Mini Split Air Conditioners

[Fred Mc]

I've noticed a couple of different kinds of house hold mini splits and wonder if they are applicable to our buses.

The first is the larger house type where the evaporater is outside and the condenser is inside.(my terminology may be wrong). The outside portion sits verticalyl outside the house. Would it be possible to mount this same unit horizontally on the roof of the bus with special brackets. The inside part would be mounted to a wall like they do in the house.

The second type is the portable unit that exhausts the hot air through a hose to the outside.(I guess this technically is NOT a minsplit) Would this work in a bus where the hose exhausted through the wall.

Just wondering?

Fred Mc.

[TomC]

I would highly recommend you NOT use any type of air conditioning that is designed for house hold use.  It is not designed for the twisting and vibration of mobile use.  While it might work for awhile, you'll most likely experience high maintenance costs from cracking freon lines, etc.  The mini splits are physically way bigger than the units that are designed for mobile use.
Two makes come to mind for mobile splits.  First is Cruise Air-been around for many years. It has an outside compressor/condenser with the freon piped indoors to your choice of several different models of evaporators-that mostly are mounted at the base of a cabinet with the duct going up to the top vented to the inside of the bus.  Second is the Tundra/Dometic truck based splits that are either all in one where you have to cut two holes in the floor for the in and out of air from the outside, or the split where the condenser is mounted outside with the compressor/evaporator inside also at the base of a cabinet ducted to the top to blow out into the bus.  Both the Cruise Air and the Tundra truck units are at www.dometicusa.com.  These units are made for mobile use.
As to the portable A/C with one or two vent hoses (two hose system is best), once again, these are house hold units that are not designed for the vibration of mobile use.  Plus they get in the way, since they are not built in.
If the Dometic Tundra truck units (condenser outside with compressor/evaporator inside) were available when I converted my bus, I probably would have used them.  As it is, I am still considering using the Cruise Air 14,000btu condensing/compressor unit with two 7,000btu blower units inside for quiet night time A/C use, since my Coleman roof top airs are not exactly quiet for night time use.  Good Luck, TomC

[Nick Badame Refrig/ACC]

Hi Fred,

I will have to second Tom's advice..  Along with the poor dehumidifacation you get from the ductless splits.

Some members have used them with good results, but no feedback with over the road testing as of yet. There is more then

one resaon that vehicle A/C systems are built with rubber refrigerent lines and their components are more rugged.

Another problem with ductless splits is their drain ports on the evaporators are ot designed to drain from both sides and this

will result in soaking your interior when you bus isn't level either parked, or on a crowned road.

Good Luck
Nick-

[Jerry Liebler]

Fred,
    I have tried portables, the ones with the exhaust hose, with very disappointing results.  They are rated very dishonestly (there are no governmental standards) and simply do not do very much cooling even if  one routes outside air directly into the condenser, which I did.  I've also used a conventional window unit, much better cooling and better energy efficiency than rooftops (which are also not subject to governmental standards).  I'm quite happy with my 10,000 BTU/h window unit installed in the rear cap.  I've also recently replaced the 'portables' (I had 2 10'000 BTU/h Sunpentown heat pumps) with an 18,000 BTU/h ductless minisplit.  It draws 13 amps of 120 (it actually is a 240 volt unit I'm feeding through an autotransformer) and easily cools the whole bus (maintaining 70 inside) when it's 95 outside, sunny and we're driving. Despite what Nick says dehumidification is outstanding and the condensate pan can have drains at both ends so out of level doesn't cause drips.  The ductless minisplits that are now being made are significantly more energy efficient than roof tops and deliver significantly more cooling under real world conditions.  Rooftops are not subject to any governmental oversight so the test conditions are not how we use them and the 'ratings' are optimistic at best.  Rooftops are rated with outside temperatures of 80 f. while the household units are rated at 95 f.  I know of one bus conversion that's been using 2 minisplits for over 10 years with no problems. The designed for vibration argument is suspect, there is no evidence that rooftops have any design feature that mitigates vibration and life of minisplits on a bus has been demonstrated .  So to summarise forget the portables and if you can fit them in ductless minisplits will give the most cooling per watt by far.
Regards
Jerry 4107 1120       

[Chaz]

I was waiting for you to weigh in, Jerry. 

