2006-10-07 23:17:56 · 10 answers · asked by Bijan G 2 in Science & Mathematics ➔ Physics
Particles of warm air get trapped between layers and therefore transfer their thermal energy to us. Duvets have layers and lots of potential to trap air. Thats why wearing 2 t-shirts is better than 1 jumper, and how hair or fur keeps animals warm.
2006-10-07 23:21:04 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Duvets are good insulators. They prevent the heat produced by the body escaping to the open air, instead trapping it between the duvet and the mattress, hence keeping the person warm.
2006-10-07 23:32:50 · answer #2 · answered by Derek T 2 · 0⤊ 0⤋
Duvets and other insulation materals keep us warm by preventing the heat transfering from our warm body the colder environment. Some insulators have better insulating properties than others: in Duvets we call this the TOG rating. In gereral engineering we call this the U-value which is thermal conductivity often measured in Watts per Metre squared per degree C.
Duvets are good insulators because they have small pockets of air in them (in their hollow fibres) and the prevent this warm air from physically moving by convection and transporting the heat away
the three ways that you can lose heat are: Radiation; Convection; and Conduction.
Radiation is very small and only comes into play with hot bodies such as electric fires
Conduction is when heat travels along materails (eg when you stand on a cold floor the heat is conducted away)
Convection is when a fluid heats up, gets less dense and there for rises, taking heat with it. Chimneys are a good example of convection at work, and sometimes if you heat a pan of water up on a stove you can see the convection trails moving in the water
2006-10-08 00:50:41 · answer #3 · answered by Me 3 · 0⤊ 0⤋
It traps air between the filling, that is what keeps you warm.
The tog rating depends on the amount of filling you have in the duvet. The higher the tog rating, the more filling - it allow the warm air to escape more slowly.
2006-10-07 23:21:16 · answer #4 · answered by peewit 3 · 0⤊ 0⤋
it holds the heat of the comforter inside the duvet. especially if comforter is down
2006-10-07 23:21:37 · answer #5 · answered by Anonymous · 0⤊ 0⤋
It has hollow fibres that trap air, your body warms the trapped air up and you stay nice and warm.
2006-10-07 23:22:55 · answer #6 · answered by Vicky 2 · 0⤊ 0⤋
Hot air trapped in funny places - thus turning over can give you a nasty draught in the nether regions
2006-10-07 23:21:36 · answer #7 · answered by MIKE D 2 · 0⤊ 0⤋
traps layers of warm air
2006-10-08 00:32:22 · answer #8 · answered by tom 1 · 0⤊ 0⤋
keeps the natural heat are body produces within its area
2006-10-07 23:22:09 · answer #9 · answered by wac_coach 2 · 0⤊ 0⤋
it uses pockets of air as insulation
2006-10-07 23:25:33 · answer #10 · answered by Alfred E. Newman 6 · 0⤊ 0⤋