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Mark
06-17-2010, 02:50 PM
I began my Prveost research about six weeks ago and I need actual personal feed back (good or bad ) from those of you that are owners and have the experince that I do not have. I sold my 40' triple slide Fleetwood coach and I am looking for (at least at this point, I believe this is what I want) a 2001 - 2003 single slide Prevost. I am getting conflicting information depending on the sales person and what coaches they have to offer. I know from my research and from what I have viewed in the POG forums that the OTR air is the best way to go BUT my question is: If a 45' bus has 3 roof a/c units will it properly cool the coach both driving with the generator running and when hooked up to power? I do live in Florida and will also travel in the southwest. Some people are saying no and those that are trying to sell a bus with 3 roof units are saying no problem. I have also inquired about a couple buses with 4 roof a/c units which obviously if 3 are functionaly acceptable 4 will be fine. Your personal feed back, good or bad, regarding 3 vs 4 roof a/c buses is greatly appreciated.

Donnie_M
06-17-2010, 03:15 PM
Welcome! Absolutly no way 3 roof airs will cool that bus in Fl! Especially on a day like today!

Mark
06-17-2010, 03:20 PM
I see so many buses with three roof airs. What are they doing during the summer months? I guess they are just unable to cool them during the heat of the day to any reasonable temp?

jack14r
06-17-2010, 03:46 PM
If you look at the non slide coaches some of them even have 4 cruise airs,I am with Donnie on this, no way 3 roofs will cool a single slide coach.I have tweaked the freon in my cruise airs to put out the coldest air possible and on the 95+ days I can maintain 72 in the coach,this is with 4 very well maintained 3 year old units.I have a roof air on a Renegade and I am on my third one in 14 years,cruise airs will last 15+ years.I really like the cruise airs over roof airs because of no holes in a roof and a very high quality home like unit,but others do admit that the roof airs are cheap to replace and do cool OK.

Kenneth Brewer
06-17-2010, 03:49 PM
Sorry, no. Perhaps for a 35' metal coach ( I still have mine), but not 45'. Not in the south, and certainly not the southern border states. Not if you want temperatures inside to be in the low to mid-seventies, with no shade trees, and outside temperatures in the mid nineties up. Even 4 units can have difficulties. That is my experience.

Pete
06-17-2010, 04:54 PM
Mark, here we go again. This subject has been debated many times on this forum. I have owned both. A coach with Prevost bus air and heat,and 3 cruise airs (a 40 footer), and a 45 footer with 4 (four) roof airs and with dash air. If I had my pick again I would go with bus air. The 45 I presently have is ok, but is not as comfortable even running 4 roof airs and the dash air, especially when driving into the sun. When parked, the coach with 4 roof airs is ok, and comfortable, but you need to run all you have during the day when on the road. Soooo, in my opinion, go with the bus air. Also, you should keep in mind that in the case you should loose your Generator when you only have roof tops, or cruise airs,and maybe dash air you are out of Business while on the road. If you loose your bus air, you do have backup with the Generator and your roof or cruise airs.........Ask Andre and Ann, they just had that situation. My two cents worth! I think I hear INCOMING! I have said before, three things you don't discuss on this site are religion, politics, and BUS AIR!

Danss
06-17-2010, 05:07 PM
i have 4 roof airs that cool great. when running I can run one roof air without generator. I close door to back area and turn on dash air and one roof air and away I go. Dan

Gary & Peggy Stevens
06-17-2010, 05:28 PM
Mark you have really opened a can of worms. Next your going to ask everyones opinion on Slides or Non Slides in Buss's..??? Just kidding you.

This is really a tough question to answer and there are right answers from every side of the equation.

I don't have OTR air, and in Texas I sure wish I did have it driving down the rode. I do have 4 roof airs, and when in the heat of the year, I drive with the generator going and all A/C's running and the blinds down most of the time, which keeps me cool going down the road.

There aren't too many OTR equipped buss's out there ( IMO ) compared to the NON OTR bus, but that is just a convertors decision. Some convertors refuse to use up the valuable space for OTR and feel they have the proper cooling power with what they put in?

