ClimateMaster Tranquility TSV 009 - Page 48

CLIMATEMASTER WATER-SOURCE HEAT PUMPS
Tranquility
®
20 (TS) Series
Rev.: June 5, 2020
ClimateMaster Water-Source Heat Pumps
48
ClimaDry
®
Modulating Reheat Option, Cont’d.
ClimaDry
®
Application Considerations
Unlike most hot gas reheat options, the ClimaDry
®
option
will operate over a wide range of EWTs. Special ow
regulation (water regulating valve) is not required for low
EWT conditions. However, below 55°F [13°C], supply
air temperatures may not be maintained at 72°F [22°C]
because the cooling capacity exceeds the reheat coil
capacity at low water temperatures. Below 55°F [13°C],
essentially all water is diverted to the reheat coil (no heat
of rejection to the building loop). Although the ClimaDry
option will work ne with low EWTs, overcooling of the
space may result with well water systems or on rare
occasions with ground loop (geothermal) systems (Note:
Extended range units are required for well water
and ground loop systems). Since dehumidication is
generally only required in cooling, most ground loop
systems will not experience overcooling of the supply air
temperature. If overcooling of the space is a concern (e.g.
computer room well water application), auxiliary heating
may be required to maintain space temperature when the
unit is operating in the dehumidication mode.
Water-source heat pumps with ClimaDry should not be
used as make-up air units. These applications should use
equipment specically designed for makeup air.
Unit minimum entering air temperature while in the
dehumidication, cooling, or continuous fan modes is
65ºF DB/55ºF WB. Operation below this minimum may
result in nuisance faults.
COAX
Note:
All components shown
are internal to the heat
pump unit.
(TO WATER LOOP)
(FROM WATER LOOP)
MODULATING
MIXING
VALVE
ENTERING
AIR
INTERNAL
PUMP
EVAPORATOR
COIL
LEAVING
AIR
REHEAT
COIL
REFRIGERANT OUT
(COOLING)
REFRIGERANT IN
(COOLING)
WATER IN
WATER OUT
Figure 24: ClimaDry
®
Schematic
Table 6: Humidistat/Dehumidistat Logic & DXM2 (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
1
Cooling input takes priority over dehumidify input.
2
DXM2 is programmed to ignore the H demand when the unit is in heating mode.
3
N/A for single stage units; Full load operation for dual capacity units.
4
ON/OFF = Either ON or OFF.
Mode
Input Output
O G Y1 Y2
3
H O G Y1 Y2
3
Reheat
No Demand
ON/OFF OFF OFF OFF OFF ON/OFF OFF OFF OFF OFF
Fan Only
ON/OFF ON OFF OFF OFF ON/OFF ON OFF OFF OFF
Cooling 1st Stage
ON ON ON OFF OFF ON ON ON OFF OFF
Cooling 2nd Stage
ON ON ON ON OFF ON ON ON ON OFF
Cooling & Dehumidistat
1
ON ON ON ON/OFF ON ON ON ON ON/OFF OFF
Dehumidistat Only
ON/OFF OFF OFF OFF ON ON ON ON ON ON
Heating 1st Stage
OFF ON ON OFF OFF OFF ON ON OFF OFF
Heating 2nd Stage
OFF ON ON ON OFF OFF ON ON ON OFF
Heating & Dehumidistat
2
OFF ON ON ON/OFF ON OFF ON ON ON/OFF OFF
Table 7: ClimaDry
®
Operating Modes