Insulation homework

For example, insulation around hot-water heaters or steam pipes cuts the heat loss to the surrounding room, while insulation in the walls of a refrigerator reduces the flow of heat from the room into the cold space in which the food is stored. Similarly, electrical insulators suppress the flow of electricity.

Super insulation is a term applied to special insulating blankets developed for spaceflight in which external temperatures approach absolute zero (–459.67° F, or –273.15° C) and people and equipment must be shielded from radiation heat loss to space. The blankets consist of multiple sheets (about 50 to 100 layers per inch) of aluminized Mylar.

Small air pockets may also be used effectively in insulating building materials. Hollow glass bricks and partially hollow concrete tile are good examples. Insulating windows consist of two or three glass panels with a thin air space between them to reduce the heat loss from a building.

A good electric insulator is one with few free electrons (electrons not tightly bound to atomic nuclei) to carry electrical current. Although again there is no perfect insulator, the resistance to current flow in a good insulator may be more than 10 24 (one followed by 24 zeros) as great as in a good electrical conductor such as silver or copper.