251934-YTG-G-0708
Johnson Controls Unitary Products
67
Altitude/Temperature Correction Factors
Air
Temp.
Altitude (Ft.)
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
40
1.060
1.022
0.986
0.950
0.916
0.882
0.849
0.818
0.788
0.758
0.729
50
1.039
1.002
0.966
0.931
0.898
0.864
0.832
0.802
0.772
0.743
0.715
60
1.019
0.982
0.948
0.913
0.880
0.848
0.816
0.787
0.757
0.729
0.701
70
1.000
0.964
0.930
0.896
0.864
0.832
0.801
0.772
0.743
0.715
0.688
80
0.982
0.947
0.913
0.880
0.848
0.817
0.787
0.758
0.730
0.702
0.676
90
0.964
0.929
0.897
0.864
0.833
0.802
0.772
0.744
0.716
0.689
0.663
100
0.946
0.912
0.880
0.848
0.817
0.787
0.758
0.730
0.703
0.676
0.651
Gas Heat Minimum Supply Air
Size
(Tons)
Heat Size
Supply Air (CFM)
Cooling
Heating
Min
Max
Min
Max
180
(15)
24 4500
7000
4500
7000
32
4500
7000
4500
7000
210
(17.5)
24 6000
8750
6000
8750
32
6000
8750
6000
8750
240
(20)
24 6000
9400
6000
9400
32
6000
9400
6000
9400
300
(25)
24 7500
12500
7500
12500
32
7500
12500
7500
12500
0.600
0.650
0.700
0.750
0.800
0.850
0.900
0.950
1.000
1.050
1.100
40
50
60
70
80
90
100
Air Temperature (ºF)
Correction Factor
Sea Level
1000 ft
2000 ft
3000 ft
4000 ft
6000 ft
7000 ft
8000 ft
9000 ft
10000 ft
5000 ft
For units with VFD and gas heat, the speed of the indoor
blower motor continues to be controlled by duct static
pressure via the VAV control board.
If there are VAV boxes present in the duct system,
the boxes must be driven to the full-open position
using a customer-supplied power source to assure
adequate airflow across electric heating elements
or gas heat exchanger tubes.
