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hillndale
05-10-2009, 10:06 PM
What does this mean? i see it mentioned frequently as an option but thought all Prevost's have a/c.
Is it a seperate or preferred system?

dale farley
05-10-2009, 10:14 PM
OTR air is a system that has a separate compressor that runs off the engine. It is in addition to the dash air on some coaches. Prevost OTR air is the best and most expensive. Country Coach installs a significantly cheaper system that does a good job if working properly. It does not have the output that the Prevost OTR air has. OTR air allows you to cool the bus while traveling without running the generator.

hillndale
05-10-2009, 10:48 PM
OTR air is a system that has a separate compressor that runs off the engine. It is in addition to the dash air on some coaches. Prevost OTR air is the best and most expensive. Country Coach installs a significantly cheaper system that does a good job if working properly. It does not have the output that the Prevost OTR air has. OTR air allows you to cool the bus while traveling without running the generator.

OK. Thanks.
Is it a common option? And does it cool just the front portion or is it ducted to the whole coach?

Joe Cannarozzi
05-10-2009, 10:52 PM
It cools the entire bus, most comes out at the bottom of the windows. The factory system is designed to keep a charter bus with all its windows and 50 large people cool on a 90+ degree day.

I give it a thumbs up. I would not buy a bus without factory OTR a/c or some form of it (CC & Marathon), it would be a deal breaker for us.

You can easily spot a coach with factory OTR air by the louvered bay doors 3rd bay back, both sides.

JIM CHALOUPKA
05-10-2009, 11:32 PM
hillndale, on you new bus look in the engine compartment. In the lower right side is the large OTR AC compressor. If you have it you lucked out.
The image depicts the OTR compressor. It is grey.

Jon Wehrenberg
05-11-2009, 07:47 AM
The description can be reduced to numbers.

Over the Road Air (OTR) is a whole coach AC system that is about 80,000 + BTU. It is used while driving since it is only engine driven. It is extremely effective. Only Liberty consistently builds and sells coaches with OTR, and a Liberty without OTR is very rare. Other converters will buiild or have built conversions with it, but they are far less common.

Those that build conversions without OTR justify that on the basis of it saves bay space (in actuality only the equivalent of 1/2 bay, if that), that their coaches can run house AC units from an inverter or engine driven generator, or they install a system as Dale says that has less output. The reality is that converting a coach with OTR is a challenge. The converter not only has to provide ducting for the OTR, but the air flow has to be balanced making an interior design an engineering challenge.

Without OTR a coach will typically have 3 or 4 Cruise Air units, 3 or four roof airs, or a couple of "package" systems. The Cruise or roof airs are likely to be around 13,000 BTU for 39,000 to 52,000 total AC capacity. The packages are likely to be around 26,000 BTU for a total of 52,000. The short version is that OTR is significantly more capable than anything else.

As long as the coach temperature is maintained it is likely the other systems will be adequate. Where problems arise is when the coach is heat soaked and the owner wants to cool it down. It will take forever. If the coach has OTR an owner can run the engine and the other AC units and in a very short period of time the coach is cool.

There is no way Cruise Airs will cool the coach in the desert southwest when driving down the road. Heat radiating from the road surface will not allow the condensing units to adequately cool the hot freon gas and they will shut down. In this instance roof airs will be the better choice. The arguments about which is best are all over the place. Those opposed to roof airs talk about the noise level. Those opposed to OTR talk about lost bay space or the fuel and HP required to run it.

Personally I will not own a coach unless it has OTR. It is at the top of the "must have" list. I will look no further once I see a coach does not have it. Others are likely to have the opposite opinion.

hillndale
05-11-2009, 07:52 AM
Wow...thanks for all the great info everyone.
This leads me to the next question- what is cruise air?

