The cooling load is a calculation determining the amount of heat that needs to be removed from a structure in order to keep the temperature inside consistent. It is one of the things considered during the design phase for a building or a heating and cooling system, along with the heating load, a determination of how much heat energy needs to be added to keep the temperature stable. The goal is to build a structure with maximum efficiency to cut down on the expenses associated with heating and cooling.
A number of factors contribute to heat inside a structure. One consideration is the temperature measured directly versus the temperature and the humidity examined together. High humidity can make low temperatures seem higher, and a building in humid conditions will have a higher cooling load, as more energy will be required to make the space comfortable for occupants. Humidity also plays a role in the heating load.
People, equipment, and processes inside a structure can all generate heat, as well as humidity and impact the cooling load. Buildings are not static spaces and their uses must be considered when evaluating heating and cooling needs. Likewise, buildings themselves can contribute to the entrapment or release of heat energy. Doors, windows, and the layout of spaces can all play a role in internal temperature, as can design features like shades, screens for partially closing off areas, and so forth.
When considering the cooling load, designers usually try to evaluate worst case scenarios. Looking at temperature data for the region, they will pick unusually high temperatures and humidity and imagine what would happen inside if everything in a building was operating simultaneously, with a full complement of staffers. This is designed to develop an extreme estimate for the cooling load, allowing for the construction of a cooling system that will be able to cope with those conditions. By designing for the most intense conditions, engineers can be assured that their heating and cooling systems will not fail in normal use.
Balancing the heating and cooling load for a structure often requires similar design features. Things like better insulation can help buildings stay cool in the summer while also keeping them warm in the winter, for example, and considerations like layout can similarly conserve energy. This is helpful in climates where dramatic temperature swings can be present, as the same general design features will address climate control needs in hot and cold weather alike.