Calculation of Heat Load

[weeliang82]

Dear all,

I would like to know the proper way to calculate the heat load when we are given data such as total sensible heat (kW) from equipment and human. Will appreciate if you guys help me calculate one example from the data below..

Example:

Building: Wax Plant
Location: Field Auxiliary Room
Area = 72.5 m2
Ceiling Height = 3.7 m
Volume: 268 m3
Cooling Density = 598 W/m3
Total Cooling = 43.3 kW
Total Sensible Heat = 30.4 kW
Air Change/hr = 26
Cooling air = 6,942 CMH

By using the basic rule of thumb, I get capacity factor of 190 (Cooling Capacity/Area in ft2)

Is there any proper way to get a more precise calculation, rather than using the rule of thumb method?

Thanks

[dougheret0]

The easiest manual way to compute cooling load is to use the Cooling Load Temperature Difference/Cooling Load Factor (CLTD/CLF) method. An explanation of this method can be found in my book HVAC Design Manual – A Mechanical Designer’s Guide to Design of Small Commercial and Institutional HVAC Systems available for free download at www.nettally.com/doughert. Details of a manual method to use this method are available from two sources that I know of: Air Conditioning Contractors of Americal (ACCA) Manual N; and ASHRAE Fundamentals 1985 and earlier.

I'm not sure the ACCA manual is available in SI, but the ASHRAE 1985 (or earlier) Fundamentals is, and can ususally be found on Ebay. The needed tables are not available in my book, but it does have a thorough explanation of the method.