Why Do Storm Doors Save Energy?
I have been getting questions asking why storm doors are so important and how do they save energy. When an engineer calculates the rate of heat loss through a door, each obstacle in the path of the heat flow needs to be evaluated. In the winter heat from inside will flow out to the cold outdoors. The object is to slow down the heat flow One of the roadblocks that heat encounters is at the boundary between each material. In the case of a plain solid wood door, the first obstacle that the heat flow hits is the boundary between the indoor air and the wood door. Every time heat flows from one material (air) into another material (wood) it is slowed down. Each boundary acts like a speed bump to the flow of heat. The next item is the wood door itself. Wood does not conducts heat slowly so it is a good material for making doors. The thickness of the wood determines how slowly the heat flows through it. The thicker the wood is, the slower heat escapes through it. The final barrier to heat flow
