Optimistic Paranoid said:
As my brother is fond of telling me, "If you have access to a machine shop, a welder, and a big enough pile of money, you can build anything." That said, I wouldn't think converting the engine a.c. to shore power would be either cheap or easy. A 3 to 6 hp motor is one honking BIG electric motor.
Yep!
In the days before electronic engine controls, I can remember that when you kicked on the AC when idling, that big old honking 454 would idle down a bit from the compressor load.
We were always told back then that it takes about 5hp to run the compressor at highway speeds, and that is exactly why using the AC dropped your gas mileage.
Just a small amount of research here on the web reveals that the average SUV or sedan has an AC system that is in the 18,000 to 40,000 btu range, (that's about 1.5 to 3.5 tons) and it takes about 2 hp per ton of btu. More or less.
Most automotive AC units are sized for the hottest summer day in a place like Phoenix, with the car having 8 big non-tinted windows, it's been sitting on hot asphalt for 6 hours, the interior is 150 degrees, and the driver expects to get in, start the motor, and have the inside air cooled down in 5 minutes.
Not really the ideal candidate for running on an electric motor mounted under the hood.
But the reason I am interested in the idea is because I think there should be some way to build a small, stand-alone, efficient, gasoline engine powered AC unit.
Don't laugh....in the trucking industry we have a frame mounted APU (auxiliary power unit) that runs the auxiliary AC compressor directly off the small putt-putt diesel motor in the APU cabinet. I believe its around 9 hp but don't quote me on that. The alternator on that small diesel motor provides DC power for hotel loads and charging the batteries, as well as powering the condenser fan outside and the blower motor in the sleeper compartment.
Anyway. What if you could buy a very small 5000 btu AC unit that looked similar to a small inverter generator, but instead of electricity, this thing had a direct drive compressor powered by the small gas engine, and then it had all the parts needed to blow cold air....bypassing all the inefficiencies and cost of using 2 separate devices. It could be roof mounted or bumper mounted and have 2 hoses for ducting air inside the RV or van, trailer, whatever.
Not like that other kickstarter thing, this would keep blowing cold air as long as you kept gasoline in the tank.
Inverter generators are very efficient and very quiet...I imagine this little portable AC would be also.
All it would take is lots money to engineer, develop, and manufacture...
Maybe *I* should open a kickstarter project!