From: Howard Beale 
Newsgroups: misc.consumers.house
Subject: Re: Expected Cost Savings with Window Insulation Kits
Date: Thu, 29 Nov 2007 13:01:55 -0600
Bytes: 1601

bodhiSoma wrote:
> On Nov 29, 1:18 pm, Bert Hyman  wrote:
>> 3M claims that their films "[increase] the R-value of single pane
>> window by 90%."
> 
> Thanks Bert, that does help.  It sounds to me like adding the film is
> giving me roughly 90% of the cost savings of adding another pane of
> glass.  That should be substantial.

I found it helped air infiltration and drafts a lot, but what's the R value 
of a single pane of glass?  1?  I'm guessing an R value of 1.9 isn't too 
much to get excited about, but overall we found it beneficial until the 
windows could get replaced.