C L I M A T E M A S T E R W A T E R - S O U R C E H E A T P U M P S
Rooftop (TRE) Series
R e v. : O c t o b e r 7 , 2 0 1 9
28
C l i m a t e M a s t e r Wa t e r - S o u r c e H e a t P u m p s
General Information
Storage
Pre-Installation
Figure 1: ClimaDry
®
II Schematic
ClimaDry
®
II Modulating Reheat Option -
ClimateMaster’s patented ClimaDry
®
II Dehumidifi cation
option is an innovative means of providing modulating
reheat without the complication of refrigeration controls.
ClimaDry
®
II 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 water
piping system. ClimaDry
®
II 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
(see fi gure 1, below).
ClimaDry
®
II Benefi ts
–ClimaDry
®
II 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 water loop temperature is. Since dehumidifi 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 water loop is cool. Supply air
temperature is fi eld adjustable to +/- 3°F [+/- 1.7°C] for
even greater fl exibility with the optional potentiometer.
It is recommended that the ClimaDry
®
supply air
temperature be set to match the space cooling setpoint
so that ClimaDry
®
does not impact room temperature.
Competitors without ClimaDry
®
II 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
®
II. ClimaDry
®
II has 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
®
II refrigerant circuit is like every other
ClimateMaster unit (without reheat), so everything the
technician already knows applies to troubleshooting the
ClimaDry
®
II refrigeration circuit. Plus, the water loop
portion of the ClimaDry
®
II option is easy to understand
and diagnose.
ClimaDry
®
II Applications
–ClimaDry
®
II can be applied
to a number of common applications, such as:
• Classrooms.
• Condominiums.
• Apartments.
• Computer rooms.
• Spaces with high latent loads like auditoriums,
theaters, convention centers, etc.
• Most applications where humidity is a problem.
• (Note: ClimaDry
®
is not for use in high fraction
outdoor air applications or in applications with
corrosive atmospheres, such as pool rooms.)
NOTE:
Brazed plate heat exchanger is used when connecting to a loop with no antifreeze.
