Insulating a Sprinter Van
Although the Sprinter Passenger model comes with an “insulation” package, its really pretty minimal. It turns out to be just some sound deadening patches pasted on the interior of the van sides and a 1″ layer of felt on the inside of the trim panels. The headliner insulation is part of the structure of the headliner and consists of some felted material that is about 3/4″ thick. Insulation is another controversial topic and I won’t get into it what is “best” but from my experience I would at least say to stay away from anything that holds water – especially fiberglass home insulation.
I lined the sides of the van with reflectix to which I bonded to some felted carpet padding (probably unnecessary but I had it laying around). I put the reflectix next to the exterior metal in case of any water leaks through the exterior trim attachments (I’m still not sure if it’s a thing or not, but I read it on a blog so it must be true). There’s a shop up here in AK that provides specialty insulation to the north-slope oil industry and they happen to have this dense polyester batting that is very effective and doesn’t retain water (I’m not sure the R value). It’s easy to work with and also relatively inexpensive. I cut this to size with scissors and stuffed it anywhere I could find a void in the van. The only place I had to glue it in place was the ceiling and there I used a light coat of 3M 90 spray adhesive.
Effectiveness
We noticed a huge improvement over the stock insulation. We have found that in very cold temps, the Espar will keep the van about 50F higher than the external temp. This is based a few nights at -25F and many nights below zero. The locations where I didn’t force insulation showed noticeable frost on the inside. At these temps we could easily tell that cold was also being conducted by the bare metal surfaces which obviously connect to the outside skin. It’s unfortunate that the factory panels in the passenger van leave this metal exposed. In the future, I will likely put up more complete side panels to cover the bare metal surfaces on the interior where possible.
