nd a detailed description of all optional components in Section K 'Options' of this handbook.

Option Use

ColdClimate design For installation of the RoofVent

unit in areas where the fresh

air temperatures fall below –30 °C

Oil-proof design When using the RoofVent

unit in applications with high oil

content in the extract air

Hygiene design When using the RoofVent

unit in applications with higher

hygiene requirements (corresponds to VDI 6022)

Fans with variable air ow rate For operation of the unit with variable air ow rate

(supply air and exhaust air)

High-pressure fan, supply air To overcome additional external pressure drop

(e.g. from supply air ducts installed on-site)

High-pressure fan, exhaust air To overcome additional external pressure drop

(e.g. from extract air ducts installed on-site)

Hydraulic assembly diverting system

To facilitate hydraulic installation

Magnetic mixing valve For continuous regulation of the heating coil (ready-to-

connect)

Fresh air silencer For reduction of noise from the weather louvre door

Exhaust air silencer For reduction of noise from the exhaust air grille

Supply air silencer For reduction of noise within the room

Extract air silencer For reduction of noise within the room

Acoustic cowl For reduction of noise within the room (in the Air-Injector)

Actuators with spring return As additional frost protection (close the fresh air

damper and the ER damper during a power failure)

Air outlet box When using the RoofVent

unit in low-roofed halls

(instead of the Air-Injector)

Drop eliminator To drain condensate from the plate heat exchanger onto the

roof

Condensate pump To drain condensate from the condensate separator through

waste water pipes directly below the ceiling or onto the roof

Heating and cooling in the 4-pipe system

Additional heating section for 2 completely separate hydraulic circuits

Design for injection system For installation of the RoofVent

unit with a hydraulic injection

system (integrated pump control)

Table C10: Availability of options for RoofVent® LKW

RoofVent® LKW

Options

6 Control systems

There are basically two possibilities for controlling the RoofVent® LKW:

System Description

Hoval DigiNet We strongly advise that the RoofVent

LKW should be

controlled by Hoval DigiNet. This control system, developed

specically for Hoval indoor climate systems, offers the

following advantages:

■ DigiNet utilises the full potential of the decentralised

systems. It controls each ventilation unit individually, depending on local conditions.

■ DigiNet allows for maximum exibility of operation with

respect to the control zones, unit combinations, operating modes and operating times.

■ DigiNet regulates the air distribution and thus ensures

maximum ventilation efciency.

■ DigiNet regulates the energy recovery output in the plate

heat exchanger.

■ The ready-to-connect units with integrated control compo-

nents are easy to plan and install.

■ Commissioning of the DigiNet is quick and easy thanks

to the plug & play components and pre-addressed control modules.

You can nd a detailed description of the Hoval DigiNet in

Section L 'Control systems' of this handbook.

Non-Hoval system RoofVent

LKWs can also be controlled with non-Hoval systems. However, the non-Hoval system must take the special features of the decentralised systems into account. In the design for non-Hoval control, RoofVent

LKW units are supplied only with a basic terminal box instead of the DigiUnit terminal box. Additional information can be found in the separate description 'Terminal box unit RoofVent

LKW' (available

on request).

Table C11: Control systems, RoofVent® LKW

RoofVent® LKW

Control systems

7 Transport and installation

7.1 Assembly

Caution

Risk of injury as a result of incorrect handling. Have transport and assembly work carried out by trained

specialists !

RoofVent

LKW units are delivered in 2 sections (roof unit, below-roof unit) on a wooden pallet. Parts which belong together are labelled with the same unit number.

Note

The following guidelines are important when preparing for assembly:

■ The units are assembled from roof level. A crane or heli-

copter is required.

■ To transport the unit to the roof, 2 hoisting slings are

required (approx. length 6 m). If steel cables or chains are used, the unit corners must be properly protected.

■ Make sure that the roof frames correspond to the speci-

cations in Section M 'System design.'

■ Dene the desired orientation of the units (position of the

coil connections).

■ The units are held in the roof frame by means of their own

weight. Silicone, PU foam or similar is required for sealing.

■ For units with exhaust air silencers, additional attachment

to the roof frame is required.

■ Follow the assembly instructions included.

Fig. C5: RoofVent® roof units are installed from roof level.

7.2 Hydraulic installation

Caution

Risk of injury as a result of incorrect handling. Hydraulic installation must be carried out by trained

specialists only !

Boiler system requirements

■ Adjust the hydraulic system to the control zone divisions.

■ Hydraulically coordinate the pipework for the individual

units within a control zone to ensure even distribution.

■ Starting at a fresh air temperature of 15 °C, the heating

medium (max. 120 °C) must be available at the mixing valve without delay in the required amount and at the required temperature.

■ A ow temperature control which is dependent on the

fresh air temperature is required.

The Hoval DigiNet control system switches the Enable heating on for 1 minute once a week. This prevents the main pump from blocking after a prolonged shutdown.

Pipework requirements

■ Use 3-way mixing valves with linear characteristics and

high quality.

■ The valve authority must be ≥ 0.5.

■ The valve actuator must have a short run time (5 s).

■ The valve actuator must be continuous, i.e. the stroke

changes in proportion to the control voltage (DC 0…10 V).

■ The valve actuator must be designed for emergency

operation with a separate manual control (AC 24 V).

■ Install the valve close to the unit (max. distance 2 m).

Caution

Risk of injury from falling parts. Do not apply any

loads to the coil, e.g. by means of the ow or return !

Note

Use the 'Condensate pump', 'Hydraulic assembly' or 'Magnetic mixing valve' options for quick and easy hydraulic installation.

Condensate drain

Dimension the slope and cross-section of the condensate

line so that no condensate backow takes place.

RoofVent® LKW

Transport and installation

DigiUnit terminal box

novaNet system bus

Power supply

Connection box

Magnetic mixing valve

Collective trouble indicator

Fresh air sensor

Room air sensor

Trouble input heating

Trouble input cooling

Main pump

DigiMaster

Zone control panel

Selector switch heating/cooling

Enable heating

Enable cooling

Heating control panel

Heating circuit

Cooling circuit

Fig. C6: Conceptual drawing for hydraulic diverting system

< 2 m

RoofVent® LKW

Transport and installation

7.3 Electrical installation

Caution

Danger from electric current. Electrical installation

must be carried out by a qualied electrician!

■ Comply with all relevant legislation (e.g. EN 60204-1).

■ For long supply lines, select cable cross-sections in

accordance with the technical regulations.

■ Carry out electrical installation in accordance with the

wiring diagram (for wiring within the unit, see Fig. C7).

■ Install the system bus for the control systems separately

from the mains cables.

■ Establish plug connections from the Air-Injector to the lter

box and from the lter box (inside) to the roof unit.

■ Wire the mixing valves to the connection box. (There is a

plug connection for Hoval magnetic mixing valves.)

■ For injection system: Wire the pump to the DigiUnit

terminal box.

■ Make sure there is onsite overload protection equipment

for the mains connection line of the zone control panel (short circuit resistance 10 kA).

DigiUnit terminal box with isolation switch

Cable feedthroughs and plug-in connections

Power supply

Bus cable

Connection box

Fig. C7: Wiring in unit

RoofVent® LKW

Transport and installation

Component Description Voltage Cable

Option

Comment

DigiUnit terminal box

Power supply 3 x 400 V LKW-6: 5 x 4 mm²

LKW-9: 5 x 6 mm² LKW-10: 5 x 10 mm²

novaNet system bus 2 x 0.16 mm² For bus cable specications,

see Section L, chap. 2.4

Heating/cooling pump 3 x 400 V 4 x 2.5 mm²

For injection system, per pump

Zone control panel 3-phase

Power supply 3 x 400 V 5 x … mm² Depending on options

novaNet system bus 2 x 0.16 mm² For bus cable specications,

see Section L, chap. 2.4

Room air sensor 2 x 1.5 mm² Max. 170 m

Shielded cable

Fresh air sensor 2 x 1.5 mm² Max. 170 m

Enable heating Volt-free

Max. 230 V

3 x 1.5 mm² 2 A max.

Per zone

Enable cooling Volt-free

Max. 230 V

3 x 1.5 mm² 2 A max.

