Keeping your home cool and comfy during the hot season is a challenge. Buying an air conditioner is not as simple as choosing a model and having it installed. There are several factors you need to consider. You need to choose the air conditioner that’s perfect for the size and cooling needs of your home. You also need to consider the noise your aircon generates and how much it costs to run.
What type of air conditioner should you get?
There are different types of air conditioner systems for homes and you need to know the difference before you choose one for you. Here we discuss how each type works and how much they cost:
Split-system
This type of air conditioner has two parts: an indoor unit and an outdoor unit. These parts are connected by pipes containing refrigerant gas. This is the most common type of air conditioner in Australia. They are good for cooling up a room or open plan area of up to about 60 square metre. A split system can range between $600 and $5500.
Multi-split system
This is similar to a split-system, except that it has one outdoor unit connected to two or more indoor units. This is good for cooling down two or three rooms that are reasonably close together. This can be used in instances when separate split-systems or a ducted system is not suitable. It is about the same price range as the separate split-systems.
Ducted system
This type has a discreet central unit, generally located out of sight in your roof, connected via air ducts to air outlets and sensors in each room. Ducted systems are good for cooling and heating an entire house. The price can range anywhere from $5000 and above.
Wall/window air conditioner
This is a single box unit installed in a window or through an external wall. This is good for cooling rooms and open-plan areas of up to 50 square metre. Smaller units can be directly plugged into a normal power outlet while larger ones may need additional wiring. It is not quite as efficient as split-systems but it is a cheaper alternative if a split-system isn’t an option. The price range is between $400–$1100.
Portable air conditioner
This is a single unit that can be moved from room to room as needed, though it can be heavy at times. Most portable air conditioners have a flexible duct that should be attached to a window to vent the heat outside. This is perfect for rooms in a house when a built-in option isn’t feasible, such as when you’re renting. It is not quite as efficient as split-systems but it is a cheaper alternative if a split-system isn’t an option.The price range is between $300–$1300.
What size of air conditioner do you need?
The first thing you need to consider when buying an air conditioner is the space of the area you want to cool down? Are you going to cool down a single room or an entire house? To determine the right AC unit size, you need a measuring tape. Then follow these instructions:
- Measure the room’s width and length in feet.
- Multiply the two numbers that you got together to get the square footage (sq. ft.)
- For instance, a 20 feet x 30 fee room would have an area of 600 sq. ft. (20 x 30 = 600).
Once you get the area, you can now shop for the right air conditioner size.
You must do an accurate calculation before buying your air conditioner, otherwise you’ll run into these issues:
- Models that are too powerful for the room size may encounter frequent short cycles to achieve the target temperature. This is because the room gets too cold or hot, and there is inadequate dehumidification. This means the air is not drying enough, making the room feel less comfortable. The short cycles then lead to increased power consumption and significant wear-and-tear on the system.
- Underpowered models, on the other hand, may have to run more often at maximum output. This could dry the air too much and create excessive wear.
The best option is to choose a model with equal or slightly greater capacity for the area of the room. For example, if you calculated that the room needs a 6kW model, then you need to look for an air conditioner with rated cooling capacity between the range 6kW to 6.5kW. It is sometimes a safer bet to get a unit slightly above the required kW capacity than slightly below it, however don’t overdo it.
Other factors you need to consider
Some air conditioner installers and online calculators provide only a simple analysis and may tend to suggest a larger capacity than you really need. However, there are a lot of variables to consider. For instance, a well-insulated room or area with south-facing windows should be at the bottom end of the capacity range, while an uninsulated area with west-facing windows should be towards the top.
Likewise, a home in Perth will likely need a more powerful air conditioner compared to a home with the same size in Sydney.
A correct calculation takes all the room’s details into account:
- The size of the room, including the length, width and height
- The type of room, whether it’s a living room, bedroom, open-plan living room and kitchen
- The size and orientation of the windows – a large window facing north or west can let in a lot of summer heat
- Presence of glass doors
- Shading and curtains on the windows
- Insulation of the ceiling, floor, and walls
- The overall local climate.
The size calculator on fairair.com.au by the Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH) can help you accurately calculate the air conditioner size that you need.
How Noisy are Air Conditioners?
Most modern split-system and ducted air conditioners are very quiet indoors, but it helps to check out the air conditioner’s noise levels before you purchase.
The noise from indoor split system units range from 19dB to 53dB, and from the outdoor units between 42dB to 69dB.
For comparison, check out some of the common sound levels:
- 30dBA: typical sound level of a quiet home
- 50dBA: interior of a quiet car while driving
- 60dBA: noise of typical conversation
- 70–80dBA: sound of the vacuum cleaner
A noisy indoor unit can be irritating and may interfere with your activities, conversation, or sleep. On the other hand, a noisy outdoor unit can also disturb you, especially if it’s too close to a bedroom or living room window, or your neighbours.So you need to consider your outdoor unit placement carefully.
It is also worth checking the local council’s noise restrictions related to the use of air conditioners. You also need to check your strata rules if you live in an apartment, especially if you’re going to install the outdoor unit close to a neighbour’s house.