Posted by Eins on November 20, 2000 at 23:44:51:
In Reply to: Vacuum an insulator??? of sound maybe posted by right on November 20, 2000 at 18:37:24:
>>...which is what the garments are for. They trap air, which absorbs the heat radiated from your body, keeping it nearer to you.
Wetsuits are still being described working "because they let in a thin layer of water which gets heated up by the body and then keeps the diver warm."
Sorry, but that's just as much BS as what you said above. I don't mean to flame you, but it is simply not true.
In a cold environment any heat taken from the body to warm up anything outside of the body (your undergarments, water in a wetsuit) IS HEAT LOST. It will always be cooler than the body, so it can't warm the body up.
A layer of undergarments (or the air bubbles in neoprene) is the best way to insulate the diver short of using Argon or a vacuum. Air has less conductivity for heat than water, but a vacuum has less than air. Of course, using a vacuum layer in rec diving is not practicable, but it would certainly insulate better.
Again, insulation is key, it prevents loss of heat. Warming up a layer to keep you warm and thus prevent heat loss is the wrong way.
Eins