Per zone

Trouble input heating 24 V 3 x 1.5 mm² Per zone

Trouble input cooling 24 V 3 x 1.5 mm² Per zone

Collective trouble indicator Volt-free

Max. 230 V

3 x 1.5 mm² Max. 6 A

Special function on terminal 24 V 3 x 1.5 mm²

Per special function

Power supply for RoofVent

LKW

3 x 400 V LKW-6: 5 x 4 mm²

LKW-9: 5 x 6 mm² LKW-10: 5 x 10 mm²

Per RoofVent® LKW

Main pump 3 x 400 V 4 x 2.5 mm²

Per pump

Humidity sensor 24 V 4 x 1.5 mm²

Max. 170 m

sensor 24 V 4 x 1.5 mm² Max. 170 m

Variant:

Zone control panel 1-phase

Power supply 1 x 230 V 3 x … mm² Depending on options

novaNet system bus 2 x 0.16 mm² For bus cable specications,

see Section L, chap. 2.4

Room air sensor 2 x 1.5 mm² Max. 170 m

Shielded cable

Fresh air sensor 2 x 1.5 mm² Max. 170 m

Enable heating Volt-free

Max. 230 V

3 x 1.5 mm² 2 A max.

Per zone

Enable cooling Volt-free

Max. 230 V

3 x 1.5 mm² 2 A max.

Per zone

Trouble input heating 24 V 3 x 1.5 mm² Per zone

Trouble input cooling 24 V 3 x 1.5 mm² Per zone

Collective trouble indicator Volt-free

Max. 230 V

3 x 1.5 mm² Max. 6 A

Special function on terminal 24 V 3 x 1.5 mm²

Per special function

Main pump 1 x 230 V 3 x 1.5 mm²

Per pump

Humidity sensor 24 V 4 x 1.5 mm²

Max. 170 m

sensor 24 V 4 x 1.5 mm² Max. 170 m

Table C12: Cable list

RoofVent® LKW

Transport and installation

8 Specification texts

RoofVent® LKW supply and extract air handling unit, consisting of:

■ Roof unit with energy recovery

■ Filter box

■ Heating/cooling section

■ Air-Injector

■ Control systems

All components are wired ready-to-connect.

8.1 Roof unit with energy recovery LW

Self-supporting, weatherproof casing made from Aluzinc

sheet steel, insulated on the inside (re protection class B1), with weather louvre door for easy access to the fresh air lter

and DigiUnit terminal box, access panel with quick-release

fasteners for easy access to the extract air lter, isolation

switch outside for interruption of the high-voltage supply. The roof unit includes:

■ Fresh air lter (bag lter, class G4) with differential pres-

sure switch for lter monitoring

■ Opposed fresh air and recirculation dampers with actuator

■ Plate heat exchanger made of aluminium with bypass,

condensate collecting channel and siphon to the roof, including ER and bypass dampers with actuators to regulate the energy recovery

■ Maintenance-free, direct-drive supply air fan

■ Maintenance-free, direct-drive exhaust air fan

■ DigiUnit terminal box with DigiUnit controller as part of the

Hoval DigiNet control system.

DigiUnit controller DU5

Control module, fully wired to the components of the ventilation unit (fans, actuators, temperature sensors, frost

controller, lter monitoring):

■ Controls the unit, including the air distribution, according

to the specications of the control zone

■ Controls the supply air temperature using cascade control

High-voltage section

■ Mains power terminals

■ Isolation switch (can be operated from the outside)

■ Motor contactor for each fan

■ Fuse for the electronics

■ Transformer for the DigiUnit controller, the mixing valve

and the actuators

■ Relays for emergency operation

■ Connecting terminals for actuators and temperature

sensors

■ Control box heating

Type LW- … /DN5

Nominal air ow rate, supply air/

exhaust air

… m³/h

Heat recovery efciency, dry … %

Active power per motor … kW

Supply voltage 3 x AC 400 V

Frequency 50 Hz

8.2 Filter box F00 / F25 / F50

Casing made from Aluzinc sheet steel with extract air grille

and access panel. The lter box includes:

■ Extract air lter (bag lter class G4) with differential pres-

sure switch for lter monitoring

■ Extract air temperature sensor

■ Sound attenuation body as supply air diffuser

Type F-…

8.3 Heating/cooling section K.C / K.D

Internally insulated Aluzinc sheet steel casing, containing the heating/cooling coil made of copper tubes and aluminium

ns, the condensate separator with collecting channel and

the frost controller; siphon for connection to a condensate line (included in delivery)

Type K.__-9

Heat output … kW

Heating medium LPHW … / … °C

At air inlet temperature … °C

Cooling capacity … kW

Cooling medium LPCW … °C

At air inlet temperature … °C

At inlet humidity … %

RoofVent® LKW

Specication texts

8.4 Air-Injector D

Internally-insulated Aluzinc sheet steel casing with:

■ Vortex air distributor with concentric outlet nozzle, adjust-

able vanes and integrated absorber hood

■ Actuator for automatic adjustment of the air distribution

■ Supply air sensor

■ Electric connection box (includes the terminals for the

heating/cooling mixing valve)

Type D -9

Floor area reached … m²

8.5 Options

ColdClimate design

■ Cold-resistant materials

■ Fans with downtime heating

■ Valve actuators with spring return and additional heating

■ Heating/cooling coil type X with water-side frost moni-

toring

■ Plate heat exchanger with differential pressure switch

Oil-proof design

■ Oil-proof materials

■ Extract air lter class F5

■ Condensate drain from the plate heat exchanger to the

drip tray in the lter box

■ Filter box F25 in oil-tight design with integrated oil/conden-

sate drip tray and drain connection

Hygiene design

■ Fresh air lter class F7

■ Extract air lter class F5

Fans with variable air ow rate VAR

■ Maintenance-free, direct-drive supply air fan with

frequency converter

■ Maintenance-free, direct-drive exhaust air fan with

frequency converter

High-pressure fan supply air HZ

Maintenance-free, direct-drive high-pressure fan supply air

High-pressure fan exhaust air HF

Maintenance-free, direct-drive high-pressure exhaust air fan

Hydraulic assembly diverting system HG

the respective heating/cooling coil and the Hoval DigiNet control system

Magnetic mixing valve ..HV

Continuous regulating valve with magnetic drive, ready for connection to the connection box, sized for the respective heating/cooling coil

Fresh air silencer ASD

Exhaust air silencer FSD

As an attachment to the exhaust air grille, casing consisting of Aluzinc sheet steel with built in sound attenuation splitters, for reducing the noise from the exhaust air grille, insertion attenuation _____ dB

Supply air silencer ZSD

As an inserted component in the below-roof unit, casing consisting of Aluzinc sheet steel with built in sound attenuation splitters, for reducing the noise in the room, insertion attenuation _____ dB

Extract air silencer ABSD

As an attachment to the extract air grille, casing consisting of Aluzinc sheet steel with built in sound attenuation splitters, for reducing the noise in the room, insertion attenuation _____ dB

Acoustic cowl AHD

Consisting of an absorber hood of large volume and a screen with a lining of sound attenuation material, insertion attenuation 4 dB

Actuators with spring return SMF

Modulating actuators with safety function in case of a power failure, mounted and wired on the fresh air damper and ER damper

Air outlet box AK

Made of Aluzinc sheet steel, with 4 adjustable exhaust air grilles (replaces the Air-Injector)

Drop eliminator TA

Consisting of aluminium ns, tted in the extract air ow

on the air inlet side of the plate heat exchanger, to drain condensate onto the roof

Condensate pump KP

Consisting of a centrifugal pump and a drip tray, max. delivery rate of 150 l/h with a delivery head of 3 m

RoofVent® LKW

Specication texts

Heating and cooling in the 4-pipe system

There is an additional heating section installed in the belowroof unit:

■ Heating section H.A / H.B / H.C

Aluzinc sheet steel casing, includes the LPHW heating coil

made of copper tubes and aluminium ns and the frost

controller.

