Fairair - The right advice means the right choice

Interactive Guide

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Remember, bigger is not always better!

Step 2 - What size do I need?

All residential air conditioners will carry a label showing the unit's cooling output in kilowatts (kW).

It is important to select an air conditioner with the right cooling output - if it is undersized it may not be able to cool the space adequately, and it's likely that the unit will have to stay on for long periods and use up a lot of electricity. By the same token, if the unit is oversized it will likely cycle on and off more often than it should, which can cause early failure, lead to inefficient operation and give poor temperature and humidity control.

To determine what cooling output you need, we perform what is called a heat load calculation. This will determine how much heat (in kilowatts) needs to be removed from the space to cool it, and thus the cooling output required from your air conditioner.

Every room and every home is different, so we recommend that you get a licensed contractor to visit your home and provide a detailed heat load calculation. Using the calculator below, however, will give you a rough idea of the cooling output you will need:



1. 1  














2. 2    


m² 







3. 3    











4. 4What is the height of the ceiling in the room you are cooling?


m

5. 5What is the total area of the internal walls with unconditioned space adjacent?




6. 6What is the total area of external walls including all the windows?  












7. 7How large are the windows? 


m² South  



m² South East  




m² South West  




m² East  




m² West  



m² North  



m² North East  




m² North West  



8. 8   




Total cooling requirement (kW) =
kW

The results given by this calculator are indicative only. AIRAH recommends that you ask a licensed contractor to check the figure given when quoting on an air conditioning system.

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Evaporative system

An evaporative system provides cooling by drawing air across a series of wetted "pads". Water on the pads evaporates as the air flows over it, cooling and humidifying the air.

Sometimes also referred to as a "swamp cooler".

Insulation

Any material that slows down the transfer of heat.

Multi-split systems

A multi-split system is a split system that has a single outdoor unit connected to multiple indoor units. It is possible to operate these systems independent of each other or at the same time. These systems are best suited to cooling multiple rooms.

Ducted system

A ducted system is one that provides cooling to multiple rooms through a series of ducts, which are usually installed in the roof.

Heat load calculation

A heat load calculation is the process a licensed contractor goes through to determine the amount of cooling required for a space. It takes into account a number of factors including the area being cooled, the physical properties of the building, its orientation, shading, insulation and local climate.

Licensed contractor

A licensed contractor is someone who holds a valid license under the Ozone Protection and Synthetic Greenhouse Gas Management Regulations 1995.

All contractors are required by Australian law to hold one of these licenses in order to handle refrigerant. Always ask to see your installer or contractor's license before they install your air conditioner.

Visit www.arctick.org to find a licensed contractor in your area.

Depending on the kind of system being installed, the contractor should also have relevant state electrical and plumbing licenses - be sure to ask your installer to provide these before they install your air conditioner.

Zoned

A zoned system is usually a ducted system or a multi-split system where different areas of the home have been divided into "zones", and the zones can be controlled independently of one another (ie: can cool one zone independent of the others, or set different temperatures in different zones).

Heat load calculation

A heat load calculation is the process a licensed contractor goes through to determine the amount of cooling required for a space. It takes into account a number of factors including the area being cooled, the physical properties of the building, its orientation, shading, insulation and local climate.

Licensed contractor

A licensed contractor is someone who holds a valid license under the Ozone Protection and Synthetic Greenhouse Gas Management Regulations 1995.

All contractors are required by Australian law to hold one of these licenses in order to handle refrigerant. Always ask to see your installer or contractor's license before they install your air conditioner.

Visit www.arctick.org to find a licensed contractor in your area.

Depending on the kind of system being installed, the contractor should also have relevant state electrical and plumbing licenses - be sure to ask your installer to provide these before they install your air conditioner.