Air Handler Selection - Heat Controller HSS Series Installation, Operation & Maintenance Instructions Manual

H E AT C O N T R O L L E R , I N C . W AT E R - S O U R C E H E AT P U M P S
R e s i d e n t i a l S p l i t - 6 0 H z R 2 2 & R 4 1 0 A
R e v. : 5 J u n e , 2 0 0 8
Equipment Selection
Air Handler Selection Example
Figure 1 shows a typical performance table for a heat pump air
handler. Suppose the evaporator temperature required is 50ºF,
the capacity required is 35,000 Btuh and the airflow required
is 1,200 CFM. Each evaporator temperature listed in the table
shows three wet bulb temperatures. As recommended in the
table notes above, select the 67ºF WB column. At 1,200 CFM,
the model 003 capacity is 36 MBtuh, which is higher than the
minimum capacity required of 35,000 Btuh. In this example,
model 003 would be the appropriate match.
Figure 1: Selecting Air Handler
Utilizing the Existing Air Handler or Coil (R22 units only)
It is recommended that a new coil or air handler be installed
with any geothermal split system compressor section due to the
low initial cost of the additional equipment versus the reliability
and benefit of new technology, increased reliability and
warranty. However, if the existing air handler must be used (R22
systems only), the following conditions apply:
• If the existing coil currently uses an orifice, the orifice must be
removed and replaced with a TXV. If the coil utilizes capillary
tubes, it will not operate properly with the geothermal split
system and should be replaced.
• If life expectancy of indoor coil (and associated components
- fan, cabinet, etc.) is less than 7-10 years, indoor section
should be replaced.
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H e a t C o n t r o l l e r, I n c . W a t e r - S o u r c e H e a t i n g a n d C o o l i n g S y s t e m s