Originally Posted by TangoTango
I have a 2014 and it blows warm too. It only gets cold if I put it on AC MAX. How is it more economical to run the rooftop AC?
The cost if running your generator vs running the chassis AC is variable.
There are so many factors that will affect your bottom line that it becomes
very hard to determine what's best when. Even altitude will play a part.
The basics are things like horsepower loss and genset fuel consumption. Then there is the engine types for both the chassis and the genset.
Most research puts the parasitic drag of the AC at an average of 5HP. It is that loss of power that costs fuel $'s. My genset is the gas powered onan 4000. The spec sheet reads that I will use about 1/2 gal per hour at 50% load.
Soooo, how much more gas do I use per hour to run the chassis AC? Too many variables for me to answer that but my estimate is that it's pretty close to running the genset under normal driving conditions.
Then I look at the goal, keeping the fur kids cool. So I run the chassis AC to defrost and when the sun is roasting us. I run the rooftop when we are bucking a headwind, traversing mountains, or when it's just too hot for the ineffecient chassis AC to keep up. We bought our mini A so we can travel comfortably so that's what we do. If there is a conflict between economy & comfort, comfort wins.