I believe more convertors choose not to use OTR, but for example Liberty ONLY uses OTR in their buss.

OK, now lets talk about your color preferences !!!! :):D

What ever you decide, and you have a long list of options and wants that must be narrowed down, Your going to have lots of fun.... Good Luck and keep all of us in the loop.

Gary S.

ajducote
06-17-2010, 05:29 PM
To add what Pete said, we have 3 brand new 15K BTU roof airs and on the way thru Tennessee I lost my generator due to a $16 start capacitor. All we had was the dash air for 2 days on the road. Now we got a little lucky, it was only in the mid to high 80 deg's and we made out ok with just the dash air while on the road. We stopped at a campground and ran the roof airs on 50 Amp shore power for the night. I have never had a bus with over the road air or cruise airs so I can not compare them to roof air. Right now I seem to be making out OK with my 3 roof airs, but they do run a lot when the temps get over 90 deg. or so.

Pete
06-17-2010, 05:53 PM
Mark, I failed to tell you that I can run 2 roof airs on the inverters while going down the road, but I feel it over works the alternator and batteries, so I Just fire up the genset, and run all four rooftop a/c's and the dash air if need be. You will be fine with 4 roof airs, but I feel it is easier to regulate the bus air (just a simple twist of the dial on the drivers dash) than to regulate 4 t-stats on my coach. The engine generates a fair amount of heat in the bedroom that you have to contend with when you stop for the night, if you don't run an a/c in the bedrooom.

jack14r
06-17-2010, 06:00 PM
I see a lot of entertainer coaches that have 5 roof airs.

Roadpilot
06-17-2010, 06:10 PM
We have 4 roof airs. Normally going down the road, we run 2 roof airs off the inverter and close the door to the back. We also have the dash air going. So far this has worked fine. We could start the genset and run all 4 roof airs but so far haven't had to. We bought the bus this winter in Florida which was cold. We haven't tried the roof airs in 100 degree temps, but our Essex, which was also 45' had 3 roof airs and it was quite comfortable in very hot weather. I'm hoping the Prevost with 4 roof airs is as good.

Alek&Lucia
06-17-2010, 06:37 PM
Hello Mark,

Right now we have H3-45 Royale with OTR.
I have to admit, that after having 2 Prevost buses with out OTR,
if we have a choice we will always prefer a coach with OTR,

Alek

tdelorme
06-17-2010, 07:21 PM
Mark, three years ago I was asking the same questions that you are asking. We live in Texas ans had never owned a coach that would stay cool driving west in the summer. We owned three Foretravels and a Country Coach and all would stay cool while parked. The first coach we fell in love with was a 1997 Marathon without Prevost OTR air. Four roof airs and dash air. The salesperson went into great detail about how running a couple of roof airs off the invertor and the dash air would keep the driver cool no matter how hot it was outside. This was in mid May and it was about 85 degrees that day so I said show me. We headed west from Arlington to Ft. Worth right into the afternoon sun. The test drive lasted an hour or so and the front of the coach was never really comfortable and I was hot when driving. We ended up buying an older liberty with OTR air and three cruiseairs. Any Prevost equipted with properly maintained OTR air and three or four Cruiseairs will keep the driver and passengers cool no matter how it gets outside. I love my Cruiseairs. The Liberty we now have has OTR air and four Cruiseairs and staying cool is never an issue.
Also, I just don't get it when it comes to running roof airs on the invertor. Use the gen set and run whatever you want to run. It's the cheapest power around and if you take care of these units they will last forever. Good luck in your search. We have several first class dealers in your area including Ken Robertson and Liberty Coach. You won't go wrong with either company.

Jon Wehrenberg
06-17-2010, 07:25 PM
Mark, Welcome to the asylum. This is a topic that has been discussed and debated, but in the end if we step back from defending the coaches we have or have had the numbers will tell the story.

OTR is about 80,000 BTUs of cooling. It was designed to cool 45 people on a coach while driving through the desert southwest in July. Keep that number in mind.

