What is the best way to insulate a window air conditioner?

Question

All I have are the flimsy plastic screens on the side of the unit through which I can even see sky so lots of heats must be passing as well. I've taped rolled up bath towels over the screens and put foam strips in the gap between the top and bottom panes. Are there any other suggestions?

Thanks for all the great information. You did such a good job I can't choose a best answer from this lot. It's up to the voters.
Thank you!

Answer 1

I cut a piece of plastic to the correct size of the gap and sealed it with duct tape to stop any leakage or draft.
It worked very well
Man rule #1: Duct tape fixes everything that a kick wont

Answer 2

Window Air Conditioner Insulation

Answer 3

This Site Might Help You.

RE:
What is the best way to insulate a window air conditioner?
All I have are the flimsy plastic screens on the side of the unit through which I can even see sky so lots of heats must be passing as well. I've taped rolled up bath towels over the screens and put foam strips in the gap between the top and bottom panes. Are there any other suggestions?

Answer 4

Best Way To Insulate Windows

Answer 5

I use whatever foam (of appropriate thickness) I have lying around, usually leftover from shipping cartons. Polyethylene is easy to cut. Polystyrene insulates better, but the thick pieces are hard to cut and the large cell kind is VERY messy. Polyurethane absorbs water, so when using it, I wrap it very securely all the way around (like a present) with overlapping duct tape. Polyurethane is the most forgiving. Being spongy, it can be cut just a little big and then squeezed into the openings, where it will usually stay. Rigid (polystyrene) and semi-rigid (polyethylene) foams have to be tailored more precisely and almost always have to be secured. For this, I use 3M Electrician's Bundling Tape (vinyl base, so it doesn't get soggy; low residue, so it doesn't harm most surfaces if left on for only a single season). If rain is likely to be plentiful (where I am, it is) or external appearance is important (visible from the street), I make a "backer" piece to go on the outside of the foam blocks by cutting same-size pieces of cheap wood veneer with a box cutter or Xacto knife. I paint them the same color as the window trim, or if I'm being lazy, I cover them with duct tape in a complementary color/pattern. I tried painting polystyrene once, but it just made it look worse!

Answer 6

Consult with your local hardware or home center. There are insulation kits that will do a much better job. They come in all sizes and shapes so get the window dimensions and a.c. dimensions first.

Answer 7

most hardware stores sell foam inserts and strip's in many sizes to insulate around the unit..also dont leave out the rest of the room,make sure other doors and windows dont leak out your a/c..

Answer 8

I'd use Styrofoam cut tight to fit so you can wedge into place it will add a r factor . i would also use duct tape to secure it and help keep out hot air flow both inside and out

Answer 9

We use 1 inch thick styrofoam to fill in the space. It cuts very easily if scored with an exacto knife . Cut your styrofoam just a little bit larger than the opening, so you can wedge it in tightly with no gaps.

Answer 10

I think what you did will work fine. I used some cheap bath towels to insulate my air conditioner... works for me.