Calculation of cooling loads made easy

The calculation of the cooling load for the design and/or correct planning of an air conditioning system of any kind or size is based on Regulation VDI 2078. This “Calculation of thermal loads and room temperatures (design of cooling load and annual simulation)” is enacted by the Association of German Engineers (abbreviated to VDI).

Unlike a formal law, a regulation is not binding. However, it includes recommendations and rules and therefore represents the state of the art.

The cooling load, room air temperature and operative room temperatures of all rooms are calculated on the basis of Regulation VDI 2078, regardless of whether they are air conditioned and, if so, how they are air conditioned. All parameters that affect the thermal behaviour of the room in any way are taken into account.

What is the cooling load?

The cooling load consists of the thermal loads to be dissipated from a room to achieve a desired temperature level, and consists of the following:

External cooling load

• transmission heat from adjoining rooms that are not air conditioned, external walls and roof areas

• radiated heat through windows

Internal cooling load

• thermal emissions from people, lighting, machinery and equipment heat

• thermal absorption by material throughput through the room

• heat from chemical reactions

Latent heat loads by moisture

Adding these loads together produces the cooling load of a room that needs to be dissipated by the air conditioning system.