I reside in an older residence, and unfortunately, the windows in my living room are non-operable. Each summer, I've faced the challenge of accidentally breaking a window pane while installing a portable air conditioner, leading to the purchase of a replacement glass when the season ends.

This year, I'm considering leaving the glass out, keeping the AC hose base in place minus the hose of course (this is the plastic part that goes in the window and attaches to the hose) and potentially covering it with a larger piece of plywood. This portion of the house isn't visible from the street, so aesthetics aren't a concern. The primary goal is to ensure insulation against the cold and snow during the winter months.

Do you have any suggestions or ideas?

The silver tape is HVAC tape. This plastic piece was cut for me since the part that came with the A/C was meant for a standard window and not my square postage stamp space.

Also the wooden frame is quite thin. I am not sure I can screw into a piece of ply wood and the frame without the cracking the frame … help!

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  • Have you considered a sheet of foam insulation instead of the plywood? Typically the stuff is pink, but I've seen it in white. You might take something like blocks of wood and buttress the plywood/insulation into place around the perimeter instead of driving fasteners into the window frame.
    – popham
    Commented Oct 5, 2023 at 22:01
  • 2
    When you say "unfortunately the windows in the living room are non-operable" do you mean they are picture windows, or do you mean they've double hung or casement windows but they're stuck because the house has settled or they've been painted shut?
    – AdamO
    Commented Oct 5, 2023 at 22:11

2 Answers 2


The problem with old, single pane glass is that it has the U-value of a piece of cardboard. Add to how these old homes often didn't insulate gaps during initial install, and that putty is dried and cracked... the glass itself is probably just as bad as this install.

  1. Ask yourself if it's the time to replace windows.

  2. You can purchase and install storm windows - exterior or interior. They're not just for storms, they function like double pane. Sure, there's no inert gas vaccuum seal, but the air in the gap is as good as a mini-attic.

  3. I'm a believer in drapes/curtains. Heavy drapes really do a lot to insulate at night. For about $700 we recouped the cost of gas heating in a single year in Seattle. You can install the honeycomb style inside the window and a fabric style over the top.

  4. You can just repair the removed pane. Scrape out the old putty, and measure to the styles, and get a custom piece cut at the hardware store. Instead of using glaziers putty for the new window, just use a silicone caulk since it's super easy to remove when you go to install the air con next summer.

For that air con, you might just see if there's another place you can vent it out rather than do this every year. I'm sure you did the best with what you had, but knocking a window-pane out to use this thing is a ridiculous idea. Send the air con up the chimney, install some rigid ducting through your wall or attic, or consider a mini split.


Replace it with a pane that has a circular hole (glaziers do these for cat flaps). when not using the hole for the AC vent, cover it with a circular piece of plywood (or clear acrylic) bolted or screwed through the middle to a square wood (or clear acrylic). the square should be large enough that the corners reach past the edges of the circle but small enough pass through it sideways.

One-hose portable ACs are horribly inefficient because they draw warm air into the house. Any other type (except those stupid ice box fans) will be much better.

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