[jracca]

The energy savings from using a DC air conditioner compared to an AC air conditioner (if they are otherwise the same) are very limited. If you already have a good inverter, I am not sure why people are crazy about DC air conditioning. You are saving less than 10% and usually paying much more to do so, and having to use much larger wiring.

I have nothing against it, but I would not pay a lot more. I would consider one if the price was similar or it otherwise fit my needs, but I have a large quality inverter and that is what I run my current air conditioner off of.

As a side note on BTU capacity, I can keep my van cool with a 5000 BTU unit, but it is very well insulated with no windows in the living area (only the cab windows and one in the isolated cargo area). Insulation and lack of windows make this possible. Also I only said I can keep it cool, it would take many hours to cool it down when its already hot.

From 98-75 degrees when outside temps were 98 took 5 and half hours. My can was parked partially in the sun and the heat index was approximately 108 degrees (for those who will say this won't work in Florida or something like that, I did my test in the Texas summer)

In a promaster I would recommend the smallest AC unit you can get by with and plan on using the HUGE (comparably) dash AC unit to cool the van down, and then use the RV air conditioner to keep it cool. You can run the dash air and RV air together for 15 - 20 minutes and then just the RV air.

Having a smaller unit that does not cycle continuously is more pleasant than having a bigger unit that is constantly kicking on and off.

If you have a well insulated van, I would think a 7k unit would actually be a pretty good size fi you are willing to keep windows covered with insulated covers and don't open the doors constantly.