Type H.__-…

Heat output … kW

Heating medium LPHW … / … °C

At air inlet temperature … °C

Design for injection system ES

Control and high-voltage section for the heating/cooling pump integrated into the DigiUnit terminal box

8.6 Control systems

Digital control system for the energy-optimised operation of decentralised indoor climate systems:

■ System set up according to OSI reference model

■ Onsite connection to the individual control modules using

novaNet system bus in a serial topology

■ Cross-communication with equal priority (peer-to-peer/

multiplier) using novaNet log

■ Fast reaction times due to data transmission on an events

basis

■ Control modules pre-addressed in the factory with

integrated lightning protection and battery-buffered RAM modules

■ No onsite engineering (binding) required

DigiNet operator terminals

DigiMaster DM5 Pre-programmed Plug-&-Play operator terminal with graphic user interface, consisting of a touch panel with colour display, installed in the door of the zone control panel.

■ Monitoring and setting the DigiNet system (operating

modes, temperature values, scheduler, calendar, alarm handling, control parameters)

DigiCom DC5 Package consisting of operating software, novaNet router and connection cables for using the Hoval DigiNet with a PC:

■ Monitoring and setting the DigiNet system (operating

modes, temperature values, scheduler, calendar, alarm handling and forwarding, control parameters)

■ Trend function, data storage and logbook

■ Differentiated password protection

DigiEasy DE5 Additional unit for operating a control zone, for installation at

any location in a triple ush socket box or in the door of the

zone control panel:

■ Display of the current room temperature set value

■ Increase or decrease the set value by up to 5 °C

■ Display and acknowledge alarms

■ Switch the operating mode

Options

■ Window for DigiMaster

■ IP65 framework

■ novaNet socket

■ novaNet router

■ 4 special functions with switch

■ 8 special functions with 2 switches

■ Special function on terminal

■ DigiEasy installation

DigiNet zone control panel

The zone control panel (coated sheet steel, RAL 7035) contains:

■ 1 fresh air sensor

■ 1 transformer 230/24 V

■ 2 circuit breakers for transformer (1-pin)

■ 1 relay

■ 1 safety relay (2-pin, external)

■ Input and output terminals (top)

■ 1 wiring diagram of the system

■ 1 DigiZone controller, 1 heating/cooling selector switch,

1 relay and 1 room air sensor (supplied) for each control zone

DigiZone controller DZ5 Control unit for each control zone, integrated in the zone control panel:

■ Processes the inputs room and fresh air temperature, trouble

heating, trouble cooling and special functions (optional)

■ Controls the operating modes according to the scheduler

■ Sets the outputs for the enable heating, enable cooling

and the collective trouble indicator

Options

■ Alarm lamp

■ Socket

■ Control of the main pump

■ 2-pin circuit breakers

■ Power supply for indoor climate units with integrated

DigiUnit controller

■ Integration of indoor climate units without integrated

DigiUnit controller

■ Room temperature average value

■ DigiPlus controller

■ Humidity sensor

■ CO

sensor

■ Base

RoofVent® LKW

Specication texts

RoofVent® twin heat

Supply and extract air handling unit with high-capacity energy recovery for heating high spaces

1 Use _______________________________________ 64

2 Construction and operation_____________________ 64

3 Technical data _______________________________ 71

4 Design example ______________________________ 78

5 Options ____________________________________ 80

6 Control systems______________________________ 81

7 Transport and installation ______________________ 82

8 Specication texts ____________________________ 86

1 Use

1.1 Intended use

RoofVent® twin heat units are used to supply fresh air, for the disposal of extract air and for heating with energy recovery in high spaces. Also included under intended use are compliance with the installation, commissioning, operating and maintenance provisions (operating instructions). Any use beyond this is considered improper use. The manufacturer shall not be held responsible for any damage resulting from such use.

1.2 User group

RoofVent® twin heat units may only be installed, operated and serviced by authorised and trained specialist personnel who are familiar with the equipment and aware of the dangers involved. The operating instructions are for English-speaking operating engineers and technicians as well as specialists in building, heating and air technology.

1.3 Risks

RoofVent® twin heat units are built to correspond to the state of the art and to the latest safety standards. However, despite all precautionary measures taken, there are still some potential hazards which are not immediately obvious, such as:

■ Dangers when working with the electrical systems

■ During work on the ventilation unit, parts (e.g. tools) may

fall or be dropped.

■ Dangers from working on the roof

■ Damage to devices or components due to lightning

■ Malfunctions as a result of defective parts

■ Hazards from hot water when working on the hot water

supply

■ Water penetration through the roof unit if the access

panels are not closed correctly

2 Construction and operation

The RoofVent® twin heat provides fresh air supply and extract air removal as well as heating for large spaces (production halls, shopping centres, sports halls, exhibition

halls etc.). It fulls the following functions:

■ Heating (with connection to the central boiler system)

■ Fresh air supply

■ Extract air removal

■ Recirculation

■ Energy recovery with twin plate heat exchanger

■ Air distribution via Air-Injector

■ Air ltration

A ventilation system consists of several autonomous RoofVent

twin heat units and as a rule, works without supply and extract air ducts. The units are installed in the roof and are also serviced from roof level.

Thanks to their high output and efcient air distribution,

RoofVent

twin heat units have a large operating range. This means that compared with other systems, only few units are necessary to create the required conditions.

2.1 Unit construction

The RoofVent® twin heat comprises the following components:

■ Roof unit with energy recovery:

self-supporting housing made of Aluzinc sheet steel, insulated inside (class B1)

■ Combi box:

contains the second plate heat exchanger, the extract air

lter and the heating coil

Note

The coil connections are located under the extract air grille; their position cannot be changed.

■ Air-Injector:

patented, automatically adjustable vortex air distributor for draught-free air distribution over a large area

The unit is delivered in 2 sections: roof unit and below-roof unit (see Fig. D1). The components are bolted together and can be dismantled individually.

RoofVent® twin heat

Use

2.2 Air distribution with the Air-Injector

The patented air distributor – called the Air-Injector – is the core element. The adjustable vanes are used to set

the air discharge angle. It depends on the air ow rate, the

mounting height and the temperature difference between the supply air and room air. The air is therefore blown in vertically downward, conically or horizontally into the room. This ensures that:

■ each RoofVent

twin heat ventilates and heats a large

oor area,

■ no draughts occur in the occupied area,

■ the temperature stratication in the room is reduced, thus

saving energy.

Above-roof unit: Roof unit with energy recovery

Below-roof unit:

a Combi box b Air-Injector

Fig. D1: Components of the RoofVent® twin heat

RoofVent® twin heat

Construction and operation

RoofVent® twin heat

Use

Actuator Air-Injector:

adjusts the supply air discharge direction continuously from vertical to horizontal

Heating coil:

LPHW coil consisting of copper tubes with aluminium ns

Access panel: Access to the heating coil

Plate heat exchanger 2:

with bypass for energy recovery control

ER damper and bypass damper 2:

opposed dampers for energy recovery regulation, with continuous actuator

Extract air lter:

Bag lter with differential pressure switch for lter monitoring

Access panel:

Access to extract air lter

ER damper and bypass damper 1:

opposed dampers for energy recovery regulation, with continuous actuator with spring return

Weather louvre door:

Access to the fresh air lter and to the DigiUnit terminal box

Fresh air lter:

Bag lter with differential pressure switch for lter monitoring

Plate heat exchanger 1:

with bypass for energy recovery control, differential pressure switch and condensate drain

Fresh air damper and recirculation damper:

opposed dampers for switching between fresh air and recirculation operation, with continuous actuator with spring return

Gravity damper:

closes the bypass during shutdown and thus prevents heat loss

Exhaust air fan:

twin impeller centrifugal fan with maintenance-free drive and variable air ow

rate for defrosting operation

Exhaust air grille:

Access to exhaust air fan

Access panel:

Access to supply air fan

Supply air fan:

twin impeller centrifugal fan with maintenance-free drive

Extract air grille

Frost controller

Fig. D2: Components of the RoofVent® twin heat

RoofVent® twin heat

Construction and operation

Fresh air inlet through weather louvre door

Filter with differential pressure switch

Fresh air damper with actuator

Plate heat exchanger 1 with differential pressure switch

Supply air fan

Silencer and diffuser

Plate heat exchanger 2

LPHW heating coil

Frost controller

Supply air sensor

Air-Injector with actuator

Extract air inlet through extract air grille

Extract air sensor

ER/bypass damper 2 with actuator

Filter with differential pressure switch

Recirculation damper (opposed to the fresh air damper)

ER/bypass damper 1 with actuator

Gravity damper

Exhaust air fan

Silencer and diffuser

Exhaust air outlet through exhaust air grille

Fig. D3: Operational diagram RoofVent® twin heat

RoofVent® twin heat

Construction and operation

2.3 Operating modes

The RoofVent® twin heat has the following operating modes:

■ Off

■ Ventilation

■ Recirculation

■ Recirculation night

■ Exhaust air

■ Supply air

■ Night cooling summer

■ Emergency operation

The DigiNet control system controls these operating modes automatically per control zone, in accordance with the scheduler (exception: emergency operation). In addition, you can:

■ manually switch the operating mode of a control zone,

■ switch each individual RoofVent

unit to operating mode Off, Recirculation, Exhaust air, Supply air or Emergency operation.

