As a thermal engineer and avid penny-saver, I have noted the effectiveness of winter window insulation kits for a long time. My dad made reusable frames that could be caulked into our windows every winter, and removed in the spring. In Minnesota, this was essential for keeping our winter heating bills manageable.
College taught me the science behind window insulation. The thin, translucent window film does not itself capture much warmth. But is turns the air between the film and the window effectively into a think down blanket. The air captured between the window and the film is quite still, and provides a significant amount of insulation.
If it weren’t for wanting fresh air in the summer, window insulation would be a great choice all year round–especially on those windows where a clear view is not absolutely essential.
Winter Window Insulation Varieties
There are a variety of methods for winter window insulation.
One of the most popular is the seasonal throw-away kits that combine either indoor or outdoor-capable double sided tape, and stretchy or shrinkable clear film. The film and tape is ripped off your windows at the end of the cold season. The two most popular kits of this sort are the ones by 3M, and Duck brand. The 3M brand window insulation kits are a bit more expensive (5 windows for about $18), but they are generally considered higher quality. Their window film is slightly clearer, and is stretchy for easily getting rid of wrinkles. The Duck brand window insulation kits, though they say are only for indoor, are said to work out door as well. I have small children who would inevitably ruin the film if put on the inside of the window where they could play with it, so I put it outside. A hair dryer can be used to shrink the film nice and taut.
Other methods involve more permanent, reusable solutions based on a reusable frame that is inserted into the window frame. These can be especially effective, and if you are not going to be moving for a good number of years, may be the cheapest solution.
How Much Can You Save With Winter Window Insulation?
How much you can expect to save on your heating bill depends on a lot of factors. Overall home insulation, how many windows you have, how insulation your current windows are, etc. But as a ball park figure, you can estimate a savings of around $20 per window insulated. This number would go up the longer and colder your winters are. Considering most insulation kits will cost you between $2 and $5 per window, the savings over a winter can be significant. My home with around 12 windows, and using the cheaper kits gives me a savings of over $200.
One of the most surprising and grateful results from insulating my windows has been a much warmer shower. We have a window to the outside right in our shower/tub area, and the cold draft flowing down from it made the second you turned off the water just miserable. After putting insulation on the outside of that window, and feeling the wonderful effects, I added a second layer of insulation on the inside for even more! Since the window is frosted and I doubt we would ever open it, I am planning on leaving it up all year round.
How Difficult is Installing Your Own Winter Window Insulation?
It is a job for one or two people, depending on how adept you are at managing thin film possibly blowing in the wind and getting stuck to your sticky tape. With just one person, you don’t have the communication challenges, but sometimes an extra hand is helpful. However, I did my own and it went fine–I did my whole house in an afternoon.