Thoughts.

[travelingalice]

If you have eps foad board insulation (less than 1 inch thick sandwiched between bubble reflectix insulation. Would eps act as an airgap for the reflectix? Or would you need a gap between foam and reflectix as well.

 

[Martian]

The bubbles are the air gap. I believe you are putting too much engineering into your premise. RV's are typically not airtight and the individual sections in the wall are not well isolated from each other which means that if the wind finds its way into the rear left wall there is a chance you will feel a breeze coming out of the wall near the front due to plumbing openings, wire run openings and poor construction.
If you are insulating to use the unit in winter, remember that humans release a lot of water through respiration and it will condense on any cool surfaces. This means that even double pane windows will have plenty of moisture running down them.
If you are trying to insulate from heat, reflectix window covers will help a lot along with vent plugs. Don't forget to cover the dome over the shower with it too.

 

[travelingalice]

The bubbles are the air gap. I believe you are putting too much engineering into your premise. RV's are typically not airtight and the individual sections in the wall are not well isolated from each other which means that if the wind finds its way into the rear left wall there is a chance you will feel a breeze coming out of the wall near the front due to plumbing openings, wire run openings and poor construction.
If you are insulating to use the unit in winter, remember that humans release a lot of water through respiration and it will condense on any cool surfaces. This means that even double pane windows will have plenty of moisture running down them.
If you are trying to insulate from heat, reflectix window covers will help a lot along with vent plugs. Don't forget to cover the dome over the shower with it too.

No replacing moldy rv floor just half of my bathroom under the bathtub not for wall and planned to us astro foam as a sealer to connects the boards to have a continuous instullation. Under my new sub floor.

 

[Martian]

Ok. Sorry If I misunderstood. Good luck with your project.

 

[Isaac-1]

I suggest you weigh everything you put in, otherwise you may find yourself in the situation a friend of mine did when redoing a camper van about 20 years ago, and find yourself way over weight before counting passengers and cargo.