Tips for Installing a Window AC Unit

Air conditioning is one of the biggest energy uses in the home. Today, and I’m going to be talking to you today about five simple things that you can do as a homeowner to make your air conditioner more energy efficient, which will save you energy, make your house more comfortable and save you money. Roughly one out of every eight dollars that Americans spend on their utility bills goes into cooling their homes. . . that’s a lot of money in and of itself but also, air conditioning is one of the big drivers of what we call peak energy, which is the strain on the grid on a hot summer day.

I’m hoping that homeowners will see this and take the 15 or 20 minutes it actually takes to do this installation to save themselves a lot of energy, a lot of money. What you see here is an example of a standard window air condition installation. This is what you might see if you use just the materials supplied by the manufacturer. This isn’t bad but there are definitely things you can do to improve it. If light comes in, air can come in too and that reduces the performance quite a bit and can really affect your comfort.

And. . . this happens all the way around your installation. So, on the side panels are made out of plastic typically– but there’s no insulating value there. So, when your window is closed — your window is actually a pretty good insulator. The accordion eliminates a lot of that. . . but we can fix that too.  There are a variety of different styles of foam. Some have different thicknesses, some have coatings that are more weather durable and it’s all up to you and your personal preference. If you choose a foam that has a color that you don’t like that much, you can also add some tape onto the outside.

Then you have your tape and this is actually fairly important. . . if you have windows that have paint or stain on them, tape could leave residue or it could peel some of that paint. So you want to be careful. If you have a window that has paint, you should consider using a tape that has a little less adhesion — it might save you some trouble later on. If you’re going to install a diverter, you’ll need a piece of semi-rigid board, medium density fiber board usually works well — you can get it faced or un-faced and usually around 1/8th to a ¼-of an inch will fit most air conditioners. And be sure that whatever tools that you’re using, you are comfortable with and always make sure that you have the proper safety equipment.

Steps to Installing the Air Conditioner

So, step one is to remove the accordion panels. . . there’s a little hole to push that up and you slide it out. No tools required, and then you can set those pieces aside. And then, on the unit itself there’s another little sliding piece and you can slide that off as well. After you remove the accordion panels, you want to replace them.  You want to make sure that it’s set correctly. You don’t want this falling out of your window.

Step two is measuring and then, cutting and installing foam. So, you’ll need to find out how wide and about how tall your air conditioner is, because even the best ac unit will fall out if not installed properly. You want to make sure the foam is nice and tight because if you have large gaps, that will make it harder to air seal and tape up later. So, now we’ll go on to the other panel.

Step three is to seal between the windows. This is an example of an open-cell foam that’s typically supplied by the manufacturer and it does a reasonable job. This is an example of closed-cell foam, which does a much better job at air sealing, so we’re going to use this.

Step four is to use backer rod — oftentimes, smaller. . . they’re sold in different diameters, so you’ll have to match it to your window — to seal up the side channels. This is an easy thing to forget — but it’s also an easy thing to fix.

Step five is to tape around all of the joints and all of the foam. You want to make sure to seal up all of the air gaps to prevent leakage. The blower door test is a fairly standard test that’s done with many home audits or energy assessments. The total air leakage reduction that came from the difference between the manufacturer’s accessories and our recommended method was roughly equivalent to a hole that was five-square inches in diameter. That is actually about 10% of the whole home’s leakage. It’s pretty substantial when you think about the fact that many homes that have a window air conditioner probably have several, so by applying this method of better installation, you can really seal up a number of holes, which are about five-square inches each.

For best performance, you can install a diverter and what this does is prevent the air that you just spent money and energy cooling from getting sucked back into the air conditioner. You’re going to be more comfortable because you’re getting the cooling effect that you’re paying for. You’re also going to be helping to reduce the strain on our nation’s power grid, so you’re improving our energy security. . . and lastly, you’re helping the environment by helping to reduce carbon emissions that come from the power that you’re using. So, this is it. It’s that easy. . . you too can save money, energy and make your house more comfortable.…