Air-conditioners are designed to control both the air temperature and humidity. Choosing the right cooling capacity for your air-conditioner is important for proper comfort and energy optimisation.
An oversized air-conditioning system is costly and may cost more to operate. It might also not properly dehumidify the space. This is because the air-conditioner cools the space too quickly and then powers down before the moisture level is reduced. On the other hand, an undersized air-conditioning system will not provide adequate cooling and dehumidification.
To properly size your air conditioning system, a useful rule of thumb is as follows:
Cooling capacity required in kW* = Total aircon floor area (m2) ÷ 5
to convert to Btu/hr, multiply the cooling capacity figure in kW by 3,412 |
Points to note:
- A larger air-conditioner may be needed for rooms with:
- Double volume (i.e. double ceiling height)
- A large window area (e.g. full-height glass windows)
- Windows orientated towards the sun (i.e. east-west direction)
- Additional heat sources such as bar fridges
- The total cooling capacity of a multi-split air-conditioner is usually the sum of the cooling capacities of the individual rooms. However, a smaller total cooling capacity may be sufficient if all the room units are not turned on at the same time.
- For a more detailed assessment of the cooling capacity required, please consult your air-conditioner supplier.
We thank Carrier, Daikin, LG, Mitsubishi Electric and Panasonic for their inputs in the development of this air-con cooling capacity guideline.