Code 1)Operating mode Use Diagram Description

OFF Off

The fans are turned off. Frost protection remains active. There is no room temperature control.

if the unit is not needed

Supply air fan ................... Off

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating ............................ Off

VE2 Ventilation

The RoofVent

during room use

Supply air fan ................... On

Exhaust air fan ................. On

Energy recovery ............... 0 - 100 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating ............................ 0 - 100 %

Defrosting

When outside temperatures are very low, condensate in the extract air may freeze. If the pressure drop in the plate heat exchanger is too high, the RoofVent

unit switches automatically to defrosting mode.

to defrost the plate heat exchanger

Supply air fan ................... Off

Exhaust air fan ................. On (50 %)

Energy recovery ............... 100 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating ............................ 100 %

REC Recirculation

On/Off operation: In the event of heat demand, the RoofVent

unit draws in room air, warms it and blows it back into the room. The room temperature set value day is active.

for preheating

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating ............................ On

*) during heat demand

RECN Recirculation night

like REC, but with room temperature set value night

during the night and on weekends

RoofVent® twin heat

Construction and operation

Code 1)Operating mode Use Diagram Description

EA Exhaust air

The RoofVent

unit extracts spent room air. There is no room temperature control.

for special cases

Supply air fan ................... Off

Exhaust air fan ................. On

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating ............................ Off

SA Supply air

The RoofVent

for special cases

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating ............................ 0 - 100 %

NCS Night cooling summer

On/Off operation: If current temperatures allow, the RoofVent

unit blows cool fresh air into the room and extracts warmer room air. The room temperature set value night is active. The unit blows the supply air downwards

vertically for greatest possible efciency.

for free cooling during the night

Supply air fan ................... On

Exhaust air fan ................. On

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating ............................ Off

*) depending on temperature conditions

– Emergency operation

The RoofVent

unit draws in room air, warms it and blows it back into the room. The heater is switched on via manual control of the mixing valve. There is no room temperature control.

if the DigiNet system is not operating (e.g. before commissioning)

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating ............................ On

This is the code for the respective operating mode in the DigiNet control system (see Part L 'Control systems').

Table D1: Operating modes of the RoofVent

twin heat

RoofVent® twin heat

Construction and operation

3 Technical data

3.1 Unit type reference

Below-roof unit

TWH - 9 / DN5 / LW.T + T. T - D / ...

Unit type

RoofVent

twin heat

Unit size

Control

DN5 Design for DigiNet 5 KK Design for non-Hoval controls

Roof unit

Roof unit with energy recovery for RoofVent

twin

Combi box

with energy recovery, extract air lter and

type T heating coil

Air-Injector

Options

Table D2: Unit type reference

3.2 Application limits

Extract air temperature max. 50 °C

Extract air relative humidity max. 60 %

Moisture content of extract air

max. 9.5 g/kg

Fresh air temperature

min. -30 °C

Heating medium temperature max. 120 °C

Operating pressure max. 800 kPa

Supply air temperature max. 60 °C

Minimum operating time VE2 min. 30 min

If the ambient humidity increases by more than 2 g/kg, a drop eliminator

for the plate heat exchanger and an extract air lter in front of the extract

air grille must be installed.

In the case of operation at a fresh air temperature of below -20 °C, a drop

eliminator for the plate heat exchanger must be installed.

Table D3: Application limits for the RoofVent

twin heat

Caution

Danger of damage to the unit as a result of condensate. At high humidity levels or extremely low fresh air temperatures, humidity in the extract air may condense in plate heat exchanger 1. Use the drop eliminator (option) to ensure that no condensate can drip into the unit.

RoofVent® twin heat

Technical data

3.3 Air flow rate, electrical connections

Unit type TWH-9

Air distribution Nominal air ow rate Supply air m³/h 7100

Exhaust air m³/h 7100

Floor area reached max. m² 674

Energy recovery Heat recovery efciency, dry % 75

Heat recovery efciency, wet % 86

Fan characteristics Supply voltage V AC 3 x 400

Permissible voltage tolerance % ± 10

Frequency Hz 50

Active power per motor kW 3.0

Current consumption A 6.5

Set point of thermal relays A 7.5

Speed of rotation (nominal) min

-1

1435

Actuators with spring return (in the roof unit)

Supply voltage V AC 24

Frequency Hz 50

Control voltage V DC 2…10

Torque Nm 15

Run time of actuator s 150

Run time of spring return s 16

Actuator (in the combi box)

Supply voltage V AC 24

Frequency Hz 50

Control voltage V DC 2…10

Torque Nm 10

Run time for 90° rotation s 150

Filter monitoring Factory setting of differential pressure switch Pa 300

Anti-icing, plate heat exchanger Factory setting of differential pressure switch Pa 300

Table D4: Technical data for the RoofVent® twin heat

RoofVent® twin heat

Technical data

3.4 Sound levels

Unit type TWH-9

Operating mode VE2 REC

Position

Sound pressure level (at a distance of 5 m)

dB (A) 52 66 51 44 48

Total sound power level dB (A) 74 88 73 66 70

Octave sound power level 63 Hz dB (A) 52 69 57 52 56

125 Hz dB (A) 63 78 67 57 63

250 Hz dB (A) 65 81 66 59 66

500 Hz dB (A) 66 81 64 56 61

1000 Hz dB (A) 71 81 65 61 60

2000 Hz dB (A) 66 80 65 56 58

4000 Hz dB (A) 58 76 62 50 50

8000 Hz dB (A) 44 70 52 42 41

with hemispherical radiation in a low-reection environment

outdoors (roof unit)

Table D5: Sound levels for the RoofVent

twin heat

RoofVent® twin heat

Technical data

3.5 Heat output

Note

Fresh air temperature -5 °C -15 °C

LPHW Size Type Q Q

TGHmax

tS∆p

QQTGH

max

tS∆p

°C kW kW m °C kPa l/h kW kW m °C kPa l/h

80/60 TWH-9 T 78 69 9.5 46 17 3326 79 68 9.6 45 17 3408

60/40 TWH-9 T 46 38 12.6 33 7 1972 48 36 12.8 32 7 2057

Legend: Type = Type of heating coil

Q = Heat output Q

= Output to cover fabric heat losses

max

= Maximum mounting height

= Supply air temperature

∆p

= Water pressure drop

= Water ow rate

Refers to: Room air 18 °C, extract air 20 °C / 40 % rel. humidity

Table D6: Heat output of the RoofVent

twin heat

Note

The output for coverage of the fabric heat losses (Q

) allows for the ventilation heat requirement

) and the energy recovery output (QER) under the respective air conditions. It is calculated as

follows:

QTG = Q + QER – Q

RoofVent® twin heat

Technical data

3.6 Minimum and maximum distances

X/2

Unit type TWH-9

Align the RoofVent® units so that no unit draws in the exhaust air from another unit as fresh air.

Provide a clear space of approx. 1.5 m on the side opposite to the coil connections for service and maintenance.

The extract air grille must be easily accessible.

The stream of supply air must be able to spread unobstructed (note position of beams and lamps).

Unit clearance X min. m 12.0

max. m 26.0

Mounting height Y

min. 1)m 5.0

max.

m 9.0 … 13.0

The minimum height can be reduced by 1 m in each case using the 'Air

outlet box' option (see Section K 'Options').

The maximum height varies depending on the ancillary conditions (for

values, see Table D6).