Jon Wehrenberg
05-11-2009, 07:55 AM
Cruise Air units are mounted with the evaporator coil and fans in the living area of the bus, with the condensing units remotely mounted in the bays or behind the front bumper. The advantage to them is they tend to be fairly quiet.

hillndale
05-11-2009, 09:11 AM
Cruise Air units are mounted with the evaporator coil and fans in the living area of the bus, with the condensing units remotely mounted in the bays or behind the front bumper. The advantage to them is they tend to be fairly quiet.

Thanks. Are they not as cold or as efficient? i haven't seen any conversions with this feature for some reason. kind of rare?

tdelorme
05-11-2009, 11:44 AM
CruiseAir units are quite common in bus conversions. Look at the roof and if there are no AC units up there you can bank on the coach having three or four CruiseAirs. Bruce's coach is an exception and there may be a few others. I prefer CruiseAirs and I'm sure there are folks who like roof air units. Both will cool a stationary coach when functioning properly. The advantage to roof air is, like Jon says, they will cool better while the coach is traveling. But, a bus with Prevost OTR air is the best option for summer travel.

Pete
05-11-2009, 12:31 PM
Having owned both, the first an American conversion (1985) with Prevost bus air and heat with 3 cruise air units. The second coach, a 1995 Vision with no bus air and heat. The current coach, (95 Vision) has dash air, and 4 roof airs, which is capable of operating the front and rear roof airs from inverters. It has 2 3,600 watt inverters operating from 2 banks of 8-D batteries. (a total of 8 8-D batteries for the house side).
So far, it works ........ok with this system. I fell for the old story of (A) it saves bay space , where do you think the batteries and inverters are housed?..in the saved bay space of course. (B) It is more efficient because it does not sap the engine hp to operate the a/c. ..Where do you think the power comes from which operates the alternator which supplies power to the batteries thru the inverters to operate the a/c units....from the engine!. and (C) why do you think most all of the converters do not build coaches with prevost road air and heat?....Because it is cheaper!
Having owned both, I would not buy another without PREVOST BUS AIR & HEAT..

It is much easier to manage, just turn it on as you would in your automobile, adjust the temperature control and you are good to go!

Also, if you should loose your bus air and heat for some reason..start the genset and run your roof or cruise airs. Or a Jon stated above if you are trying to cool a hot coach prior to a trip run both systems for a few minutes to cool the coach for travel, then shut down the genset and use the bus air and heat.

I have heard these arguments pro and con for years, but if you travel in the hot regions of this United States, you need Prevost Bus Air and Heat. Just ask someone who has owned both!

Now having said that, those of us who do not own a coach with Prevost Bus Air & Heat should not get rid of our coaches, we should just contend with batteries/inverters, or run our gensets, roof airs or cruise airs, our dash airs
and not be quite as comfortable. (maybe change our shirts before we arrive so as to not have sweaty armpits, and look as though we have traveled in comfort to our destination).

Its really not all that bad, just trying to make my point on the ease of operating a prevost with bus air.

phorner
05-11-2009, 12:47 PM
I have not yet found a day that was hot enough to overwhelm the Prevost OTR air conditioning.....

In fact it, if left to maximum cool, it will drive you out of the coach in search of some relief from the cccccold! :eek:

We'll be travelling the desert southwest extensively this summer, so a real test is yet to come.

hillndale
05-11-2009, 02:07 PM
Having owned both, the first an American conversion (1985) with Prevost bus air and heat with 3 cruise air units. The second coach, a 1995 Vision with no bus air and heat. The current coach, (95 Vision) has dash air, and 4 roof airs, which is capable of operating the front and rear roof airs from inverters. It has 2 3,600 watt inverters operating from 2 banks of 8-D batteries. (a total of 8 8-D batteries for the house side).
So far, it works ........ok with this system. I fell for the old story of (A) it saves bay space , where do you think the batteries and inverters are housed?..in the saved bay space of course. (B) It is more efficient because it does not sap the engine hp to operate the a/c. ..Where do you think the power comes from which operates the alternator which supplies power to the batteries thru the inverters to operate the a/c units....from the engine!. and (C) why do you think most all of the converters do not build coaches with prevost road air and heat?....Because it is cheaper!
Having owned both, I would not buy another without PREVOST BUS AIR & HEAT..

