Window Insulation

When you look around the home there are several areas of a home that are good candidates for insulation, including the attic, the basement,  between walls and windows and doors. Windows and doors are obvious candidates for insulation because they are the areas of a building that open directly to the outside.

There are several reasons why windows are good candidates for insulation. No window seals completely perfectly and there will always be some gap between it and wall around the window. Over time windows become less effective at sealing just because of general wear and tear, since windows are mechanically dynamic. 

Once a building owner has decided to insulate their windows there are several options they have to do the job. One option is to use cheap insulation film or putty. Insulation film is plastic film that is placed over a window. The idea behind it that it reduces the transfer of heat from the inside to the outside. Heat flow can be divided into radiation and convection. With regard to insulation, convection refers to the flow of heat from warmer to cooler areas. Window insulation film that works using this principle is called convection control film. The aim of this kind of window insulation is to reduce the transfer of heat from the window to the air by slowing down heated air particles trying to flow through the window. The idea behind this kind of insulation film is similar to double glazing. It is not a permanent solution and needs to be reapplied every winter and removed every spring. The other kind of window film insulation is called solar control film, or solar window film.  It goes directly onto the window pane and and is meant to remain there permanently. It works by reflecting the sunlight's infrared energy and absorbing its ultraviolet energy. This kind of film works by reflecting heat inside and disperses it there, not allowing it to dissipate through the window.

The problem with window films is that they do not address the main problem of drafts and cold spots in homes which can be air leaks and under-insulation in other areas of a building. Insulation can be thought of as a blanket fleece around the building, if there a break in it or parts that it doesn't cover, cold air will find it's way in. That said there are solutions that can specifically help to winterproof windows.

One solution is installing  window insulation foam around a window frame. Window insulation foam  an expanding plastic foam specifically designed to create a seal around windows. It also works for doors that have drafts. In order to do this , the frame around the window or the window itself must be removed to apply the foam into the space between frame and window.  Any old worn insulation should be removed. After that the new spray foam insulation can be applied to fill the space. This kind of foam doesn't expand a lot which makes it easy to control how much has been used where and see what spaces need more insulation.