Man siting on sofa with air conditioner

Factors to Consider when Buying an Air Conditioner

Category: Features

Buying an air conditioner requires more than just personal preferences. It also requires some basic understanding of the costs of cooling a room, and the room size. Established air conditioning experts and contractors in Sydney recommend these simple steps to take to determine the right type and model to buy for your home.

Proper Sizing

When buying an air conditioner, its cooling capacity should fit the requirements of the room. Air conditioners are rated according to their cooling capacity, which is measured in British Thermal Units (BTU). These range from around 5,000 to 14,000 BTU per hour. It typically requires 20 BTU per square feet. If the room is in the shade, there is 10% less energy required. If it is a sunny room, there is an additional 10% requirement. If it is a kitchen, another 20% capacity is required.

Other factors include room height, local climate, shade, and window size. It is also possible to have additional savings if there is a ceiling fan in the room. This will enable better circulation of the cool air from the air conditioner. In terms of energy efficiency, the air conditioner should comply with Energy Star 4.0 standards. The standards state that the unit should be 10% more energy efficient than the minimum federal government standards.


Although you would be tempted to buy a large air conditioner for a small room, this might cause some inconvenience to the user. Air conditioners will cool the room to the temperature set with the thermostat before it dehumidifies. A large unit would cool the room too fast and might not have the time to dehumidify it before cycling off and on again. If the room were too cool before dehumidification, it would feel clammy and uncomfortable due to the excess water vapour.

On the other hand, a smaller unit would run more efficiently and be more effective in dehumidification. In addition, the larger unit would turn itself off and on more often because it reaches the thermostat setting faster.