[77newell]

I have used Armaflex foam insulation around the engine area of my coach, this is a black flexible flame resistant insulation that comes in a variety of thicknesses. I found it's combination of stiffness and flexibility made it easy to handle. It lacks the aluminum reflector on the material that Sean posted about. I've heard of people using plain polystyrene or urethane foam but there is no way I'd use those around the engine compartment due to the fire hazard. I have used those materials for insulating other places such as storage bay floors and walls.