It is much easier to manage, just turn it on as you would in your automobile, adjust the temperature control and you are good to go!

Also, if you should loose your bus air and heat for some reason..start the genset and run your roof or cruise airs. Or a Jon stated above if you are trying to cool a hot coach prior to a trip run both systems for a few minutes to cool the coach for travel, then shut down the genset and use the bus air and heat.

I have heard these arguments pro and con for years, but if you travel in the hot regions of this United States, you need Prevost Bus Air and Heat. Just ask someone who has owned both!

Now having said that, those of us who do not own a coach with Prevost Bus Air & Heat should not get rid of our coaches, we should just contend with batteries/inverters, or run our gensets, roof airs or cruise airs, our dash airs
and not be quite as comfortable. (maybe change our shirts before we arrive so as to not have sweaty armpits, and look as though we have traveled in comfort to our destination).

Its really not all that bad, just trying to make my point on the ease of operating a prevost with bus air.

too late for me. our featherlite on order has no OTR air...:(
However, we do a lot of driving in the southwest but much of it is in the mountains. I'm thinking the genset is probably a better way to go in that case bc don't need to waste any engine power needed for the steep inclines. Plus i would think 4 15K BTU roof airs would be more than enough to make it icey cool inside.

ps: of course, still wish we had OTR...oh well:(

Jon Wehrenberg
05-11-2009, 02:38 PM
With 80,000 + BTUs available for OTR it has excess capacity. So on a 45 foot coach 4 AC units of 13,000 to 15,000 BTUs should be ample.

The key however is to never let the inside temps get away from you.

We learned the hard way. We were in Washington DC a few years ago and would be gone for the day. At 8:00 when we left we had two cruise airs set and working. In the 95 degree days the coach was about 85 when we got back to it at about 5:00 when we returned.

Even with all 4 cruise airs turned on it was a couple of hours before the inside temps began to get comfortable. It was cooler inside than outside, but it was still hot. The only way to get down to where we wanted it was to run the OTR.

When we owners are asked about coaches by potential buyers we always encourage the making of a list of features that are "must have" features. Anytime OTR is brought into the discussion, owners of coaches tend to defend what they have. I suppose that is normal, but few owners of a OTR equipped coach would seek out one without it. Salesmen over the years have created some really well polished reasons why OTR is not needed, but when buying a Prevost a good rule to follow is that often "too much is just not enough."

Ray Davis
05-11-2009, 02:44 PM
My case may be just one of bad luck ...

http://forum.prevostownersgroup.com/showthread.php?t=281

Long story short, traveling from Salt Lake City in June, temperature outside is verging on 120 degrees, pavement probably 150 degrees, ALL of my A/C systems fail. Newly serviced by Prevost, my CC OTR compressor locks up, and a short time later, my cruiseairs all fail with thermal shutdown.

Unfortunately, this saga continued for several months, as I fought to get the A/C working, and spent thousands of dollars doing it.

Because I live in the west, and any normal travel requires going through the desert (and quite likely in summer), wouldn't want cruise airs. My current bus has OTR, and I'm tickled with it. Still have to try it in the heat of the summer, but I'm not expecting any issues.

Ray

Jon Wehrenberg
05-11-2009, 03:12 PM
The Cruise Airs did not fail, but were unable to function because the heat radiating from the road did not allow the condenser units to adequately cool.

This is where roof air units are significantly better.

Jerry Winchester
05-11-2009, 03:34 PM
Cruised into Houston yesterday with the OTR air just kicking while the outside air temp was 91. And from the pool of water in the hanger when I shut it down, I would say it was doing a good job of de-humidification.

This is our second coach with OTR air and while the R-12 system was unbeatable from a coldness standard, the new one keeps the coach real nice and since I have chicks scattered out thru the whole thing, it makes my life way easy.

