Air is not a good conductor of heat because it, being a gas with only a few particles in a big space, cannot store much energy by volume as it doesn't have much material in which to store the energy.
However, air can move heat by convection, which means by moving and circulating it can transport the heat from one place to another. Because air moves with very little resistance it can easily move a lot of heat this way.
So air is good insulation only if it is in very small pockets where the air cannot circulate easily. A lot of insulators actually trap tiny pockets of air to create insulation, such as foam or even fine knitted clothing.
As you should know, the purpose of insulation is to create dead air space. DEAD air does not transfer temperatures.
Good insulation and good draught proofing are essential to reduce fuel use.
The air in a double pane window is insulation from cold weather.
Putting thicker insulation in than will fit will make it less efficient. Any insulation needs to have air separating the layers of insulation.
Straw (the leftover stems of the wheat or other cereal grain after the grain is harvested) is not a particularly good insulation for a building. The idea of insulation is to create trapped air spaces, preferably lots of them. Since straw does not usually pack very well (except in a baler), it's difficult to force it to create the kind of trapped air that fiberglass batts, for example, will make. It's better than nothing, but not much. It also MUST be treated with a fireproofing chemical.
for thermal insulation
Air pockets can act as good insulation because they limit heat transfer by reducing the convection of air. Materials like foam, fiberglass, or double-pane windows utilize this principle to improve insulation in buildings and homes.
it is good heat insulator, as it has air in it. as air is a good insulator of heat, the sponge, which has lots of pockets of air also becomes a good insulator
Air pockets hold heat, so they probably have a lot of them.
Good insulation in the attic and walls. Central air.
Air is not a good conductor
I am not sure where you heard this but the thickness of old putty against the thickness of insulation for r-value is not as good. The best insulator is air. Fiberglass insulation has a high r-value because of the air it holds not the fiberglass itself. So that's why you don't cram 6in fiberglass into a 4in space, it does not work when you compress it.
Duvets and loft insulation are good insulators because they trap air within their layers, creating a barrier that helps reduce heat transfer. The air pockets in duvets and loft insulation act as a buffer, preventing heat from escaping and keeping the surrounding environment warmer. Additionally, the materials used in duvets and loft insulation are designed to be thermally efficient, further enhancing their insulating properties.
Styrofoam is a very porous material; air from the closed pores has a bad thermal conductivity.
As you should know, the purpose of insulation is to create dead air space. DEAD air does not transfer temperatures.
There is loft insulation to keep in all the warm air from the heater
The insulation is a better insulator than air is. Pockets are there to allow 'slow' airflow so the house breathes and keep the insulation from molding.Also the air only acts as an insulator if it is trapped. If free it moves around and loses it insulating ability. Air in your attic (loft) Does act like insulation, but a very poor one.The same principle is in your double pane storm windows. if one of the panes crack, or breaks, the insulating value of the window falls.