[Mageeacres]

Hello all, 
     Has anyone ever contemplated replacing the front and rear overhead ac units with a mini split in the basement on a classic coach?? 

Or have I lost my mind for considering?

     My coach is a 1980 classic 37 foot (no slides for y’all whipper snappers) lol. I have a free basement compartment just to the aft of the curb side center entrance. Removing the loud old top singular ac units and replacing them with 14” power vents and having a central unit in the basement for ac for a mature classic coach …wouldn’t that be awesome using 21st century technology?. Is it possible??? Thanks in advance for your replies. I probably have 900 to 1000 cubic feet I’m guessing in the classic. 
Thanks in advance for your replies.

[Jack Houpe]

How much room do you have? Measure up and down side to side of compartment, you will have to cut a couple holes in the floor for ventilation of the compressor. Pictures are worth a thousand words here.

[Richard]

Anything is possible.

The bigger challenge will be with the interior and what you are willing to do.

You will have to decide whether to use wall mounted cassette units or hidden ducted units. Get the dimensions for both, take a tape measure, and figure out where you are going to put them.

[Little]

Not a Newell but we put a mini split unit in our 1979 MCI a few years ago. I don't have any pics but from memory:

We had to use a hole saw to cut thru the body into the bay.
We cut a large rectangular hole in the bay door and installed a louver type vent.
We used the same louvered vent for out gen.

Our A/C unit came with long pipes. We cut those to length. They recommended coiling them up but we had nowhere to mount(store) them.
We ducted the system thru the bus cooling/heat system.

We started on this project many yr ago as the bus A/C didn't work and I wanted to get rid of the huge heavy compressor in the rear when we built the tow hitch.
Our daughter is living in the bus 100+ miles from here while her house is built. If we go that way I'll take some pics. I don't remember it being a difficult job but everything seems to take a long time. Good luck. Mark

[Jonestead]

As stated, anything is possible
No you are not crazy you are just considering installing new equipment
Measure for everything plan your desired system, then measure for everything again and again until you feel like your ready then do it.
Look forward to seeing your plan as it progresses into reality

[Mageeacres]

Thanks for the replies.
      I figure I have about 220 sq ft of air space in the coach all else is cabinetry and furniture etc (as opposed to just the shell estimated 290ft2). And enough room in the central basement with necessary ventilation of course for efficient heat removal for one each condenser compressor. and topside enough space for each blower/ evaporator, one mounted fore and one mounted aft on the interior, (probably mounted within the outdated tv cabinets.) …of course these being heat pumps they will definitely be able to assist in heating the Classic existing three propane heaters and four electric heaters dispersed strategically within the coach.   
    The power requirements are 120vac at about 600 watts each. We Will be installing each unit on separate legs of the 50 amp circuit as not to tax the individual dual breakers in the power panel, (ok one project at a time, I definitely would have used single breakers at the expense of a larger breaker box. IMHO ). Thus allowing when the generator or 50 amp shore power to be able to run both simultaneously or one unit for sure when only 30 amp service is available.
    I Had considered a dual mini split system however that would limit the shore power to 50 amp service for 220 vac service necessary for the single compressor/condenser and I need the lesser current draw latitude for when traveling and if only 30 amps shore power are available or inverter power limited by cloudy or inclement weather.
    This power arrangement would at this time mimic the existing power setup of the current two Coleman rooftop 13500 btu units. The advantages of the new single mini splits is that at 12000 + btu each they will use about 20 to 30% less energy and that’s definitely a benefit when the time comes to upgrade from flooded batteries to lithium, and solar as the roof will not be cluttered with the noisy 1970s inefficient technology by designing something with too much loss of cooling to the condenser so close to the evaporator…  again … in my humble opinion.
    So it looks like minimal drilling is required for the flexible (yes they make those now) freon/electrical lines while running 9’ of 10/3 Romex to the panel box from the basement will leave two circuits to use where the existing rooftop inefficient ac units were and to install a dc power updraft/downdrafts vent as needed in those fall and spring times where beautiful weather persists. And of course, routing of the condensate drains for each to a possible central collection point . (collecting the the condensate water back into a/the potable water tank, Hmmm an endless supply of clean water… another benefit). I’ll have to think on the risks of potability or at least other uses like keeping the window washer reservoir full or using the water for other uses.
    Ok now for the money…the cost for two mini split systems at this time is roughly 30% less than replacing the two existing noisy inefficient 70s technology.. I digress.
      Ok thanks for listening and
I definitely appreciate your comments.
Thanks to all the newell gurus out there.
m-

[HoosierDaddy]

I have engineered ( in my mind) installing mini-splits into my 316. The main issue I have not figured out is how to move enough air through the outside condenser based on what I understand the requirements to be.

[Mageeacres]

That too is my main concern evacuating the heat from the condenser units in the basement. I was thinking about a couple of thermostatically controlled vent fans to continually move air ducted through the basement space. One pushing and one pulling the air from one side of the coach to the other.

[HoosierDaddy]

Moving air from one side to the other is probably ideal for the condenser. I have a concern about air noise on the passenger (entry door, patio area) side. My coach was built as an entertainer coach with four basement Duotherm units. One of the units actually draws air in and exhausts through the center-bottom of the coach . It works but I wonder about efficiency since the two bottom ports are right next to each other. The other three are on driver side and draw air in from the side and exhaust out the bottom.

[Jack Houpe]

They make 12k btu heat pumps inverter mini splits in 120vac, two of them would be perfect for your coach. Each one will draw right at 1000 watts on high and ramp down to less than 500 when the coach cools down. As far as the venting of the compressor cut two holes one on each side of the compressor then seal the compressor to the walls of the bay with 1" foam this way the air is forced in and out through the holes. I would say 12x 24" rectangle holes would be pliantly big. Yes they do make flexible refrigerant lines I've used them on a door I mounted the compressor to, after I was happy that the system was going to work I built a fancy box around the compressor. The box cost more than the mini split system to make. Getting rid of the roof top unit opened up space for two 385w panels, when the van was at its set point for temp it was powered totally off the sun at 485 watts.