The main function of heat loss and heat calculation of profit : assessment of capacity that will be needed for different heating and air-conditioning components necessary to maintain comfort in space. These calculations are therefore based on the maximum load for heating and cooling and corresponds to the climatic conditions, which are far from the extremes that are usual. Standard exterior design values of temperature, humidity and sunlight, can usually be obtained from the directory.....

A number of load-calculation procedures have been developed over the years. Those developed by ASHRAE will be used here. Although other procedures differ in some respects, they are all based on a systematic evaluation of the components of heat loss and heat gain. Loads are generally divided into the following four categories.