I know very little on this subject but i have seen Jerry's set up and it's "cool"! (pardon the pun!  )
He had it at the rally in Cincy and I visited his house in KY. I think anyone who seen it was impressed with the set-up and the amount of electricity it uses.
I have roof tops, but I do believe I would go this route in the future.

  Chaz

[edroelle]

I am not as knowledgeable as some of the experts, but can only give you information from my limited experiences. 

1.  A lot of people with Cruise-airs are having to refill the freon.   It may be because of the installation, but they are not overly reliable even in professionally converted coaches.

2.  I installed window a/c in my MCI 8 by creating a split system (silver soldered) - evaporators in cabinets and condensers in old condenser location.   As with wiring, I tried to use good judgement on vibration by attaching lines, etc.   While I owned the coach, I had no problems and great performance (we were in 107 degrees a couple of times.)  But (yes, there is a but), the installation was excessively time consuming.

My point is, it is challenging for any air conditioner manufacturer to engineer a reliable unit, for mobile use.   I would be interested in any design elements that have been designed-in, to  a mobile unit.  They may be able to be incorporated into a split air installation.

If I converted another bus, I would at least consider, and further investigate, split airs.

Ed Roelle
Flint, MI

[Sam 4106]

Hi Guys,
I think the issue of whether an appliance is designed for mobile use is insignificant. After all bus convertions have had house refrigerators installed in them for at least 20 years without problems. How similar is a house refrigerator to a house A/C? Refrigeration is what they both do, right?
Thanks, Sam 4106

[kyle4501]

Just use appliances designed for California    & the shaking shouldn't be an issue. 

I believe Ed has hit the nail on the head, the quality of the install has more to do with sucess than many may want to admit. Like Nick said, use rugged components, not low bid.

Also pay attention to the whole system & get all the details right. (Jerry is enjoing the results of getting it right.)
If you mess up the condensate drain, you'll be dealing with water in places it shouldn't be. 
If you mess up the air flows, you'll not get the performance you were expecting.

I'll be using split systems for my A/C, but that's a ways down the road.

[Kwajdiver]

Guys,

Is there a website for the split system.  I'm sitting in Phoenix and my two roof airs can not keep up. 
(Of course I should be heading south to Gulfport the end of next week.   At least I hope too.)

Also, does anyone make an air cooling system just to keep the driver area cool?

Bill

[Jerry Liebler]

Bill,
    Regarding keeping the driver cool.  One little detail of installing my ductless split I'd do differently next time.  I put the indoor unit behind the driver and think it would be better on the curb side.  The air flow is out and down and the copilot gets the coolest air in my set up but if I had the indoor unit behind the copilot I'd get the coolest  breeze. 
Regards
Jerry 4107 1120

[Jerry32]

I just installed a mini split heat pump in my bus and took it on its first journey. I still have the bus A/C for over the road so can not give you any info on that. I drove to Lewiston ID and camped at the Hells GAte state park on the snake river. the humidity was high and temps ran to 104 F I only had the one unit and it is a 1 ton unit mounted to blow in the front of the bus. It did cool the front and kept the temps down in the back to around 85 F. Not only that I had tried it on a cold morning previously and it heated up things in a hurry.  OT I took the jet bout tour of Hells canyon (184 miles round trip) and was glad to get back to aic conditioned bus allthough I enjoyed the tour very much but it was 104 F that day. Now I know why thy call it hells canyon (deepest canyon in north america) Jerry

[Nick Badame Refrig/ACC]

Hi All,

I love all the replies so far..  Jerry Liebler, I didn't mean any disrespect to you! You have a great talent with your reseach you did on yours.

