Unit installation
August 2012 Application Note 1021
©2012 Mitsubishi Electric US, Inc.
P a g e | 2
When air conditioners and heat pumps are installed in areas above sea level, capacity is
reduced due to decreased air density. Equipment size must be increased to meet the
load requirements. The following correction factors apply to CITY MULTI and Mr. Slim
air conditioners and heat pumps for both heating and cooling operation. The indoor and
outdoor units need to be sized based on the capacity reduction due to the decreased air
density.
Examples:
Air-Source System
An air-source system installed at 5,000 feet above sea level would operate at 83% its
normal capacity when compared to its performance at sea level. Therefore, the indoor
unit(s) and outdoor unit(s) need to have at least 17% higher capacity to provide the
same cooling and heating performance as the units would at sea level conditions.
Water-Source System
With a water-source system installed at 5,000 feet above sea level, the indoor units
would operate at 83% their normal capacity when compared to their performance at sea
level. Therefore, the indoor unit(s) would need to have at least 17% higher capacity to
provide the same cooling and heating performance as the units would at sea level
conditions. The water-source units can be sized based on their standard capacity at sea
level. However, depending on the indoor units selected, the size of the outdoor unit may
have to be increased to meet the maximum connected capacity requirement. The
maximum connected capacity for PQHY Series is 130%; the maximum connected
capacity for PQRY Series is 150%. Table 1 lists the capacity correction factors.
Table 1. Capacity Correction Factors
Altitude
Feet Above
Sea Level
Air-Source Systems
Water Source Systems
Indoor
Unit
Outdoor
Unit
Indoor
Unit
Water-Source
Unit
0
1.00
1.00
1.00
1.00
1000
0.96
0.96
0.96
1.00
2000
0.93
0.93
0.93
1.00
3000
0.90
0.90
0.90
1.00
4000
0.86
0.86
0.86
1.00
5000
0.83
0.83
0.83
1.00
6000
0.80
0.80
0.80
1.00
7000
0.77
0.77
0.77
1.00
8000
0.74
0.74
0.74
1.00
9000
0.71
0.71
0.71
1.00
10000
0.69
0.69
0.69
1.00
Due to continuing improvement, above specification may be subject to change without notice.
2013 P-Series and M-Series - Application Notes (June 2013)
APP-69