Mini ductless heat pump A/C on a small FG trailer

[GlenDReed]

I am considering removing my Dometic A/C on my 13' 2016 Scamp and somehow adding a single zone mini split ductless heat pump. I know this would be difficult to install, but the Dometic A/C is so loud, that I can hardly stand to use it and am avoiding trips for which it would be necessary. There are at least two brands of 9000 BTU ductless mini-split 115 volt A/C available which have rated watts of 965 and rated amps of 8.6. Also, I think that I would be able to power it using a Goal Zero Yeti 3000 Lithium Portable Power station, which has 3000 Watt surge and 1500 Watt sustained power. Together this would solve the noise problem inside the trailer and avoid running a gas generator. I live in Amarillo, TX.
Does anyone have experience or ideas on any of this?

[gordon2]

Did you see this?

http://www.fiberglassrv.com/forums/f...tml#post714000

[GlenDReed]

No, I did not. Thanks

[Tom 72]

I am a fan of the idea. I think I've seen other threads on the topic here. Try a search. Mini splits also provide some heat when they run backwards as a heat pump. It's probably enough for 2-3 seasons, and is more efficient than resistance heat, I think.

Sorry I can't help you engineer it. But I would have someone sew a cover to prevent the fan blades turning while towing, and protect it.

[GlenDReed]

Thanks for the input. I am still in early planning stage. But I have run across another option at minihvac.com. It's the MPS 4,000 BTU Mini Heat Pump Air Conditioner. Available in 115v 60hz and 230v 50/60hz. That is Also able to run on 12/24VDC with our optional 1000W inverter/charger. Testing demonstrates that this unit will run on a Honda EU1000 with ECO-THROTTLE on without any problems! The digital control comes included in the package. This unit is reverse cycle which means that it can both heat and cool. It's a lot more money, but would be a lot easier to install.

[Tom 72]

The Mabru Power Systems unit is interesting. There's a lot to be said for simple & easy. One thing to check is whether 4,000-ish BTU is enough or close enough to it. It seems most units are larger, there must be a reason. Will this handle running constantly? In a pinch you could partition your RV with a curtain. Good luck.

[CarlD]

I believe the MPS system is has a water cooled heat condenser. It is designed for boats.

[rubicon327]

Originally Posted by GlenDReed

I know this would be difficult to install, but the Dometic A/C is so loud, that I can hardly stand to use it and am avoiding trips for which it would be necessary. There are at least two brands of 9000 BTU ductless mini-split 115 volt A/C available which have rated watts of 965 and rated amps of 8.6.

I did the install on the Escape that was linked to in post #2. I used a Fujitsu 9RL2 which is 9,000 BTUH. Great unit, but not cheap. I got mine at a trade warehouse, but another member noted they are also available here:
https://www.ecomfort.com/Fujitsu-9RL2/p65505.html

Wired on 15A circuit and provides heat too.

Have a listen. You may need to turn your volume up to hear the indoor unit running. When I say quiet I don’t mean kind of quiet I mean super quiet.

https://m.youtube.com/watch?v=wv6kTkllmqA

[rbryan]

I know I keep saying it Dave, but don't be surprised if some day this Texan shows up at your door in New Jersey with a mini-split unit in the back of his truck and a forlorn "help me" look on his face...:

[Davie B]

I want to recommend the Pioneer minisplits sold on Amazon. It’s not on my camper (I installed a window unit on the LiteHouse “U-Haul” style) but use it to cool a small studio. They are inexpensive and pretty easy to install.

[rubicon327]

Originally Posted by Davie B

I want to recommend the Pioneer minisplits sold on Amazon. It’s not on my camper (I installed a window unit on the LiteHouse “U-Haul” style) but use it to cool a small studio. They are inexpensive and pretty easy to install.

That's a good find. I did a comparison of the Pioneer 9,000 BTUH model to the Fujitsu 9,000 9RL2 that I installed. They are very similar in all respects. The only real differences I see are that the Pioneer outdoor unit is about 4" wider, but the Pioneer indoor unit is about 4" narrower in width. Indoor noise level very similar. Pioneer outdoor noise level 56 dbA vs. 47 for the Fujitsu. Pioneer has a slightly wider outdoor temperature operating range. The Pioneer is a lot cheaper. Based on retail pricing about 45% cheaper.

I still would not have been able to use the Pioneer though because of the design of the front shape and air outlet on the indoor unit. The Fujitsu allowed me to recess in a front cabinet about 5" so it only protrudes about 3".

[Alex Segal]

I have one of the pioneer units from amazon, great customer service from the company that sells them. It worked great in my guest house and so quiet. I thought it would be super to have that quiet unit in a trailer.



My only concern would be the effect of vibration and shaking of the compressor unit when towing. I have shock absorbers installed in my Casita, (thanks to Orbital Machine Works) and they help smooth out the ride, but still bounces enough that it could have an effect on something manufactured to be stationary.

[redbarron55]

Originally Posted by Alex Segal

I have one of the pioneer units from amazon, great customer service from the company that sells them. It worked great in my guest house and so quiet. I thought it would be super to have that quiet unit in a trailer.



My only concern would be the effect of vibration and shaking of the compressor unit when towing. I have shock absorbers installed in my Casita, (thanks to Orbital Machine Works) and they help smooth out the ride, but still bounces enough that it could have an effect on something manufactured to be stationary.

