View Single Post
Old 12-21-13, 02:22 AM   #30
ctgottapee
Helper EcoRenovator
 
Join Date: May 2013
Location: Central IL
Posts: 94
Thanks: 33
Thanked 8 Times in 7 Posts
Default

Don't get me wrong, I understand your sentiment.

The intent was to indicate that bubble wrap may not be any more of a miracle than say standard plastic film, which is basically what it is with plastic bubbles on it. And then the degree of miracle is more in its low perm and air restriction; the R value is the skin effect which is about R1 if you seal it properly.

The trapped pocket of air in most cases where one would use this approach would not be insulating as it's not trapped on the window side due to air infiltration - hence why the plastic covering helps so much. The air pocket in a window only has R value because it's sealed.
The more aesthetic and long term approach would be to air seal the window or replace it.
As the test noted it still didn't do much even with a window that probably had a fairly sealed installed as it is extremely difficult to get a true trapped air pocket; windows have multiple gaskets and are filled under vacuum.
Unfortunately the bubbles don't do much as they are not contiguous nor thick enough to have an insulating value - 3/4" is generally what you need for an air gap to have an insulating value. Trapped air in some insulating products is where the benefit comes, but as a whole contiguous unit, if some parts don't have the uniformity it loses sig R value.
Bubble wrap can be free if you can get it wide enough for a window, although it doesn't have a WAF. At the point of using bubble wrap on a home window, one might consider just replacing the window with an insulated wall. The wrap would be equally helpful in hot summers too.

I love the DIY stuff and people sharing info, and my intention is not to stomp on your share, but we should always strive to present a full picture, otherwise we chase shadows and sometimes do more harm than good. There is nothing wrong with declaring a winner with caveats or only in certain restrictions. This type of effort seems more suited to say garages or storage basements and similar type of buildings to get quick cheap help where you can live with the visuals.

We have to be careful not to fall into the candle flower pot heater realm

Quote:
Originally Posted by AC_Hacker View Post
Why don't you do the control comparison?

-AC
ctgottapee is offline   Reply With Quote