Especially when I pass the SOB's with the windows down or some guy has his old lady panting like a road lizard with her mouth over the AC outlet trying to find some tepid air.

Ray Davis
05-11-2009, 04:34 PM
The Cruise Airs did not fail, but were unable to function because the heat radiating from the road did not allow the condenser units to adequately cool.

Maybe it's not called a failure, but the darn things stopped operating completely! And I agree, the roof airs would have been much better in that particular instance. So, now my coach has both roof airs, AND OTR.

I'm looking for down-right chilly on my next summer trip! :rolleyes:

hillndale
05-11-2009, 04:57 PM
Our last coach had just two roof airs (plus dash air) and we took a trip thru Yuma and the low desert last summer. It was around a constant 118-120 degrees and the coach was nice and cool the whole time. I never shut it off in fear that we wouldn't be able to get it cooled off again but i'm thinking maybe the roof airs are the best best overall for consistent maximum cooling. Engine temperature continued to run within the normal range (even when we got to the Santa Ana mountains) but i'm wondering with an OTR type system if that would have been the case. Downside of course is the genset running constantly but that was worth it to keep everyone on board happy.

PS: still jealous of everyone with OTR of course :)

Jon Wehrenberg
05-11-2009, 08:15 PM
There is a POG member who has been silent here. He has the answer for getting performance out of Cruise Airs when the heat radiating off the roads is capable of shutting the units dow,

Jim Shoen has added misters to his condensing units tied into a pressure switch and his water system. When the pressure in the condensing unit builds because it is too hot for condenser cooling the misters come on and spray water across the coil.

This is a very effective way to make Cruise Airs work if the coach does not have roof airs.

Jim??? Where are you?

grantracy
05-12-2009, 06:04 AM
Jon: is that why I sometimes get a Hi PS when driving?

Jon Wehrenberg
05-12-2009, 07:24 AM
Gran,

That is exactly why.

The highway is heating up in the sun and the temperatures radiating from it as you cruise down the road are just too hot for the condensing unit in the Cruise Airs.

When you are parked however, the underside of the coach is in the shade and the intake cooling air is closer to the ambient air temperature so the Cruise Airs work as intended. In addition to Jim Shoen's misting system I seem to recall someone created a way to get more air flow across the condenser coils as another way to cure the problem.

We learned this many years ago on a trip when the OTR on our bus had a bad circuit breaker. At the time I though we could just run the generator and all the Cruise Airs to stay comfortable. It did not happen. Every one of them shut diown. Only after the sun went down did we start getting the Cruise Airs to function. What a miserable trip.

I will never own a bus without OTR.

truk4u
05-12-2009, 08:46 AM
Hillndale,

You'll be just fine without OTR, many of us don't have it and your roof airs will take good care of you while driving when needed.

I'm on my 3rd bus without OTR and surprised I'm still here. According to some, I should by now just be a small puddle of goo after melting from the sun while driving the bus!:D Hope I can get through the summer without intravenous feedings from dehydration brought on by the lack of OTR.:p

dalej
05-12-2009, 09:13 AM
Well said Tom!

We too are still alive from being slow roasted in our Prevost w/o OTR air oven. :)

GDeen
05-12-2009, 09:20 AM
...........

In addition to Jim Shoen's misting system I seem to recall someone created a way to get more air flow across the condenser coils as another way to cure the problem.
..............



Steve Bennett's personal bus has a high capacity blower setup that he says works nicely to help his cruiseairs ginning in the heat.

Pete
05-12-2009, 11:04 AM
If I offended some by my post on OTR I did not intend to do so. And if it was offensive, I think you should go back and re-read the post carefully.

My statement was simply that I have owned both, and my opinion is that the OTR is preferable.

If anyone else can say they have owned one of each, and can say they prefer a NON OTR coach, I have a hard time believing it.