Cruise Airs and roof airs each have around 13,000 to 15,000 BTUs of cooling. I do not know what driver's air has for capacity. It is probably akin to a system that might be found in a large SUV.

If you want to be able to stay cool and comfortable while driving in the summer heat, when the outside air heat is being absorbed by the coach as it travels down the road there is no substitute for OTR in terms of performance. That is the reason why entertainer coaches will be found with 5 roof airs. That number of units approaches the capability of the OTR. Keep in mind that entertainers and their crews who use the coaches are accustomed to continuous generator usage also so they are not the least bit hesitant to use all the cooling capacity available if needed.

If you have not seen if discussed keep in mind that if you do not have OTR, do not plan on Cruise Airs as installed in our coaches to perform as well as they should as a substitute when traveling. They are best when the coach is not in motion. They require cool air passing through the bay mounted condensing units for maximum efficiency. When you need cooling the most the Cruise Airs are likely to let you down because the heated air radiating from a hot highway is likely to prove inadequate for cooling and the units will shut down unless the units have been modified by forcing additional air through the coils or by having a water misting system for cooling.

Roof airs are the best alternative to OTR when in motion, but again use caution. Either plan on running the generator, or make certain you know and understand how many units will run from your inverters.

As to the number of AC units, if you have three on a 45 foot coach you must stay ahead of the game. Those units will be hard pressed to bring a heat soaked coach down to a comfortable temperature. Four will struggle. If one fails to operate you may find yourself very uncomfortable. You never want to let the coach get warm if you only have three units because they just will struggle to maintain temperature, much less pull it down. The reasons for debates on this topic is probably the differences in how different people tolerate heat. I'm with Jack. 72 degrees is getting close to perfect, and on hot days it is likely to take four units to get to and to maintain that temperature.

Finally, energy is energy is energy. Don't let anyone provide you with a helping of manure with respect to trying to convince you any of the choices and how they are powered is any more or less efficient with respect to the use of diesel fuel. If you want to maintain a specific temperature it will take the same amount of energy to get to and to maintain that temperature. Whether it is powered by the generator, the bus engine or inverters which are getting there power via the bus alternator about the same amount of fuel or power will be consumed.

dmatz
06-17-2010, 08:00 PM
I have one of those single slide 3 roof air units. It works and on hot days it is marginal. I have replaced one so far and used a larger unit and when I do the other 2 if I still have this bus I will do the same. Every thing has a down side working on the otr and cruise air are very difficult to work on because os space to get to them. 4 would be better. It's worked ok for us. Definitly need to not let the bus get wicked hot or it will take a long time to cool down. If the ac is to big you will cool it off without removing enough humidity. I am sure you are more confused than ever.

Donnie_M
06-17-2010, 08:09 PM
Mark, if you can get a "great deal" on it, get it and add another roof air. One thing is for sure, a roof air is more efficient than a power hungry Cruise Air..lol A Cruise Air draws 14-17 amps to achieve 14-18 degree temp split. Roof airs draw 12-14 amps and can can get 22-24 degree split out of the box!

Mark
06-17-2010, 08:23 PM
It sounds like as I expected, OTR air is the best way to go but some of the buses that I have been looking at have roof air and based upon what I'm reading and reading between the lines on some of the responses 3 roof air buses will NOT cool

Mark
06-17-2010, 08:31 PM
I think I will have to keep my search to OTR air, cruise air and 4 roof air coaches only. Thank you for the help. Now I must search harder or add more money to my search because it seems that most OTR buses are Liberty buses that bring a higher purchase price and I dont want to compromise giving up a single slide. Therefore my true option may remain a non Liberty bus with the single slide and either cruise air or FOUR roof airs which should keep me in my price range.

Kenneth Brewer
06-17-2010, 10:38 PM
Mark, in my view there is one thing more to emphasize: With OTR (Prevost) the coach is cooled without closing the blinds/drapes. In fact, the OTR has to because it won't work with the blinds down because the OTR ducting (on non-slides, certainly) by using ducting/grating at the base of the windows. Closing the blinds blocks the air and blows/bows out the blinds. Addtionally, when the OTR is used (and I would follow Jon's advice about using CruiseAirs while on the road), it will cool the whole coach whether the bedroom and/or galley door is closed or not. Now I guess I will wait for the incoming as well.

