Add an extra pane to your windows

I have an old house, and two of the windows are still single paned. As part of my ongoing energy efficiency improvements, I wanted to reduce the air and heat leakage from them, and reduce condensation on the glass. Since it's not in the budget to replace them this year, I needed a reasonably priced fix.

I decided to add a pane of acrylic on the inside of each window.

Materials:
- Clear acrylic panes (plexiglass, lucite, etc)
- Double sided foam tape (found in the weatherstripping aisle)
- Cove trim (optional) and fasteners
- Caulking
- Dessicant (optional)

Tools:
- Work gloves (acrylic can be very sharp)
- Safety glasses (you like your eyes, right?)
- Measuring tape and pencil/pen
- Exacto knife
- Miter box and saw
- Caulking gun
- Hammer (if nailing on trim)

Step 1: Air seal the window

The first thing to deal with is air leakage. I got out the trusty caulking gun and caulked around the edge of each pane of glass, and filled in any gaps around the window frame. The caulk I used is water based clean up, so a wet finger made sure that I got all the gaps, and a damp rag cleaned everything off the glass. I used white indoor/outdoor 25 year caulk.

Let the caulk cure, per the tube instructions. You want the window and caulk very dry before you install the acrylic.

Comments

[dreiseratops]

Id love to hear about temps & energy cost reductions through the coming weeks.
Looks good.

[psullivan1]

If they end up fogging up, you could drill a small hole in the plexi. Cool instructable.

[Mar HK]

I'm hoping that once things warm up again the dessicant between the glass and plexi will dry out the air trapped in there.