Toshiba 20, 27 User Manual

ClimaDry

ClimaDry Whole House

noitpO noitacﬁidimuheD

Tranquility 27 Tranquility 20

Applications Guide

97B0051N01

Revision: 18 April, 2008B

Table of Contents

Model Nomenclature Example 2

ClimaDry Overview 3

ClimaDry Beneﬁts 3

ClimaDry Features 3

ClimaDry Applications 3

ClimaDry Sequence of Operation 5

ClimaDry Component Functions 6

ClimaDry Application Considerations 6

ClimaDry Schematic 7

TT Blower Data 8

TS ECM Blower Data 9

TS PSC Blower Data 10

Reheat Coil Pressure Drop Table 11

TS Air Coil Face Area Table 11

Wiring Diagram 12

Flushing/Purging Units 13

Revision History 14

A0 7 2 DG 0 1 D L K

4 5 6 7

9 10 12 13 14

026, 038, 049, 064, 072

Unit Size

Return Air Flow Configuration

Voltage

C = CXM

Controls

D = DXM

A = Current Revision

Revision Level

Heat Exchanger Options

Cabinet

Supply Air Flow & Motor Configuration

1 2

TT = Tranquility Two-Stage Scroll

Series

V = Vertical Up

Configuration

L = Left Return R = Right Return

0 = None

Water Circuit Options

S = Standard

Standard

H = Horizontal

D = Vertical Down

0 = Residential

1 = HWG w/Internal Pump

Supply Configuration Motor

K TTV N TTD P TTH W TTH

Top

Down

Back

Straight

ECM ECM

ECM

Standard

Coated Air Coil

Copper Cupro-Nickel

A J

Rev.: 18 April, 2008B

ClimaDry

D N/A

G = 208-230/60/1

Notes

= Only Available With ClimaDry Option

= Not Available On DownFlow Units

� CAUTION! �

Water Source Heat Pump systems (including Water Loop Heat Pump systems) must have antifreeze protection to 20°F [-6.7°C] for ClimaDry applications. The ClimaDry option MUST NOT be used on open water loop systems, or any system without antifreeze protection.

Notes:

1. ClimaDry reheat option must be ordered with original equipment (cannot be eld added). Unit must have DXM control. Not available for units with internal water valve, or ow regulator options. Check unit product catalog for limitations and specic requirements.

2. ClimaDry cannot be used on open loop systems, only closed loop systems.

3. ClimaDry systems must use appropriate antifreeze solutions.

4. ClimaDry is not recommended for applications with poor water quality (see water quality guidelines in unit IOM). The copper heat exchanger with cast iron pump (standard ClimaDry option) are designed for closed loop systems.

5. Max working water pressure for the ClimaDry option is 145psig.

6. Available with TT, TS models. Check unit product catalog data nomenclature for models with ClimaDry reheat option.

7. Thermostat must be either:

1. Thermostat with dehumidication mode (similar to ATA32U02)

2. Thermostat and separate humidistat or dehumidistat controller (see Table 3 for DXM DIP settings).

8. ClimaDry units must have minimum entering air temperature of 70°F DB / 61°F WB

ClimaDry Whole House Dehumidication - ClimateMaster Geothermal Heat Pumps - Rev.: 18 April, 2008B

Overview

ClimaDry™ Whole House Dehumidication Overview

Indoor Air Quality (IAQ) and Relative Humidity (RH) are increasingly becoming design issues that must be addressed by selecting heating and cooling equipment with advanced capabilities. The ClimateMaster ClimaDry™ reheat option (patent pending) offers unique features unlike anything currently available today.

ClimateMaster’s ClimaDry reheat option is an innovative means of providing modulating reheat without the complication of refrigeration controls. ClimaDry is Hot Gas Generated Reheat, which utilizes one of the biggest advantages of a water source heat pump (WSHP), the transfer of energy through the loop piping system. ClimaDry simply diverts condenser water through a water-to-air coil that is placed after the evaporator coil. If condenser water is not warm enough, the internal “run-around” loop increases the water temperature with each pass through the condenser coil.