Ray Davis
06-18-2010, 12:24 AM
If you look back in the threads far enough, you'll find my saga of my first bus, a 40 foot (non-slide) with 3 cruise airs and the country coach OTR system. Coming from Salt Lake City heading towards Las Vegas at mid day (late June), the outside temp was well over 110. My compressor seized on the CC OTR, so I fired the generator and turned on the three cruise airs. As Jon mentioned, cruise airs get their air intake from down low, front of the bus. So, while driving, I'm guessing that the road temp was in excess of 140 degrees in the desert. Within an hour, all three cruise airs shut down on thermal overload. I limped in to Vegas, putting ice cubes in wet towels and wiping ourselves down as we drove.

My current bus has Prevost bus air, and 4 roof airs. A recent trip to Arizona over July 4th weekend it was 105 outside. With the bus air going, my wife was wearing a jacket inside the coach. However, when parked in the 110 degree heat of Arizona, 4 roof tops barely kept up with the heat, basically running 24/7.

Just FYI.

Ray

Jon Wehrenberg
06-18-2010, 07:12 AM
Finally we are getting some open discussion about how well the various AC options work. Usually the discussion tends to folks defending what they have. OTR based solely on the numbers is going to cool and keep cool significantly better than any other option. That is not debateable. While being used OTR cools the entire coach so after a long day of driving you will not have to crawl into a heat soaked bed because while driving all the available AC was dedicated to the front of the coach.

OTR is going to be more and more difficult to find because as coaches get more slides the converters are just not going to be able to offer OTR because of ducting issues. Even a one slide coach loses the ducting along the windows on the portion that slides. Even with a no slide coach OTR is a challenge to converters because in addition to dealing with the floor plan and cabinetry, consideration must be given to ducting and balancing the air flow. It is so much simpler for a converter to just stick a bunch of roof or Cruise Airs on the coach and BS the customers about how much more storage space you get and how you don't lose all the HP driving the big compressor. (I'll bet every single time you mention to a salesman you want OTR those arguments against it will be repeated.)

But while Cruise Airs and roof airs have their advantages one of the facts of life is that neither is perfect and like most things on the conversions the choice is a compromise. When buying a coach it is the converter who makes the decision based on how they have their systems set up so a buyer of a coach who decides on the systems they want has also in effect chosen the converter.

With rare exception if a buyer wants an OTR coach it is going to be a Liberty. If the buyer wants an OTR coach with roof airs it is probable it will be one of the rare non-Liberty OTR coaches and those on the market can probably be counted on the fingers of one hand with three or four missing.

I think the issue of price should be examined before making a blanket statement that the Liberty coaches carry a higher price. Maybe they do. Maybe not. What is important is recognizing that the purchase of a single slide OTR coach is not going to be cheap no matter who converted it, and if the object is to buy the cheapest coach it may mean giving up OTR. Then as an owner you get to experience what has been expressed here about marginal cooling. I cannot think of anything worse than to spend serious money for a coach that does not perform as a "million dollar" coach is expected to perform. Might as well buy a plastic one. I am heavily biased toward Liberty because I have over 20 years of ownership now and I am still in awe of their reliability and ease of working on one. It doesn't hurt that I also like their quality level which is as good or better than anything out there.

If we were to ever get another coach (unlikely because we like what we have) our list of priorities would have OTR at the top of the list. The lack of OTR would be a deal breaker. That is how important it is to us. We have other priorities, such as private toilet, long range fuel, dinette booth instead of a table, sofa and two chairs instead of two sofas, etc. We got the first three, but can live without the dinette and having two living room chairs. Notice that I did not list a preference between roof airs or Cuise Airs. I like our Cruise Airs, and I prefer them for several reasons, but roof airs are a great backup if the OTR fails to work. I cannot say that about the Cruise Airs.

I think you are taking the right approach to seeking a coach by focusing on the systems that make the coach enjoyable.

