When I started one of the requirements was that I remove the cargo bulkhead from my van - company were we signing with wanted maximum space for freight - all the way up to the back of the seats if necessary. So that meant that I'd have to heat/cool the entire interior ...... not knowing how often I'd have to be camping out overnight this posed a bit of a problem - so I decided to insulate the van, along with putting in the E-Track and plywood flooring.
When I started doing this I think it was in February, dead in the middle of a horrible cold snap with temps way below average. Luckily I had a friend with a heated polebarn that allowed me to use it. The Sprinter barely fit inside - with about a foot or less at the front and rear. It took forever to get this project completed - I think over a month - and I didn't spend much time really doing anything else.
I'd have to say that it has paid off in spades - while it hasn't been terribly hot we have had a number of sunny days and the heat gain inside the van has been minimal - I haven't had to turn on the AC yet. And during the time that it was cold the cab heater was more than enough to keep it toasty inside.
