Mini Split AC - Condenser unit in fifth wheel basement??

[longbedbob]

Instead of adding a second roof mounted AC to our fifth wheel, I'm investigating a mini split unit instead. Weight, but most importantly, power considerations are my motivations.

Most of the information that I've found deals with folks either mounting the condenser unit to the tongue or creating a shelf and mounting to the rear of the camper.


What I have not yet found is anyone mounting the condenser inside of the front basement.

I suspect that clearance might be an issue.

My front basement runs the entire width and has a front facing access panel. Based on the dimensions that I'm seeing, I think there is space.

I would need to leave that access panel when the unit is operating.

The fan unit would be above in the bedroom. There's already a wall dividing the bedroom and bathroom that has a hard mounting point for a TV. I could route the refrigerant lines along the wall from below. Any condensate drain would go through the wall and connect to the sink drain on the other side.

Anyone seen something like this?

Thanks.

[PButler96]

colliehauler wrote:
Hopefully the Forest River will be better engineered.

ROFLMAO, that's funny.

[spoon059]

longbedbob wrote:
Instead of adding a second roof mounted AC to our fifth wheel, I'm investigating a mini split unit instead. Weight, but most importantly, power considerations are my motivations.

OP, curious if you ever moved forward with this and how it worked out.

[JoeH]

I saw an old restored pull behind a few weeks ago that had a mini-split on the A frame hitch

[jjrbus]

RV basement air have been around for ages. I helped someone install one over 20 years ago. Will not see them as they are expensive.

Now that I think about, unit performed very well and needed to be replace at about 15 years old.

[colliehauler]

hottub wrote:
check out the new Forest River River Ranch fifth wheels coming out in Oct.
ac units mounted in basement

Alpha Leisure use to have basement mounted units. My understanding is they didn't work well and failed often. Hopefully the Forest River will be better engineered.

[hottub]

check out the new Forest River River Ranch fifth wheels coming out in Oct.
ac units mounted in basement

[jjrbus]

Inverter, heat pump minis "modulate" ie they have a variable output. My 9k Daikin's will put out from 4000 to 11000 btu. Need to check maker of unit to see what they put out. In humid areas the lower the btu's the better as it keeps the humidity down. Another nice feature is they do not start on high, but start on low and ramp up to the needed output. Which makes them ideal for small generators.

I do not think there are any specs for roof air, manufactures do not want to tell anyone anything.

[C_Schomer]

A tight rv doesn't have much latent load so 450 cfm/ton would be muy bueno to work mostly on the sensible load. I've never seen specs on an rv roof AC but I'd be surprised if they deliver 12k btuh net. A real 2T 14 seer mini split would be heaven. Craig

[jjrbus]

If I had room for the evaporator I would have put a mini in my Toyota years ago! Have 3 in my house, self installed.

There will be no condensate in the bay, the inside evaporator is what produces the condensate.

There have been minis put in bays so should be doable, with my limited knowledge I would not go that route. The minis move huge amounts of air to cool, I would guess a 1000 cu ft a minute, as an example a roof air pushes about 300 feet a minute into the living space. If you can leave both bay doors open and not fill the bay up with stuff would work. With the exhaust side as close to the door as possible.

Be aware the cheap mini's directions can be horrible if not wrong, have no technical back up, no parts so they are disposables. Buy from bigger online sellers and not from a van in a Wal Mart parking lot.

[GordonThree]

Don't be too discouraged from your project. I don't think the condenser would burn out being installed in the storage compartment, unless it had some sort of manufacturing defect to being with.

Problem I see is all the heat it will dump finding it's way back into the RV living space. The pass-through basement in my RV is constructed of stapled together pieces of 3/8 OSB, not insulated or sealed at all. The basement is essentially "indoor" space that was covered up from the inside and then they put doors on it for the outside.

How is your basement constructed? Can you bolster the construction to seal it against air leaks and insulate it to keep the heat out?

Check out this blog, of an old bus converted to an RV. The owners installed a mini-split in a basement compartment, as well as separate air conditioner to cool their battery bay.

http://www.beginningfromthismorning.com/

[Captain_Happy]

Every thought about having a shelf built and welded to the 5th wheel mount hitch to mount it on. That it would outside with plenty of air flow around it. Just an idea.

[longbedbob]

What appealed to me about front mounting the condenser was the convenience. My batteries, inverter and bedroom are in very close proximity so very little routing would be required.

There is no wall space at the rear of the camper to mount the air handler. If I rear mount the condenser then I would have to remove the underpan and route 30' or so plumbing and wiring to reach the bedroom. After previously running wires and outlets for my inverter, I'm not keen on repeating that process.

The front compartment idea was worth investigating. But, as pointed out above, there are clearance issues that make this type of installation not feasible. Sure... I *could* do it. But I could also be replacing condenser units every season because they fail from lack of ventilation.

Time to try something else.

Thanks for the input.

[valhalla360]

LanceRKeys wrote:
I would be concerned about the added heat load to the camper. Along with leaving the access door open, you may need a fan to force some air movement. I would also caution you on draining the condensate to the sink drain. That is going to add quite a bit of water to your grey water tank. If you camp in a hot humid place without full hookups, that could be a problem.

You may be onto something, keep us updated as to what you find.

It's amazing how much condensate an air/con unit can create.

We had a 12k btu unit on our boat and the drain plug got blocked so it went into the bilge. I noticed it about a day after last checking the bilge (which is normally dry). Used the shop vac to get around 25gal of water out of the bilge.

Adding a support on the rear is likely a much better option (don't bolt it to the paper thin bumper). I've seen a few of those done. It doesn't look bad. It's easy to access for cleaning and doesn't eat up storage space. Plus your gear can remain locked in the storage compartment.

[wowens79]

You need airflow around the unit, a quick google search and the on I saw wanted 20” above it, 12” in the intake side, and 79” on the exhaust side. I think it will have to be outside.