Selection Procedure - Payne PY3G Series Product Data

SELECTION PROCEDURE (WITH EXAMPLE)
1. Determine cooling and heating requirements at
design conditions:
Given:
Required Cooling Capacity (TC)
Sensible Heat Capacity (SHC)
Required Heating Capacity . . . . . . . . . . . . . . .
Condenser Entering Air Temperature
Indoor- -Air Temperature 80°F (26°C)edb 67°F (19°C) ewb
Evaporator Air Quantity . . . . . . . . . . . . . . . . . .
External Static Pressure . . . . . . . . . . . . . . . .
Electrical Characteristics . . . . . . . . . . . . . . . . . . .
2. Select unit based on required cooling capacity.
Enter Net Cooling Capacities table at condenser entering
temperature of 95°F (35°C). Unit 036 at 1200 cfm and 67°F
(19°C) ewb (entering wet bulb) will provide a total capacity of
34,400 Btuh and a SHC of 25,900 Btuh. Calculate SHC correction,
if required, using Note 4 under Cooling Capacities tables.
3. Select heating capacity of unit to provide design
condition requirement.
In the Heating Capacities and Efficiencies table, note that the unit
036090 will provide 72,000 Btuh with an input of 90,000 Btuh.
. . . . . . . . . . 34,000 Btuh
. . . . . . . . . . . . 25,000 Btuh
60,000 Btuh
. . . . . . . 95°F (35°C)
1200 CFM
0.300 IN. W.C.
230- -1- -60
4. Determine fan speed and power requirements at
design conditions.
Before entering the air delivery tables, calculate the total static
pressure required. From the given example, the Wet Coil Pressure
Drop Table, and the Filter Pressure Drop Table:
External Static Pressure
Filter
Wet Coil Pressure Drop
Total Static Pressure
Enter the table for Dry Coil Air Delivery—Horizontal and
Downflow Discharge. At .530 IN. W.C. ESP, the closest speed to
1200 CFM is Med- -High (orange wire), which delivers 1316 CFM
at .6 in ESP.
5. Select unit that corresponds to power source
available.
The Electrical Data Table shows that the unit is designed to operate
at 230- -1- -60.
12
0.300 IN. W.C.
0.130 IN. W.C.
0.100 IN. W.C
0.530 IN. W.C