Buy the Perfect Air Conditioner for Your Space with These 3 Easy Steps
I’m a huge baby about temperature, and fans sometimes just don’t cut it. So in the midst of a recent heatwave, I decided I was going to bite the bullet and get a window-unit air conditioner. But when I started researching online, I found myself confused by the cooling and efficiency numbers of various units, with prices seemingly directly correlated with each. Given the size of my apartment, how big of an air conditioner did I need?
Counterintuitively, it seems sizing up on your A/C is actually worse for efficiency. “Air conditioners remove both heat and humidity from the air, but if the unit is too large, it will cool the room, before it has a chance to remove the humidity. This will leave your room feeling damp and clammy,” explains the Energy Star website.
But an air conditioner that’s too small isn’t great, either. Before you buy anything, there are several factors worth considering. For starters, you’ve most likely seen the letters “BTU” that seem to appear in every unit’s description after sets of numbers. And you’re also probably wondering how to properly measure your room for an air conditioner (it’s not exactly as simple as measuring for a new couch).
Here, you’ll find your guide to BTUs, measuring for an air conditioner, and figuring out what size air conditioner you’ll need. Keep this as a reference so you can stay cool and comfortable this summer.
What does BTU mean?
BTU stands for British Thermal Unit, and it measures the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. According to the U.S. Energy Information Administration (EIA), one BTU is about the same amount of energy you’d get from burning a match.
More BTUs equal more energy used, and more energy used equals more cooling potential. In other words, a higher BTU air conditioning unit will be suited to cooling a space with more square footage.
When buying an air conditioner, you’ll match up the unit’s BTUs with how much square footage is in your room. More on that below.
How do I calculate the right size air conditioner?
Consumer Reports recommends 20 BTUs per square foot of the living space (or spaces) you want to cool down. But no worries about having to do any confusing equations — luckily there’s a convenient list for figuring how much A/C power you need for a room, based on the room’s square footage.
- 150 – 250 sq. feet: 6,000 BTUs
- 250 – 300 sq. feet: 7,000 BTUs
- 300 – 350 sq. feet: 8,000 BTUs
- 350 – 400 sq. feet: 9,000 BTUs
- 400 – 450 sq. feet: 10,000 BTUs
- 450 – 550 sq. feet: 12,000 BTUs
- 550 – 700 sq. feet: 14,000 BTUs
- 700 – 1,000 sq. feet: 18,000 BTUs
- 1,000 – 1,200 sq. feet: 21,000 BTUs
- 1,200 – 1,400 sq. feet: 23,000 BTUs
- 1,400 – 1,500 sq. feet: 23,000 BTUs
- 1,500 – 2,000 sq. feet: 30,000 BTUs
- 2,000– 2,500 sq. feet: 34,000 BTUs
My air conditioner was for my living room, so I measured the room with a handy tape measure.
My living room is roughly 330 square feet, which means I need an A/C unit with a capacity of 8,000 BTUs — way less than I expected.
Of course, a room’s environment doesn’t just depend upon square footage. In some cases there might be environmental issues to be aware of. For example, in very sunny rooms, you should increase the necessary capacity of an air conditioner by 10 percent. For very shady rooms, decrease it by 10 percent.
If there are often more than two people in the room, add 600 BTUs per person into the equation.
If you are cooling the kitchen, remember that ovens and stovetops put out a lot of heat, and your A/C will have to compensate. Add 4,000 BTUs for any unit you install in a kitchen.
The last thing you should consider when buying an air conditioning unit is what type of A/C unit will serve your room best.
Is a wall-through unit the same as a window unit?
While both wall-through A/C units and window A/C units are used in places that don’t have central air conditioning, the two A/C styles are very different.
Wall-Through Air Conditioning Units
A wall-through A/C is a year-round fixture that’s installed in a customized hole through an exterior wall. Unless your apartment already has one, this option is usually better reserved for places you own because it typically requires a pro to cut the wall opening through which the unit is installed.
A wall-through air conditioning unit will need to have ventilation on both sides. The interior side will blow cool air into your home; the exterior side will release heat from the refrigerant.
If you do go the wall-through route, keep in mind that you need to buy a unit made for this purpose; a window A/C won’t work here.
Window Air Conditioning Units
Window units, on the other hand, don’t require any alterations to your home. Instead of cutting into a wall, you’ll use a window as the opening where you’ll mount the A/C unit.
Because window units don’t require any permanent alterations to your home — and the units can be taken with you — they’re a great pick for renters.
Make sure to follow the unit’s instructions for mounting it securely in an appropriate window.
Other A/C Styles
If you’re unable to mount an air conditioning unit in a window or through a wall, you might consider a portable air conditioner. These use a tube that fits into a window to release heat from the refrigerant, and can be easily wheeled from room to room as needed.
Best Air Conditioners to Buy
If you’ve done your calculations and chosen a unit type, it’s time to buy!
To help you get started with your A/C shopping, we’ve compiled a list of the best window air conditioners that’ll help you keep your space refreshingly cool. Here are some of our top picks.