Guess there is now three things you should never discuss: politics, religion, and PREVOST OVER THE ROAD AIR!

Jerry Winchester
05-12-2009, 11:21 AM
Pete,

Don't fret. The Krakman just leaves the door of his fridge open to suppliment the cooling. Of course that lowers the temp of the beer and causes a simultanious issue with the "Low Beer" light on the dash, but he just has a case of OTR envy. He'll get over it.

dale farley
05-12-2009, 11:25 AM
Pete,

I doubt that any of the guys are really offended. I have never had Prevost OTR air, and I am perfectly satisfied with my CC OTR air, but in reality, I have never had to use it.

If I had Prevost OTR air, I would certainly be looking for reasons to like it as we most often do when we have any feature on our bus. I am sure it will keep the bus cooler than any other source available. The only time I would hate that I had the Prevost unit would be when I had to do major repairs, such as replace the compressor.

Fortunately, most of us concentrate on the things we like about our current coach and accept the things we may not like as well as another available option that we don't have. If we don't do that, we would all go nuts trying to keep up with the Jones.

dalej
05-12-2009, 12:26 PM
Pete-

All is good! We just spur each other and try to hang on for 8 seconds. :)

Jon Wehrenberg
05-12-2009, 12:55 PM
Pete, Fear not. Truk is a little grump living down there near Hotlanta without OTR trying to make like everything is OK. In reality he just wishes he had it.

Those of us with OTR know the truth.

JIM CHALOUPKA
05-12-2009, 01:01 PM
I thought all Liberties had OTR?

JIM

Jon Wehrenberg
05-12-2009, 01:10 PM
No. In later years I think all except maybe special order coaches come with it, but in the early years Liberty had two versions of their coach with the less expensive model only having driver's air.

jack14r
05-12-2009, 02:06 PM
Liberty is building their first 3 slide H3 and because of weight they are not going to have OTR in this one.The OTR weighs 700 pounds.

rfoster
05-12-2009, 02:33 PM
Jack: So how are the going to keep it cool while moving?

I don't have Prevost OTR air but I do have a funeral home fan from Denny.

Micki is driving and I am a riding on our way to the Dan and Jo all u can eat Mississippi Mini Rally in Bay St Louis.

And I ain't sweated a bit yet. But you know how women drivers are.:cool:

Maybe at the crap tables?

Yall come

Jon Wehrenberg
05-12-2009, 02:40 PM
For the sake of whoever strokes the check for that H3 I hope they put at least 5 roof airs on that bus.

If I was spending an amount of money for a bus that a 3 slide Liberty is going to take I would want to be able to stay at 70 degrees inside the coach while crossing the desert on a 110 degree day. I'll bet that won't happen.

tdelorme
05-12-2009, 04:22 PM
I thought all Liberties had OTR?

JIM
Here's one Jim. This is a real nice 96 Liberty with no OTR air. I think it was at Paul's when you picked up your bus.
http://www.mrolivers.com/RV_Slot_03/RV_Description.html

jack14r
05-12-2009, 06:37 PM
Like Jon,I really like OTR air and heat.I know that it cost more from Prevost as well as more labor and materials for the converter and also weighs more.A Liberty without OTR is IMHO almost a sin in 2009,it will be interesting to see if an old Liberty customer buys this one or someone that has never had bus air.I don't know but I bet that it has 2 Outback 3500 watt inverters with six 8D batteries and 4 cruise airs.Traveling in the desert when two cruise airs overheat just turn on the other two until the others cool down and then begin the cycle again.

Jon Wehrenberg
05-12-2009, 07:17 PM
Jack,

Tell the truth. You just take delivery of your new three slide Liberty H3 Elegant Lady with (only) four Cruise Airs and you head out to the desert in August.

What will your first reaction be when you find out you are working your fingers to the bone pressing buttons to cycle the AC units on and off so you can keep the inside of your new pride and joy at a comfortable 90 degrees after you just traded in a coach with OTR?