Gary Carmichael
06-18-2010, 01:29 PM
Interesting OTR was a question we posed to the the salesman at Liberty, not being familiar with the system they just said do you want to stay cool on a hot day! Boy were they right on! an added bonus we both drive and one can go to the bedroom take anap in cool comfort. In the other coach we had to close the bedroom off ,and as someone mentioned in a previous post it was hot ion that area for several hours after we parked.

rbeecher
06-18-2010, 04:40 PM
It sounds like as I expected, OTR air is the best way to go but some of the buses that I have been looking at have roof air and based upon what I'm reading and reading between the lines on some of the responses 3 roof air buses will NOT cool
Mark,

As you can see this is an excercise in partisan politics. If a bus owner has it, it's the greatest thing in the world. If they don't, or even did, and don't anymore, it isn't as good as when they had it. I had a 40 foot Vogue with OTR and three roof airs plus the drivers (dash) air. The OTR was overkill. Like you, I was very concerned about looking at a bus without OTR. So when I found the next bus of my dreams, a 2002 Marathon XLII with 3 roof airs, I made sure I waited for a blazing hot day when I went to inspect the coach, my personal PDI if you will. My instructions to Marathon in Florida were to close the bus up, A/C off and leave the shades up until I arrived. I even requested the bus be parked away from everything so it was not in any shade. When I arrived at mid day it was very, very hot, like what we are experiencing now. I proceeded to take my time inspecting the outside and all external systems. Once completed, I went for a drive, a long one. There had been no A/C on in the bus for 6 hours! Started the bus, turned on the drivers air and then one roof air then the other. In a Marathon XLII you can run two roof airs off the inverters going down the road. I have never, and I repeat, never, had a need for OTR and frankly, I wouldn't buy it again unless the bus was everything else I wanted and just happened to have OTR. My bus resides in south Florida. It has spent many weekends over the two years I have owned it sitting on hot asphalt or concrete in race track paddocks. We spend most of the time in the bus in Florida. When we are going down the road, my wife keeps her blanket on with the two out of three roof airs set at 72 degrees. From my experience, there really isn't an issue with any of the A/C set ups as long as they are properly maintained. You are welcome to visit or contact me if I can be of further help in any way.

Richard Beecher
2002 Marathon XLII 45
2010 Mini S toad

charlesebrownjr
06-18-2010, 08:11 PM
Someone please help me with the terminology of these A/C units. What is Cruise Air, OTR A/C or Bus Air. I have a 40' 99 CC XL with three roof airs (which will not run off the inverters) I don't like the noise of the roof airs but have to live with it.
I have an engine driven compressor which runs A/C units under my kitchen cabinets and under one night stand in the bedroom. This A/C units keep the bus cool on the road.
Thanks All

Kevin Erion
06-18-2010, 09:51 PM
I know this is going to sound like I am drinking from the same pond as Richard. I am on my 2nd Marathon, the first was a 99XLV and now an 01 XLII 45. Both buses had Prevost dash air and 3 cruise airs. We travel as a family, 4 girls and a driver, that would be me! Most of our trips start in late June when the kids get out of school and we go East, the desert, AZ, New Mexico, Texas and so on. It is always hot on our trips and I like to be cool when I drive, ask GaryD, so the dash air is aimed at the driver. The bedroom cruise air and the front cruise air will keep it to the point everyone but the driver is watching TV wraped up in blankets. The wife goes into the bedroom and disapers for hours on end, says she has a great book, I don't buy that, She is sleeping! Shades down, cool, black and a very faint vibration, wow, I can only dream because I am driving!
The point is I have never had Prevost OTR and may never, I would if everything else is the way it should be, but for now I never worry about when we should leave, or what the temp is outside. When it's hot, I am more worried about the temps I see on my tires from the infa red temp gun, but I do slow down and go Jon's speed to keep the tires cool and cozy.
And I have never felt like I needed to start the gen and run the 3rd cruise air, something I keep as an option.

garyde
06-18-2010, 10:29 PM
I would think the XLII has better insulation and with its dual glazed windows it is going to retain cooler temps and keep the heat out better. Certain the OTR keeps my Coach very cool inside. Having the vents at the base of the windows also helps by starting the air circulation lower and cools the glass and walls keeping the heat transfer from the outside to a minimum. Even with the engine heat coming radiatig in the bedroom the OTR keeps the room very cool. You can't really tell how hot it is outside without sticking your hand out the window.

