When shopping for an air conditioner, it’s important to think about the size of the room(s) it will cool so you choose a unit that’s an appropriate size. An air conditioner’s size is a measure of how much cool air it can generate, not its physical dimensions.
Why You Shouldn’t Get an AC That’s Too Big or Too Small
Getting a bigger air conditioner (AC) than you need doesn’t mean that it will do a better job of keeping your home cool. A unit that’s too large may not remove enough humidity from the air and it will waste electricity, which will lead to high utility bills. An AC that is too small will have a hard time keeping your home cool.
Figure Out How Many BTUs Your AC Should Be
Calculate the number of square feet in the area that the air conditioner will need to cool. You can do that by multiplying the length of the room by its width. If your home has an open floor plan, or two or more rooms without a door between them, the air conditioner will have to cool the entire space. Add together the square footage of all those rooms to choose a unit that’s the right size.
When you look at air conditioners, you will notice that each has a number of BTUs, or British thermal units. This is a measure of an air conditioner’s cooling capacity.
In general, an AC should have 20 BTUs for every square foot of space that it will need to cool. There are exceptions to that rule of thumb, however. If a room gets a lot of sun, if multiple people spend time there on a regular basis or if the area to be cooled includes a kitchen, you’ll need a more powerful air conditioner. If the room is shaded for a good part of the day, an AC with fewer BTUs may work fine.
A Professional Can Give You a More Accurate Estimate
The information above is only intended to give you a general estimate. Several other factors, such as the amount of insulation in your home, the height of the ceilings, the amount of heat transfer between walls and your region’s climate, can influence the size of the air conditioner you will need.
An HVAC technician can use software to give you a more accurate estimate so you can be confident that you’re buying an air conditioner that is right for you. A professional can calculate the air conditioner size you need for a particular room or for your entire house.