Insulation
I will be purchasing an Imagine Grand Design 2018 RB2600. The insulation is listed as, Floor R-30, Roof R-40 but the walls are listed as R-7. I was wondering if this is sufficient insulation for the t...
Forum Discussion
TurnThePage wrote:
The Imagine line uses that "radiant foil" insulation to get those big numbers in the floor and ceiling. I'm not knowledgeable enough to know exactly how the system works, but I'm comfortably sure you're not actually getting R40 insulation value.
Yes, the folks who make the reflective barrier/plastic insulation tout those high R- numbers and the way they back up their claims is that it is calulated using the foil barrier film and an airspace that is hermetically sealed. The bulk of the insulation value is done by the sealed airspace and not the plastic film. The RV mfgs just copy and paste the barrier R- number information into their brochures. It is deceptive and borderline, fraudulent.
When I restored my old Starcraft, the major impetus was to get as much insulation value as possible in the spaces available. To that end, I used extruded polystyrene in the frame cavities, A polystyrene film as vapor barrier, and an additional polystyrene panel over the frame and underneath the paneling that serves as a thermal break. Wheel weels were treated the same. I also installed Low-E windows. I accomplished what I set out to accomplish and the interior noise level is super quiet. With the door shut, I can barely hear passing vehicle traffic.
A 1200W heater at 25f ambient will raise the interior temp from 25f to 75f within 30 minutes.
