Naked Science Forum

General Science => General Science => Topic started by: Isaac Lee on 12/02/2011 01:30:07

Title: Why are some clothes warmer than others?
Post by: Isaac Lee on 12/02/2011 01:30:07

Isaac Lee asked the Naked Scientists:
   
Hey Scientists!

Why do some clothes keep you warm while others do not?

Thanks!

Isaac Lee
Grade 9

What do you think?

Title: Why are some clothes warmer than others?
Post by: Mazurka on 28/02/2011 15:10:31

It is nearly always to do with how well the material the clothes are made from traps air. 

Still air is a very good insulator and to a limited extent, air that is trapped in fabric warms up with body heat.  If the fabric is good at trapping air (like a wool jumper or polyester fleece) it will feel warmer than a fabric that is not as good at trapping air (like cotton)

This is why some coats have different layers - an outer water and wind proof layer, a middle layer of insulation and an inner layer to make it comfortable. 

It is also why wearing two thin jumpers is warmer than wearing one thick one as the thin ones will trap air between them as well as in their fabric.

One material that works differently is neoprene that wetsuiits are made from. Neoprene traps water really well, which warms up a lot with body heat.

Title: Why are some clothes warmer than others?
Post by: ns8t on 08/03/2011 20:06:56

Cotton fabric, like blue jeans, are known as the death fabric because wet cotton as one of the Base layers of winter wear will not hold your body heat.  The general rule for insulation is that 'Wet insulaton is no insulation'.  This rule is slightly different with wool fabric. Wool retains insulative value when slightly damp, because the moisture is drawn up off the surface of the skin.  Wool is more suitable for a base layer, if you can tolerate the scratchy texture, but its sponge-like qualities make it unsuitable for a outer layer because it lacks a moisture repellent surface or tight knit fibers to break the wind.  It is not too baaaa aad