What size air conditioner do I need?

So you've browsed through a few air conditioning catalogs to find a new air conditioner and it's becoming painfully apparent that the options are just about endless. How is anyone supposed to decide on the right system with all the industry speak and variables? Our air conditioner specialists recommend starting with the basics and working on from there. Let's start with air conditioner size.

Air Conditioner Size Guide


How big an air conditioner do I need?

Finding the perfect air conditioner for an area or room goes beyond just measuring the floor space, although that's a great place to start. Factors that will influence which air con you need include:

  • direction windows face
  • the size of windows or glass doors
  • external shade such as eaves, trees, and other buildings
  • whether your ceiling or walls are insulated
  • ceiling height

If you're installing a reverse cycle air conditioner the flooring in your home can affect how the air con heats your home during winter. Tile or timber floors tend to keep a room cooler and carpet is a great insulator it will help keep your home cozy and warm.

Calculating air conditioning size for a room

As a general guide, going off room size in isolation, for each 10 square metres of space you'll need about 1 to 1.5 kW of cooling to efficiently keep your room comfortable in summer.

The cooling level is often listed in the air conditioner model specifications as Cooling Capacity. Retailers tend to list the cooling capacity in the product name, for example:

  • Fujitsu ASTG09KMCA 2.5kW Reverse-cycle air conditioner, or
  • Mitsubishi Electric MSZ-GL Series 3.5kW Reverse-cycle split system air conditioner

OK, it's time to break out the tape measure. Take a quick measurement of the room you are wanting to cool. Whip out the calculator or dust off a few brain cells and multiply the length by the width.

Eg - 6 metres width x 7 metres length = 42 square meters

A room which is 42 sqm, has ceiling insulation, minimal windows or good window coverings, is reasonably shaded with trees and eaves and has a standard ceiling height of between 2.4 and 2.7m is suited to a split system air conditioner of around 5kW.

For rooms which get hotter (ie, full sun without insulation etc) you may need a larger unit to ensure the air conditioning doesn't have to work overtime to cool the room; which in turn can reduce the energy efficiency, increasing running costs.

Don't fall into the trap of installing an air con which is too big for the room thinking it will cool better. It will just cost you more than necessary to run.

Still scratching your head? Fujitsu has taken some of the mystery out of choosing the right sized air conditioner for your home with their Economatch air conditioner guide. It will quickly find the most energy efficient system for your needs.

Fujitsu General Economatch

Get help from the professionals

Calling in an experienced air conditioner technician is the best way to ensure you're are investing in the most economical and energy efficient air conditioner. The professionals will take into account all factors which can affect how a cooling system will work in your home.

Finding the perfect air conditioner for your home or business is just one step away. Contact our team of air conditioner specialists on 07 3883 2119 or complete the booking request for the best advice across Brisbane north.

References - http://www.harveynorman.com.au/air-conditioning-buying-guide, https://www.appliancesonline.com.au/split-system-air-conditioner-buying-guide/