How To Install A Window Air Conditioner?

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Do you have a new window air conditioner, and you’re wondering how to install it? Wonder no more, for we’ve researched this question, and we have the answer for you.

Here are the summarized steps to install a window air conditioner on a double-hung window:

  1. Measure the width and the height of the window where you plan to install an air conditioner.
  2. Pick an air conditioner that matches the size of the window and the size of the room.
  3. Carefully unbox your air conditioner.
  4. Screw in the top mounting rail.
  5. Install weatherstrips.
  6. Slide the two side curtains into the support rails on each side of the air conditioner.
  7. Install the curtain frames.
  8. Snap the side curtains into the frames.
  9. Measure the width of your window and mark the center.
  10. Lift the air conditioner into the open window. Align the middle of the air conditioner with the center mark that you made.
  11. Slide the window down. The top mounting rail should be in front of the window.
  12. Extend the curtains to fill the open area on both sides of the air conditioner.
  13. Drill pilot holes for the screws that will hold the curtain frames in place.
  14. Screw the four screws into the pilot holes for each side of the window rail. One at the top and another one at the bottom.
  15. Loosen the screws on both sides of the air conditioner.
  16. Slide the side bracket into place, one for each side.
  17. Screw the side bracket into place.
  18. Install the window lock bracket.
  19. Trim foam sheets that match the measurements and install them over the air conditioner curtains.
  20. Install the top window gasket between the window frame and the glass pane.

The steps may be lengthy, but they are simple to follow. Read about the detailed steps in the succeeding sections, including how to install a window air conditioner without using screws. Read on!

old air conditioner installed on window - How To Install A Window Air Conditioner

How to install a window air conditioner?

A small air conditioner in the window of a brick apartment building.

Here are the detailed steps on how to install a window air conditioner.

Choosing The Right Air Conditioner

  1. Choose a window to install your air conditioner. The ideal window is one where your air conditioner will not be exposed to direct sunlight and has an isolated power outlet that only the air conditioner will use. An exclusive power outlet is important to prevent overloading your circuits.
  2. Get the dimensions of your chosen window. Ideally, it should be able to open to at least 13 inches vertically and is at least 20 inches wide.
  3. Pick up an air conditioner that meets the dimensions of your window. The air conditioner should also have the capacity to cool the room where you will install it. You will need an average of 20 BTU per square foot of floor area. Do not get an air conditioner that is too powerful or too weak than what you need because this will cause your air conditioner to waste energy.

Unboxing Your Air Conditioner

Carefully unbox your air conditioner. Air conditioners are naturally heavy, so getting help to unbox it may be necessary.

The first thing you need to do is verify the box's contents. Make sure that the contents are complete. Bring it back immediately if you’re missing an item when you unbox it.

Preparing Your Air Conditioner For Installation

Air conditioner with toolbox and tools. Repair of air-conditioner concept

  1. Take the top mounting rail and screw this on top of your air conditioner. This serves as a support for the curtain frames. It is also what holds your air conditioner in place as it rests against the bottom of your partially closed window.
  2. Measure the length of the window rail and trim two weatherstrips to match this length.
  3. Install one weatherstrip under the window frame that will close over the air conditioner. Install the other weatherstrip on the window frame where you will rest your air conditioner.
  4. Take the curtain frame from the box and measure its height. The height that you will measure should be the height that is opposite the opening.
  5. Trim two weatherstrips to match this measurement.
  6. Install weatherstrips to the side of the window rail.
  7. Slide the two curtains into the rails on both sides of the air conditioner.
  8. Insert the window rail into the top mounting rail, then into the mounting rail under the air conditioner. Most air conditioner models label their window rails so that you’d know which one should be installed on the right side and which one to the left.
  9. Extend the curtains until they reach the inner edge of the window rail. Press the curtains gently against the window rail to lock them into place.

Mounting Your Air Conditioner To The Window

  1. Use a level to get the incline of your window. Ideally, your air conditioner should be inclined slightly towards the back. An incline to the back ensures that the water condensate will flow outward instead of into your house.
  2. Cut a shim that is of the right thickness if you need to set an incline. Shims are used to set an incline or alignment. The length of the shim should match the width of the window's opening.
  3. Screw the shim into place once you have the right measurements. Keep in mind that you only need a slight incline. Too much incline and the side curtains might no longer line up with the side of the window frame to make a seal.
  4. Measure the width of your window to mark the center.
  5. Lift the air conditioner to your window. We strongly suggest that you get help for this. The second set of hands reduces the risk of possible accidents that might happen while you’re positioning the air conditioner.
  6. Align the center of the air conditioner to the center mark that you made.
  7. Slide your window down to partially close over the air conditioner. The top mounting bracket should be in front of the window to support the air conditioner.
  8. Extend the curtains to both sides to fill the gap between the air conditioner and the window.

Securing Your Air Conditioner In Place

  1. Each window rail has two screws—one to fasten it to the top of your window and another at the bottom. Drill pilot holes for the screws on both sides.
  2. Screw the four screws to keep the window rail in place.
  3. Locate side screws—one on each side of the air conditioner—and loosen them.
  4. Slide the side brackets over the screws.
  5. Drill pilot holes for the side brackets and install the screws that will keep the air conditioner in place.
  6. Tighten the side screws.
  7. Install the window lock bracket to prevent your window from getting accidentally opened. If your window is made of wood, screw it onto the window stile. If you have a vinyl window, screw the bracket on the side window jamb.

Adding Insulation

  1. Measure the width and height of the curtains on both sides.
  2. Trim self-adhesive foam sheets that match the measurements and install them over the air conditioner curtains.
  3. Install the foam to seal the gap between the top window stile and the windowpane.

How to install a window air conditioner without screws?

And old styled air conditioner on the wall.

The installation of a window air conditioner involves drilling holes into your window, and this can be a deal breaker for some homeowners. Fortunately, there is a simple hack that will let you install a window air conditioner without drilling any holes in your window.

The method that we will teach you will give your air conditioner the same level of safety against accidentally dropping it. Before we begin, you will need two L-brackets and two felt washers.

Follow all the steps from sections “Choosing The Right Air Conditioner,” “Unboxing Your Air Conditioner,” and “Preparing Your Air Conditioner For Installation.” Proceed to the next section and follow the steps until you get to the installation of a shim.

Skip screwing the shims if you need to install shims. Use a small piece of double-sided tape to keep the shim in place.

Position the L-bracket where you can screw it to the top mounting rail after you finish the section. The opposite end hooks on the handle of your window. Drill holes where you can screw the L-brackets on the top mounting rail.

Glue the felt washer under the opposite end of the L-bracket so that it will not scratch the window handle.

The window will not open because the weight of the air conditioner is pulling it down. And since the L-bracket is hooked to the window handle, it will not slide out and fall.

Metal L-brackets from Teenitor are available on Amazon. Check it out through this link.

Black felt washers from Fender are available on Amazon. Check it out through this link.

Conclusion

old air conditioner installed on window

Installing a window air conditioner can be a simple weekend DIY project. However, it is best done with an assistant to help with lifting the air conditioner.

If you enjoyed reading this article, you might find the articles below equally enjoyable to read:

Can You Install A Window Air Conditioner Through A Wall [And How To]?

Can Lightning Strike A Window Air Conditioner?

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