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The Home Depot

Window AC Installation Made Easy

Pro Referral > Home Guides > Heating & Cooling > Window AC Installation Made Easy
Window AC Installation Made Easy

Don’t sit in your house and melt from the heat. Even if you don’t have central air, you can still get much-needed relief with a window air conditioning unit. Built for fast cooling, window air conditioners install quickly with a minimum of effort.


As you’re contemplating a new window air conditioning unit, check out the Energy Star website for valuable information about how to choose a unit with high energy efficiency. The more energy efficient your air conditioning unit, the more money you’ll save as you bask in the cool comfort of your living room.


Armed with information and facts about air conditioning, you’ll be ready to install your window AC in a fast and easy manner.

  1. 1.Choose the Window

    For the best results, you’ll need to choose a window for optimal cooling. A window with shady conditions will help your air conditioner run more efficiently due to the reduced sun exposure. Most window units install ideally in double-hung windows. Measure the dimensions of the window opening before you buy a unit to make sure that the air conditioner will fit in the window opening.

  2. 2.Choose the Unit

    Don’t sit in your house and melt from the heat. Even if you don’t have central air, you can still get much-needed relief with a window air conditioning unit.

    Measure the width and length of the room and multiply the two figures together to get the area of the room. Once you have the area, you’re ready to determine the air conditioner capacity you need. For example, if your room has an area of 360 square feet, you will need an air conditioner with a BTU of about 9,000. Don’t forget to factor in the number of windows in the room and the sun exposure through the windows – you may want to increase the BTU capacity slightly if you get streaming southern or western exposure sunlight through the windows.

  3. 3.Prepare for Installation

    Clean the window glass and the windowsill before installing the air conditioner. If there are storm windows or screens, you will need to remove them or slide them out of the way before you place the air conditioner in the window. Determine where the holes in the spacers and brackets will hit the windowsill so you can drill pilot holes. As painful as it may seem to drill into your window frame, a couple of holes in the windowsill will be worth the security of knowing that your air conditioner isn’t going anywhere after you install it.

  4. 4.Install the Unit

    Get an assistant to give you a hand and position the air conditioner in the open window. Center the unit between the left and right sides of the window and position the spacers and brackets around the edges of the air conditioner. Close the window snugly against the top of the air conditioner. While your assistant holds the air conditioner steady, install the mounting hardware through the holes in the spacers and brackets – using the pilot holes you predrilled. This will hold the unit securely in place. Don’t skimp on mounting hardware – use every piece provided with the air conditioner to ensure a safe installation. Slip these pieces in to the spots where the lower frame and the upper sash don’t quite meet because of the air conditioner to keep out as much warm air as possible.

  5. 5.Chill Out

    Plug the unit into a three-prong outlet. If you don’t have a three-prong outlet nearby, use a special air conditioner extension cord rated for the extra load of an air conditioner. Now turn on the air and chill out in your cool, comfy room. You’ll be enjoying the cool fruits of your labor in a short time when the temperature and humidity level of your home start dropping.

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