[VAC] Re: insulation - heaters - cold climates

["Lewis A. Lindner" <llindner@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

As you may have gathered from the replies you've already received, the only honest answer 
probably is: "it depends".  It depends upon the age of your a/s, how it is set up, and how 
well it has been kept up.  

At one extreme, the newest coaches have had special attention given to the issue, and even 
have extra insulation between the ribs and the interior skin to decrease heat transfer by 
that route.  Some as far back as thirty years ago were double-glazed.  All of them for many 
years have had a layer of fiberglass sandwiched between the inner and outer aluminum skins.  

How well does this work?  You probably can judge this only by gathering the individual 
experiences of other owners, and try to extrapolate that to your own personal comfort level.  

John and Dan already have outlined their experiences for you.  My own personal experience is 
based on three winters in the less draconian climate of central Ohio, in a fairly stock '72 
Safari.  That means single-glazed windows, a single 600 watt radiant heater, the original 
22,000 BTU Suburban furnace for two winters, and a 32,000 BTU Atwood replacement for the 
third.  

During these three winters I have experimented quite a bit to see just how much I would have 
modify this setup in order to remain comfortable -- and let it be said from the beginning 
that I am not into martyrdom or "tough".  This is how it has turned out for me:

Particularly with the Atwood replacement, there has been no trouble keeping the interior of 
the coach at temperatures above 70 for any external temperature down to zero, even with no 
modifications.  However, that is not the same as "comfortable".  In the first place, the 
unmodified coach has a lot of infiltration, through holes in the floor, around the 
wheelwells, around the refrigerator, around the battery, etc.  Secondly, vents covered with a 
single layer of aluminum and windows glazed with a single pane get very cold and transfer a 
lot of heat fast.  Therefore, even when the thermometer says the temperature is fine, one can 
feel chilled due to drafts and radiation of body heat to the cold surfaces -- particularly 
near the large wraparound front window.  

To this point I have experimented with only a couple of minimalist modifications.  The most 
helpful was to Scotch tape a single layer of Saranwrap over the air conditioner, two of the 
three vents, and one of the side windows.  The other has been to make liberal use of pillows 
and a comforter between someone sitting on one of the beds and the wall.  With these, I have 
managed to remain quite comfortable throughout all three winters, as has my wife (who 
actually prefers cooler temperatures than I).  I have kept a supply of heavy-gauge clear 
plastic film oon hand for more aggressive glazing, and a suppy of caulk to seal off the the 
cracks around refrigerator, etc., but have not been motivated to use either as yet.

While I'm sure this would not suffice at -20, the only real downside to this arrangement so 
far has been the rate of propane consumption.  I go through about thirty pounds a week at 
freezing temperatures, and in just a few days at the single digits.  I do plan to caulk the 
cracks and to recarpet the coach up to the beltline (similar to the current production) 
sometime this year.  Were I then to put plastic film over all the windows and vents, I'm sure 
my propane consumption would drop back drastically.  I probably am too lazy to expend the 
energy Dan has unless I decide to do January in North Dakota -- a highly unlikely 
proposition.  

Hope this is of some use to you.  This is a fascinating topic for me, and I would like to see 
more on it.

                        -- Lew #4239

'72 Safari
bicycle