If you've decided you need a heater to heat your home, this calculator will help estimate the required capacity.
These are the heating capacities needed to maintain a temperature difference of up to 12C between indoors and outdoors. In extreme climates this may not be enough and you may need a larger capacity. The calculator can only be used to estimate the required capacity of a an electric or gas room heater, not for ducted systems.
Adapted from CSIRO's publication Room heaters and coolers - choosing the best size (by permission CSIRO Australia).
The calculator helps you to estimate the heat losses of the room(s) you want to heat, and the capacity your heater needs to have to replace those losses. Follow these steps to calculate how much heating capacity you need:
- Insulate, then calculate. Prevent heat losses in winter as much as you can before investing in a new heater.
- Measure the different elements (ceiling and walls, for example) of your room as required in the calculator, and enter their size in square metres (multiply length by height or width to calculate square metres).
- If you plan to buy a reverse-cycle air conditioner and use it for cooling as well, you'll also have to estimate your cooling needs to find the model with both the cooling and heating capacities which are closest to your requirements.