Bryant 579F User Manual page 188

579F240 (20 Tons) (cont)
Temp (F)
Air Entering
Condenser
(Edb)
54/0.65
TC 250
75 SHC 250
kW 15.8
TC 243
85 SHC 243
kW 17.6
TC 236
95 SHC 236
kW 19.5
TC 228
105 SHC 228
kW 21.6
TC 220
115 SHC 220
kW 23.9
TC 218
117 SHC 218
kW 24.3
TC 215
120 SHC 215
kW 25.1
LEGEND
BF — Bypass Factor
Edb — Entering Dry-Bulb
Ewb — Entering Wet-Bulb
kW — Compressor Motor Power Input
ldb — Leaving Dry-Bulb
lwb — Leaving Wet-Bulb
SHC — Sensible Heat Capacity (1000 Btuh) Gross
TC — Total Capacity (1000 Btuh) Gross
NOTES:
1. Direct interpolation is permissible. Do not extrapolate.
2. The following formulas may be used:
sensible capacity (Btuh)
t = t –
ldb edb
1.10 x cfm
Wet-bulb temperature corresponding to enthalpy of air
t =
lwb leaving evaporator coil (h
total capacity (Btuh)
h = h –
lwb ewb
4.5 x cfm
Where: h = Enthalpy of air entering evaporator coil
ewb
PERFORMANCE DATA — 579F (cont)
COOLING CAPACITIES (cont)
58/0.52 62/0.40
250
250
15.8
244
244
17.8
236
236
19.5
228
228
21.6
220
220
23.9
218
218
24.3
215
215
25.1
)
lwb
Evaporator Air Quantity — Cfm
10,000
Evaporator Air — Ewb (F)/BF
67/0.26
256 267
227 200
15.9 16.1
249 262
220 198
17.7 18.0
241 252
212 194
19.7 19.9
234 242
203 190
21.8 22.0
223 232
207 186
23.9 24.2
221 230
205 185
24.4 24.7
218 226
203 183
25.1 25.4
3. The SHC is based on 80 F edb temperature of air entering evaporator coil.
Below 80 F edb, subtract (corr factor x cfm) from SHC.
Above 80 F edb, add (corr factor x cfm) to SHC.
BYPASS
FACTOR
(BF)
0.05 1.04
0.10 0.98
0.20 0.87
0.30 0.76
0.40 0.65
0.50 0.55
0.60 0.44
0.70 0.33
Interpolation is permissible.
Correction Factor = 1.10 x (1 – BF) x (edb – 80).
188
72/0.24 76/0.24
294 314
161 127
16.7 17.1
284 303
158 124
18.5 18.9
274 292
154 121
20.4 20.9
263 281
151 117
22.5 22.9
251 268
147 113
24.7 25.2
249 266
146 112
25.2 25.6
245 —
145 —
25.9 —
ENTERING AIR DRY-BULB TEMP (F)
79 78 77 76 75
81 82 83 84 85
Correction Factor
2.07 3.11 4.14 5.18
1.96 2.94 3.92 4.91
1.74 2.62 3.49 4.36
1.53 2.29 3.05 3.82
1.31 1.96 2.62 3.27
1.09 1.64 2.18 2.73
0.87 1.31 1.74 2.18
0.65 0.98 1.31 1.64
80/0.04
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under 75
over 85
Use formula
shown below.