Bryant 581C - Manual (Page 188)

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