Features Include:

• Modulating reheat for precise control of supply air temperatures

• 100% reheat (operates as a whole house dehumidier)

• “Neutral” supply air temperature even at part load (non-design) conditions

• Supply air temperature adjustment, +/- 3°F [+/-1.7°C] from 72°F [22°C] factory setpoint with optional potentiometer

• Integrated factory supplied reheat controls – simply attach a humidistat or dehumidistat

• Microprocessor (DXM) controls standard

• Ultra simple refrigeration circuit

• All water system eliminates refrigeration circuit modications (same refrigeration circuit as units without ClimaDry)

• Stable refrigeration pressures, even at low EWTs

• All components located inside the cabinet

•

Moves heat of rejection from ground loop to supply air stream

ClimaDry Benets

ClimaDry is like no other reheat option on the market. Proportional reheat is controlled to the desired leaving air temperature set point (factory set point of 72°F, [22°C}), no matter what the loop temperature is. Since dehumidication operation will occur under less than full load cooling conditions a good percentage of the time, it is important to have a reheat function that provides 100% reheat in the spring and fall when the loop is cool. Supply air temperature is eld adjustable to +/- 3°F [+/- 1.7°C] for even greater exibility with an optional potentiometer.

Competitors without ClimaDry typically use an on/off (non-modulating) refrigeration based reheat circuit, typically referred to as “Hot gas reheat” (HGR). HGR needs higher condensing temperatures to work well, typically 85°F [29°C] entering water temperature (EWT). With HGR, cooler water temperatures produce cooler supply air temperatures, which could overcool the space, requiring additional space heating from another source or a special auto-change-over relay to allow the unit to switch back and forth between reheat and heating. Rarely does HGR provide 100% reheat, like ClimaDry.

A key benet to ClimaDry is a simple and easy to troubleshoot refrigerant circuit. No switching valves or hard to diagnose leaky check valves are utilized. No unusual refrigerant pressures occur during the reheat mode. The ClimaDry refrigerant circuit is like every other ClimateMaster unit (without reheat), so everything the technician already knows applies to troubleshooting the ClimaDry refrigeration circuit. Plus, the water loop portion of the ClimaDry option is easy to understand and diagnose.

Availability

ClimaDry is currently available on ClimateMaster residential Tranquility 27™ (TT) and Tranquility 20™ (TS) series units (vertical and horizontal units only).

ClimaDry Applications

With the ClimaDry option, return air from the space is conditioned by the air-to-refrigerant (evaporator) coil, then reheated by the water-to-air (reheat) coil to dehumidify the air, but maintain the same space temperature (thus operating as a whole house dehumidier). The moisture removal capability of the heat pump is determined by the unit’s latent capacity rating. Latent Capacity (LC) equals Total Capacity (TC) minus Sensible Capacity (SC). For example, at 85°F [29°C] EWT, the moisture removal capability (latent capacity) of a ClimateMaster size 036 heat pump is 9.6 MBtuh [2.8kW] as shown in gure 1.

Dividing the latent capacity by 1,069 BTU/LB of water vapor at 80°F DB and 67°F WB [26.7°C DB and 19.4°C WB] moist air enthalpy, converts the amount of moisture removal to pounds per hour (multiply pounds per hour by 0.4536 to obtain kg/hr). Calculations are shown in gure 1. Most ClimateMaster heat pumps have a sensible-to-total (S/T) ratio of 0.72 to 0.76. Therefore, approximately, 25% of the cooling capacity is dedicated to latent cooling capacity (moisture removal). When selecting a unit with ClimaDry, the space sensible and latent loads should be calculated. If the unit will be used for space cooling, a unit with at least enough capacity to satisfy the building sensible load should be selected. If the latent cooling load is not satised by the selection, a larger unit with enough latent capacity will be required. The ClimaDry Option can be used for the additional moisture load. If the unit will be used for dehumidication purposes only, the latent capacity is

ClimaDry Whole House Dehumidication - ClimateMaster Geothermal Heat Pumps - Rev.: 18 April, 2008B

the only consideration necessary. In this case, sensible load is immaterial. Example latent capacities for a typical ClimateMaster heat pump are shown in table 1. ClimaDry is especially useful in Northern Climates, where the heat pump may be oversized in the cooling mode to provide enough heating capacity. Units with ClimaDry will compensate for these applications by operating as a whole house dehumidier when necessary to maintain space Relative Humidity (RH).

Since the ClimaDry option is internal to the unit, installation is much easier than a separate whole house dehumidier. Plus, an additional compressor and controls can be eliminated, simplifying the system and lowering operating and installation costs.

