Design and Technical Manual

2. MODEL SELECTION
Fig 2
z
(X
1
, Y
1
)
(X
2
, Y
2
)
(X, Y)
x
y
i) Refer to 4. CAPACITY TABLE to nd Y
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 (kBtu/h )
Indoor unit
connecting
capacity (%)
Outdoor
temperature
(°F)
Indoor temperature
70°F DB 75°F DB 80°F DB 85°F DB 90°F DB
60°F WB 63°F WB 67°F WB 71°F WB 73°F WB
TC IP TC IP TC IP TC IP TC IP
120
23 53.2 2.50 56.3 2.55 59.7 2.65 64.8 2.75 68.6 2.80
32 53.2 2.56 56.3 2.75 59.7 2.80 64.8 2.90 68.6 2.95
41 53.2 2.61 56.3 2.85 59.7 2.90 64.8 3.05 68.6 3.10
50 53.2 2.70 56.3 2.95 59.7 3.05 64.8 3.05 68.6 3.20
59 53.2 2.90 56.3 3.20 59.7 3.30 64.8 3.35 68.6 3.40
68 53.2 3.55 56.3 3.60 59.7 4.00 64.8 4.05 68.6 4.10
77 50.8 4.20 54.6 4.40 58.0 4.70 63.5 4.80 65.2 4.85
86 47.8 4.76 51.5 5.13 55.3 5.33 61.4 5.45 63.1 5.51
95 45.0 5.24 48.1 5.79 53.2 5.90 55.3 5.93 57.0 5.96
104 41.6 5.20 44.0 5.90 47.1 5.96 49.1 5.98 53.6 5.98
115 36.8 4.94 39.9 5.06 41.3 5.15 44.0 5.20 45.4 5.28
●●●
●●● ●●● ●●● ●●● ●●● ●●● ●●● ●●● ●●● ●●● ●●●
●●● ●●● ●●● ●●● ●●● ●●● ●●● ●●● ●●● ●●● ●●●
100
23 45.0 2.00 49.5 2.11 53.2 2.25 59.7 2.40 64.8 2.50
32 45.0 2.08 49.5 2.14 53.2 2.30 59.7 2.45 64.8 2.55
41 45.0 2.12 49.5 2.19 53.2 2.40 59.7 2.50 64.8 2.65
50 45.0 2.16 49.5 2.25 53.2 2.50 59.7 2.60 64.8 2.80
59 45.0 2.21 49.5 2.40 53.2 2.75 59.7 2.80 64.8 3.00
68 44.0 2.45 49.1 2.63 52.9 3.00 59.4 3.10 64.8 3.20
77 43.0 2.80 48.5 3.20 52.2 3.50 58.7 3.90 62.8 4.00
86 41.6 3.81 47.4 4.15 51.9 4.41 58.0 4.70 60.4 5.00
95 39.9 4.67 46.1 4.95 48.0 5.19 53.2 5.26 54.6 5.34
104 38.2 5.01 42.7 5.12 44.4 5.21 48.5 5.32 51.2 5.41
115 35.5 4.75 37.5 4.97 39.2 5.05 42.7 5.10 44.0 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 (kBtu/h) Y1 = 48.0 Y Y2 = 53.2
Y= (53.2-48.0) / (120-100)

(117-100) + 48.0 = 52.4 (kBtu/h)
- (02 - 08) -
MODEL SELECTION MODEL SELECTION