5168276-XIM-B-0216
Johnson Controls Unitary Products
29
Figure 21: Altitude/Temperature Correction Factors Imperial
Figure 22: Altitude/Temperature Correction Factors Metric
The examples below will assist in determining the airflow
performance of the product at altitude.
Example 1:
What are the corrected CFM, static pressure, and
BHP at an elevation of 5,000 ft. if the blower performance data
is 6,000 CFM, 1.5 IWC and 4.0 BHP?
Solution:
At an elevation of 5,000 ft. the indoor blower will still
deliver 6,000 CFM if the rpm is unchanged. However, Table 16
must be used to determine the static pressure and BHP. Since
no temperature data is given, we will assume an air temperature
of 70°F. Table 16 shows the correction factor to be 0.832.
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
0.600
0.650
0.700
0.750
0.800
0.850
0.900
0.950
1.000
1.050
1.100
Air Temperature (ºC)
Correction Factor
Sea Level
305 Meter
610 Meter
914 Meter
1219 Meter
1829 Meter
2134 Meter
2430 Meter
2743 Meter
3048 Meter
1524 Meter
4.4 10 15.5 21 26.6 32 38
