System information

Carrier Geothermal Heat Pump Systems
39
Residential Products Technical Guide
• Once the equipment is selected for sensible cooling and
the proper size for heating has been determined, the latent
cooling requirements should be considered. In the product
catalog data, TC (Total Cooling capacity) and SC (Sensible
Cooling capacity) are shown. Latent capacity equals TC
minus SC. The heat gain calculation should also show TC and
SC, which can be compared to the product catalog data. In
most residential applications, properly selected equipment
for heating and cooling will provide adequate latent capacity
to maintain 50% to 55% RH (Relative Humidity). However,
especially in humid climates, the latent capacity may not
be suffi cient to satisfy the latent load (this is true of any
residential air conditioning system). In those cases, equipment
selection should include two-stage operation, ECM fan and in
some cases additional dehumidifi cation equipment. Two-stage
operation increases equipment run time, thereby increasing
the amount of moisture removal over time. The ECM fan
option provides a dehumidifi cation mode that operates the
fan at about 25% less than the normal airfl ow in the cooling
mode (the heating mode is unaffected). Finally, Whole House
Dehumidifi cation can be applied to further assist in removing
moisture in extreme climates.
Figure 19: Geo A Bin Report From GeoDesigner Software
ASHRAE Summer and Winter Comfort Zones (I.P. Units)
Acceptable ranges of operative temperature and humidity for people in typical
summer and winter clothing during primarily sedentary activity.
Equipment Sizing