How do I calculate what size air conditioner I need?

Ensuring that you calculate the right size for the air conditioner for your space will allow you to enjoy a pleasant cooling experience.

The thought of getting an air conditioning system for your home can be exciting. Knowing that you no longer have to endure the intensity of the heat that summer brings and that you can enjoy the pleasure of a good cooling system can provide relief for your home.

When buying an air conditioner, it is important to get the size right. You cannot simply pick whatever unit you like, since size is the most important factor to consider.

The size of your unit can be the difference between having an enjoyable experience and a dreadful one.

Air conditioner size

Air conditioners come in a range of shapes and sizes. In choosing the right size of air conditioner, it does not necessarily pertain to the physical size of a unit, but rather, in this case, to the cooling capacity of the unit.

This requires you to calculate the capacity you need for the size of your room or space.

How do I calculate what size air conditioner I need?

It is imperative that you get an AC unit that is the right size for your home or the specific room or space that you intend on cooling.

There are a few calculations to make to determine the size of air conditioner you will need. The first one is to calculate the square footage of the space.

This is done by multiplying the length and width of a room. For triangular spaces, divide the result (your square footage) by 2.

Next, you need to multiply the square footage by 20, which is the ballpark figure of British Thermal Units (BTUs) per square foot. The result will be a general estimate of the BTU size that you should look for in an air conditioner.

Doing this will ensure that you have a guiding figure for how many BTU’s to look for in a unit.

BTU = square footage (length x width) x 20 (BTU per square foot)

Steps to calculate the air conditioner size that you need

Step What to do
1 Measure length and width of all living spaces
2 Add all measurements up to determine the total square footage
3 Multiply the total square footage by 20

Additional calculations that may be necessary

Some additional calculations can give you a better BTU estimation, this way you can get a more precise BTU size air conditioner.

The United States Energy and Environmental Protection Agency recommends that if your home is shaded, you should subtract 10 percent of the capacity you got or add 10 percent if your house gets a lot of direct sunlight.

If a property has more than two people occupying it at a time, you need to increase the capacity you have calculated by about 600 for accuracy.

The importance of choosing the right size air conditioner

The right sized BTU air conditioner can be the difference between having the best cooling experience with your air conditioner or the worst.

If you mistakenly purchase a bigger BTU unit for a room that is small, your unit’s cooling can become overpowering and too cold.

The same applies to getting a BTU unit that is too small for a large room – your air conditioner will not cool your space adequately.

Square feet as an indicator of the BTU’s needed

The size of your room will determine what size air conditioner you need. This is why it is important to calculate the square footage of your space, as air conditioners will tell you that a certain BTU size unit can only effectively cool a room of a certain square footage, or rooms of up to a certain square footage.

An example of this is that an air conditioner of 8 000 BTU can only effectively cool down a room or space of approximately 300 to 400 square feet.

Final thoughts

Before going out and purchasing an air conditioner, you need to do a number of calculations that will guide you in choosing the right size air conditioner.

Making the mistake of purchasing the wrong size unit can lead to some serious issues with ineffective or excessive cooling.

This can make for an uncomfortable and inconsistent experience with your air conditioner in terms of cooling a room down at an efficient and comfortable rate.

Calculate your square footage, multiply it by 20, and make adjusted calculations according to the unique features of your home, room, or space.

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