520413-BIM-A-0209
18
Johnson Controls Unitary Products
CFM Static Pressure and Power-Altitude and Temperature
Corrections
The information below should be used to assist in application of
product when being applied at altitudes at or exceeding 1000
feet above sea level.
The air flow rates listed in the standard blower performance
tables are based on standard air at sea level. As the altitude or
temperature increases, the density of air decreases. In order to
use the indoor blower tables for high altitude applications,
certain corrections are necessary.
A centrifugal fan is a "constant volume" device. This means
that, if the rpm remains constant, the CFM delivered is the
same regardless of the density of the air. However, since the air
at high altitude is less dense, less static pressure will be
generated and less power will be required than a similar
application at sea level. Air density correction factors are shown
in Table 7 and Figure 10.
NH/NJ-20C00F
7.5
208-3-60
19.2
None
---
---
---
43.2
45
20 KW
15
1
41.7
84.9
90
32 KW
24
2
66.7
109.9
110
52 KW
39.1
2
108.4
151.6
175
230-3-60
19.2
None
---
---
---
43.2
45
20 KW
20
1
48.1
91.3
100
32 KW
32
2
77.0
120.2
125
52 KW
52
2
125.1
168.3
175
460-3-60
9.6
None
---
---
---
21.6
25
20 KW
20
1
24.1
45.7
50
32 KW
32
2
38.5
60.1
70
52 KW
52
2
62.5
84.1
90
575-3-60
7.8
None
---
---
---
17.6
20
20 KW
20
1
19.2
36.8
40
32 KW
32
2
30.8
48.3
50
52 KW
52
2
50.0
67.6
70
1. Minimum Circuit Ampacity.
2. Dual Element, Time Delay Type.
3. HACR type per NEC.
Table 6:
Electrical Data - Electric Heat (Continued)
Motor HP
Power Supply
Supply
Blower
Motor
Electric Heat Option
MCA
1
(Amps)
Max Fuse
2
/
Breaker
3
Size
(Amps)
FLA
Model
KW
Stages
Amps
