pnichols wrote:
We keep all rooftop vents and windows closely tight during hot weather travel in our 24 foot E450 Class C. We then keep the dash air flow and dash air conditioning system set to Max A/C so interior air is merely reciculated over and over - hence the Ford air conditioning system does not have to continuously cool new hot air from the outside - it just has to keep the already cooled interior air cool ... which is a way more efficient way to use the dash air's cooling capacity.
What we wind up with is an entire coach interior that can be kept cool using only the Ford A/C system ... because it's so powerful and we're using it in the most efficient way. Our rooftop A/C system never is needed when traveling in even the very hottest outside temperatures.
As a bonus, the interior of the coach stays dust-free much longer because there is no constant flow of outside air coming into it from the cab air flow set to constantly get new outside air ... which then flows throughout the coach and out any open vents or windows in the coach ... depositing dust inside while this is going on as we travel down the road.
If we ever need to leave the roof vents open for some reason when traveling, they're protected from being ripped off via vent covers we've installed over them which still allow the vents to remain open. With vent covers, we can also leave the vents themselves open for fresh air ventilation when it's raining or snowing while camped.
I just did the same as you yesterday.
Small MB Sprinter class C.
Vents closed, air on max, air on recirculate.
Worked very well except MB decided to limit air recirculation to only 30 minutes and it resets to fresh air.
When plugging in or on generator, we just start the RV air conditioner.