What Size Of An Air Conditioner Do I Need: 5 Things To Consider


When people speak about the size of the air conditioner, it doesn’t literally mean that they are talking about the physical dimension of the air conditioner. Instead, it means they are talking about the units you need for the air conditioning installation.

The size of the unit defines how much power the respective air considers consumers and how big and small the room can offer its services. Whether you are looking for a window air conditioner or a central AC, choosing the right unit size will help your AC to perform effectively.

Choosing the correct size of an AC can be a daunting task. You need to be well-versed in your needs and what size will offer a solution to your needs. If you try to play safe and get a small unit, you might experience insufficient cooling. And if you get a big AC, you might have to pay higher electricity bills.

Instead of having a guessing game, it is better that you talk with an aircon installer. They will be able to give you an estimate of what you need.

What Size Of Air Conditioner Do You Need?

Well, there is no exact answer to that. It all depends on your needs and the other factors that we are about to mention below.

  • The size of your room.
  • The location of your house.
  • Climatic condition.
  • Number of openings in your house.
  • How much insulation you have.
  • Number of people live in the house.
  • Number of appliances present in the room that generate heat.

These factors play a direct role in determining the exact size needed. Air conditioning installation is all about taking these factors into consideration to offer the best services. Professionals take these factors, run them through a complex calculator and then come with the tonnage capacity of the air conditioner.

The Rules Of Keeping Cool

When you are out there looking for an air conditioner for your needs, you need to have enough knowledge to differentiate different types of ACs. For instance, a window air conditioner has a cooling capacity from 5000 BTU to 12,000 BTU. And the general thumb rule states that you atleast need 20 BTU per square foot.

However, while calculating the BTU, you must also take the height of the ceiling, number of windows and doors into consideration. Measure the volume of the room and see how many square feet it is. If there are other rooms joined with the help of a door, take that room into consideration as well.

Don’t Over Kill

Most people think that bigger units are better. Yes, they do offer sufficient cooling, but the power consumption is higher. Hence, you might find yourself receiving high electricity bills every month.

To dispute the rumor that bigger air conditioners are always better, you must understand that air conditioners extract moisture from the air. This is the reason spending a lot of time on the air conditioner makes your hand all sticky. Hence, selecting the right size of an air conditioner is a must.

Insulation Variables

Insulation also plays an important role in determining the right unit size of the air conditioner. For better performance, you indeed ensure that your room is perfectly insulated. If you have open doors and windows, then the size of the air conditioner will increase.

If you have a two-story home, then the downstairs will have less load as it has additional insulation in the form of a second story. In addition to that, if your windows and door are not well insulated, you might as well have to look for a larger AC to maintain the cooling system.


The location of the house matters a lot. Every region has different weather climates. Depending on how cool and warm your region is or how humid it can be in summer, you need to select the size accordingly. For instance, if you live in Brisbane, the area can become very humanoid during the summer. So, you need a system that complements the climatic condition.

Final Tip

Air conditioners come in different types and fulfill different needs. So, you are free to choose anyone. But here is a pro tip for you. Instead of going with a window air conditioner, go with wall-mounted ACs. they are more efficient and offer better cooling.

Usually, wall-mounted air conditioners are mounted 5 feet to 6 feet above the floor. So, when cool air flows through, it gets more chances to spread all over the room—this also helps to stir the room’s temperature more thoroughly.

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