I wouldn't worry particularly about the compressor as these things are built to be shipped around the world.
The worry is really in the flare fittings and the very slight leaks that are probably inevitable and occasionally need to be topped off.
The problem is that these are critically charged and are difficult to judgehow much needs to be added.
The issue is that unlike the regular systems the EEV that feeds the inside coil is actually in the compressor unit and then entire circuit, lineset and coil is treated as the inside coil.
There is one charging port in the low side and none readily available for the high side.
It can be done and is probably easier done when the unit is set to a low temp with a high load and charge looking at a wattmeter for compressor load.
If you install a minisplit then make certain that you get a very good flare and a good tight fitting.Pressure test and pull a hard vacuum.
Again I wouldn't worry about the mechanical bits in the unit, but make sure you get a good install.

[rubicon327]

Originally Posted by Alex Segal

My only concern would be the effect of vibration and shaking of the compressor unit when towing. I have shock absorbers installed in my Casita, (thanks to Orbital Machine Works) and they help smooth out the ride, but still bounces enough that it could have an effect on something manufactured to be stationary.

I understand and respect this concern, but no risk, no reward. A few of us have went out front and proven using a residential/light commercial mini split can be done with little issue. If you have the outdoor unit mounted on the tongue it is a fairly smooth ride. I did rubber mounts to take vibration from the road and any during operation. Also hold the unit down with a ratchet strap to reduce stress on the mounts while towing and protect with a modified plastic propane cover.

I agree with redbarron55. I did some of my own flares and routed the refrigerant lines carefully with smooth transitions to avoid kinking. A high quality install is critical. We did a nitrogen pressure test at 300 psi and then drew a good vacuum. Going down the road everything moves together so I’m not worried about high stress on any part of the lines or the connections over time. This has been in operation for over two years now and traveled at least a few thousand miles.

[Borrego Dave]

The noise of the roof air comes up regularly here and really has me scratching my head. Without starting something that will go sideways I have to ask/comment. My SDs roof air cycles, it's just back round white noise to me, kind of like falling asleep with the TV on. The first night out it does startle you a bit, the second night no. Yes, it is noisier than your homes central air cycling but your central unit is outside the house, not on the roof. Wouldn't a box of ear plugs from Harbor Freight be first choice to try before a split system? Anyway, maybe I'm lucky I sleep like a rock , it's just not something that bothers me at all, I'm glad it's there when I need it. OK, let the beating begin .

[rubicon327]

Originally Posted by Borrego Dave

The noise of the roof air comes up regularly here and really has me scratching my head. Without starting something that will go sideways I have to ask/comment. My SDs roof air cycles, it's just back round white noise to me, kind of like falling asleep with the TV on. The first night out it does startle you a bit, the second night no. Yes, it is noisier than your homes central air cycling but your central unit is outside the house, not on the roof. Wouldn't a box of ear plugs from Harbor Freight be first choice to try before a split system? Anyway, maybe I'm lucky I sleep like a rock , it's just not something that bothers me at all, I'm glad it's there when I need it. OK, let the beating begin .

Dave: While reducing noise/vibration for sleeping was a major concern it is also nice to be able to have a conversation during the day. Our roof top unit was that loud. The fan didn’t cycle so I actually had wired in a relay to a thermostat that killed the unit when it reached set point, but man when that thing kicked back on you knew it. Other added benefits of the mini-split are that they provide quiet heat, better dehumidification (not oversized and has a dry mode), better air distribution in the trailer due to position and moving vanes, lower outdoor noise level, remote controlled, washable filters, reduce the overall weight and reduce the mass up high, better aesthetics with cleaner roofline, reduced overhead clearance (garage), allow for the roof opening to become a skylight or additional fan, increases headroom in trailer, condensate drained to bottom of trailer rather than running down the side, and low start up and running amps (wired on 15A circuit) so easily run on 2KW generator. None of these may matter to someone else (or matter enough to justify the cost), but they do to us. Kimberley who made some of Australia’s nicest caravans had a tech article that said that split systems were the only way to go.

[cpaharley2008]

Dave,
Do you know your tongue weight on your 19 with the batteries and a/c up front?

[Alex Segal]

Thank you both for your scholarly replies. That certainly addresses my concerns.


Now if I can just get Larry Gamble at Little House Customs to start installing them....

[BDRoorda]

Professionally as a former HVAC Tech, I think the mini splits are a great advancement and well fitted for this application. I personally did a heat loss heat gain calculation on our CT13 and a 9000 BTU mini-split would work well for camping in a wide variety of temperatures.

I personally waft with doing a mini split versus a self contained like the ClimateRight. The smaller size of the 2500 BTU cooling one (we have an LP furnace) in our CT13 would work well and the low current draw could fare well off grid if/when need on battery/solar power. https://climateright.com/

[redbarron55]

The outside unit weighs about 65 lbs and the inside unit about 16 and throe 5 in for the lines.
So 65 lbs in the front and 16 in the back the added weight on the tongue 40 lbs (maybe yes maybe no).
I installed my battery (G29) under the bed behind the axle and tried to make up for the added weight of the heat pump during the build.
The tongue weight on my FrankenScamp is about 300 with the LP tank installed.
You have to remember that the weight of the rooftop unit is coming off and it is usually slightly behind the axle.
I just put 9200 miles on my Scamp this last summer with no problems.
I have a total of probably over 20,000 miles on the trailer with the heat pump.
Remember if you are an "All Electric" kinda guy you can have heating and cooling in the same package and can remove the gas heater, if equipped.
The mini-split is very quiet and that is a big plus and many of the Scamp-ins we have attended people have noted how quiet it is.
It is a little bit of a pain to route the lineset, but it can be done. Remember that the lines are both cold as they are logically and physically part of the evaporator coil because the orifice (or more properly the EEV) is located within the condenser unit.