Bryant 581A/B - Manual (Page 159)

159
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).
579F300 (25 Tons) (cont)
Temp (F)
Air Entering
Condenser
(Edb)
Evaporator Air Quantity — Cfm
11,250
Evaporator Air — Ewb (F)/BF
54/0.61 58/0.47 62/0.30 67/0.16 72/0.17 76/0.17 80/0.00
75
TC 295 295 298 319 342 367 392
SHC 295 295 285 245 193 151 108
kW 20.3 20.3 20.4 20.9 21.2 21.5 21.9
85
TC 288 287 289 310 334 359 384
SHC 288 287 278 241 190 148 106
kW 22.5 22.4 22.4 23.1 23.7 24.4 25.3
95
TC 278 278 280 318 323 346 —
SHC 278 278 269 150 186 144 —
kW 24.6 24.6 24.7 30.0 26.0 26.7 —
105
TC 269 269 272 285 310 332 —
SHC 269 269 259 232 182 140 —
kW 27.0 27.0 27.1 27.6 28.4 29.1 —
115
TC 259 260 262 273 297 318 —
SHC 259 260 247 227 177 136 —
kW 29.7 29.6 29.8 30.2 31.1 31.8 —
117
TC 257 257 261 271 294 — —
SHC 257 257 245 226 176 — —
kW 30.3 30.3 30.3 30.7 31.6 — —
120
TC 254 254 257 267 — — —
SHC 254 254 242 224 — — —
kW 31.1 31.1 31.3 31.6 — — —
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
0TF
Q004
-0
12
579
F18
0
-300