Heating Calculator

How it works

At its most basic, the heat required in a building or room can be calculated by considering the current temperature, the required temperature, the dimensions of the space and the heat loss.

Our engineers have very sophisticated tools and computer modelling software to determine the type and power of the heating system that is appropriate to your premises. They will take into account a number more factors than used in this simple calculator, such things as machinery and office equipment, thermal gain from windows, ventilation, the location of premises and building construction and of course it’s thermal properties. They will also take into account how your other HVAC units will integrate with the proposed solution.

Get started with our online heating calculator

For a quick and simple indication of the kW’s of heating you require this heating calculator is a useful starting point. It uses CIBSE recommended criteria for UK conditions for heating calculations which are -3 to +18 degrees Celcius. Thus heating equipment is expected to achieve a 21 degrees Celcius difference, and our calculator will automatically work within these defined maximum parameters and reduce target temperatures as necessary to reflect expected capabilities. Please be aware that it is only an approximate measure and does not replace the need for expert advice from Clean Air and a detailed heating calculation.

Your room




The specifics:

Please indicate the temperature you want to achieve in degrees Celcius


Enter a value of –3 degrees Celcius or higher, this being the coldest temperature suggested by the CIBSE for UK conditions when sizing heating systems


Select the description which best describes the area you want to heat:

When considering the occupant density consider how many people, computers, televisions and other things that produce heat are in the room.

For large scale project professional heating solutions advice should be sought.