How many BTUs window air conditioner do I need?

The amount of BTUs your window air conditioner needs depends on the size of your room and some other factors, but there are many models to choose from.

The British Thermal Unit (BTU) of an air conditioner is a unit of measure for its cooling capacity and this makes it easier to compare different models.

It is imperative that you figure out how many BTUs you need for the size of the room that you are trying to cool. There are many factors to consider, but fortunately, there are window air conditioner models for small and large rooms.

What is BTU and why does it matter?

When you are shopping for a new air conditioner, you may come across many BTU values. BTU essentially measures how much energy your air conditioner uses to remove heat from your space and cool it down.

Since all air conditioner manufacturer brands use this unit of measure for their air conditioners, it has become one of the best ways for customers to compare the prices and features of models that have more or less the same cooling capacity across a wide range of brands and types of air conditioners.

How many BTUs window air conditioner do I need?

It is important that you try to match the BTU of any air conditioner that you buy with the size of your room. Your air conditioner needs to extract excess heat and moisture from the air in your room to cool the room down.

However, if your air conditioner’s BTU is too low for the size of your room, the air conditioner will not have the capacity and power to cool down the larger amount of air in the space and your room may never reach your desired temperature.

On the other hand, and air conditioner with a BTU that is too high for the size of your room will cool the air in the room too quickly, which means that it will short cycle and this can make the room feel clammy and can be a waste of energy.

This is why it is crucial to ensure that you buy a window air conditioner that has the right amount of BTUs for the size of the space that you want to cool.

In order to make this simpler, many manufacturers have guidelines for how many BTUs your window air conditioner needs to have for different-sized spaces, such as:

Size of the room (in square feet) BTUs needed
100 to 150 5000 or 6000
150 to 250 6000 or 7500
250 to 300 7500 or 8000
300 to 350 8000 or 9000
350 to 400 9000 or 10000
400 to 450 10000 or 11000 or 12000
450 and above 12000 and above

What can affect the BTU-to-room size ratio?

Even though these BTU and room size ratio charts can be a good guide to find the window air conditioner that is suitable for your space, there are various factors that can influence the amount of BTUs needed for a space, such as:

Factor Influence on the amount of BTUs that you need
A heavily shaded room You need about 10 percent less BTUs than usually required
A room that gets a lot of sun You need 10 percent more BTUs than guidelines suggest
More than two people regularly use the room at a time You can add about 600 BTU for every additional person
Your space also has a kitchen or bathroom You may need as much as 4000 BTUs more than guidelines suggest

Best window air conditioners for small spaces

If you have a smaller room of between 150 and 250 square feet, a window air conditioner with fewer BTUs will be the ideal option for you, such as:

Window air conditioner model Price Cooling capacity Where to buy
Keystone KSTAW06CE Window Mounted Air Conditioner $289.99 This window air conditioner has 6000 BTUs, and is suitable for rooms of up to 250 square feet

Buy it on Amazon
Emerson Quiet Kool EARC5MD1 Window Air Conditioner $189.99 This air conditioner has 500 BTUs and can cool rooms of up to 150 square feet

Buy it on Amazon
BLACK+DECKER BD05MWT6 Window Air Conditioner 5000 BTU $149.99 This model has 5000 BTUs and is suitable for rooms of up to 150 square feet

Buy it on Amazon

Best window air conditioners for large spaces

On the other hand, some window air conditioner models are specifically designed to work in much larger spaces, such as:

Window air conditioner model Price Cooling capacity Where to buy
BLACK+DECKER BD145WT6 Window Air Conditioner Unit $655.99 This model has 14500 BTUs and can cool spaces as large as 700 square feet

Buy it on Amazon
TOSOT GJC12BR-A3NRNJ1C Window Air Conditioner $429.99 This 12000 BTU model is suitable for spaces that are up to 550 square feet

Buy it on Amazon

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