What Size Air Conditioner Do You Need For Your Home?

The Australian heat can be unbearable in the summertime, and good quality air conditioning is the best way to stay comfortable when things get sweltering. One thing that confuses a lot of potential buyers is the size of air conditioner they will need.

This guide will provide some clarity and go through all of the details to give you a clearer picture of what you might need for your home.

Introduction to air conditioning sizes 

The first step in finding the right sized air conditioner is to understand their unit of measurement. In Australia, the output of air conditioners is measured in Kilowatts (often expressed as kW). Kilowatts are one thousand watts, which is a measure of energy over time.

Why is it important to get the right size?

The short answer is efficiency. Although it might seem that bigger can only be better, that is not the case with modern air conditioners. Instead, air conditioners run optimally when they are sized to the conditions. 

In fact, a bigger unit may end up costing you more in energy bills and become an unnecessary bill for your household. If your air conditioner is too big, it may not be able to sufficiently wind down the amount of cooling or heating it provides to your home’s needs, instead conditioning more air than you need or want, which is less comfortable and more expensive.

If your air conditioner is too small, the risk is that in order to try and provide the temperature you want, it will be performing in constant overdrive as it tries to keep up with the large space. So whilst it may be able to keep your home close to the temperature you want, it won’t be running in the most ideal way. This constant running at a high level will mean that it is not working efficiently, which will likely cost you significantly more in electricity.

What factors affect the size of air conditioner that I will need?

Air conditioning is much more complicated than it may seem at first. The size of your house is important in determining your air conditioning needs,as are the number of rooms or zones you want to be able to condition at any one time. 

Additionally, there are many other factors that can have a surprising amount of influence on the size of air conditioner that will best suit your home.

The amount of insulation in your house is a crucial consideration because it can affect your house’s ability to maintain its temperature. If your home is well insulated, you likely won’t need as much heating or cooling capacity as one with poor insulation.

Another prominent factor is the climate that your home is located in. The tropical and subtropical areas of Australia tend to have much greater demands than the cooler regions of Australia. Due to Australia’s climate, you also need to consider the capacity of your unit.

If you are in temperatures that exceed over 35°C, you will find that your air conditioning unit will decrease in efficiency and lose more cooling capacity. In short – the hotter it is, the less capacity your air conditioner will have. As an example, if you have a 14kW system operating in temperatures over 35°C, you might find that unit is reduced to something closer to 10kW or 12kW capacity. That’s why ActronAir systems come with Power Cooling technology, allowing them to better maintain capacity in heat for more powerful cooling when you need it most. 

Some other factors that influence the size of air conditioner that you will need include

  • What type of lighting you have
  • How much lighting you have
  • Your type and quantity of ducting
  • The number of windows and their efficiency
  • The amount of heat transfer between walls
  • The number of skylights
  • The number of people living in your home
  • The type of foundation your home is built on

As you can see, it’s quite complicated!

How do I calculate the size of the air conditioner that I will need?

The three main ways to calculate your air conditioning needs are:

  • Using a formula
  • By using an online calculator, or;
  • By getting a professional to visit your home to calculate things precisely

At ActronAir we always recommend getting a professional to give you expert advice, as it’s the best way to get a properly sized unit based on your home and your lifestyle. 

Using a formula to calculate your air conditioning needs

Using a formula to estimate your air conditioning needs is quick and easy, but it’s also very rough and doesn’t consider many of the important factors outlined above. It’s an excellent way to get a general idea of your needs. Still, if you’re after a truly accurate understanding, it’s probably best to use one of the other two methods before you commit to anything.

To estimate the amount of air conditioning you will need for your daytime living area, you will first need to determine its area. You will need to find the length and width of each room and multiply them. Then, you have to add the area of each room together for the total. This figure needs to be in square metres.

What you do next will depend on your ceiling height:

  • If your ceiling is 2.4m high, you will need to multiply the daytime living area (m²) by 150 (watts)
  • If your ceiling is 2.7m high, you will need to multiply the daytime living area (m²) by 160 (watts)
  • If your ceiling is 3m high, you will need to multiply the daytime living area (m²) by 175 (watts)

These calculations will give you the number of watts you need, and you can then move the decimal point three points to the left to convert it to kilowatts.

As an example:

For a house with a daytime living area of 100m² and a height of 2.4m, the calculations would be:

  • 100m² x 150 watts = 15,000 watts
  • 15,000 watts = 15 kilowatts

A 15kW unit is roughly the right size for this house.

Using an online calculator to figure out your air conditioning needs

Using an online calculator will give you a more accurate estimate than the above method, but you will also have to consider more factors. Fairair has a good calculator that will help you figure out the number of kilowatts you will need.

Using a professional to figure out your air conditioning needs

The most accurate way to find out the air conditioning capacity that you will need for your home is by getting a professional to come in and calculate it. They have years of experience, which they can use to get the most accurate estimate of your air conditioning needs. They will consider each factor and help ensure that you have the perfect sized air conditioner for your home.

The ActronAir Difference

Only ActronAir systems are uniquely designed for Australian conditions, so only Actron air conditioners provide you with performance tailor made for here:

So if you want a system that can keep you in your element in Australian conditions, remember to ask for an Actron

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