Author: Brian Ashworth September 8, 2022

Guest Post by Sherazi Khan

Contrary to what most individuals believe, a bigger air conditioner isn’t always better and a smaller one isn’t always cheaper.

To properly cool a room or the entire home, one needs to choose the right air conditioner size that can efficiently cool the room from getting overworked yet not too powerful that it fails to dehumidify a room.

The question is, what size of air conditioner do you need?

Also, how do you calculate the air conditioner size needed to cool your room?

In this article, we’ll talk about those things as well as the other factors that can affect the ability of your air conditioner to cool your room. . . but first, let’s discuss why choosing the right size is important.

Why Choosing The Right Air Conditioner Size is Important

When talking about air conditioners, size has nothing to do with the physical dimensions of the air conditioner.

Rather, it talks about the power it has in kW.

The more kW it holds, the larger the room it can cool, and vice versa.

Too Large?

An air conditioner that is too large for the room results in:

• • • A surge in electric bill
    • Unnecessary wear and tear to the air conditioning unit
    • Clammy room

Because a large air conditioner can cool the room fairly quickly, it shuts on and off more frequently to keep the room at the target temperature.

This not only results in a surge in the electrical bill but also results in unnecessary wear and tear to the air conditioning unit.

Aside from cooling the room, air conditioners also remove the humidity from the room, and because an overpowered air conditioner shuts off prematurely, it may fail to dehumidify the room resulting in a clammy, moist, uncomfortable room.

Too Small?

On the other hand, an air conditioner that is too small for the room can:

• • • Never cool the room
    • Increase electrical bill
    • Early damage to the unit

A small air conditioner needs to work at its maximum power for long periods in order to try to get to a temperature it may never reach.

As a result, this creates an increased power consumption and strain on the unit.

Furthermore, it may never achieve the desired temperature you want for your room or the entire home.

So, What Size Air Conditioner Should I Get?

To calculate the air conditioner size that you need, experts recommend that you multiply your room’s area by a standard multiplier which is 140.

However, this multiplier isn’t entirely accurate.

It only gives you a ballpark as to what size of air conditioner you would need and doesn’t take into account the other factors that play into cooling your room.

Furthermore, it only works well for small rooms.

For example, a 20m² room multiplied by 140 is 2.8kW. But, you can either get a 2.5kW or a 3kW depending on the other factors that affect your room’s temperature.

In a rush? Here’s a recommendation table you can use to quickly find the air con size you need.

Room Size	Recommended Air Con Size
20m² or smaller	2 – 3kW
20 – 40m²	3 – 5kW
40 – 50m²	4 – 7kW
60m² or bigger	7 – 9kW

Of course, it’s always better to consult the help of a professional regarding this matter. They can recommend the right air conditioner that fits your needs.

Another viable option is to install a centralized air conditioning system. Professional installers segregate your entire home into zones and determine how much cooling or heating power that zone needs.

Other Factors That Affect a Room Temperature

As mentioned, there are other factors that could affect the ability of your air conditioning unit to cool your room.

Ceiling height – Rooms with higher ceiling means that more space needed to be cooled. Hence, a room with ceilings higher than 3 meters will need a larger air conditioning unit.

Room insulation – Rooms with good insulation are better at keeping the room cool and keeping heat out. Thus, a well-insulated room will need a smaller-sized air conditioner.

Location – Rooms that are facing direct sunlight heat up faster. Hence, they require a larger air conditioner to cool.

The number of people – Rooms occupied by more people like the living room or kitchen may need a larger air conditioner. Conversely, the room of your child can get away with a smaller one.

Air conditioner placement – Placing an air conditioner low or facing a large piece of furniture or divider makes it hard to cool the room. Hence, finding the perfect place to set up your air conditioner is as important as choosing the right size.

Final Thoughts

Choosing the right air conditioner size is paramount to achieving the desired comfort in your home.

Calculating the right air conditioner size is also relatively easy if you follow our recommendations above.

According to experts, a 2.5kW air conditioner for the rooms and a 7kW air conditioner for an open space living area is enough for a standard Australian home.

However, when in doubt, it’s always best to ask for help from the experts.