RV A/C System--Would Sanyo Mini-Split work?

techntrek · September 2010

Anyone try one of these in a mobile application? This thread has already convinced me to get one for a hard to heat/cool room in our house, but I'm also thinking about changing out the RV A/C in our travel trailer. I've figured out where to mount both parts (wall mount on the front wall and the condenser on the tongue, about a 1-foot run of pipe), but I'm worried about damage due to vibration since these weren't intended for that application.

If you wonder why, the current A/C is incredibly loud, you almost can't have a conversation when its on. That's wonderful when you are trying to sleep. The low db levels reported here would be heaven. Its also too big, 11,000 btu for about 100 sq. ft. airspace and the trailer is very well insulated. 2" foam in the walls when most trailers only have 1", and several inches in the floor. Sticking the Sanyo on "low" all day would be much more appropriate. I could also then run it from a PSW inverter during lunch breaks (12 amps @ 12 volts is doable for a half-hour).

PhilS · September 2010

Re: Sanyo mini split AC (inverter/variable speed)

techntrek wrote: »

Anyone try one of these in a mobile application? This thread has already convinced me to get one for a hard to heat/cool room in our house, but I'm also thinking about changing out the RV A/C in our travel trailer. I've figured out where to mount both parts (wall mount on the front wall and the condenser on the tongue, about a 1-foot run of pipe), but I'm worried about damage due to vibration since these weren't intended for that application.

If you wonder why, the current A/C is incredibly loud, you almost can't have a conversation when its on. That's wonderful when you are trying to sleep. The low db levels reported here would be heaven. Its also too big, 11,000 btu for about 100 sq. ft. airspace and the trailer is very well insulated. 2" foam in the walls when most trailers only have 1", and several inches in the floor. Sticking the Sanyo on "low" all day would be much more appropriate. I could also then run it from a PSW inverter during lunch breaks (12 amps @ 12 volts is doable for a half-hour).

I've never heard of anyone trying to install one of these in an RV but....

... if you replaced the (included) copper tubing with an appropriate flexible hose I think it work, and work well.

You'd have to confer with experts to determine the "appropriate flexible hose". It would have to safely contain the pressure (whatever that is?) and also be compatible with R410a freon and oil. I would think normal A/C hose (like in an auto) would work since R410a is more environmentally friendly (therefore less damaging to hoses?) and it'll hold the pressure. Also, hoses could be made in any length at A/C shops or many auto parts stores (the real ones, not the chains).

If possible, you'd want the air handler mounted high on the wall (may not be possible) and the condenser should mount fine on a tongue, which would be longer than one foot of hose.

The nice thing is that once everything is installed and the system vacuumed, the freon is already in the unit. Open the valves and enjoy the cool air.

Just my opinions after installing one in our house, I'm not a professional A/C person although I've worked with R-12, R-22, R134 and now R410a. Please don't have your lawyer contacting me if it doesn't work. I have had RVs for 30 years and do all my own work.

Phil

BB. · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

PhilS suggested that this might be better in its own thread. Original Sanyo Mini-Split thread here:

Sanyo mini split AC (inverter/variable speed)

Regarding copper lines--Copper work hardens from bending/flexing. If you firmly mount the units and don't let a 3' unsupported coil hang out where vehicle vibrations can get it banging around--you may be OK.

Note: If you have flexing (say between trailer tongue and body)--you may need to put a couple of coils of copper (supported in soft mounts) to prevent the flexing from being concentrated in a short run of tubing if you do not find a satisfactory flex line.

-Bill

techntrek · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

Wondered for a sec what happened, but quickly figured you moved us to a new post. I'm an admin on an RV forum where I have also brought this idea up (and linked to the original Sanyo thread so you may get some questions there). Several of us are growing more interested in trying this the more we think about it, so I may have to figure out the details in earnest. The basic model we all have is the same, Forest River R-pod, so we all have the same problems.

With only a foot or two of lines, I wonder if an evacuation is even worth it. The other thread mentioned how that is rarely done overseas in home installations where we can assume there are many feet of line. Plus this system would encounter very light use relative to one used in a home. I agree that a flex line is in order since I would expect some flex between the tongue and body.