Ductless splits are very economical. They are capable and worthey of your bus conversion. But, in most appliances on the market today, there

is a dollars and cents factor for the manufacture. Theese company's design the average appliances to only last a predetermined amount of time.

What do I mean by that? Usually after 5 years your appliance will malfunction. When you inquire about a replacement part you hear 1 of 2 things.

Either the part is unavailable or the cost over exceeds the price of a new one. Why, because if they didn't sell you a new one every 5 years, they

will go out of business's. Thats where the big profits come from.  Remember many years ago, the old refrigerators.. Frigidaire, Philco, Kelvinator...

Some of those lasted 60 years. Why, because they made them too well. So the company's were bought out by White Industries and on they

went to making crappy stuff...lol 

Back to the Ductless Splits, If a part fails you, where are you going to get a replacement part on the road? not Camping World  or Walmart.

Most likely, if your ductless split isn't a Sanyo or a Fujitzu, you wont get that part too quickly. And for reasons I stated above.

We bus nuts are pioneers on reinventing the wheel...I'm guilty of that all the time. So, only after doing alot of goofy things that now don't make much sense,

I have come to realize that sticking with the tried and true things make much more sense. After all, any appliance besides your A/C, you most likely

can do without on a 100 deg. day. But not your A/C or Heat.

Ok, I'm ready for the slap to the back of my head...

Nick-

[TomC]

Out of all the appliances that are available for conversions, the roof top air conditioner is probably the cheapest thing around.  As previously posted, the Cruise Air split can cost up to $4,000, the Tundra split around $1,800, a roof top air around $700.  Plus the fact that you can replace an entire roof top air easily in about 2 hours.  How long to work on a split system-more like hours possibly into days to wait for parts, as Nick has said.  I know roof tops are ugly, but both the Duo Therm Penquin and the Carrier low profile are good ones.  Even if the roof top airs only last 5 years, they are still the best bang for the buck for A/C both sitting and going down the road.  Ever see a band bus with 5 or 6 roof tops?  They will never be hot!  Good Luck, TomC

[Jerry Liebler]

Nick makes  a good point about longer term parts availability.  That's a risk I'm taking.  However The mini- split I have cost, in  round numbers $1000.  For that I have a single unit that keeps my bus very comfortable on less power than almost all roof tops and many others have difficulty cooling similar buses with two rooftops.  I do have significant backup cooling with the rear window unit.  By the way that window unit could be replaced in about 15 minutes with a new one from far more places than one could get a rooftop unit and at a cost of under $300 to boot.  Yes the initial installation took a bit of time but if the ductless split must be scrapped in the future most of the installation will easily adapt to a replacement unit of similar design.  The Cruise-airs are pricey because they are not produced in anywhere near the volume of residential ductless splits.  Also because of the new government standards for residential air conditioners they are much more energy efficient than any RV product.  Energy usage matters if you want to run the AC off of  an inverter while driving and at those many parking places where 30 amps, 20 amps or even 15 amps is all that's available.  Every bus converter should seriously consider residential window units and ductless minisplits and not blindly choose RV airconditioners wether they are roof warts, Cruise-airs or ducted bay mounted units.
Regards
Jerry 4107 1120   

[Don4107]

The main reasons I am planning minisplits or some type of basement air is I never want to listen to another rooftop air again and the 4107 is already 11'+.  I don't want to raise the roof just to have room to put ducts in to quiet the dumb things down.  My experience is that for the number of hours they run they don't last very long and if you run two make more noise, in stereo no less, than some generators,   I don't like the water running down the side of the coach and I can't hear anything else when they are grinding away.  They are inefficient and drive you nuts with the noise.  They look horrible on an otherwise clean roofline and they are way too loud for my afternoon nap. 

We have 'lived' with rooftops in the S&Ss and our other bus, never again.