Table D7: Minimum and maximum distances

RoofVent® twin heat

Technical data

3.7 Dimensions and weight

Roof unit LW.T

Combi box T

Cable feedthroughs for electrical connections

Access panel

Air-Injector D

Return

Flow

Condensate drain connection

Fig. D4: Dimensional drawing for RoofVent® twin heat (dimensions in mm)

RoofVent® twin heat

Technical data

Type T

Water content l 7.6

Connection " Pipe thr. 1 ½

(female)

Table D8: Heating coil data

Unit type TWH-9

Roof unit kg 560

Below-roof unit kg 296

Combi box (incl. coil) kg 240

Air-Injector kg 56

Total kg 856

Table D9: Weight of the RoofVent® twin heat

3.8 Air flow rate with additional pressure drops

Pressure increase in Pa Example:

An additional pressure drop of 84 Pa results in a

new air ow rate of

6530 m³/h.

TWH-9

240

5500 6000 6500 7000 7500

220

200

180

160

140

120

100

Air ow rate in m³/h

Diagram D1: Air ow rate for RoofVent® twin heat with additional pressure drops

RoofVent® twin heat

Technical data

4 Design example

Design data

■ Required fresh air ow rate or air change rate

■ Hall geometry (length, width, height)

■ Design fresh air temperature

■ Desired room temperature (in the occupied area)

■ Extract air conditions

■ Fabric heat losses (portion to be covered by the

RoofVent

units)

■ Internal heat gains (machines, lighting, etc.)

■ Heating medium

The extract air temperature is generally higher than the temperature in the occupied area. This is the result of unavoidable temperature stratication in high spaces, but is reduced to a minimum with the Air-Injector. A temperature gradient of only 0.2 K per metre height can therefore be assumed.

Example

Fresh air ow rate ......................................25'000 m³/h

Hall geometry (L x W x H) ....................50 x 44 x 10 m

Design fresh air temperature. .............................. -5 °C

Desired room temperature...................................18 °C

Extract air conditions ............................... 20 °C / 40 %

Fabric heat losses ........................................... 220 kW

Heat gains ......................................................... 10 kW

Heating medium ................................. LPHW 80/60 °C

Room temperature:..............................................18 °C

Temperature gradient: .................................. 10 · 0.2 K

Extract air temperature: ....................................= 20 °C

Required number of units n

req

Based on the air ow rate per unit (see Table D4), calculate

the required number of units.

req

= V

req

/ V

req

= required fresh air ow rate in m³/h

= air ow rate per unit in m³/h

req

= 25'000 / 7'100

req

= 3.52

Select 4 TWH-9s.

Actual fresh air ow rate V (in m³/h)

V = n · V

n = Selected number of units

V = 4 · 7'100 V = 28'400 m³/h

Effective fabric heat losses Q

Teff

(in kW)

Tef f

= QT – Q

QT = fabric heat losses in kW Q

= internal heat loads in kW

Tef f

= 220 – 10

Tef f

= 210 kW

Necessary output to cover fabric heat losses per unit Q

(in kW)

= Q

Tef f

/ n

req

= 210 / 4

Tef f

= 52.5 kW

Checking the heat output

Compare the required output for coverage of the fabric heat losses per unit with the data in Table D6. Increase the

number of units if the heat output is insufcient.

Actual output Q

= 69.0 kW

Required output = 52.5 kW

→ OK

RoofVent® twin heat

Design example

Checking the ancillary conditions

■ Maximum mounting height

The actual mounting height (= distance between the oor

and the bottom edge of the unit) must not exceed the maximum mounting height H

max

(see Table D6).

■ Maximum oor area reached

Calculate the oor area reached per unit using the

selected number of units. If it exceeds the maximum value listed in Table D4, increase the number of units.

■ Compliance with minimum and maximum distances

Check the resulting distances based on the space requirements and arrangement of the units, using the information in Table D7.

Actual mounting height = 8.5 m Max. mounting height H

max

= 9.5 m

→ OK

Floor area per unit = 50 · 44 / 4 = 550 m²

Max. oor area reached = 674 m² → OK

Minimum and maximum distances can be complied with when units are arranged symmetrically.

→ OK

Denitive number of units

With a larger number of units, there is more exibility of

operation. However, the costs are also higher. For an optimal solution, compare both the costs and ventilation quality of the system.

Select 4 TWH-9s. They guarantee cost-effective and energy-saving operation.

RoofVent® twin heat

Design example

5 Options

RoofVent® twin heat units can be adapted to the requirements of the specic project with a series of

options. You will nd a detailed description of all optional components in Section K 'Options' of this

handbook.

Option Use

Hygiene design When using the RoofVent

unit in applications with higher

hygiene requirements (corresponds to VDI 6022)

Hydraulic assembly diverting system

To facilitate hydraulic installation

Magnetic mixing valve For continuous regulation of the heating coil (plug-in)

Fresh air silencer For reduction of noise from the weather louvre door

Exhaust air silencer For reduction of noise from the exhaust air grille

Supply air silencer For reduction of noise within the room

Extract air silencer For reduction of noise within the room

Acoustic cowl For reduction of noise within the room (in the Air-Injector)

Air outlet box When using the RoofVent

unit in low-roofed halls

(instead of the Air-Injector)

Extract air lter in front of the

extract air grille

To protect plate heat exchanger 2 against dirt build-up

Drop eliminator To drain condensate from plate heat exchanger 1 onto the roof

Condensate pump To drain condensate from plate heat exchanger 2 through

waste water pipes directly below the ceiling or onto the roof

Design for injection system For installation of the RoofVent

unit with a hydraulic injection

system (integrated pump control)

Table D10: Availability of options for the RoofVent® twin heat

RoofVent® twin heat

Options

6 Control systems

There are basically 2 possibilities for controlling the RoofVent® twin heat:

System Description

Hoval DigiNet Ideally, RoofVent

twin heat units are controlled via the Hoval

DigiNet. This control system, developed specically for Hoval

indoor climate systems, provides the following advantages:

■ DigiNet utilises the full potential of the decentralised

systems. It controls each ventilation unit individually, depending on local conditions.

■ DigiNet allows for maximum exibility of operation with

respect to the control zones, unit combinations, operating modes and operating times.

■ DigiNet regulates the air distribution and thus ensures

maximum ventilation efciency.

■ DigiNet regulates the energy recovery output in the plate

heat exchanger.

■ The ready-to-connect units with integrated control compo-

nents are easy to design with and to install.

■ Commissioning of the DigiNet is quick and easy thanks

to the plug & play components and pre-addressed control modules.

You can nd a detailed description of the Hoval DigiNet in

Part L 'Control systems' of this manual.

Non-Hoval system RoofVent

twin heat units can also be controlled via nonHoval systems. However, the non-Hoval system must take the special features of the decentralised systems into account. In the design for non-Hoval control, the RoofVent

twin heat is delivered with a basic terminal box instead of the DigiUnit terminal box. Additional information can be found in the separate description 'Terminal box unit RoofVent

twin heat'

(available on request).

Table D11: Control systems for the RoofVent® twin heat

RoofVent® twin heat

Control systems

7 Transport and installation

7.1 Assembly

Caution

Risk of injury from incorrect handling. Transport and assembly work to be carried out only by trained

specialists!

RoofVent

twin heat units are delivered in 2 sections (roof unit, below-roof unit) on a wooden pallet. Parts which belong together are labelled with the same unit number.

Note

The following guidelines are important when preparing for assembly:

■ The units are assembled from roof level. A crane or heli-

copter is required.

■ For the transport of the unit to the roof 2 hoisting slings

are required (approx. length 6 m). If steel ropes or chains are used, the unit corners must be properly protected.

■ Make sure that the roof frames correspond to the speci-

cations in Section M 'Planning information'.

■ Dene the desired orientation of the units.

■ The units are held in the roof frame by means of their own

weight. Silicon, PU foam or similar is required for sealing.

■ For units with exhaust air silencers, additional attachment

to the roof frame is required.

■ Follow the assembly instructions included.

Fig. D5: RoofVent® roof units are installed from roof level.

7.2 Hydraulic installation

Caution

Risk of injury from incorrect handling. Hydraulic instal-

lation must be carried out by trained specialists only !

Boiler system requirements

■ Adjust the hydraulic system to the control zone divisions.

■ Balance the pipework for the individual units within a

control zone to ensure even temperatures.

■ Starting at a fresh air temperature of 15 °C, the heating

medium (max. 120 °C) must be available at the mixing valve without delay in the required amount and temperature.

