Improving window performance - short of replacing them?
With all the smoke in the air we're realizing the house we bought several months ago is not as airtight as we would hope. The windows look to be original wood frame double hung windows. Are there ways to improve the airtightness of the windows without replacing them completely? Is it dependent on the particulars of the window - that is, some windows in better shape can be saved but ones that haven't been as well cared for have to go? At what point is it just worth it to replace them completely?
Oct 28, 2019
Parent Replies
On the East Coast nobody has airtight windows. The houses are old, the windows swell and shrink depending on the weather. In the winter, you have to manually seal them to keep the cold out. To make them airtight just go to the hardware store and buy some window tape, and tape it around the edges of the windows. There is also something that looks like shrink wrap which you can seal entirely around the window and then shrink tight with a hair dryer. But for the smoke, window tape will do just fine, and you can easily remove it if you need to open the window. You can also buy weather strips for your door so the seal is better.
Please, please, please don’t replace the beautiful original wood windows with ugly new ones. I know that it is tempting for energy and sound proofing reasons, but a lot can be done short of destroying the historical fabric of your house. The Berkeley Architectural Heritage Association had a seminar I attended on rehabbing and adding weatherproofing to old windows. I don’t know if they still have it but I’m sure they can point you to resources. There are also some good companies in the area that specialize in rehabbing and replacing with the old type of window where needed (if a sash has dry rot, for example).
Good companies in the area include:
https://www.woodwindowswarehouse.com/index-1.php
https://www.johnstatondoorsandwindows.com/
https://www.kinneywoodworks.com/windows
You could use 3M indoor or outdoor insulation film, which attaches to the window frame and provides an airtight barrier. Also improves the thermal performance of single-pane glass. The downside is that then you cannot open the windows when you want to, so you could consider only putting it on certain windows.
You might be able to get a good seal with weather stripping from the hardware store. There is a peel and stick product that has a foamy side and a sticky side. It comes in different widths so try to get a measurement of the gap between your window and the sill before you go to the store and purchase it. I used weather stripping on my 1895 house's wooden windows and we no longer have unpleasant drafts. It's cheap and effective.
I highly recommend the book Working Windows by Terence Meany. It goes through the inner workings of old wooden windows and how to improve their performance in DIY ways that were pretty accessible to us as new homeowners. We used the guidance there to insulate our original windows and found that, except for two in very, very poor condition with lots of dry rot and gaps, we were able to get all tight enough to be "good enough." We also had an energy audit done a few years back that found that, with that insulation, the windows were not a high priority investment from an energy use perspective, which made us feel good about that decision. (We did replace the two that were in very poor condition, and that has helped that room a great deal.)
We have ordered inserts called Indow to help seal our windows. They can be taken in and out and are custom made to any window. They also help with reducing noise from outside.
I used a company called Indow Windows for the huge windows on the front of my 1890's Victorian. They work wonders, and were much cheaper than replacing them with new windows. It's basically a custom insert that goes in behind your window that seals it off, but it's perfectly clear and you can't tell it's there.