Quote: (Originally Posted by
Steve)
The space blanket I have in my outdoor survival kit isn't directional. It isn't even that shiny. It works by trapping radiant heat, reducing convective and evaporative heat loss. They work well in wet windy places. They work best when wrapped tightly for good reason.
This is the same issue with scrubbers, the metal, plastic, wood if you like will absorb some of the heat energy from the scrubbing process. It will then loose some of this heat through conduction and convection. It isn't directional.
Was he at all serious when discussing radiated energy?
Umm yeah, I think so. It was a test he did a long time ago and he mentioned it quickly. I think the jist was that in order to focus the heat most effectively in a particular direction, the best way would be use a shiny or polished surface. It seems to work well enough with lasers. I guess another example of this principle at work is the lining of a thermos having a mirror like shine, very thin and then a large-ish airspace, then an outer case, usually made of plastic.
My space blaket was directional and reasonably shiny, as shiny as aluminizied fabric can be, there was definitely an in and an out side. Are you saying that both sides were the same on yours?
I have been saying all along that absorbed heat loss is not directional in nature, to the great protestations of others. -Andy