The temp differences in our 3 similar wind up campers at Xmas when trying to kee

Just back from our Xmas hols with my 2 brothers and thought you may be interested in our setups for trying to keep our cool and the actual temperature differences between all 3.

We were all in wind up camper vans, me a 95 Jayco Swan, Bros 2 in a 05 Corimal and Bros 3 in a 70s Viscount. I though it would be interesting to check the actual temps inside all 3 when looking at our various setups. We all decided to put a large silver tarp up, but each did it different. I keep a good size gap between the tarp and van/annexe roof. B2 simply lays his tarp directly over his van roof to avoid the tedious job of getting it all up high; and B3 had his tarp up off one end of his van/annexe only due to lack off support poles etc. Inside temps were taken in the same place, height etc and were:

Me 25.6 degrees
B2 was 32.1 degrees and
B3 was 27.9 degrees.
Outside at the time it was 34.6 degrees.

So I guess all the work involved sticking my tarp up is worthwhile after checking the temps. We were all camped directly next to each other. I thought the later model Corimal would have had better insulation in his fibreglass roof than my older metal Jayco one. Apparently it doesnt help him at all though. Funnily enough it was 29.9 degrees in B2's annexe when i tested it so it proved the gap over his annexe was working okay but was being harshly treated by the heat inside his van pumping out into his annexe from his fans running inside. We all had fans runnning at the time too. I found inside our annexe was just slightly cooler than our van but think this was due to the larger gap between the annexe roof and the underside of the tarp.

I find it takes longer to put up the tarp properly secured etc than to put up my van, annexe, bed flies etc. Maybe next time i spend the extra time putting the tarp up my SWMBO will agree it is really worthwhile in the end rather than complain about how long it takes after seeing the numbers firsthand for herself. And thats not even taking into account how much rain it also kept off in the first week of our break. We collected plenty of drinking water off our tarps during that rain too. Now all I have to do is work out a quicker way to get it all up and I am set....