The most common type of insulation that is thought of is thermal insulation. This is the type of insulation you would find in most buildings and homes. It is designed to lower the transfer of heat between the inside of a building and the outside environment. It allows a building to retain its heat during the winter months while still keeping it relatively cool inside during the hot summer months. While there is no substance that can totally stop the transfer of heat between one area and another, there are a variety of new materials that can greatly slow this transfer.
In order for a building to be properly thermally insulated, it must first meet certain specifications. Among these specifications, the building must be reasonably air tight. If a building is not able to keep the air from flowing in and out, then no thermal insulation will allow the building to maintain its internal temperature. However, if the building is air tight enough, then the thermal transfer will be much slower, and therefore the insulation will work much more effectively.
How well a particular insulation material works is based on its R-value. This value is a measure of the material's thermal resistance; the characteristic which makes a material a good insulator. A material with a higher R-value will be a better insulator than a material with a lower value, because the higher R-value material will be able to prevent more transfer of heat. A material's thickness, density, or the makeup of its molecular structure are the primary factors in preventing heat transfer. Furthermore, insulation with more layers can also decrease heat transfer and increase effectiveness, as each layer of material will be able to prevent its own amount of heat transfer by absorbing or reflecting the radiation, conduction and convection present in heat.
Electrical insulation works in much the same way as thermal insulation, except it acts on electricity instead of heat. An electrical insulator is any material which can support or separate conductors of electricity without allowing an electrical current to pass thorough itself. These materials allow no electrons to flow through them, and can therefore be used as shielding for wires and other such electrical devices.
Acoustic or Soundproof Insulation
As is the case with thermal and electrical insulation, soundproof insulation works in much the same way. With soundproof insulation, sound waves are not able to travel through a particular material. This can be done by either using a material that simply lowers the intensity of a sound by using some kind of dampening system, absorbing or blocking some of the sound waves that pass through a particular material, or by using a machine that can generate anti-noise that synchronizes with the sound waves in a room and effectively eliminates them.