Our EuraMobil doesn’t have air conditioning but it has a three position switch above the habitation door that when switched on sucks air from under the van and distributes it from vents at the roof. EuraMobils reasoning is that it is always cooler beneath the van. It obviously isn’t as good as proper air conditioning but does help to cool the van in hotter climate. It’s just a thought for those with no air conditioning. I think a home made version would be a good job