Air Conditioner Size Calculation:
How it works - which air-conditioner is the right one for you?
Have a look at our in-depth air conditioner size calculation below to determine which aircon will be the right unit for your home or office.
A Standard or Normal room heat load = around 1 person for every 14 m2, a closed door, brick walls, insulated ceilings and one standard sized window. If this is the case, you may use the recommended sized air conditioner for your calculation.
An Insulated room heat load = 1 person for every 14 m2, insulated roof, walls, floors and doors; no appliances and a small window. Here an air conditioner size can be dropped to the next smaller size.
A High room heat load room = big windows, non-insulated walls and ceilings, electrical equipment, open doors, lots of people movement and more than 1 person per 14 m2. Depending on how many of these conditions are met, you might have to increase the air conditioner size by up to 2 sizes if needed.
If the room is bigger than the table below, half it, or quarter it, and multiply the air conditioners required by the same factor. The air conditioner installer should then space the air conditioners around the room appropriately.
|Cooling Required (btu)||Room m3|
|9000||0 - 40 m3|
|12000||41 - 57 m3|
|18000||58 - 78 m3|
|24000||79 - 105 m3|
|30000||106 - 131 m3|
|32000||132 - 144 m3|
|36000||145 - 166 m3|
|48000||167 - 210 m3|
|55000||211 - 270 m3|
|96000||271 - 460 m3|
Technical Heat Load Calculation to determine the right air conditioner for your needs
A more technical way to calculate the required air conditioner, is to take the m2 x 550 (assuming a 2.4 metre ceiling height); or take the (btu / 550) x 2.4 (2.4 metres is a standard ceiling height; please note that this could be bigger number). This method will tell you if a specific air conditioner will work in a room in standard or normal conditions.
|Cooling Required (btu)||Room m2*||Bracket|
|9000||18 m2||450 mm|
|12000||24 m2||450 mm|
|18000||36 m2||450 mm|
|24000||48 m2||550 mm|
|30000||60 m2||650 mm|
*Ceiling Height up to 2.4m
Please note that a bracket will be needed if it’s a new installation to mount the outside (condenser) unit - normally around 2.4 metres off the ground. We have added these as a recommended item on the purchase of any unit, but you may source these from the installer if you prefer. Please remember to notify the chosen installer before installation that they would have to supply such a bracket if you do not purchase it with your air conditioner from our website.
Some split air conditioner units come with standard 3 metre pipe kits. If a split unit does not come with a pipe kit, one will be recommended at the time of purchase. You can also get the installer to supply this at an additional cost. Please remember to notify them of this as well.
We cannot provide a cost of installation on our cassette, under ceiling or hide away air conditioners, as these runs are specific to each installation and costs vary significantly.
Find the perfect air conditioner for you here and if you are still unsure which air conditioner is the right one for you, please call us on 064 889 0199.