Insulation, one of the drawbacks of using an ambulance as a camper is the massive amount of thermal bridging. This occurs whenever a material goes from outside to inside and conducts temperature. Unfortunately, aluminum is a great conductor. This is how I insulated my diy ambulance camper.
The idea is to provide an insulation layer between the outside metal wall and inside wall.
Most ambulances come with some kind of insulating material between the “studs”. Although this helps we really need something inside the studs.
In my application I’ve got both the fiberglass insulaton between the framing then a 1” layer of pink xps between the frame and interior walls.
A good solution for aluminum walls and studs. Especially when considering the fact that I can block off the front greenhouse.
A great benefit of this pink xps insulation is that it’s available at Home Depot.