IDk I get these wild ideas late at night while surfing the net. Why couldn't a person replace that engine driven a\c compressor with an electric one, say from a residential central air unit? The benefits to me would be significant. No eyesores one the roof, you could use the existing evap and condenser, and could be used OTR or off shore power\genny?
Thoughts, ideas, critics?? (I love a challenge) ??? ;D
Much appreciated, Joe
You'd probably need a 10 ton compressor which would only operate on 240vac. A 50 amp power pole might run it, but I have my doubts. I have three roof top A/C's that usually two cool just fine running down the road-just to give you an idea. Good Luck, TomC
energy is energy right? if used correctly and made to be efficient i think it could work? two roof top unit running approx 15kBTU each can be run and keep you cool. a 2 ton unit cools most 1600 ft homes? i would thing it be a lil overkill? the higher volt operation is a turn off though. Just an idea? has anyone ever heard of this before or am I dreaming.lol :P
Hi Joe,
Yes, you can. But, alot of thought has to come into play..
The largest [medium temp] single phase hermetic compressor is 60,000 btu's or 5 tons. Anything larger will
jump to 3 phase electric. You will have to concider the conditions, the places you will use your coach, and
if the places you stay will have 50A/230v electric service. If not, you will have to depend on a full time generator.
A much easier way to go is to build a home type split system [air handler/condencer]. Try and go see some
entertainer coaches, many have this type installed with 17K+ gensets running full time.
The short of it is that roof tops will give you the same amount of cooling in multipals and still have redundency
with the 115v option.
Good Luck
Nick-
check out mini split heatpumps put in eBay search ( mini-split) I'm using in new project and many others on board have before me. heat and AC in one efficient unit.Use search function at top as it has been discussed here. Bob PS will eliminate all he high demand DC loads from fans the most amp eating thing in bus.
Quote from: bioVenture on December 05, 2010, 10:15:26 PM
energy is energy right? if used correctly and made to be efficient i think it could work? two roof top unit running approx 15kBTU each can be run and keep you cool. a 2 ton unit cools most 1600 ft homes?
Sorry, but that's not how it works.
Yes, a pair of 15,000 BTU/hr roof airs will cool an RV (barely -- most 40' rigs have three of them). To turn a bus into an RV that could be cooled that way, you'd need to remove/cover much of the glass, add quite a bit of insulation, seal up a bunch of leaks, and, importantly, have only two or perhaps three people aboard.
The factory road air is made to cool a bus load of 48+ passengers in the factory configuration will less than ideal insulation and lots of glass under less than ideal conditions. You simply can't compare it to a 2-ton residential unit.
Is the road air overkill for a conversion configuration? Almost certainly. But you can't just put a little 30,000 BTU/hr refrigeration compressor on it and expect it to work -- there is an enormous amount of refrigerant in that system, and the condensers and evaporators are huge. In order for it to work at all you will need to drive it with a compressor nearly as large as the engine-driven factory unit. As Nick writes, that will require a three-phase motor -- motors that large are simply not made in single-phase (and certainly not in 120-volt).
Lots of other ways to cool your coach when parked; you've heard a couple of them already and you will hear more I am certain. But driving the factory road air electrically is not a practical option in any way. The decision most converters face early on, if they have a working road air in the shell when they get it, is whether to keep the road air for use while driving, in addition to a separate system for while parked, or to ditch the road air entirely to recover the space and weight for other purposes. This last subject has been discussed here extensively and there is plenty of information in the archives, with adherents on both sides.
HTH,
-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
I had same thoughts. One reason I did not is the huge power demand of the condenser and evaporator fans plus the huge amount of refrigerant the massive system requires..Big bucks in today's market.Even if the compressor is plugged into a shore supply you still have to run the huge DC fans mine had 100 amp breakers on them. Facts for consideration. Bob
I would like to add info on Heat Pumps.
Joe, and anybody that lives in the northern part of the country. [NC KY NV] on up.
Heat pumps will start to loose their efficency at 40 deg's F. They will still produce heat
at 40 but will no longer be economical. At 30 deg's F, they will start to ice up on the
outdoor coil. [evap in heat pump mode] The system will still prodece heat inefficienty
except when the system has to defrost. Then you will see no heating at all... At 20 deg's,
you better have a back up system like a webasto or LP unit!
Heat Pumps work very well in their intended climate.. [In the south] That's why residential
systems have electric resistance back up heat for emergency and defrost cycles.
Good Luck
Nick-
Well it was worth a thought. Thanks for all the info. I still want to use a basement type a\c though. I will keep looking and keep thinking ;D
Quote from: bioVenture on December 05, 2010, 09:10:35 PM
IDk I get these wild ideas late at night while surfing the net. Why couldn't a person replace that engine driven a\c compressor with an electric one, say from a residential central air unit? The benefits to me would be significant. No eyesores one the roof, you could use the existing evap and condenser, and could be used OTR or off shore power\genny?
Thoughts, ideas, critics?? (I love a challenge) ??? ;D
Much appreciated, Joe
Just wanted to say welcome neighbor. Its nice to have other busnuts so close. Also your not the only one who gets them late night brain farts.
Quote from: timetogo40 on December 06, 2010, 10:29:36 AM
Quote from: bioVenture on December 05, 2010, 09:10:35 PM
IDk I get these wild ideas late at night while surfing the net. Why couldn't a person replace that engine driven a\c compressor with an electric one, say from a residential central air unit? The benefits to me would be significant. No eyesores one the roof, you could use the existing evap and condenser, and could be used OTR or off shore power\genny?
Thoughts, ideas, critics?? (I love a challenge) ??? ;D
Much appreciated, Joe
Just wanted to say welcome neighbor. Its nice to have other busnuts so close. Also your not the only one who gets them late night brain farts.
We are beginning to see there are much more of us nuts around than i orig. thought ;D ;D