I'm still getting excited at the thought of running this sparingly while boondocked. With the Peukert effect helping out, 3 batteries could give a full night's sleep in comfort. Add some PV and you could squeeze out 2 nights.

solar_dave · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

you might look at these as well
http://www.friedrich.com/products/ductless-splits/wall-mounted/overview/

I have a 36,000 BTU unit with 3 air handlers in my new building and it has a super quiet setting (along with low, med,high) that is almost dead quiet.The outdoor unit is pretty noiseless as well.

They offer recessed ceiling mounting and with a cover on the roof might be more to your liking.

PhilS · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

techntrek wrote: »

With only a foot or two of lines, I wonder if an evacuation is even worth it. The other thread mentioned how that is rarely done overseas in home installations where we can assume there are many feet of line. Plus this system would encounter very light use relative to one used in a home. I agree that a flex line is in order since I would expect some flex between the tongue and body.

I have no doubt you could skip the evactuation and it'd work ok. It cost me an extra $100 to buy another vacuum pump and a bottle of oil and the adapters from eBay. Our humidity is usually low, even today it's 40%. When I did my install, it was lower.

Maryland certainly isn't that way. I've been there many times. Not like Houston, for sure, but still plenty humid.

Any moisture in those lines could find it's way to a small orifice and then freeze, causing the cooling to stop, at best.

As I said in the other thread, my friend in Pakistan lives in a humid area, has three mini-splits, and none of them were evacuated at installation (which cost him $10 US each).

But I chose to spend $100 more on making a perfect install for a $1600 unit. In your case, buy a vacuum pump then ship it along to the next person in your FR forums asking for shipping and 85% of the cost. The next person does the same and by the time a half-dozen members have installed a mini-split, you'd all have spent $20 each to have a better installation.

Phil

techntrek · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

MD has its dry days, especially in the winter, so I could wait to air out the lines and connect them on a really dry day. I'll have to think about getting the pump - I like your pay-it-down-the-line solution for the cost!

I emailed the company mentioned on the first page of the original mini-split thread about flexible lines, no reply yet.

Dave Angelini · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

Some of the other brands, Fujitsu for one will not honor warranty unless purchased from one of their dealers. The Sanyo units will honor a 5 year warranty install by owner if the system is vacuumed down by a licensed HVAC technician.

We need it today hey Phil! To the OP, use the landline!

dwh · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

Aren't the Fujitsus 240v as well?

n3qik · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

As for copper lines. I would not worry too much, as your LP lines are copper with longer runs to stove, fridge and hot water heater.

techntrek · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

Dave, "use the landline"?

Ken, true, I went out to my travel trailer tonight to measure the available space and had the same thought when I looked at the LPG tank. Same stuff, but its all located where its firmly mounted, too. Where I'm considering running the lines would let me secure all of it, so I may be fine.

The good news for me is there is enough room on my tongue for the condenser and there's a good place to mount the inside unit. Just gotta figure out running it off-grid, and then make the leap.

n3qik · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

Another thing is the tongue is the smoothest riding part the the TT.

Had a fifth wheel with rear kitchen. Used lots of straps to keep the dishes in place.

icarus · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

RV's are full of copper lines, water, propane etc. I see no reason why copper line wouldn't work, assuming you leave some room for vibration, but as Phil says,, I'm no A/C expert either.

Tony

Dave Angelini · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

techntrek wrote: »

Dave, "use the landline"?

Ken, true, I went out to my travel trailer tonight to measure the available space and had the same thought when I looked at the LPG tank. Same stuff, but its all located where its firmly mounted, too. Where I'm considering running the lines would let me secure all of it, so I may be fine.

The good news for me is there is enough room on my tongue for the condenser and there's a good place to mount the inside unit. Just gotta figure out running it off-grid, and then make the leap.

On this side of the Mississippi a land line is a telephone! I would not e-mail the supplier I used but rather telephone.

If you really are trying to make this work without a grid based power source you might go back and read the thread again. For this to work into the evening (6 or 7 pm) offgrid you need to either have a big battery bank and enough solar to charge it, or a tracked or staggered south-east and south-west array. You can get into damaging a trailer battery pretty fast unless this is well thought out!

DWH, I looked into getting the Fujitsu's bothe 120 and 240vac and they are not good with warranty for offgrid applications which are typically off the map so to speak. They have awesome specs for energy usage.

techntrek · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

I figured on using 3 to 5 group 27's. Three would work for one night, and 5 for two nights, relying on the Peukert effect to get some extra amps out. I have 16 in my battery bank at home I can borrow from. It would only happen maybe 3 times a year so I would rotate through the bank to maintain even useage.

