Heating Load Calculator

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Introduction to our heating calculator

A room heating load is made up of heat flowing out of the room through the walls, floors and ceiling and because of ventilation or air infiltration. Beneficial heat gains from solar, appliances or people are not accounted for in the calculation.

To use the FairAir Heating Load estimator you will need to know:

  1. The region (climate area) that the room is located in
  2. The dimensions of the room to be heated: length (m), width (m), height (m)
  3. The total area (m2) of ceiling, floor, external walls, external glazing (windows and doors) and internal walls (separating walls/doors) to other rooms or areas that are not included in the heated room.
  4. The type of construction of the main building elements: roof/ceiling, floor, glazed windows and doors, internal and external walls, including whether they have been insulated or not

Based on the user input and the in-built default assumptions, the FairAir Heating Load estimator will provide an estimate of the heating load for that room.

Find out more about Energy Efficiency, Installation and Maintenance.


The FairAir Heating Load estimator is an estimate only, based on a series of assumed default values and a series of user inputs. AIRAH recommends a full load calculation be completed by an air conditioning or heating contractor or designer. Individuals with load estimation experience are best placed to provide the most accurate heating load estimate appropriate to the actual loads and the occupant needs.