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What Size Air Conditioning Unit Do I Need?

Size Matters When it Comes to Selecting Your Air Conditioner

You are done with the heat and humidity in your home and ready to bite the bullet for an air conditioning unit. Now, what do you do? Here are some Q&A’s to help you evaluate air conditioner units and sizes.

Carrier Air Conditioner

Q: I’m planning for a central air unit, what should I do first?

A:  Call your local Carrier dealer or HVAC expert for a consultation. Their technicians can determine what size unit and type of system will work best for your family’s cooling needs. Installing a central air system is quite a process, so let the experts handle this project!

Q:  Shouldn’t I just get the biggest unit possible, just to make sure it cools my house the best?

A:  No, this is an air conditioning myth! Bigger isn’t always better. In central air conditioning, too big a unit is an energy hog and therefore won’t save you money on your energy bills, even if it has a high energy star rating. If the unit is too large, it will cool the room quickly, but only remove some of the humidity. This leaves the room with a damp, clammy feeling. A properly sized unit will remove humidity effectively as it cools.

Q:  What about a window unit - can I just run to the big-box store and buy a window air condititoner?

A:  You can, but you too, need to know what size unit will work best for your space and you probably want to research what brand will bring you the biggest comfort at the best cost (and if you’re installing it yourself, which one has the easiest installation process).

Q:  How do I determine what size window unit is right for me?

A:  You can do the math: multiply the length of the room times the width of the room or area to be cooled. Then, multiply that total times 25 BTU (cooling capacity is measured by British thermal units, or BTUs). This BTU number will allow ample cooling in that room, whether it is a rainy, moist day or a hot, sunny, humid day. Another good source for air conditioner window unit sizing is Energy Star which has a chart already factored out on what size window air conditioning unit you’ll need based on room square footage (length x width).

Q:  What if the room I want to cool is especially sunny?

A:  Increase the BTU capacity by 10%

Q:  My window unit will be in my kitchen, does that make a difference?

A:  Yes, because of the extra heat generated by appliances, and the extra humidity that comes with cooking and washing dishes - so increase the capacity by 4,000 BTUs

Q:  Can I save a little extra money by getting a smaller unit? 

A:  Smaller BTU units will have to continually run, just to keep up. This will increase your electric bill and it is unlikely the unit will be able to cool the area effectively.

Still have more questions about purchasing an air conditioner? Ask your local Minnesota air conditioning expert and remember, the size of the air conditoning unit is very important - too little is never enough and too much of a good thing isn’t a wise choice either.



For home maintenance and comfort tips, visit! Stay Comfy, Minnesota is your Minnesota resource for air conditioning repair, furnace repair and HVAC tips and advice.

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