I obsessed quite a bit about the insulation I was going to use.  Denim is a popular choice. Its R-Value is around 15.  If I opted for fiberglass insulation, I could boost R value to 38 but I would have to deal with formaldehyde offgassing and eventual glass fiber degradation from vibration over time.  Also, the benefit of a higher R value just wasn’t there for me.  At some point after I park the van, I’ll have to heat or cool it. Depending on the temperature I’ll just have to run my equipment longer, and that’s basically the material difference.  I felt that in combination with the Hushmat soundproofing I added, the Denim would suffice.

It was pretty easy to work with it. It cuts easily, it’s not itchy, the size and thickness was perfect for all of the cavities. I sourced this from Lowes hardware locally.  I feel that if it is truly inferior, I’ll discover it soon enough and I’ll make an effort to pull down my trim panels and replace it. So far though, I don’t think this will be the case. I made sure to not impede access to electrical connections or door closing rods or cables when I installed the insulation. I checked for areas where wire or cabling may chafe and mitigated as necessary.

My windows are more of a liability to temperature control and I’ll be making some insulated window covers for them anyway.  The remaining crevices not reachable by hand or denim will have expanding foam applied to help curtail some of the temperature changes a bit too. I’m not sure how effective it may be and I’m not going to get scientific about it. I have a few cans lying around and I’ll use them up. Lastly, part of this phase will include adding a vapor barrier. Something as simple as 3mil plastic sheeting will suffice.