■ Control of the ow temperature which is dependent on the

fresh air temperature is needed.

The Hoval DigiNet control system switches on the 'Enable heating' for 1 minute once a week. This prevents the main pump blocking after a prolonged shutdown.

RoofVent

unit pipework requirements

■ Use 3-way mixing valves with linear characteristics and

high quality.

■ The valve authority must be ≥ 0.5.

■ The valve actuator must have a short run time (5 s).

■ The valve actuator must be continuous, i.e. the stroke

changes in proportion to the control voltage (DC 0…10 V).

■ The valve actuator must be designed for emergency

operation with a separate manual control (AC 24 V).

■ Install the valve close to the unit (max. 2 m distance).

Caution

Risk of injury from falling parts. Do not apply any

loads to the coil, e.g. by means of the ow or return!

Note

Use the 'Hydraulic assembly' or 'Magnetic mixing valve' options for quick and easy hydraulic installation.

RoofVent® twin heat

Transport and installation

DigiUnit terminal box

novaNet system bus

Power supply

Connection box

Magnetic mixing valve

Collective trouble indicator

Fresh air sensor

Room air sensor

Trouble input heating

Main pump

DigiMaster

Zone control panel

Enable heating

Heating control panel

Fig. D6: Conceptual drawing for hydraulic diverting system

< 2 m

RoofVent® twin heat

Transport and installation

7.3 Electrical installation

Caution

Danger from electric current. The electrical installation

is to be carried out only by a qualied electrician!

■ Comply with all relevant legislation (e.g. EN 60204-1).

■ For long supply lines, select cable diameters in accord-

ance with the technical regulations.

■ Carry out electrical installation in accordance with the

wiring diagram (for wiring within the unit, see Fig. D7).

■ Install the system bus for the control systems separately

from the mains cable.

■ Establish plug connections from the Air-Injector to the

combi box and from the combi box (inside) to the roof unit.

■ Wire the actuator of the ER/bypass damper 2 to the

DigiUnit terminal box.

■ Wire the mixing valves to the connection box. (There is a

plug connection for Hoval magnetic mixing valves.)

■ For injection system: Wire pump to the DigiUnit terminal

box.

■ Make sure there is onsite overload protection equipment

for the mains connection line of the zone control panel (short circuit resistance 10 kA).

DigiUnit terminal box with isolation switch

Actuator of ER/bypass damper 2

Plug connection, actuator

Cable feedthroughs and plug connections, Air-Injector

Power supply

Bus cable

Connection box

Fig. D7: Wiring in unit

RoofVent® twin heat

Transport and installation

Component Description Voltage Cable

Option

Comment

DigiUnit terminal box

Power supply 3 x 400 V 5 x 6 mm²

novaNet system bus 2 x 0.16 mm² For bus cable specications,

see Part L, Chap. 2.4

Heating pump 3 x 400 V 4 x 2.5 mm²

For injection system

Zone control panel 3-phase

Power supply 3 x 400 V 5 x … mm² Depending on options

novaNet system bus 2 x 0.16 mm² For bus cable specications,

see Part L, Chap. 2.4

Room air sensor 2 x 1.5 mm² Max. 170 m

shielded cable

Fresh air sensor 2 x 1.5 mm² Max. 170 m

Enable heating volt-free

max. 230 V

3 x 1.5 mm² 2 A max.

Per zone

Trouble input heating 24 V 3 x 1.5 mm² Per zone

Collective trouble indicator volt-free

max. 230 V

3 x 1.5 mm² Max. 6 A

Special function on terminal 24 V 3 x 1.5 mm²

Per special function

Power supply for RoofVent

twin heat

3 x 400 V 5 x 6 mm² Per RoofVent® twin heat

Main pump 3 x 400 V 4 x 2.5 mm²

Per pump

Humidity sensor 24 V 4 x 1.5 mm²

Max. 170 m

sensor 24 V 4 x 1.5 mm² Max. 170 m

Variant:

Zone control panel 1-phase

Power supply 1 x 230 V 3 x … mm² Depending on options

novaNet system bus 2 x 0.16 mm² For bus cable specications,

see Part L, Chap. 2.4

Room air sensor 2 x 1.5 mm² Max. 170 m

Shielded cable

Fresh air sensor 2 x 1.5 mm² max. 170 m

Enable heating volt-free

max. 230 V

3 x 1.5 mm² 2 A max.

Per zone

Trouble input heating 24 V 3 x 1.5 mm² Per zone

Collective trouble indicator volt-free

max. 230 V

3 x 1.5 mm² Max. 6 A

Special function on terminal 24 V 3 x 1.5 mm²

Per special function

Main pump 1 x 230 V 3 x 1.5 mm²

Per pump

Humidity sensor 24 V 4 x 1.5 mm²

Max. 170 m

sensor 24 V 4 x 1.5 mm² Max. 170 m

Table D12: Cable list

RoofVent® twin heat

Transport and installation

8 Specification texts

Air supply and extraction unit RoofVent® twin heat, consisting of:

■ Roof unit with energy recovery

■ Combi box

■ Air-Injector

■ Control systems

All components are wired as ready-to-connect.

8.1 Roof unit with energy recovery LW.T

Self-supporting, weatherproof casing made from Aluzinc

sheet steel, insulated on the inside (re protection class B1),

with weather louvre door for easy access to the fresh air

lter and unit control box, access panel with quick-release fasteners for easy access to the extract air lter, isolation

switch outside for interruption of the high-voltage supply. The roof unit includes:

■ Fresh air lter (bag lter class G4) with differential pres-

sure switch for lter monitoring

■ Opposed fresh air and recirculation dampers with actuator

with spring return

■ Plate heat exchanger made of aluminium with bypass,

differential pressure switch, condensate collecting channel and siphon to the roof, including ER and bypass dampers with actuators with spring return to regulate the energy recovery

■ Maintenance-free, direct-drive supply air fan

■ Maintenance-free, direct-drive exhaust air fan with

frequency converter

■ DigiUnit terminal box with DigiUnit controller as part of the

Hoval DigiNet control system

DigiUnit controller DU5

Control module, fully wired to the components of the ventilation unit (fans, actuators, temperature sensors, frost

controller, lter monitoring):

■ Controls the unit including the air distribution according to

the specications of the control zone

■ Controls the supply air temperature using cascade control

High-voltage section

■ Mains power terminals

■ Isolation switch (can be operated from the outside)

■ Motor contactor for each fan

■ Fuse for the electronics

■ Transformer for the DigiUnit controller, the mixing valve

and the actuators

■ Relays for emergency operation

■ Connecting terminals for actuators and temperature

sensors

■ Control box heating

Type LW.T-9 /DN5

Nominal air ow rate supply air/

exhaust air

7100 m³/h

Heat recovery efciency, dry 75 %

Active power per motor 3.0 kW

Supply voltage 3 x AC 400 V

Frequency 50 Hz

8.2 Combi box T.T

Casing made from Aluzinc sheet steel with extract air grille and access panel. The Combi box contains:

■ Aluminium plate heat exchanger with bypass; including

ER/bypass dampers with actuator for control of the energy recovery

■ Extract air lter (bag lter class G4) with differential pres-

sure switch for lter monitoring

■ Extract air temperature sensor

■ Sound attenuation body as supply air diffuser

■ LPHW heating coil consisting of copper tubes with

aluminium ns

■ Frost controller

Type T.T-9

Heat output … kW

Heating medium LPHW … / … °C

at air inlet temperature … °C

8.3 Air-Injector D

Casing made from Aluzinc sheet steel with:

■ Vortex air distributor with concentric outlet nozzle, adjust-

able vanes and integrated sound attenuation cowl

■ Actuator for automatic adjustment of the air distribution

■ Supply air sensor

■ Electric connection box (includes the terminals for the

mixing valve heating)

Type D -9

Floor area reached … m²

RoofVent® twin heat

Specication texts

8.4 Options

Hygiene design

■ Fresh air lter class F7

■ Extract air lter class F5

Hydraulic assembly diverting system HG

Prefabricated assembly for hydraulic diverting system, consisting of magnetic mixing valve, regulating valve, ball valve, automatic air vent and screw connections for connection to the unit and to the distributor circuit; ready-to-connect mixing valve for connection to the connection box; sized for the respective heating coil and the Hoval DigiNet control system

