Thin cocoon or thick patchwork?

[VanTalk00]

Hey Long-time Van Dwellers,

This is a question meant to draw out your intuition about where you feel the most heat loss or gain.  When you answer, try to take on the mindset of someone (like me) building a small cargo van, where every cubic inch is a big deal.

Choose either 1 or 2.  Then say the next most important thing you would do to improve efficiency, given your choice.

1 - Thick patchwork)  Fill every nook and cranny of the sides and top with insulation, but leave the bare metal parts exposed (ribs, anchor points, etc). 

2 - Thin cocoon)  Create a sealed cocoon using 1/2" sheet foam on all six sides.  So this is less insulation than 1), but it covers all exposed metal parts and creates an air-tight seal all around. (I would also provide vents, etc.)

The real question here is the importance of covering those metal parts.

I know everyone is going to say, "DO BOTH".  The point, here, is, WHICH is more effective?  I probably will end up doing both, but I may be less diligent in doing one or the other based on what works best.

Thanks!

Jim

 

[John61CT]

The amap complete seal (aka vapor barrier) is more important than R value.

No thermal bridging via metal through to the skin.

But once you have that, any significant air spaces should be filled, ideally with closed cell foam, polyiso, thinsulate etc.

Inside the ribs, lowest priority.