Would pink solid foam insulation, fit tightly on the inside of a window frame in my cabin, save energy?
Yes, but only on north facing windows and only when the cabin is not occupied. When occupying the space it will be very important to remove the foam. Foam insulation provides fuel in the event of a fire as well as a significant source of smoke. Codes require it to be covered with a material providing a thermal barrier between the occupied space and the foam. An example of a thermal barrier would be ½ inch gypsum board. One problem with interior placement is the entire window would be below the dew point and vulnerable to condensation. Placement of the foam on the exterior would keep the window to the interior of the dew point and protecting the window. However, if your windows are still under warranty, you may want to ask the manufacturer if doing this will void your warranty. Exterior insulating shutters are far more benign. However, assuming the cabin to be heated, removal of shutters in very cold weather exposes insulated glass to a thermal shock and sudden temperature change. It ca
