Retrofitting Air Conditioning Systems

[K4Eagle]

I have a blank '89 coach that will be converted into an RV, and I'm trying to avoid throwing air conditioners on the roof (for aesthetics) and instead use the existing ducting and mechanics.  Has anyone on here tried using a "dual pump" setup in the existing systems: using the engine-driven pump or a 220v AC pump to the existing condensers/evaporators?  I'm lucky that the existing system on this '89 is r134a, so I'm tempted to try some experimentation, along with a 110v fan to cool the condenser instead of the hydraulic fan setup in place today.

[beltguy]

Matthew (do you go by Matt?), I recall this being discussed some time ago -- I think on another board.  It is an interesting question.  To my knowledge, it has not been done.

If I understand your thinking, you want to have two compressors in the system - one engine driven and one electric motor driven.  I am not an AC expert by any stretch of the imagination, but I think the concept could work.  That said, the Eagle factory system is huge and rather complex and one that is old and perhaps prone to parts failure and leakage.  An electric motor driven compressor would have to be pretty darn big to address the size of the system.

If your present system is working and holding a charge, then you have a starting point.  If it is not working, then you will probably be in for a lot of headaches.

You are probably correct that you may have to use a 220 volt motor to handle the size of compressor you need.  That would make boon docking in hot climates a challenge.  You would have to run a large generator or be on a 50 amp power pole.

Many folks are now using mini splits.  When they were first adapted to bus use many years ago, folks were quite skeptical.  However they are much more common today and seem to work well.  For a bus your size, you would probably need at least two units.  That take up a lot of bay space, but it would give you redundancy.

Keep us posted. 

Jim

[rusty]

When the eagle 25 was built in Brownsville it had two compressors. One was 220 volt and one was motor driven. I never heard how it worked. I know that bus was for sale lately maybe the current owner can answer if it works or not. Also that is a complete new system not using any of the original eagle AC.
wayne

[K4Eagle]

Thanks for the input.  I'm really just starting in on this idea. 

We have a 17.5kw 220v diesel generator that will be installed, so we have the power to drive pretty much anything if we wanted.

I'm also now entertaining a commercial bus AC install, but I need more info on the power requirements for those;  if some models are all electric, what do modern busses use to power them, and is that something the existing generator on the 6v92T can support, or does it need an accessory? 

It gets bewildering with all the options:

-Driving: Prefer to use existing bus AC system, if not, then roof mounted via engine-derived power supply (not generator)
-RV Park: Plug in, but can a standard plug in run a large bus roof system?
-Off Grid: Generator

Another caveat is that I have yet to "fix" the current AC system; It is sealed with some pressure, but system will not activate compressor clutch.  At this point in the game, if the current system is a bust, then we can remove one variable and go the all electric option for AC system.

Thanks for reading this brain dump!