Thread: Cold Safe Room
View Single Post
Old 08-30-2010, 06:23 PM   #8 (permalink)
wyatt
EcoModder
 
Join Date: Jul 2008
Location: North Central Alabama
Posts: 572

Big Salsa - '04 Toyota Sienna LE

Silver - '10 Toyota Prius III
Thanks: 110
Thanked 123 Times in 71 Posts
Quote:
Originally Posted by RobertSmalls View Post
Interesting fact: adding additional insulation to a cylinder can INCREASE heat transfer by increasing the outer surface area faster than it increases the insulation thickness. I don't believe this applies to any geometry but cylinders.
And small cylinders at that. In college, we had a lab that centered on this idea, and found that in theory, this is true, but in practice, it is only true on hypodermic-needle-size cylinders, and not true for larger cylinders. So feel feel free to pack on the insulation!

If you are actually going to attempt something like this, you will want to make sure things are sealed up tight, and then have a heat exchanger for getting fresh air. If there is much of a draft, you will find that you lose most of your heat just to that. If you have it all sealed up with no fresh air able to get in, you could suffocate.
__________________
  Reply With Quote