• Sprinter-Forum - Using Reflectix / Rattletrap Incorrectly? - I am rethinking my insulation approach… has a long and involved discussion of insulation approaches. Seems like some thorough analysis, but need to review in more detail
    • possibly look at Dow Thermax for roof, since there’s both less available space and heat gain/loss through roof is significant
  • other well-regarded approach is polyiso attached with Great Stuff (specific varient)
  • Promaster roof ribs are slightly more than 1” high so SM600 Thinsulate will be compressed, or need to extend the ribs lower. Probably want to do that anyway, so there’s insulation between the ribs and ceiling
  • various recommendations - with Thinsulate may still be worth adding some butyl panel dampner (Noico, Dynamat)
  • BabyBuffy Silver Vixen ceiling
  • Insulating for Sound has some analysis of sound insulation using polyiso and dedicated sound insulation (Audimute peacemaker) in extended windowed promaster. Adding Mass Loaded Vinyl (MLV)
    • commentary on Thinsulate effetiveness
    • rattletrap in cab area
    • how to avoid water infiltration into thinsulate and condensation on interior of van skin? Or don’t worry about it?
  • insulation techniques with thinsulate
  • tyvek thermarap as a combo encapsulation (but not vapour barrier) and fibrous insulation
  • more insulation analysis
  • Mojogoat “Just finished sound proofing and insulating the drivers and passengers step wells. Covered in sound mat then a couple of layers of Thinsulate. There is a potential problem as the wells have no drain, bottom screws are not sealed so water will collect there. You have to remove the wheel arch and pillar plastics, the drivers side brake plastic too. Quite an easy improvement, 15 minutes each side. I plan on sealing the screws and carpeting the steps attached with velcro so the carpet will absorb the moisture rather than seeping into the well area.”



  • MaxxFan or Fantastic Fan
    • MaxxFan can stay open in rain or while driving
    • Hein makes a variety of roof adapters for Sprinter/Transit/Promaster since the roof isn’t flat
  • Charger7022 recommends “when you install your maxx fan. put a light as close to it as you can, because at night before you go to bed pop the screen out and leave just that light on and within 20 mins all the bugs that got in throughout the day will be sucked out and you can sleep bug free.”
  • swamp cooler for roof vent fan

Floor Vent

Floor vents are useful to provide make-up air for the roof vent/fan, in cases where opening windows is undesirable, or to pick up cooler air from below the van. Dave Orton built one behind his refrigerator to provide cooler air to the coils there. CargoVanConversion added a floor vent in his B-pillar in a Transit - maybe could do something similar on a Promaster? Other Promaster builds have used similar approaches, or other valve closures.

FaroutRide built a floor vent (TODO perhaps with MLV closure, or am I misremembering?)