Snap Air Conditioning

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Aircon Supply & Install Specialists

Air Conditioner Size Calculator / Guide

What size air conditioner do I need?

Here at Snap Air Conditioning, we want to help you in making an informed choice about the Air Conditioner size you need for a room.  

We have put together an Air Conditioner size guide to help you with your choice.  

Our Simple Air Conditioner Size Guide / Calculator​

Choosing the right air conditioner size for a given room size is very important. Each size AC Unit has been designed to service a particular square meterage to ensure efficiency of the unit, maintain warranties and also to help minimize your electricity bill. 

Use our air conditioning size guide to search for the right kw rating for your room. A smaller air conditioner will have a hard time cooling a large room, or it might not be able to cool it at all. Choosing a larger air conditioner could cool the room too fast, but will not dehumidify the room. This leaves the room cold and, at the same time, humid and the AC unit is not designed for these conditions.

Another problem we have seen is the air conditioner is too big for a room and the thermostat does not have time to correct the temperature properly which means it is worker harder than it needs to and was designed for. Therefore, it is crucial to decide what kw rating or sizing of aircon you need before installing one.

There are four main classes that affect how big your Air Conditioning needs to be:

A Class

Air Conditioning in a home with Insulated roof space, walls and sub floor, full brick or brick veneer construction, average size windows with awnings, full shading south facing aspect, temperate weather conditions.

B Class

Installing aircon in a home with insulated roof space, full brick or brick veneer construction, average size windows with internal shades, north facing aspect, temperate climate.

C Class

Cooling your home with Insulated roof space, full brick or brick veneer construction, average size windows with internal shades, east facing aspect or sub tropical climate.

D Class

Running AC with little or no insulation, weatherboard, fibro or brick veneer construction, large windows, no shading from the sun westerly facing aspect.


Split System Air Conditioner size calculator

Room size you are cooling

The size of the room will effect the cooling & heating capacity of your air conditioner.  The size is calculated by length x breadth.  Say for a normal bedroom size 4m x 4m = 16sqm .   You would look at the table above and see that a 2.5kw unit will be sufficient most of the time, unless you have a fibro, un-insulated house. At which point we would recommend a 3.5kw as the 2.5kw will not cool to the desired temperature, will need to work harder than recommended by the manufacturer and will use a lot of power trying to keep up.

Air Conditioner size guide Australia
insulation to help with air conditioning sizing guide


Is your ceiling space in your home insulated and what kind of insulation is installed?  There are many different installations with many different ratings. The type of insulation you have will determine the effectiveness of your unit so keep this in mind when using our calculator.


location also makes a big difference.  If you’re located on the Bay side and get a nice bay breeze every day,  your property is going to be a lot cooler.  If you are located inland somewhere like the North side of Ipswich where it generally is a lot hotter,  you will require a more powerful Air Conditioner to fight the extra heat load.  Have a look here at the temperature map of QLD to determine where you may be and take this into consideration as well.

qld temperature map
orientation affects sizing calculation of air conditioner size


The orientation of your room also affects the cooling capacity of the area. For instance, if you have a long living room with big glass sliding doors and windows along the northern face you are going to be getting a lot of that summer heat coming through whereas if you had a southern facing living area, you would be much cooler as you are not getting any sun shining through the windows or on the walls generating heat.

Our Clients Testimonials


Great job installing my new AC unit, good range, reasonably priced and very friendly and helpful office staff and installers.

Linda De George

Jacqueline Prior

William and Omar installed our new replacement air conditioner. Their work was done speedily and efficiently. Two great guys from Snap Air Conditioning. Highly recommended.

Cecil Wray

A Farley

The price was very good, with no hidden costs. We had to wait two weeks for installation due to busy period but they showed up on time when they said they would. Finished efficiently and cleaned up after themselves. Very polite and easy to deal with.

A Farley

Kevin Mallett

Just had our living room air con unit replaced, through this company, really happy with the really prompt service and professional quality work. Thank you.

Kevin Mallett


Excellent company the staff pleasant and knowledgeable. Very pleased with the work done. Highly recommended.


Julia A

Kelly, the point of contact for Snap, is brilliant. We had a problem with our installation (manufacturer issue) and she was a pleasure to deal with while that got sorted. She is a credit to the company, and I am sure she would look after you too if you chose Snap for your air conditioning.

Jessica Page

Fabrice Turpin
Perfect installation, friendly and professional team!

Fabrice Turpin

Why Choose Snap Air Conditioning

Licensed & Insured Technicians

All of our technicians are fully qualified and certified through the Electrical Safety Office (ESO) and/or Arctick. All of our technicians are employees (not subcontractors) and are provided with ongoing in-house training. This ensures a professional, customer service focused experience that remains focused on YOU our valued clients.

100% Satisfaction Guaranteed

We are on the firm belief that ALL feedback - good or bad - is valued feedback. We would love to hear of your experience with us so we can ensure we are meeting the highest standards and rectify any issues that may arise to maintain our high customer satisfaction rate which is shown through our 5 star google reviews.

12 Month Workmanship Warranty

We offer a 12 month workmanship warranty on all of our work. This means in that 12 month period if you experience any issues we will come out and investigate at no charge to you! * See Terms & Conditions

Wide Variety of Services

We don’t just offer air conditioning services. We also offer regular maintenance on your unit, investigations of any units not working (and solutions for repair/replacement). We also have fully qualified Electricians and can help with other electrical needs as well!

Interest-free Finance

Get your dream air conditioning system installed in your home or business without paying the upfront price. Contact us today to find out how we can assist.

Wealth of Experience

We have been offering air conditioning installation services to our local community for over 15 years. We have likely seen or heard it all and if we are unable to provide a solution while we attend we will investigate solutions and come back to you. This means we are able to provide you with the best benefits of our industry experience.

Customer Support

We have a dedicated customer support team who will take of your concerns quickly. We genuinely care and will offer before, during and after sales support to ensure your satisfaction - every single time!

On-Time Services

We can guarantee that we will be on time where possible. Obviously things do happen outside of our control however this is where our customer service team shine! They will keep you as up to date as possible if there are any delays with the technician.

Honest, Affordable, Transparent Quotes

We know what is important to you - honesty, transparency and affordability. We will provide an upfront quote and the technicians will confirm all aspects of the installation on arrival so if there are any changes needed you are aware BEFORE the works are carried out. This means there are no hidden surprises!

We Genuinely Care

We genuinely care about our customers. From the initial phone call through to the installation and any follow ups made you will receive the very best from our team.

If you need cost-effective air conditioning for your home or business, call us on 📞1300 007 627 to get started. We have the most reliable & efficient solutions for you.

How can we help you today?

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