AC question: 2 compressors in a single system?

[JustKip]

Just looking for ways to save space and weight. Is it possible to have a single evaporator (and maybe a single condenser too) plumbed to be powered by a belt driven compressor when driving, and then an electric compressor when parked?
As much space as the interior parts take, it sure would be nice to get rid of some superfluous pieces.

[cadillackid]

there are threads on this.. it takes horsepower to make cool air.. Joeblack is using a pony diesel engine to build his system out to be useful parked and driving... you are going to need a 2-3 HP motor at least to spin that belt driven compressor when parked. and 5-6 for driving.. adding a 2nd compressor presents many challenges..



electric compressor add-on? I wouldnt do it..

you cant just pipe it in.. you have to valve it off from the main.. and in doing so you somehow have to ensure that all the oil didnt end up in one compressor vs the other.. enough oil to have 2 compressors may mean too much oil could potentially circulate around because it all ended up in one compressor when you shut it down and valved it off.. so you either need manual high pressure valves capable of refrigerant pressures.. or you need fancy expensive electric ones..



thus why the pony engine ideas are in my opinion better.. however of course those make noise.. though you can probably isolate for the noise..





you can however get clever with how you build your driving A/C out.. incvorporate the units into cabinets, replace the evaporators with bulkhead mount slim-line units designed to fit in the space above the windshield, build basement boxes for them?



it takes a lot of A/C to cool a moving bus.. even a nicely insulated one..

if your bus has 2 A/C systems in it and you are insulating top to bottom you can pull one out and move the other toward the front. and likely be able to keep yourself and passengers cool while driving..

-Christopher

[JustKip]

Thanks Christopher
The mechanics of high pressure valving, and oil isolation was exactly the info I was looking for.
Also was wondering about the difference in demand between being stationary and moving, and if the smaller electric compressor would be effective in a larger system, but the portetiaal problems already mentioned are enough to be a deal breaker.
2 units it is.