12
6. Capacity Calculation Due to Capacity Modication Coefcient
(1) Calculation method of refrigerating capacity----cooling capacity to be known=refrigerating 
      capacity*(A*B*C*D*E)W
E. Capacity compensation value of pipe length, pipe diameter and height drop
C. Capacity modication value under airow variation 
     rate of indoor unit group (only for duct unit)
A. Capacity compensation value of indoor                  
     air wet-bulb temperature condition
B. Capacity compensation value of outdoor   
     air dry-bulb temperature condition
D. Capacity compensation suitable for 
     total capability of indoor unit group
1.2
1.1
1.0
0.9
0.8
15 20 24
Indoor air dry-bulb temperature (°C )
Capacity modication value
1.2
1.1
1.0
0.9
Outdoor air wet-bulb temperature (°C )
Capacity modication value
-5 200 255 3010 3515 40 43
1.1
1.0
0.9
80 90 100 110 120
Airow variation rate (%)
Capacity modication value
120
100
100 120 130
80
60
40
20
20
40 60 80
0
Total capacity of indoor unit group (%)
Standard
capacity
Notes for E:
(1) The mian pipe (from outdoor to the rst branch pipe) diameter should be enlarged one size 
when the single way pipe length is over 90m.
(2) When in cooling mode, outdoor is lower than indoor; or when in heating mode, outdoor is higher than indoor, the 
  compensation factor should be decreased the below value from gure E.
0.95
1.00
0.90
0.85
0.80
0 20 40 60 80 100 120 140
Capacity modification value
Single way pipe length (m)
Liquid pipe
: φ12.7
Gas pipe
: φ19.05
Liquid pipe:
φ9.52
Gas pipe:
φ
15.88
Vertical height drop between 
indoor and outdoor
5m 10m 15m 20m 25m 30m 35m 40m 45m 50m
Adjustment factor 0.003 0.006 0.009 0.012 0.015 0.018 0.021 0.024 0.027 0.03
Notes for E:
(1) The main pipe (from outdoor to the rst branch pipe) diameter should be enlarged one size 
when the single way pipe length is over 90m.
(2) When in cooling mode, outdoor is lower than indoor; or when in heating mode, outdoor is higher than indoor, the 
  compensation factor should be decreased the below value from gure E.