Running a 120v a/c unit off starter battery

jrnymn7 wrote:

Gdetrailer wrote:

Salvo wrote:
I'm pretty sure I've seen a 120V, 60 Hz alternator link a year or so ago. Can't come up with it right now though.

Sal

MrWizard wrote:

Salvo wrote:
The OP may want to consider a second alternator that outputs 120V ac.

Sal

The Hz/frequency would be way too high, it would still need to be converted

In the past there has been add on 120V 60hz alternators, but the problem was they MUST have a STEADY engine RPM. The same goes for PTO driven alternators which use a PTO provided at the transmission. These types of 120V AC were designed for stationary power in a emergency vehicle.

The only way non stationary use would work is if the alternator was used to drive an inverter sort of like a portable inverter gen.

Instead of messing around with these half baked workarounds perhaps you should consider having an aftermarket engine driven A/C unit installed..

HERE is one of MANY aftermarket A/C systems which are available..

HERE is a Internet search of Aftermarket A/C systems...

Yes, an aftermarket auto A/C system will cost a bit more than a window shaker and inverter BUT you will not need to worry about batteries or if your alternator will handle it.

Besides a small 5K BTU window shaker is going to barely cool off any bus bigger than a SMALL mini van type. If you are doing a 60 passenger bus that 5K btu is not going to work at all..

i'm only cooling about 500 cubic feet... about the space of a small bathroom... of course keeping in mind it's a metal vehicle, and not a room in a wood and drywall house. but it does o.k.

i'll re-look at the aftermarket a/c's, but if memory serves me well, i was looking at a lot more than the cost of an alternator and wiring.

Small metal box with very little or no insulation plus single pane windows and a lot of engine heat = a LOT OF COOLING NEEDED.

Even small cars have around one ton of cooling (12,000 BTU) so like I mentioned 5K is going to be on the small size. Not to mention the smaller A/Cs have LESS CFM of air flow. It may "cool" but I am a bit doubtful that it is going to be comfortable.

My experience with window shakers is this, double the capacity for the square footage listed, then you will be in the ball park. Just for the record, I have an upstairs bedroom which is about 200 square ft. The whole house A/C doesn't cool it enough so I put a window shaker in, 8K btu and that BARELY cools off the room.

I used TWO window shakers in my 26ft TT when rebuilding it, 10K for the main part and a 6.5K in the master bedroom. These A/C units barely keep the trailer at 75 degrees with 95 degree outside temps...