Specification Sheet
Specificatio ns subject to change without notice.
518 71 2005 06
9
SELECTION PROCEDURE (WITH EXAMPLE)
1. Determine cooling and heating requirements
at design conditions:
Given:
Required Cooling Capacity (TC) 34,500 Btuh.......
Sensible Heat Capacity (SHC) 26,000 Btuh........
Required Heating Capacity 60,000 Btuh...........
Condenser Entering Air Temperature 95F(35C)...
Indoor- Air Temperature80F(27C) edb 67F(19C) ewb
Evaporator Air Quantity 1200 CFM.................
External Static Pressure 0.200 IN. W.C.............
Electrical Characteristics 208- 1 - 60................
2. Select unit based on required cooling
capacity.
Enter Net Cooling Capacities table at condenser entering
temperature of 95F(35C). Unit 36 at 1200 CFM and 67F
(19C) ewb (entering wet bulb) will provide a total capacity of
35,800 Btuh and a SHC of 26,950 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
36 size unit will deliver 34,800 BTUH at the AHRI high temp
rating point. To achieve 60,000 BTUH, accessory electric heat
will be required. Use the Balance Point Worksheet to plot the
load line with the unit capacity. The difference between the
load line and unit capacity at the design heating temperature is
the amount of electric heat that will be required.
4. Determine fan speed and power require-
ments 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 0.200 IN. W.C.
Filter 0.130 IN. W.C.
Wet Coil Pressure Drop 0.18
IN. W.C.
Total Static Pressure 0.51 IN. W .C.
Enter the table for Dry Coil Air Delivery— At 0.50 IN. W.C.
ESP (external static pressure) and MED - LOW speed the
motor delivers 1140 CFM. To achieve 1200 CFM, a higher
speed tap is required.
5. Select unit that corresponds to power
source available.
The Electrical Data Table shows that the unit is designed to
operate at 208/230- 1 - 60.