257098-BTG-A-0506
Unitary Products Group
15
TABLE 12: STATIC RESISTANCES
1000
1200
1400
1600
1800
2000
2200
2400
2600
0.07
0.08
0.09
0.11
0.13
0.15
0.17
0.20
0.23
5-15KW
0.04
0.05
0.06
0.07
0.08
0.10
0.12
0.14
0.16
20-30KW
0.06
0.07
0.08
0.09
0.11
0.13
0.15
0.17
0.20
0.06
0.07
0.08
0.09
0.10
0.11
0.12
0.14
0.16
BOTTOM DUCT CONNECTIONS
1
ELECTRIC
HEATERS
1
RESISTANCE, IWG
CFM
DESCRIPTION
ECONOMIZER
1, 2
1. Deduct these resistance values from the available external static pressure shown in SUPPLY AIR BLOWER PERFORMANCE Tables.
2. The pressure through the economizer is greater for 100% outdoor air than for 100% return air. If the resistance of the return air
duct system is less than 0.25 IWG, the unit will deliver less CFM during full economizer operation.
TABLE 13: ELECTRIC HEATER CFM LIMITATIONS
UNITMODEL SIZE NOMINAL
TONS
VOLTAGE
MINIMUM SUPPLY AIR CFM
HEATER SIZE NOMINAL KW
5
7
10
15
20
30
3
208/230-3-60
1100
1100
1200
1200
1300
-
460-3-60
-
1100
1200
1200
1300
-
575-3-60
-
-
1200
1200
1300
-
4
208/230-3-60
1300
1300
1300
1300
1300
-
460-3-60
-
1300
1300
1300
1300
-
575-3-60
-
-
1300
1300
1400
-
5
208/230-3-60
1600
1600
1600
1600
1600
1600
460-3-60
-
1600
1600
1600
1600
1600
575-3-60
-
-
1600
1600
1600
1800
