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lastword's avatar
lastword
Explorer
Mar 26, 2019

Ductless AC instead of roof mounted AC

In addition to my roof repairs I am replacing the AC unit on my trailer.
Does anyone have any experience with the Mini Split Ductless AC Heat Pump reliability on an RV? I have seen installs on youtube and they all claim no problems with it. I worry about the bouncing going down the road causing a freon leak, But when I look at the construction of both roof and ductless I don't see significant difference in the build quality or design. So I'm thinking there should be no problem.
Planning to mount the outdoor unit and a generator to a welded platform on the rear of the camper and install a small brush guard and backup camera, and make sure the line-set is insulated and supported properly.
The unit I am planning to use ($460.00 delivered).

https://www.ebay.com/itm/12000-BTU-15-SEER-110V-Mini-Split-Confort-System-Ductless-AC-Heat-Pump-110V/303081116734

Says its good to 600 square ft, I have a little over 200, heating and cooling.
I have worked in manufacturing and installed and maintained many AC units. I have all the tools vacuum pump and hoses/gauges.

Thoughts? Sanity Check!

29 Replies

  • S Davis wrote:
    I would be worried about the flair joints typically found on mini splits, these units when using R410a can reach pressures as high as 550psi during normal operation. I would look for a unit that the piping could be braised, don't know if there are any.

    The SMRT way to get a line set for these mini-splits is the premade ones that also come with powe /control wire . I only installed Carrier & LG Mimi's when I was in business and never saw one that didn't use Flare fittings which requires a really good flare tool. You also need the service valve hose adapter for your gauges
  • I would be worried about the flair joints typically found on mini splits, these units when using R410a can reach pressures as high as 550psi during normal operation. I would look for a unit that the piping could be braised, don't know if there are any.
  • Not an AC tech but have installed a few, RV thin walls and poor insulation along with single pane windows make oversizing necessary.
    I would upsize by 50% to 100% meaning 9=12K Btuh.
    It wont hurt anything, if anything it will just shorten the cycles a bit. You may even get lucky enough at a 9-11k level to be able to start and run on a 2ooo watt genny for future boondocking.
  • The sizing might be pretty close the old AC coming out of the camper uses a RK160AT-024-J7 compressor rated at 115V 1hp and 13k BTU.
    If anything it may be a little bit too small at 12k BTU. Thoughts?????

    I'm getting mixed messages.
    Conversion charts show 6k to cool 150 to 200 sq ft.
    Check the chart on the bottom of the page. I have 147 sq ft to cool and heat. 12k puts me about 3x the rate they recommend.
    I should be able to hang meat, lol
    https://www.ebay.com/itm/Klimaire-12-000-BTU-21-5-SEER-AC-Commercial-Ceiling-Cassette-Heat-15FT-Kit-220V/132165174666?hash=item1ec5a8858a:g:ZPYAAOSwsDZb6sSH
    If I need to reduce cooling I can block the intake some or slow the fan or put in a smaller expansion valve. If I need more cooling well too bad If I don't get a large enough unit.

    My wife has to have the noise from a fan to sleep so air circulation into the bedroom should not be an issue

    The line set will travel straight to a 36 inch wide floor to ceiling closet and then down to the floor level passing under a couch/bed and then out the back of the camper to the outdoor unit, two 90 degree sweeping bends. I will buy copper and insulation from my local ac supplier to make the line set. It will be encased in a cut resistant sleeve and supported by straps every foot or so.
    The condenser water drip line will follow the same path until it it is about 3 ft behind the tires and will then exit the floor of the camper.

    To stabilize the compressor unit I plan to mount with rubber bushings on the bottom and screw on a bracket on the top and use rubber bushings there as well. Movement in all directions should be restricted to less than 3/8 inch and will leave the last 2 feet of the line-set to have freedom of movement. If the line-set fails it should be at the last rigid support.

    The connections are single flare with a plastic bushing.

    It is nice having some one to bounce ideas off of thanks to all!
  • I've had heat pumps in the s @ B for 42 years and IMHO they suck.
    bumpy
  • We installed a few of those in guard shacks, they seem to work well, filter changes were frequent and the fans were still nosier than I would have liked, but at least the compressor noise would be moved outside so it was much less noise than a window style unit. Just make sure you isolate it from the frame.
  • The main trouble I have seen using units not made for vehicular use is the compressor mounting. They often use very flexible mounts to reduce noise, but over the road travel will move the compressor enough to break the copper lines.
    You can deal with it up front, though.
  • MINI

    The concept may be fine but I wonder about the quality of CoNfort vs CoMfort and others like Mitsubishi Carrier etc.

    The reduced noise would be very nice. Others with AC experience may comment on sizing and if it's too large for the area.

    Where would you mount it and how do you picture the line set entering the RV? Drain line etc.
    Wondering if bedroom would get too hot.

    Some manufacturer offer a ceiling cassette that may fit the existing hole.

    I've seen mention of flaring issues and it's probably because they single flared vs the double flare. Double flare is easy and no big deal.
  • I like the idea myself. The noise from the rooftop units is awful. Buy a really good flaring tool and you should be ok.Good luck.