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Full Version: Van insulation for short term large temperature swings?
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Hi, I'm to convert a high top cargo van to live in. One of the first things to think about before I build the interior is insulation. Thing is that I go to places where it's hot during the day but cold during the night, so large temperature swings on the same day. It can be freezing at night while it's warm during the day. How do I insulate to prevent being cold at night while also not being too warm during the day? I'm going for a stealth setup so not a lot of windows. i.e. desert climate. I also would like to just go to cold places during the winter and warm places during the summer without having to dismantle my interior to take out or put in in insulation. I'm just worried that a setup that will keep me warm when it's cold outside will make it too hot when it's warm outside. What did/would you guys do to be climate flexible?

Insulation is what will keep you warm, when it is cold.
Insulation can also assist you in preventing heat absorbed in the metal skin to radiate into your van.

Shade and insulation (from radiant heat sources and from direct sunlight) will assist you in keeping cooler during the hot period of the day. 

Ventilation is how you get rid of the internal heat that might have crept into your van during the hot period of the day.
Low thermal mass (of interior things that got warm ) will help your ventilation period be shorter.

You might also consider what bothers you the most;  being too cold or being too hot?
Another thing to consider is if you will only be using passive methods of managing temperatures, or if you will add active methods to the mix of methods you will use, to keep cold or warm?

Insulation, shade solutions, considering thermal mass (of the interior), opening doors (or windows or ventilation hatches) - could be considered  passive methods.

Adding fans, heaters or coolers - could be considered active methods. 

Since you are planning to use in a variety of different scenarios, then I thing combining with different (and flexible) and a mix of passive/active methods will always give you the best solutions to keep as warm or cold as you prefer.
All insulation does is slow down the migration of heat, doing an effective job will help in both directions, no need for a different design for each.

Except for against both heat and cold, I'd go for equal R-value all round, don't neglect the floor if running aircon.

Obviously a big box van is easier and has more room to sacrifice, 3-4" would be very effective, but few go that far except in extreme conditions, or minimizing fuel usage.

Without active heating or cooling, best you'll get is close to outside temps.

Beyond R-value, as close to a continuous sealed envelope as possible is required, and protection against condensation on the inside metal surfaces.

Controlled ventilation to the outside is key, high CFM fan like MaxxAir or Fantastic Fan.

There are lots of past threads giving many different views of the details.
For warmth, maybe toy with the idea of sleep accessories for backpackers and basic insulation installed just to quiet the van down when traveling, still using a heater of course as needed. For cooling, air flow, and shade when camped via netting or canopy of some form. I say this based on your title of the thread, "short term", so my focus was on personal comfort vs general van comfort, and the fluctuating temps you mentioned. If you're too warm/cold you can dress accordingly, but if the van's too warm/cold, energy or fuel consumption is likely.