Ray Davis
06-18-2010, 11:38 PM
My second coach, after selling the Country Coach, had 3 roof airs (it was a 40 footer). I will admit, I never had any A/C issues with it, however it was destroyed in a fire before I had a chance to travel in summer in it.

As mentioned current coach has bus air, and I'm happy with it. I'm not sure it's a deal breaker if looking for the next bus. But, I will say I am extremely pleased how cool the bus air keeps the coach.

Ray Davis
06-18-2010, 11:44 PM
Charles,

So, there is essentially 3 (actually 4 different kinds of A/C) in most buses around today.

Roof air, we're all familiar with. Same stuff that's on top of any plastic coach.

Bus Air or OTR air is the A/C system put in seated coaches, powered by a huge compressor in the engine bay. Air comes up through ducts in the windows, and cools the entire coach. I think it's like a 7 ton compressor, and it will keep a coach icy cold. It's also takes a lot of bay space, and is pretty pricey option.

Cruise Air is units that are generally stored in the bay or up front behind the bumper area. They typically run only on shore or generator power (sometimes on large alternators you might use one or two).

Country Coach also made their own version of OTR for awhile (don't know if it went into 1999 or not), but they had their own compressor in the engine compartment, and generally had a 3 zone system, that it fed.

Generally these coaches would also have a dash-air system which was powered by another compressor in the engine. My CC didn't have the Prevost dash air, but only the CC OTR system.

I hope that helps a bit.

Ray

Kenneth Brewer
06-19-2010, 12:05 AM
My last comment on this thread this year. Any system that will keep the coach cool is a good system if it is reliable, and would handle southwestern desert places like Phoenix or Tucson which can and will get over 110 in the summer, and perhaps camping in Death Valley NP type environments, both when on the road and when parked (camping) without benefit of shade. These conditions will be encountered sooner or later, I would think, and as someone has already said it would be a shame if after spending money for a "million-dollar" motorcoach such places would have to be avoided in order to remain comfortable. If you are reasonably assured of this, or that you would not be visiting or traveling through such places, you will have what you need, and you can feel confident in your decision.

rfoster
06-19-2010, 07:16 AM
FYI I learned this week that roof air comes in two different BTUs 13500 or 15000.

I learned this as a result of being on the warm side at the beach last week with temps near 100 degrees and no shade. I had 2 of my , 13500 roof airs replaced yesterday with two 15000 BTU by Russell Coach in Knoxville. I called Rob from the beach and asked if he worked on them and he said no he just replaces them, when they start to fail it is time to replace.

So that is what we did and of course I am not at the beach but it was 92 degrees here yesterday and I had the temp in the coach at a cool 69 degrees.

Rob @ Russell Coach is a pleasure to do business with.

Jon Wehrenberg
06-19-2010, 07:34 AM
Anyone trying to decide on the AC systems for a coach purchase needs to recognize that what might be comfortable for some may not be for others and that is likely why there are choices.

Both my wife and I are very uncomfotable in heat. Heat to me is defined as anything over 72 degrees. And I want cold air blowing on me while I drive. I have an aunt and uncle that will wear a coat if the temperature drops into the seventies and they set the AC in their house at 85. If they were part of this discussion you would think one roof air would be all that was needed.

So everyone here is providing their evaluation of the AC systems based on their perspective and they are all correct.

There is one recurring theme here that needs to be understood. From reading the posts it could be thought that having ample AC capacity means everyone in the coach is going to be wearing blankets or coats. The reality is that no matter how much cooling capacity a coach has, and in whatever form it takes all systems are controllable and once the desired temperature set point has been reached the AC units cycle on and off to maintain temperature. What has not been stated here and needs to be recognized is each system is likely ducted differently so in addition to being able to maintain a given temperature the AC system needs to be able to disperse its cooled air in such a manner as to not have hot or cold spots.

