Service Manual

12
6. Capacity Calculation Due to Capacity Modication Coefcient
(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 modication value under airow 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 wet-bulb temperature (°C )
Capacity modication value
1.2
1.1
1.0
0.9
Outdoor air dry-bulb temperature (°C )
Capacity modication value
-5 200 255 3010 3515 40 43
1.1
1.0
0.9
80 90 100 110 120
Airow variation rate (%)
Capacity modication value
120
100
100 120 130
80
60
40
20
20
40 60 80
0
Total capacity of indoor unit group (%)
Standard capacity
0.95
1.00
0.90
0.85
0.80
0 10 20 30 40 50 60 70
Capacity modification value
Single way pipe length (m)
Liquid pipe: φ12.7
Gas pipe: φ19.05
Liquid pipe: φ9.52
Gas pipe: φ15.88
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 98 7/16 ft (30m).
(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.
Vertical height drop
between indoor and
outdoor
16 3/8ft
(5m)
32 13/16ft
(10m)
49 3/16ft
(15m)
65 5/8ft
(20m)
82ft
(25m)
98 7/16 ft
(30m)
Adjustment factor 0.003 0.006 0.009 0.012 0.015 0.018