Help!! AC for a cargo trailer- still confused.. Ecoflow delta pro?

[missingegg]

The issue with using polyiso and spray foam in a trailer is flex.
Spray foam hardens and becomes brittle, it will seperate from the trailer and allow gaps and air and moisture will invade.
There is some spray foam that remains flexible, permatex? Not sure... but that might be an option. Otherwise, butyl sealant for the seams to remain air tight.
The aluminum skin might be a high quality radiant barrier if an air gap is maintained. No point using foil faced foam when it's inside an aluminum wall.

Excellent point! I should have said: Although there are DIY spray foam insulation kits, you really do want a professional spray foam contractor for a job like this. There's a wide variety of chemical formulations for spray foam, and you want a foam that both has good adhesion to whatever material the trailer skin is made from, and also a little flex to stand up to the flex and vibration that a building wouldn't experience. A good spray foam contractor can help you select the right foam. Or potentially tell you that spray foam is a bad idea for the project.

 

[12VoltInstalls]

Closed cell foam will give you ~R6 per inch after it's aged

I’d call it more like R5 fwiw

 

[12VoltInstalls]

good spray foam contractor can help you select the right foam. Or potentially tell you that spray foam is a bad idea for the project.

Spray foam is a terrible idea for several reasons. But given the alternatives it is a fantastic option.

Foam cracking in cold climates in attics and ceilings is not uncommon btw. Sectioning foam 16OC or 24OC mitigates that a fair amount in trailers.

There is a laminating foam that is a bit less R I’m told but is more resilient up to 2” and is apparently what they use in stressed-skin RVs where the walls are long uninterrupted continuous panels and either fiberglass or aluminum outside and from appearances some kind of composite/HDF mongrel on the interiors. I did not find a way to retrofit hidden wiring in the few I had to work on.

 

[GooseF16]

The issue with using polyiso and spray foam in a trailer is flex.
Spray foam hardens and becomes brittle, it will seperate from the trailer and allow gaps and air and moisture will invade.
There is some spray foam that remains flexible, permatex? Not sure... but that might be an option. Otherwise, butyl sealant for the seams to remain air tight.
The aluminum skin might be a high quality radiant barrier if an air gap is maintained. No point using foil faced foam when it's inside an aluminum wall.

aluminum trailers in general, make another challenge about heating.. my old ATC was a b!tch to cool.. it had a 15k and an 8k, and it would barely keep up on a 5500 Onan.. But, my friends that covered their roof with solar panels actually kept some of the heat off the top of the trailer.. the Back walls got really hot too.. the awning was required to be down when sunny, and I had a 10 ft pop up to keep the sun off the front bedroom.. it was a complete disaster to cool.. but it was charcoal color too.. get a light color.. so I ended up selling it b/c I could not reliably keep it cool enough to even leave a dog in there while I went for dinner or something.. so each is different, but I can say that my current winny unit with the one piece roof is much cooler to the touch, and the 13k unit cools it frigid.. point is in some cases all the insulation in the world wont help a giant heat sink.. so each is different.. but if you cover the roof with panels it seems to help not trap heat in the aluminum roof. It also got really cold in the winter on the floor, so I had to put a carpet and pad down for cooler temps.. it was simply a battle, and I lost.. Im told they have made some improvements in this regard but the pricing has run away.

good luck.. thats a cool trailer!