In theory, the little air space between the outside wall of the camper and the reflectix will be hotter than the air space on the other side of the reflectix, inside the cabinet. I'd be surprised if it made a huge difference, though.
I have a similar problem in the winter. I get a lot of condensation on that cold exterior wall, because of the reduced airflow inside the cabinets. I think what I'm going to do is, 1. Make new cabinet doors with an outer frame of wood, and the panel portion is screen. And, 2. Make boxes that fit the inside of each cabinet, including the curved outer walls, but a bit smaller, so there is about an inch air gap between each inner box and the original cabinet.
I'm hoping that if I do both these things, I can put my clothes in the cabinets and they won't get moldy.
If I were concerned about food storage, I think I would do the grill doors and some sort of thin insulation, and not the inner boxes. Reflectix would work.
I think the grills are important, so that cool air from the inside of the living space can get into the cabinets.
3/4 timing in a DIY van conversion. Backroads, mountains, boondocking, sometimes big cities for a change of pace.
