GP Series Portable Chillers Chapter 7: Appendix 78 of 90
Notes:
Customer use of ductwork requires the high pressure fan option.
Allow 30 in. (77 cm) minimum clearance around the chiller footprint to facilitate free passage of
cooling air and service accessibility.
Figure 20 shows the pressure loss per foot of ductwork. Calculate the total equivalent length before
using the data below.
Support ductwork from the building structure, not off of the chiller.
Back draft damper to outside must be closed at all times when fan/blower is not operating. Size the
damper so that the pressure drop across is no greater than 0.2 in WG (50 Pascal) at the rated output.
Chillers are designed to operate at a condensing entering air temperature of 60ºF (16ºC) minimum
without optional Variable Frequency Drive.
Figure 20 - Loss of Pressure through round duct - inches of water column per equivalent foot
60 hz Condenser Fan Flow Rate (cfm / cmm) 50 hz Condenser Fan Flow Rate (cfm / cmm)
Nominal
Duct
Diameter
(in / cm)
GPAC-20
GPAC-30
GPAC-40
GPAC-50
GPAC-20
GPAC-30
GPAC-40
GPAC-50
4230 / 120
6343 /
180
8458 /
240
12687 /
360
3525 /
100
5286 /
150
7048 /
200
10573 /
300
18 / 45 0.003 0.007 0.013 0.03 0.002 0.005 0.009 0.020
20 / 50 0.002 0.005 0.008 0.02 0.001 0.003 0.005 0.012
22 / 55 0.001 0.003 0.005 0.01 0.002 0.003 0.007
24 / 60 0.002 0.003 0.007 0.001 0.002 0.005
26 / 65 0.001 0.002 0.004 0.001 0.003
28 / 70 0.001 0.003 0.002
30 / 75 0.002 0.002
32 / 80 0.002 0.001
36 / 90 0.001
Note: 1 inch of water column = 250 Pascal