Unit installation

APPENDIX
82
USEFUL EQUATION AND DATA
WATER SYSTEM EQUATION:
H = 500 x GPM x ∆ T
H = Total heat (Btu/ Hr.)
GPM = Water flow rate (Gallons per minute)
∆ T = Temperature difference (°F)
500 = Equation factor
For systems with glycol solution, this equation can be used with a modified equation factor
(depending on the glycol concentration as tabulated below:
Ethylene Glycol
TEMPERATURE °F.
% GLYCOL
SOLUTION
FREEZE
POINT
BOILING POINT
SPECIFIC
HEAT
SPECIFIC
GRAVITY
(1)
EQUATION
FACTOR
0 +32 212 1.00 1.000 500
10 +26 214 0.97 1.012 491
20 +16 216 0.94 1.027 483
30 +4 220 0.89 1.04 463
40 -12 222 0.83 1.055 438
50 34 225 0.78 1.067 416
60 -60 232 0.73 1.079 394
70 <-60 244 0.69 1.091 376
80 -49 258 0.64 1.101 352
90 20 287 0.60 1.109 333
100 +10 287+ 0.55 1.116 307
Notes:
1. Specific gravity with respect to water at 60°F.
SYMBOLS COMMONLY USED IN CHILLED WATER PLANT DRAWINGS:
Piping: