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What Size Air Conditioner Do I Need

What Size Air Conditioner Do I Need?

 |  Air Conditioning, Blog

What Size Air Conditioner Do I Need?

When you plan to purchase a new air conditioning system, one of the things you want to know is the answer to “How big of an air conditioner do I need?” Most homeowners in Arizona are concerned more about the cost of buying the unit and its installation. They base the acquisition on the price, so they choose a smaller A/C for their house, thinking that they can save money.

On the other hand, some people go for a larger unit. The hot summers are often the reason why they select a larger size of air conditioner than needed for their house, but the truth is, both too small and too large systems are incorrect. You want the right size so it can be sufficient for your space, which will let you save more money every month while you feel more comfortable at home.

The Downsides of Choosing the Wrong Size for Your A/C Unit

Some homeowners buy an air conditioning system that is too large for their place. They believe it would help them cool better during the summer season when the dry heat strikes in the Phoenix Valley. However, an oversized A/C is less effective and wastes energy.

When the unit is too big for a room, the room’s temperature will go down very quickly. At the same time, the A/C will only get rid of a little bit of the humidity in the air. This results in the room having a damp and clammy feeling. Additionally, the cost of the unit, installation, and electric bills are much higher. The unit should be the correct size to remove humidity as it cools the room. You will also have to worry about maintenance expenses because the A/C will have to keep cooling a larger place, which subjects the unit to undue stress.

Find Out Your AC Size

How to Calculate AC Size Based on Your House’s Square Footage

The first thing to note is that a “ton” is not about weight, but rather is regarding the ability of the system to cool a place. A ton is equivalent to cooling 12,000 British Thermal Units (BTUs) in an hour. Therefore, a two-ton A/C can cool 24,000 BTUs every hour. A BTU is the amount of energy needed for heating cooling a pound of water with one degree Fahrenheit.

In this case, a ton of air conditioner means that it can cool 12,000 pounds of water, raising its temperature to one degree in one hour.

Phoenix has mild winters and dry summers, and houses often do not have basements. It is recommended that when your home is between 600 to 900 square feet, a 1.5-ton A/C unit can supply the cooling that you need. Meanwhile, you need two tons if your home is more than 900 square feet up to 1,200 SF.

Benchmarks for Air Conditioner Size:

  • 1,201 to 1,500 square feet homes should use 2.5 tons.
  • If your home size is higher than the number above but is less not more than 1,800 square feet, you can go for a three-ton A/C.
  • Choose a unit that is 3.5 tons if your home measures more than 1,800 but not more than 2,100 square feet.
  • A four-ton unit is suitable for homes that are more than 2,100 square feet up to 2,400 SF.

Using the measurements above, you can get a general idea as to how large your unit should be when you buy and install one. In addition, there are three techniques to pin down what size your AC should be for your space.

How to Know What Size Air conditioner Do I Need? The Top Three Techniques

In the first method, you need to use an equation. To get the required tonnage for your home in Arizona, here is what you need:

(Total square footage of the house x 30 / 12,000)

Typically, you would need to subtract one after getting the answer to the equation above. However, since the climate in Phoenix Valley is hot, you do not have to deduct one more point. Therefore, if your home is 1,500 square feet, your air conditioning unit should be 3.5 to four tons.

The second method is to consult an A/C expert at Isley’s Home Service to learn about the ideal size. You will need to input some information, including your location, the summer and winter temperature, and the shade you get on your house to get the results.

Finally, you can use an AC sizing graph (example below) that is accurate and shows the whole map of the United States. Locate Arizona and your square footage, and find the right size air conditioning system for your space before purchasing.

Speak with an AC Expert

air conditioners buyers guide for room size