I'm pretty sure even if they all worked as they were supposed to that 4 Cruise Airs will not cool that much interior with the slides open. Remember, these coaches aren't the white Winnebagos but are the fashionable dark colors.

It will feel like the North Pole when you jump in that coach after standing out in the hot desert sun, but after being in it for a little while and it can't get out of the 80s inside I can just see the new owner going ballistic.

Nope......five roof airs and an engine driven generator.

truk4u
05-12-2009, 08:50 PM
Pete - Note the smiley faces in my post...;)

Right now I'm in AL on my way to the MS eatfest and have 2 floor fans, 1 ceiling fan, 3 cruiseairs and the fridge door open so we can be comfortable without OTR. It's tough, but hopefully things will cool down and we can at least close the fridge door. I think it's much cheaper to just buy a new fridge and keep the door open instead of all that maintenance and upkeep with one of those big clunky OTR deals.:rolleyes:

Dale J - How are we ever going to get through the summer without OTR?:(

Pete
05-12-2009, 10:07 PM
Tom...
It seems that those without OTR always travel north and south so the sun won't get into the windshield and on the driver/co-pilot.

If you recall, I do not have OTR either, but have an ample supply of right guard on hand.

Hope you guys have a great time at the eat-fest, tell everyone hello for E.J. and I. We would be there except we were just in Biloxi this past week, and E.J.'s grand daughter has her dance recital this week end in Dallas.

Loc
05-13-2009, 07:44 AM
I have melted and turned into a pile of goo working in NY all because of not having OTR air.:eek: In fact, I have decided that all my problems are truly to blame on not having OTR.:D I am starting a support group for non-OTR bus owners. Pete you can join even though we know you are not a true believer.

Having had both a bus air coach and a non-bus air coach, I prefer the bus air coach. That being said, I just paid a small fortune / five year college tuition to have a new generator put in the bus and I plan to run the darn thing with all four roof airs running every single minute I am in the bus including winter. I may shut it down in campgrounds, but I haven't decided.

Pete
05-13-2009, 09:49 AM
Loc,
Sign me up! I know the group will need all the help it can get!
Now I need to get busy changing the oil in my genset so I can run my 4 roof top a/c's. It only takes a 20kw genset to operate them.

Jerry Winchester
05-13-2009, 11:41 AM
I have melted and turned into a pile of goo working in NY all because of not having OTR air. In fact, I have decided that all my problems are truly to blame on not having OTR. I am starting a support group for non-OTR bus owners. Pete you can join even though we know you are not a true believer.

Sounds like our favorite government employee is about to go postal. I hope BHO doesn't get a report on your carbon footprint.

GDeen
05-13-2009, 07:56 PM
Sounds like our favorite government employee is about to go postal. I hope BHO doesn't get a report on your carbon footprint.

At least he would probably let MHO tour the climate destroying Millennium without removing her $500 tennis shoes.....

tdelorme
05-13-2009, 08:25 PM
Sounds like our favorite government employee is about to go postal. I hope BHO doesn't get a report on your carbon footprint.


JDUB, campaign vehicles driven by employees of the Administration are exempt. Loc has nothing to fear. Well, nothing but hot weather.

Jerry Winchester
05-14-2009, 11:36 AM
I guess it doesn't matter today as his coach is keeping your coach company at Prevost.

Kenneth Brewer
05-14-2009, 01:28 PM
We visited Death Valley this past early December, when it was quite pleasant and cool. Without really getting involved in this thread, I am curious if anyone visited Death Valley in the summer, with or without OTR, and how they feel their A/C systems fared in that kind of heat (>100 degrees).

Jerry Winchester
05-14-2009, 04:04 PM
The highest ambient temp I have operated OTR and Cruisairs in is 117 deg. and that was coming out of Palm Springs in late June. The OTR worked well, but I had a weak circuit breaker in the condensor fan unit that shut it down. There is a whole thread on here somewhere that discusses that deal.