Magnetic mixing valve ..HV

Continuous regulating valve with magnetic drive, plug-in for connection to the connection box, sized for the respective heating coil

Fresh air silencer ASD

Exhaust air silencer FSD

Supply air silencer ZSD

As an inserted component in the below-roof unit, casing consisting of Aluzinc sheet steel with built in sound attenuation splitters, for reducing the noise in the room, insertion attenuation _____ dB

Extract air silencer ABSD

As an attachment to the extract air grille, casing consisting of Aluzinc sheet steel with built in sound attenuation splitters, for reducing the noise in the room, insertion attenuation _____ dB

Acoustic cowl AHD

Consisting of an absorber hood of large volume and a screen with a lining of sound attenuation material, insertion attenuation 4 dB

Air outlet box AK

made of Aluzinc sheet steel, with 4 adjustable exhaust air grilles (replaces the Air-Injector)

Extract air lter in front of the extract air grille AF

As an attachment to the extract air grille, casing consisting of

Aluzinc sheet steel with inserted minipleat lter (class G4)

Drop eliminator TA

consisting of aluminium ns, tted in the extract air ow

on the air inlet side of the plate heat exchanger, to drain condensate onto the roof

Condensate pump KP

consisting of a centrifugal pump, a drip tray, max. delivery rate of 150 l/h with a delivery head of 3 m

Design for injection system ES

Control and high-voltage section for the heating pump integrated into the DigiUnit terminal box

RoofVent® twin heat

Specication texts

8.5 Control systems

Digital control system for the energy-optimised operation of decentralised indoor climate systems:

■ System set up according to OSI reference model

■ Onsite connection to the individual control modules using

novaNet system bus in a serial topology (by electrical installer)

■ Cross communication with equal priority (peer-to-peer/

multiplier) using novaNet log

■ Fast reaction times due to data transmission on an events

basis

■ Control modules pre-addressed in the factory with

integrated lightning protection and battery-buffered RAM modules

■ No onsite engineering (binding) required

DigiNet operator terminals

DigiMaster DM5 Pre-programmed Plug-&-Play operator terminal with graphic user interface consisting of a touch panel with colour display, installed in the door of the zone control panel

■ Monitoring and setting the DigiNet system (operating

modes, temperature values, scheduler, calendar, alarm handling, control parameters)

DigiCom DC5 Package consisting of operating software, novaNet router and connection cables for using the Hoval DigiNet with a PC:

■ Monitoring and setting the DigiNet system (operating

modes, temperature values, scheduler, calendar, alarm handling and forwarding, control parameters)

■ Trend function, data storage and logbook

■ Differentiated password protection

DigiEasy DE5 Additional unit for operating a control zone, for installation at

any location in a triple ush socket box or in the door of the

zone control panel:

■ Display the current room temperature set value

■ Increase or decrease the set value by up to 5 °C

■ Display and acknowledge alarms

■ Switch the operating mode

Options

■ Window for DigiMaster

■ IP65 framework

■ novaNet socket

■ novaNet router

■ 4 special functions with switch

■ 8 special functions with 2 switches

■ Special function on terminal

■ DigiEasy installation

DigiNet zone control panel

The zone control panel (coated sheet steel, RAL 7035) contains:

■ 1 fresh air sensor

■ 1 transformer 230/24 V

■ 2 circuit breakers for transformer (1-pin)

■ 1 relay

■ 1 safety relay (2-pin, external)

■ Input and output terminals (top)

■ 1 wiring diagram of the system

■ 1 DigiZone control, 1 relay and 1 room air sensor

(included) for each control zone

DigiZone controller DZ5 Control unit for each control zone, integrated in the zone control panel:

■ Processes the inputs room and fresh air temperature,

heating trouble and special functions (optional)

■ Controls the operating modes according to the scheduler

■ Sets the outputs for the enable heating and the collective

trouble indicator

Options

■ Alarm lamp

■ Socket

■ Control of the main pump

■ 2-pin circuit breakers

■ Power supply for indoor climate units with integrated

DigiUnit controller

■ Integration of indoor climate units without integrated

DigiUnit controller

■ Room temperature average value

■ DigiPlus controller

■ Humidity sensor

■ CO

sensor

■ Base

RoofVent® twin heat

Specication texts

RoofVent® twin cool

Supply and extract air handling unit with high-capacity energy recovery for heating and cooling high spaces

1 Use _______________________________________ 90

2 Construction and operation_____________________ 90

3 Technical data _______________________________ 97

4 Design example _____________________________ 10 6

5 Options ___________________________________ 108

6 Control systems_____________________________ 109

7 Transport and installation _____________________ 110

8 Specication texts ___________________________ 114

RoofVent® twin cool

Contents

1 Use

1.1 Intended use

RoofVent® twin cool units are used to supply fresh air, for the disposal of extract air and for heating and cooling with energy recovery in high spaces. Also included under intended use are compliance with the installation, commissioning, operating and maintenance provisions (operating instructions). Any use beyond this is considered improper use. The manufacturer shall not be held responsible for any damage resulting from such use.

1.2 User group

RoofVent® twin cool units may only be installed, operated and serviced by authorised and trained specialist personnel who are familiar with the equipment and aware of the dangers involved. The operating instructions are for English-speaking operating engineers and technicians as well as specialists in building, heating and air technology.

1.3 Risks

RoofVent® twin cool units are built to correspond to the state of the art and to the latest safety standards. However, despite all precautionary measures taken, there are still some potential hazards which are not immediately obvious, such as:

■ Dangers when working with the electrical systems

■ During work on the ventilation unit, parts (e.g. tools) may

fall or be dropped.

■ Dangers from working on the roof

■ Damage to devices or components due to lightning

■ Malfunctions as a result of defective parts

■ Hazards from hot water when working on the hot water

supply

■ Water penetration through the roof unit if the access

panels are not closed correctly

2 Construction and operation

The RoofVent® twin cool provides fresh air supply and extract air removal as well as heating and cooling for large spaces (production halls, shopping centres, sports halls, exhibition

halls etc.). It fulls the following functions:

■ Heating (with connection to the central boiler system)

■ Cooling (with connection to water chiller)

■ Fresh air supply

■ Extract air removal

■ Recirculation

■ Energy recovery with twin plate heat exchanger

■ Air distribution via Air-Injector

■ Air ltration

A ventilation system consists of several autonomous RoofVent

twin cool units and as a rule, works without supply and extract air ducts. The units are installed in the roof and are also serviced from roof level.

Thanks to their high output and efcient air distribution,

RoofVent

twin cool units have a large operating range. This means that compared with other systems, only few units are necessary to create the required conditions.

2.1 Unit construction

The RoofVent® twin cool comprises the following components:

■ Roof unit with energy recovery: self-supporting casing

made of Aluzinc sheet steel, insulated inside (class B1)

■ Combi box:

contains the second plate heat exchanger and the extract

air lter

■ Heating/cooling section:

coil connections possible on each side (usually underneath the extract air grille)

■ Air-Injector:

patented, automatically adjustable vortex air distributor for draught-free air distribution over a large area

The unit is delivered in 3 sections: roof unit, combi box and heating/cooling section with Air-Injector (see Fig. E1). The components are bolted together and can be dismantled individually.

RoofVent® twin cool

Use

2.2 Air distribution with the Air-Injector

The patented air distributor – called the Air-Injector – is the core element. The adjustable vanes are used to set

the air discharge angle. It depends on the air ow rate, the

mounting height and the temperature difference between the supply air and room air. The air is therefore blown in vertically downward, conically or horizontally into the room. This ensures that:

■ each RoofVent

twin cool ventilates, heats and cools a

large oor area,

■ no draughts occur in the occupied area,

■ the temperature stratication in the room is reduced, thus

saving energy.

