E – 1817 HVAC Cooling Load Calculations and Principles

Heating and cooling load calculations are carried out to estimate the required capacity of heating and cooling systems, which can maintain the required conditions in the conditioned space. To estimate the required cooling or heating capacities, one has to have information regarding the design indoor and outdoor conditions, specifications of the building, specifications of the conditioned space (such as the occupancy, activity level, various appliances and equipment used etc.) and any special requirements of the particular application. For comfort applications, the required indoor conditions are fixed by the criterion of thermal comfort, while for industrial or commercial applications the required indoor conditions are fixed by the particular processes being performed or the products being stored.

Generally, heating and cooling load calculations involve a systematic and step wise procedure, which account for all the building energy flows. In practice, a variety of methods ranging from simple rules-of-thumb to complex transfer function methods are used to arrive at the building loads. This 6- hour course provides a procedure for preparing a manual calculation for cooling load using CLTD/CLF method suggested by ASHRAE and includes two detailed examples. For more advanced methods such as TFM, the reader should refer to ASHRAE and other handbooks.