Bryant 581A User Manual
Page 14
GROSS COOLING CAPACITIES (cont)
581A240 (20 TON)
Air Entering
Evaporator
Air Entering Condenser (F)
75
85
95
Cfm
BF
Ewb
(F)
Capacity MBtuh
Compressor
kW
Capacity MBtuh
Compressor
kW
Capacity MBtuh
Compressor
kW
Total
Sensible
Total
Sensible
Total
Sensible
6000
0.03
72
290.0
142.6
17.12
280.0
139.2
18.78
268.0
135.0
20.40
67
264.0
176.2
16.56
254.0
172.0
18.16
242.0
167.2
19.68
62
242.0
208.0
16.08
228.0
202.0
17.52
214.0
196.0
18.96
7000
0.04
72
300.0
151.4
17.36
286.0
147.0
18.98
274.0
142.8
20.60
67
272.0
189.4
16.76
262.0
185.8
18.38
250.0
180.8
19.94
62
250.0
228.0
16.28
236.0
222.0
17.76
222.0
214.0
19.24
8000
0.05
72
304.0
159.0
17.46
292.0
154.8
19.12
280.0
150.8
20.80
67
278.0
202.0
16.90
266.0
198.0
18.50
254.0
193.8
20.20
62
256.0
244.0
16.46
244.0
238.0
17.98
230.0
228.0
19.48
9000
0.05
72
306.0
166.4
17.52
296.0
162.2
19.26
284.0
158.6
21.00
67
284.0
214.0
17.08
272.0
212.0
18.70
258.0
206.0
20.40
62
260.0
258.0
16.58
250.0
250.0
18.16
240.0
240.0
19.72
10000
0.06
72
308.0
176.2
17.54
302.0
170.6
19.42
286.0
165.2
21.00
67
286.0
228.0
17.14
274.0
224.0
18.80
262.0
218.0
20.40
62
266.0
266.0
16.68
258.0
258.0
18.34
246.0
246.0
19.94
581A240 (20 TON) (cont)
Air Entering
Evaporator
Air Entering Condenser (F)
105
115
125
Cfm
BF
Ewb
(F)
Capacity MBtuh
Compressor
kW
Capacity MBtuh
Compressor
kW
Capacity MBtuh
Compressor
kW
Total
Sensible
Total
Sensible
Total
Sensible
6000
0.03
72
256.0
130.2
22.00
240.0
125.6
23.60
224.0
119.8
25.00
67
226.0
161.2
21.20
210.0
154.6
22.60
193.8
148.2
24.20
62
199.6
189.0
20.40
185.0
181.2
21.80
170.4
170.4
23.40
7000
0.04
72
260.0
139.6
22.20
246.0
133.8
23.80
230.0
128.4
25.40
67
234.0
174.8
21.40
218.0
168.6
23.00
199.2
161.8
24.40
62
208.0
206.0
20.80
194.8
194.6
22.20
181.0
181.0
23.80
8000
0.05
72
264.0
146.4
22.40
252.0
141.8
24.00
236.0
136.8
25.60
67
238.0
188.0
21.60
222.0
181.6
23.20
204.0
174.8
24.60
62
218.0
218.0
21.00
206.0
206.0
22.60
192.4
192.4
24.20
9000
0.05
72
268.0
154.2
22.60
256.0
149.8
24.20
238.0
144.4
25.80
67
242.0
200.0
21.80
226.0
194.4
23.40
210.0
188.0
24.80
62
228.0
228.0
21.20
214.0
214.0
22.80
200.0
200.0
24.40
10000
0.06
72
272.0
161.4
22.60
256.0
157.0
24.20
240.0
152.0
25.80
67
246.0
212.0
22.00
230.0
206.0
23.40
214.0
199.4
24.80
62
236.0
234.0
21.60
222.0
222.0
23.00
208.0
208.0
24.80
LEGEND
BF
— Bypass Factor
Edb
— Entering Dry Bulb
Ewb
— Entering Wet Bulb
kW
— Compressor Motor Power Input
MBtuh — Btuh in thousands
NOTES:
1. Direct interpolation is permissible. Do not extrapolate.
2. The following formulas may be used:
sensible capacity (1000 x MBtuh)
t
= t
–
ldb
edb
1.10 x cfm
t
= Wet-bulb temperature corresponding to enthalpy of air
lwb
leaving evaporator coil (h
)
lwb
total capacity (1000 x MBtuh)
h
= h
–
lwb
ewb
4.5 x cfm
Where: hewb = Enthalpy of air entering evaporator coil.
3. The sensible heat capacity is based on 80 F entering dry-bulb (edb)
temperature of air entering evaporator coil.
Below 80 F edb, subtract (corr factor x cfm) from the sensible heat
capacity.
Above 80 F edb, add (corr factor x cfm) to the sensible heat
capacity.
Correction Factor = 1.10 x (1 – BF) x (edb – 80).
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