System information

ClimateMaster Geothermal Heat Pump Systems
31
Residential Products Technical Guide
Options
ClimateMaster residential geothermal heat pumps have a number
of options to customize the installation to the customer’s
individual needs.
ECM Fan
The ECM (Electrically-Commutated Motor) or variable speed
fan motor is standard on Tranquility
®
30 and 22 series units.
For Tranquility
®
20 series water-to-air units, a PSC (Permanent
Split Capacitor) fan motor is standard, and the ECM motor is
available as an option. The ECM motor has a number of features
such as soft start, constant CFM [l/s], dehumidifi cation mode and
numerous airfl ow settings (4 heating airfl ow choices, 4 cooling
airfl ow choices, 3 dehumidifi cation mode airfl ow choices, 4
auxiliary heat airfl ow choices, and 1 constant fan airfl ow).
Hot Water Generator
The HWG (Hot Water Generator) or desuperheater option
provides considerable operating cost savings by utilizing excess
heat energy from the heat pump to help satisfy domestic hot water
requirements. The HWG is active throughout the year (any time
the heat pump is operating), providing virtually free hot water
when the heat pump operates in the cooling mode, or hot water
at the COP of the heat pump during operation in the heating
mode. Actual HWG water heating capacities are provided in the
appropriate heat pump performance data. All ClimateMaster heat
pumps equipped with the HWG option include a built-in water to
refrigerant heat exchanger that eliminates the need to tie into the
heat pump refrigerant circuit in the fi eld. The control circuit and
pump are also built in for residential equipment.
Figure 21 shows a typical example of HWG water piping
connections on a unit with built-in pump. Electric water heaters
are recommended. If a gas, propane, or oil water heater is used,
a second preheat tank must be installed. If the electric water
heater has only a single center element, the dual tank system is
recommended to insure a usable entering water temperature for
the HWG.
Typically a single tank of at least 52 gallons [235 liters] is used to
limit installation costs and space. However, a dual tank, is the most
effi cient system, providing the maximum storage and temperate
source water to the HWG.
It is always advisable to use water softening equipment on
domestic water systems to reduce the scaling potential and
lengthen equipment life. In extreme water conditions, it may be
necessary to avoid the use of the HWG option since the potential
cost of frequent maintenance may offset or exceed any savings.
ClimaDry
®
II Whole House Dehumidifi 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 patented ClimateMaster ClimaDry
®
II reheat option offers
unique features unlike anything currently available today.
ClimateMaster’s ClimaDry
®
II reheat 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
loop 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.
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 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 loop is cool. Supply air temperature is fi eld adjustable to
+/- 3°F [+/- 1.7°C] for even greater fl exibility with an
optional potentiometer.
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.
Figure 21: Typical HWG Installation
HWG Connections
Options
Electric
Water
Heater