2. MODEL SELECTION
Fig 2
(X
1
, Y
1
)
(X
2
, Y
2
)
(X, Y)
x
y
i)   .    n 
1
and Y
2
 using X
1
 and X
2
.
ii) Calculate capacity of outdoor unit using 
following equation:
Y=(Y
2
-Y
1
) / (X
2
-X
1
)
 (X-X1) + Y
1
Capacity ratio of indoor units to outdoor unit, X  (%)
Capacity of outdoor unit,  Y  (kW ) 
Indoor unit 
connecting
capacity (%)
Outdoor
temperature
(°C)
Indoor temperature
21.0°CDB 23.0°CDB 27.0°CDB 29.0°CDB 32.0°CDB
15.0°CWB 16.0°CWB 19.0°CWB 21.0°CWB 23.0°CWB
TC IP TC IP TC IP TC IP TC IP
120
-5.0  15.6 2.50 16.5 2.55 17.5 2.65 19.0 2.75 20.1 2.80 
0.0  15.6 2.56 16.5 2.75 17.5 2.80 19.0 2.90 20.1 2.95 
5.0  15.6 2.61 16.5 2.85 17.5 2.90 19.0 3.05 20.1 3.10 
10.0  15.6 2.70 16.5 2.95 17.5 3.05 19.0 3.05 20.1 3.20 
15.0  15.6 2.90 16.5 3.20 17.5 3.30 19.0 3.35 20.1 3.40 
20.0  15.6 3.55 16.5 3.60 17.5 4.00 19.0 4.05 20.1 4.10 
25.0  14.9 4.20 16.0 4.40 17.0 4.70 18.6 4.80 19.1 4.85 
30.0  14.0 4.76 15.1 5.13 16.2 5.33 18.0 5.45 18.5 5.51 
35.0  13.2 5.24 14.1 5.79 15.6 5.90 16.2 5.93 16.7 5.96 
40.0  12.2 5.20 12.9 5.90 13.8 5.96 14.4 5.98 15.7 5.98 
46.0  10.8 4.94 11.7 5.06 12.1 5.15 12.9 5.20 13.3 5.28 
          
          
100
-5.0  13.2 2.00 14.5 2.11 15.6 2.25 17.5 2.40 19.0 2.50 
0.0  13.2 2.08 14.5 2.14 15.6 2.30 17.5 2.45 19.0 2.55 
5.0  13.2 2.12 14.5 2.19 15.6 2.40 17.5 2.50 19.0 2.65 
10.0  13.2 2.16 14.5 2.25 15.6 2.50 17.5 2.60 19.0 2.80 
15.0  13.2 2.21 14.5 2.40 15.6 2.75 17.5 2.80 19.0 3.00 
20.0  12.9 2.45 14.4 2.63 15.5 3.00 17.4 3.10 19.0 3.20 
25.0  12.6 2.80 14.2 3.20 15.3 3.50 17.2 3.90 18.4 4.00 
30.0  12.2 3.81 13.9 4.15 15.2 4.41 17.0 4.70 17.7 5.00 
35.0  11.7 4.67 13.5 4.95 14.0 5.20 15.6 5.26 16.0 5.34 
40.0  11.2 5.01 12.5 5.12 13.0 5.21 14.2 5.32 15.0 5.41 
46.0  10.4 4.75 11.0 4.97 11.5 5.05 12.5 5.10 12.9 5.15 
X
2
Y
2
X
1
Y
1
Capacity ratio of indoor units to outdoor unit X1 = 100 % X =  117 % X2 = 120 %
Capacity of outdoor units (kW) Y1 = 14.0 Y Y2 = 15.6
Y= (15.6-14.0) / (120-100) 
 (117-100) + 14.0 = 15.4 (kW)
- (02 - 08) -
MODEL
SELECTION
MODEL
SELECTION