Above-roof unit: Roof unit with energy recovery

Below-roof unit:

a Combi box b Heating/cooling section c Air-Injector

Fig. E1: Components of the RoofVent® twin cool

RoofVent® twin cool

Construction and operation

RoofVent® twin cool

Use

Actuator Air-Injector:

adjusts the supply air discharge direction continuously from vertical to horizontal

Heating/cooling coil:

LPHW/LPCW coil consisting of copper tubes with aluminium ns

Access panel: Access to the heating/cooling coil

Plate heat exchanger 2:

with bypass for energy recovery control

ER damper and bypass damper 2:

opposed dampers for regulation of energy recovery, with continuous actuator

Extract air lter:

Bag lter with differential pressure switch for lter monitoring

Access panel:

Access to extract air lter

ER damper and bypass damper 1:

opposed dampers for regulation of energy recovery, with continuous actuator with spring return

Weather louvre door:

Access to the fresh air lter and to the DigiUnit terminal box

Fresh air lter:

Bag lter with differential pressure switch for lter monitoring

Plate heat exchanger 1:

with bypass for energy recovery control, differential pressure switch and condensate drain

Fresh air damper and recirculation damper:

opposed dampers for switching between fresh air and recirculation operation, with continuous actuator with spring return

Gravity damper:

closes the bypass during shutdown and thus prevents heat loss

Exhaust air fan:

twin impeller centrifugal fan with maintenance-free drive and variable air ow

rate for defrosting operation

Exhaust air grille:

Access to exhaust air fan

Access panel:

Access to supply air fan

Supply air fan:

twin impeller centrifugal fan with maintenance-free drive

Extract air grille

Frost controller

Condensate separator

Condensate drain connection

Fig. E2: Components of the RoofVent® twin cool

RoofVent® twin cool

Construction and operation

Fresh air inlet through weather louvre door

Filter with differential pressure switch

Fresh air damper with actuator

Plate heat exchanger 1 with differential pressure switch

Supply air fan

Silencer and diffuser

Plate heat exchanger 2

Heating/cooling coil LPHW/LPCW

Frost controller

Condensate separator

Supply air sensor

Air-Injector with actuator

Extract air inlet through extract air grille

Extract air sensor

ER/bypass damper 2 with actuator

Filter with differential pressure switch

Recirculation damper (opposed to the fresh air damper)

ER/bypass damper 1 with actuator

Gravity damper

Exhaust air fan

Silencer and diffuser

Exhaust air outlet through exhaust air grille

Fig. E3: Operational diagram RoofVent® twin cool

RoofVent® twin cool

Construction and operation

2.3 Operating modes

The RoofVent® twin cool has the following operating modes:

■ Off

■ Ventilation

■ Recirculation

■ Recirculation night

■ Exhaust air

■ Supply air

■ Night cooling summer

■ Emergency operation

The DigiNet control system controls these operating modes automatically per control zone, in accordance with the scheduler (exception: emergency operation). In addition, you can:

■ manually switch the operating mode of a control zone,

■ switch each individual RoofVent

unit to operating mode Off, Recirculation,

Exhaust air, Supply air or Emergency operation.

Code

Operating mode Use Diagram Description

OFF Off

The fans are turned off. Frost protection remains active. There is no room temperature control.

if the unit is not needed

Supply air fan ................... Off

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating/cooling ................Off

VE2 Ventilation

The RoofVent

unit blows fresh air into the room and draws off spent room air. Heating/cooling and energy recovery are controlled depending on the heat demand and temperature conditions. The room temperature set value day is active.

during room use

Supply air fan ................... On

Exhaust air fan ................. On

Energy recovery ............... 0 - 100 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating/cooling ................0 - 100 %

Defrosting

When fresh air temperatures are very low, condensate in the extract air may freeze. If the pressure drop in the plate heat exchanger is too high, the RoofVent

unit switches automatically to

defrosting mode.

to defrost the plate heat exchanger

Supply air fan ................... Off

Exhaust air fan ................. On (50 %)

Energy recovery ............... 100 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating ............................ 100 %

REC Recirculation

On/Off operation: During heat or cool demand, the RoofVent

unit draws in room air, heats or cools it and blows it back into the room. The room temperature set value day is active.

for preheating or precooling

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating/cooling ................On

*) during heat or cool demand

RECN Recirculation night

like REC, but with room temperature set value night

during the night and on weekends

RoofVent® twin cool

Construction and operation

Code

Operating mode Use Diagram Description

EA Exhaust air

The RoofVent

unit extracts spent room air. There is no room temperature control.

for special cases

Supply air fan ................... Off

Exhaust air fan ................. On

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating/cooling ................Off

SA Supply air

The RoofVent

unit blows fresh air into the room. Heating/cooling is controlled depending on the heat/cool demand and temperature conditions. Spent room air passes through open windows and doors or another system provides extraction. The room temperature set value day is active.

for special cases

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating/cooling ................0 - 100 %

NCS Night cooling summer

On/Off operation: If current temperatures allow, the RoofVent

unit blows cool fresh air into the room and extracts warmer room air. The room temperature set value night is active. The unit blows the supply air downwards

vertically for greatest possible efciency.

for free cooling during the night

Supply air fan ................... On

Exhaust air fan ................. On

Energy recovery ............... 0 %

Fresh air damper .............. Open

Recirculation damper .......Closed

Heating/cooling ................Off

*) depending on temperature conditions

– Emergency operation

The RoofVent

unit draws in room air, warms it and blows it back into the room. The heater is switched on via manual control of the mixing valve. There is no room temperature control.

if the DigiNet system is not operating (e.g. before commissioning)

Supply air fan ................... On

Exhaust air fan ................. Off

Energy recovery ............... 0 %

Fresh air damper .............. Closed

Recirculation damper .......Open

Heating/cooling ................On

This is the code for the respective operating mode in the DigiNet control system (see Part L 'Control systems').

Table E1: Operating modes of the RoofVent

twin cool

RoofVent® twin cool

Construction and operation

3 Technical data

3.1 Unit type reference

Below-roof unit

TWC - 9 / DN5 / LW.T + T - K.C - D / ...

Unit type

RoofVent

twin cool

Unit size

Control

DN5 Design for DigiNet 5 KK Design for non-Hoval controls

Roof unit

Roof unit with energy recovery for RoofVent

twin

Combi box

T with energy recovery and extract air lter (without coil) T.T with energy recovery, extract air lter and coil type T (for 4-pipe system)

Heating/cooling section

K.C Heating/cooling section with coil type C K.D Heating/cooling section with coil type D

Air-Injector

Options

Table E2: Unit type reference

3.2 Application limits

Extract air temperature max. 50 °C Extract air relative humidity max. 60 % Moisture content of extract air

max. 9.5 g/kg

Fresh air temperature

min. -30 °C Heating medium temperature max. 120 °C Operating pressure max. 800 kPa Supply air temperature max. 60 °C Minimum operating time VE2 min. 30 min Amount of condensate max. 150 kg/h Air ow rate min. 5000 m³/h

If the ambient humidity increases by more than 2 g/kg, a drop eliminator

for the plate heat exchanger and an extract air lter in front of the extract

air grille must be installed.

In the case of operation at a fresh air temperature of below -20 °C, a drop

eliminator for the plate heat exchanger must be installed.

Table E3: Application limits for the RoofVent

twin cool

Caution

RoofVent® twin cool

Technical data

3.3 Air flow rate, electrical connections

Unit type TWC-9

Air distribution Nominal air ow rate Supply air m³/h 7000

Exhaust air m³/h 7000

Floor area reached max. m² 661

Energy recovery Heat recovery efciency, dry % 75

Heat recovery efciency, wet % 86

Fan characteristics Supply voltage V AC 3 x 400

Permissible voltage tolerance % ± 10

Frequency Hz 50

Active power per motor kW 3.0

Current consumption A 6.5

Set point of thermal relays A 7.5

Speed of rotation (nominal) min

-1

1435

Actuators with spring return (in the roof unit)

Supply voltage V AC 24

Frequency Hz 50

Control voltage V DC 2…10

Torque Nm 15

Run time of actuator s 150

Run time of spring return s 16

Actuator (in the Combi box)

Supply voltage V AC 24

Frequency Hz 50

Control voltage V DC 2…10

Torque Nm 10

Run time for 90° rotation s 150

Filter monitoring Factory setting of differential pressure switch Pa 300

Anti-icing, plate heat exchanger Factory setting of the differential pressure switch Pa 300

Table E4: Technical data for the RoofVent® twin cool

RoofVent® twin cool

Technical data

Hoval RoofVent LHW-9, RoofVent LKW-9, RoofVent LHW-10, RoofVent LKW-6, RoofVent LKW-10 Design Handbook

Specifications and Main Features

Frequently Asked Questions

User Manual