Air Conditioners

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Essential Facts

The first two things you need to consider when shopping for an air conditioner  is determining what size you need and then looking for the most energy efficient model (star rating) within your size range.

  • Size: Air conditioners are measured by the capacity of heat they remove from (or add to) the air. The output will depend on your needs -- the size of the room and type of room use, as well as outside climate and your home's energy efficiency. Outputs are measured in kilowatts (kW). As a general rule, you'll need 125 watts (0.125kW) for every square metre of floor space in a living area, and 80 watts (0.080kW) for each square metre in a bedroom. The price of an air conditioner is related to the kW output. Remember too that bigger is not necessarily better - you don't want to buy a unit that is too powerful for the space you are cooling because it will be unnecessarily expensive to run and will make the living space clammy. 
  • Star rating: Air conditioners sold in Australia will have two types of labelling -- a blue band of stars, for cooling-only systems, and a red and blue band of stars for air conditioners that cool and heat. The more stars the more efficient the unit is, with six being the most stars.

Square Metres

watts, kW needed

Top Choice

kW

Star rating

EPA sound level

14 sq. m. - bedroom1120, 1.1LG LWG050AC-6  (window)1.734.5 n/a
20 sq. m. - bedroom1600, 1.6Fujitsu AST07JCC  (split) 2.16.0 65 dBA
25 sq. m. - living area3,200, 3.2Daikin FTKS35E  (split) 3.55.5 62 dBA
30 sq. m. - living area3750, 3.7Electrolux-Kelvinator EWH12CRB  (window) 3.9  5.0 53 dBA
35 sq. m. - living area4375, 4.3Daikin FTKS50F  (split) 5.05.0 61 dBA

Types of Air Conditioning Systems

The next decision will be whether to buy a window-wall air conditioning system or buy a split system.  In terms of star rating, both types can be very efficient, however, split systems tend to be quieter indoors (not always though), but they are also more expensive.

  • Window-wall system: These fit into the opening of a window and are available in cool-only and reverse cycle (heats the air). 
  • Split system: These models are mounted near the top of walls and are designed to blend in with an interior.
    • Reverse cycle - These models can be used to heat the air on cool winter days. 
    • Inverter or variable speed - These models may appear less efficient as a conventional air conditioner, but they are much more efficient when running continuously at a mid-load setting -- which is typically how air conditioners run in hot climates.
  • Portable unit: These systems use the same air cooling and heating process as a split system and they can be moved from room to room or home to home, making them a good choice for renters.

Window-wall systems - highest star ratings (by www.energyrating.gov.au)

Less than 2 kW (cool only)

2 - 3 kW (cool only)

3 - 4 kW (cool only)

2 -3 kW (reverse cycle)

3 - 4 kW (reverse cycle)

Split systems (Reverse cycle) - highest star ratings (by www.energyrating.gov.au)

2 - 3 kW (cooling only)

3 - 4 kW (cool only)

2 - 3 kW (reverse cycle)

3 - 4 kW (reverse cycle)

4 - 5 kW (reverse cycle)

Air Conditioner Brands

Other Considerations

Window Size and Installation

  • Make sure that the air conditioner you want will fit in your window -- measure your window two or three times for accuracy.
  • Even the lightest air conditioner might weigh more than 20kgs, and a large unit might be close to 50kgs. Keep this weight in mind when you make plans to install it. (You'll probably want to invite a friend or family member to help you.)
  • Models that come with a slide-in chassis are easier to install - a framework is installed in the window first, and the heavier air conditioning unit slides in easily. However, this method of installation takes a bit longer than the conventional air conditioner.
  • Through-the-wall air conditioners require you to cut a hole in your wall; this is more difficult and is, of course, a permanent installation.

Noise

  • Some models run whisper-quiet, others sound like freight trains.  Be sure to check with your local council for noise limitations and make sure you purchase a unit that won't cause you to get a fine.
  • Quieter models may be more expensive, but if you plan to use the air conditioner in your bedroom, you may want to make the investment.

Warranty

  • A warranty is a good thing to have, especially on something as important as an air conditioner.
  • Most models come with a one-year warranty; sometimes this can be extended to 4- or 5-year plans.
  • If you have someone else install your A/C unit, find out if there is a warranty on the labour as well.

Electrical Outlets

  • Before you buy a unit, check the kind of electrical plug that it uses and make sure you have the appropriate outlet in the area you want to use the A/C.
  • Most experts recommend running the air conditioner on its own circuit to avoid overloading the electrical system.

Unit Features

  • Remote Control - particularly useful for air conditioners installed high above the ground.
  • Programmable Timer - set it to turn the AC on half an hour before you come home from work.
  • Air Direction - for best cooling, figure out whether you need the air to blow to the left or to the right - many models blow better in one direction than the other.
  • Temperature Range
  • Temperature Increments
  • Sleep/Energy Saver Setting
  • Slide-out Filter - makes cleaning easier.
  • Fan Speed Setting
  • Dirty Filter Indicator

External Links