I'm 90% sure I'm going to get one of these for home, so I might wait to see how these perform/sound before ordering for the RV. It would also be nice to get the units in-hand to play around with mounting locations before committing.

PhilS · September 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

techntrek wrote: »

I figured on using 3 to 5 group 27's. Three would work for one night, and 5 for two nights, relying on the Peukert effect to get some extra amps out. I have 16 in my battery bank at home I can borrow from. It would only happen maybe 3 times a year so I would rotate through the bank to maintain even useage.

I'm 90% sure I'm going to get one of these for home, so I might wait to see how these perform/sound before ordering for the RV. It would also be nice to get the units in-hand to play around with mounting locations before committing.

If you end up getting two units, then the cost of a vacuum pump would be half for each even if you didn't send it on to others.

There would have to be SOME degradation of the cooling without evacuating the lines. How much? Who knows. Maybe only a couple of percent. Maybe 5%? I doubt it'd be more than that, but even 5% would be unsatisfactory for me. Some competing manufacturers state that no evacuation is necessary, it just wasn't claimed for these Sanyos.

Some manufacturers said the lines and air handler came filled with nitrogen. I suspect that by the time it's all hooked up. air and humidity would've leaked in.

As far as using the copper lines: properly secured I'm sure they'd be fine if you put a few strategic 'coils' in for flex.

Phil

Shadowcatcher · November 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

One alternative that a number of us with teardrops have done is to adapt a 5,000 BTU ~4A window shaker with a goesinta and goesouta 4" hose. This could easily be scaled up to a larger unit.
With the first version I used an adapter that went into one of the windows. Version two uses two 4" marine deck plates in the side of the trailer and a Johnson controls commercial thermostat that controls the AC with wires inside one of the hoses. All you hear is a rush of air.

notsobright · November 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

Shadowcatcher wrote: »

One alternative that a number of us with teardrops have done is to adapt a 5,000 BTU ~4A window shaker with a goesinta and goesouta 4" hose. This could easily be scaled up to a larger unit.
With the first version I used an adapter that went into one of the windows. Version two uses two 4" marine deck plates in the side of the trailer and a Johnson controls commercial thermostat that controls the AC with wires inside one of the hoses. All you hear is a rush of air.

Ive been thinking about doing this for my cargo trailer. got any more details? looking at the window units it seems you would need to build some type of enclosure around them, no?

Shadowcatcher · November 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

For ours a plenum was made that incorporates two four inch duct ends for the in and out air flow, the control wires run inside the duct and through the deck plates in the side of the trailer. There are conventional 4" louvers on the inside. This connects with a Johnson controls thermostat on the inside. The power cord plugs into a dedicated plug on the outside of the trailer.
The AC unit will sit on the ground under the trailer or next to it, when in use. I do plan on adding some aluminum diamond plate and a carry handle(s) as well as heavy aluminum screen over the coil fins to protect them.
I have seen a couple of units that have only the cold air duct going into the trailer (one hose) and there is no reason that a plenum using larger hose can not be constructed. The interior of our tear is a bit over 400 cubic feet, big for a tear small for a CT.
Air flow can be helped along using a bilge blower in the 4" hose if necessary.
As a separate issue I will be adding some very elaborate air filters to take out smoke. I had a serious issue last you at Chain O Lakes with a temperature inversion and smoky camp fires (it was worse than LA many years ago) and had a serious asthma attack as a result.
The big advantage is this can be done cheaply, be much quieter (no transition of vibrations from the AC) and can be left home when you don't need it.

techntrek · November 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

Hmmm, something to think about. Certainly far cheaper and easier to "install". Have you measured the surge and running amps on your unit? Is it one of the newer models (all r-410a now, I think?) or an older model?

Shadowcatcher · November 2010

Re: RV A/C System--Would Sanyo Mini-Split work?

This is a Frigidaire 5000 btu that I picked up a the end of the season in 09 for $50. it is listed at 515 W but running it is less. We have one of these that we use in a spare bedroom and find it does well. The beauty of this is that any window unit can be made to work. The wiring is easy to hack and conceivably if you make the plenum accessible the thermostat in the unit will work as it reads the incoming air form the trailer. I went with a Johnson controls commercial digital thermostat so that it also controls the heater. In 400 cubic feet accuracy in temperature control is important.

RV A/C System--Would Sanyo Mini-Split work?

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