RULES OF THUMB GUIDANCE
General. The following information provides guidance
that could be used in planning to estimate utility requirements
and to assess the adequacy of equipment sizing during design
reviews. Note that it is preferable to do a quick block load
calculation instead of using these rules of thumb.
Air Conditioning Capacity.
See Table 21.
Heating Capacity. 35 to 40 Btu per square foot for
mild climate region (less than 4,000 degree days), no fresh air
See Table 22.
Chilled Water Circulation.
2.5 to 3.0 gallons per
minute per ton.
Gallon per minute
(20 degree drop)
Gallon per minute =
500 x TD (temperature drop)
Condenser Water. Required thermal capacity of cooling
= 15,000 Btu/h per ton, or
= 3 gpm per ton
1 pound of steam per 1,000 Btu.
120 gallons per 1,000 pounds steam.