So I fired up the generator and turned on the Cruisairs. As Jon relayed in a earlier post, the Cruisairs sucking that hot air off of the blacktop didn't last long as they were HIPSI or some other issue and they started falling off line.

The last trip thru PHX at 114, the OTR worked fine, but I did have the shades lowered about half way to keep some of the direct heat out.

phorner
05-14-2009, 04:04 PM
We'll be headed in that direction....... in July, so we'll have a pretty good test of the OTR air conditioning underway.

Keep ya posted as to how we make out....

GDeen
05-14-2009, 04:12 PM
The last trip thru PHX at 114, the OTR worked fine, but I did have the shades lowered about half way to keep some of the direct heat out.

Was that in the XLII or the old bus Jerry?

garyde
05-14-2009, 10:10 PM
Several times passing thru Arizona in the summer, temp is over 100, and its 72 inside the Coach. I didn't even think about it until stopping at a rest stop and stepping outside into a heat wave.

Jerry Winchester
05-16-2009, 03:06 PM
My PHX trip was in the new bus. The Palm Springs trip was the inagural trip on the XL when we bought it in San Diego. I was a dumb as a box of Loc but made it home anyway.

Loc
05-16-2009, 06:18 PM
That's way harsh.

Mabruteam
06-08-2021, 07:40 AM
The question is why they don't install ultra compact inverter
belly AIR CONDITIONING units? 24V directly from a nice lithium battery bank, this way the alternator can keep up with the load at cruising, less belts and systems to go wrong, conform air Cond idle law, no noise, solar, generator by charging the batteries the same way we do on boats..

Fratto
06-08-2021, 10:46 AM
Might be fun if the make them air cooled? All of the marine type units that I have seen are raw water cooled. And I have never seen one that has the capacity of the OTR units.

Gil_J
06-08-2021, 05:41 PM
The question is why they don't install ultra compact inverter
belly AIR CONDITIONING units? 24V directly from a nice lithium battery bank, this way the alternator can keep up with the load at cruising, less belts and systems to go wrong, conform air Cond idle law, no noise, solar, generator by charging the batteries the same way we do on boats..

What's the manufacturer and model?

I've only seen one coach with DC powered air conditioners. They were 48VDC roof air units. The problem with DC powered is the huge current demands. A much gem higher voltage is needed. My new home unit has a 400V DC fan motor.

I'd like to see a mini-split with a ducted or floor standing indoor unit that it's 120VAC powered. I've looked at every manufacturer that I can find and none offer one.

georgiapeachinc
06-08-2021, 06:58 PM
I concur with the OTR A/C as our liberty is so equipped. Cool as a cucumber going down the super slab! Only draw backs are it does affect your MPG slightly,it is rather noisy when parked with the RPM elevated and if you happen to hit a patch of road that is unpaved it creates an enormous cloud of dust. We have an unpaved portion of road leading up to our getaway property and we shut off the OTR for the last mile to to avoid a dust storm. Aside from that you learn to live with the tiny draw backs. The loss of primarily 2 bays is not even worth mentioning in our situation.

Fratto
06-09-2021, 01:57 PM
Gil, I am not sure what you have in mind, but you might look at some of the new VRF systems. While the evaporator units were initially very small, they are making larger and more substantial evaporators with a fair amount of static pressure to push duct work every day. I don't see why you couldn't adapt one of these to a vertical orientation (if they dont already have one). It might take some case work or making your own case.

Ben Ochs
06-11-2021, 02:12 PM
Jon, Do you have a ballpark figure on how many pounds of refrigerant an OTR system requires?

I have a 1994 Marathon (#0280) with both Cruiseair and OTR.

Thanks,

Ben

Mabruteam
06-17-2021, 05:44 PM
RV air conditioning is a mystery to me, after 40 years designing units for the marine industry I found all the bay units to be far from efficient, the roof top are also far from efficient, Why not go for variable speed dual inverter 24v compressors, they are quiet, compact low profile and efficient. All that coupled with a lithium Po4 battery bank, will simplify the complete setup. I started already and I will be testing on my old new to me XL45 Marathon.