Figure 1: Example Size 036 Performance

Performance Data Model 036

Table 1: Typical Unit Latent capacity

Latent Capacity at 85°F [29.4°C] EWT

Size MBtuh lbs/hr kW kg/hr

18 4.7 4.4 1.4 2.0

24 6.1 5.7 1.8 2.6

30 6.8 6.4 2.0 2.9

36 9.6 9.0 2.8 4.1

42 11.0 10.3 3.2 4.7

48 12.7 11.9 3.7 5.4

60 15.2 14.2 4.5 6.4

70 16.9 15.8 5.0 7.2

ClimaDry Whole House Dehumidication - ClimateMaster Geothermal Heat Pumps - Rev.: 18 April, 2008B

ClimaDry Sequence Of Operation

A heat pump equipped with ClimaDry can operate in three modes; cooling, cooling with reheat, and heating. The cooling/heating modes are like any other ClimateMaster WSHP. The reversing valve (“O” signal) is energized in cooling, along with the compressor contactor(s) and blower relay. In the heating mode the reversing valve is de-energized. Almost any thermostat will activate the heat pump in heating or cooling modes. The DXM microprocessor board, which is standard with the ClimaDry option, will accept either heat pump (Y,O) thermostats or non-heat pump (Y,W) thermostats (see CXM/DXM AOM for detailed DXM information).

The reheat mode requires either a separate humidistat/ dehumidistat or a thermostat that has an integrated dehumidication function for activation. The DXM board is congured to work with either a humidistat or dehumidistat input to terminal “H” (DIP switch settings for the DXM board are shown below in table 2). Upon receiving an “H” input, the DXM board will activate the cooling mode and engage reheat. Table 3 shows the relationship between thermostat input signals to the DXM board and unit operation.

There are ve operational inputs for single stage units and seven operational inputs for two stage units:

-Fan Only

-1st Stage Cooling

-2nd Stage Cooling

-1st Stage Heating

-2nd Stage Heating

-3rd Stage Heating (If applicable)

-Reheat Mode

• Fan Only: A (G) call from the thermostat to the (G)

terminal of the DXM control board will bring the unit on in fan only mode.

•

1st Stage Cooling: A simultaneous call from (G), (Y1), and (O) to the (G), (Y1), (O/W2) terminals of the DXM control board will bring the unit on in 1st Stage Cooling.

Table 2: Humidistat/Dehumidistat Logic and DXM 2.1, 2.2., 2.3 DIP settings

Sensor 2.1 2.2 2.3 Logic Reheat (ON) - H Reheat (OFF) - H

Humidistat OFF OFF OFF Reverse 0 VAC 24 VAC

Dehumidistat OFF ON OFF Standard 24 VAC 0 VAC

Table 3: ClimaDry Operating Modes

Input Output

Mode

No Demand ON/OFF5OFF OFF OFF OFF OFF ON/OFF5OFF OFF OFF OFF OFF

Fan Only ON/OFF5ON OFF OFF OFF OFF ON/OFF5ON OFF OFF OFF OFF

Cooling 1st Stage ON ON ON OFF OFF OFF ON ON ON OFF OFF OFF

Cooling 2nd Stage ON ON ON ON OFF OFF ON ON ON ON OFF OFF

Cooling & Dehumidistat

Dehumidistat Only ON/OFF5OFF OFF OFF OFF ON ON ON ON ON OFF ON

Heating 1st Stage OFF ON ON OFF OFF OFF OFF ON ON OFF OFF OFF

Heating 2nd Stage OFF ON ON ON ON/OFF5OFF OFF ON ON ON ON/OFF5OFF

Heating 3rd Stage

Heating & Dehumidistat

Cooling input takes priority over dehumidify input.

DXM is programmed to ignore the H demand when the unit is in heating mode.

N/A for single stage units; Full load operation for dual capacity units.

Single stage unit: W = 2nd Stage backup elec. heat; Two-Stage units: W = 3rd stage backup elec. heat.

ON/OFF = Either ON or OFF.

O G Y1 Y2

ON ON ON ON/OFF5OFF ON ON ON ON ON/OFF5OFF OFF

OFF ON ON ON ON

OFF ON ON ON/OFF5ON/OFF5ON OFF ON ON ON/OFF5ON/OFF5OFF

W H O G Y1 Y2

OFF OFF ON ON ON ON

Backup

Elec Heat

Reheat

OFF

ClimaDry Whole House Dehumidication - ClimateMaster Geothermal Heat Pumps - Rev.: 18 April, 2008B

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