Mabruteam
06-29-2021, 09:08 AM
My old XLV 1999 #539 Marathon is equipped with OTR and 3 Cruisair units, 2 X 4000w trace inverters, 6x 250ah lithium batteries, we added 2 MPS low profile 24v roof top units, I came out to the conclusion that if I build a new coach I will equip it with only 24v roof top units, maybe 3 or 4 but nothing else. We run 2 all night and our battery bank goes down only about 20%, they are quiet and ultra efficient, hot air goes up not down so conditioning the air is much easier, this is the way they look.
The question is: why have so many systems? 24v units will run on the engine alternator on batteries, on shore power with the bat charger.. My 2 units are doing a phenomenal job to keep us comfortable, we will be covering our roof with solar panels to make it even more interesting. Generator is charging our batteries in a record time..
We changed out refrigerators by dual voltage 24v 115v but most of the time they run on 24v..
Now changing the oil on our generator is not as often.
http://forum.prevostownersgroup.com/attachment.php?attachmentid=17584&stc=1

Joe Camper
06-29-2021, 09:45 AM
Stupid question. Is this possible to do 12v. Im currently in planning stages on redoing the camper side of my pete, from scratch, 1 month away. Its 12 v.

Nother question what does one cost?

Mabruteam
06-29-2021, 09:51 AM
My old XLV 1999 #539 Marathon is equipped with OTR and 3 Cruisair units, 2 X 4000w trace inverters, 6x 250ah lithium batteries, we added 2 MPS low profile 24v roof top units, I came out to the conclusion that if I build a new coach I will equip it with only 24v roof top units, maybe 3 or 4 but nothing else. We run 2 all night and our battery bank goes down only about 20%, they are quiet and ultra efficient, hot air goes up not down so conditioning the air is much easier, this is the way they look.
The question is: why have so many systems? 24v units will run on the engine alternator on batteries, on shore power with the bat charger.. My 2 units are doing a phenomenal job to keep us comfortable, we will be covering our roof with solar panels to make it even more interesting. Generator is charging our batteries in a record time..
We changed out refrigerators by dual voltage 24v 115v but most of the time they run on 24v..
Now changing the oil on our generator is not as often.
http://forum.prevostownersgroup.com/attachment.php?attachmentid=17584&stc=1

Mabruteam
06-29-2021, 10:02 AM
We have the MPS 12000 12v on our sprinters service vans, they run at max speed at 45amp, and at low econo night time about 25amp.. I get them for $1200 lel me know how many you want?

Gil_J
06-29-2021, 02:21 PM
We have the MPS 12000 12v on our sprinters service vans, they run at max speed at 45amp, and at low econo night time about 25amp.. I get them for $1200 lel me know how many you want?

Can you supply a link to these units?

Mabruteam
07-09-2021, 12:34 PM
https://mabrustore.com/products/mabru-rv-self-contained-12v-12-000btu-vehicle-air-conditioner-vans-bus-trucks-rv-splitter-vans

Gil_J
07-11-2021, 10:23 AM
https://mabrustore.com/products/mabru-rv-self-contained-12v-12-000btu-vehicle-air-conditioner-vans-bus-trucks-rv-splitter-vans

I'm a bit skeptical on the power use for 12KW BTU. Your site suggests 24V systems, but I didn't find any. I would be curious if there is a low profile 24V system and, if so, is there an installation manual? Will it supported ducted systems? The limited specifications suggests its thermostat only displays Celsius. Can that be true?

PrevostNewbie
05-28-2022, 04:49 PM
That is it! The last of the non functioning AC junk going in the trash. The copper tubing was very soft and thin.

http://forum.prevostownersgroup.com/attachment.php?attachmentid=18357&stc=1