I have no clue whatsoever about how roof airs or installations other than my Liberty work, but I do know my OTR is superior to the Cruise Airs in cooling without having hot or cold spots in the coach. For example, my front Cruise Air moves a lot of air around the living room (salon for rich folks), but there is one spot on the passenger side sofa where the cold air blows directly on you. The other Cruise Airs and other places in the coach are OK, so give some thought to the cooling systems with respect to distribution but do not worry about having excess capacity. It is like horsepower. You only pay for what you use.

charlesebrownjr
06-19-2010, 09:13 AM
Thanks Ray, I just was confused about the different systems and how they were installed in the bus.

jack14r
06-19-2010, 02:26 PM
I also think that there are other considerations in regard to HVAC units,all units that are low in the coach(in the bays) will help the coach drive better because the center of gravity of the coach has been reduced.Donnie said that cruise airs can draw 14-17 amps,I have never seen over 14 with any of my 4,I do agree that the differential of cruise airs is usually 15-18 degrees,I do have one that is close to 20,but I also have one that is 13.Donnie also said that roof airs will have 20-22 degrees of differential,I agree but I cannot get a roof air to live past 5 years and cruise airs are usually still going at 15 years old.

Donnie_M
06-19-2010, 06:26 PM
I also think that there are other considerations in regard to HVAC units,all units that are low in the coach(in the bays) will help the coach drive better because the center of gravity of the coach has been reduced.Donnie said that cruise airs can draw 14-17 amps,I have never seen over 14 with any of my 4,I do agree that the differential of cruise airs is usually 15-18 degrees,I do have one that is close to 20,but I also have one that is 13.Donnie also said that roof airs will have 20-22 degrees of differential,I agree but I cannot get a roof air to live past 5 years and cruise airs are usually still going at 15 years old.Im sorry to disagree, but I have been working on Cruise Airs for 24 plus years. In a boat they are the best, in an air cooled environment, they are the least efficient of all RV a/c units. If you would like to look at my HVAC report (a report I use to separate different unit types) I can show the ratio of Cruie Air repairs vs roof air. The older Cruise Airs, 90's were worse on efficiency, but the newer units 2005 and up ( with the new style Hot Gas Bypass valve) are the most problematic. What meter are you using to test "fla"? The best efficiency from a Cruise Air unit can only be achieved by blowing the supply air directly from the evaporator into the living area, any ducting drops the Cruise Air efficiecy. Now let's look at the cost.... How much does 1 roof air cost? How much does an inefficient Cruise Air cost? I rest my case! You can buy 4 roof airs for the price of 1 Cruise Air (retail of course)

Donnie_M
06-19-2010, 06:34 PM
One more thing, call AAP Monday and see how long it takes to get a new evaporator or condensing unit...BTW.. I could be wrong on the exact year of the hot gas bypass change, but the old style can be identified by looking at the body. It has what appears to be a "stud" with a nut on the end while the new (pos) style has a plastic cap covering the body. The best thing to do if you have the new style is cut the worthless valve (it allows you to operate in heat pump mode, which is a total waste anyway, a couple of degrees colder outside) out and solder the lines so as to "by pass" " the bypass"!!

garyde
06-19-2010, 07:02 PM
Cruise Airs are quietier than the roof units. But because they draw air from the underside rather than the roof they will not work well with hot ground surfaces. But they are not th primary source for A/C when traveling.

Donnie_M
06-19-2010, 07:53 PM
Cruise Airs are quietier than the roof units. But because they draw air from the underside rather than the roof they will not work well with hot ground surfaces. But they are not th primary source for A/C when traveling.
That is true with the traditional method of installing roof airs. There are some very unique ways of installing the units and routing the return air, which yield a "quieter than a Cruise Air" result. Again, remember, ALMOST every RV service center in the US has access to a replacement roof unit! The same cannot be said about the others....

Donnie_M
06-19-2010, 07:56 PM
Oh and FYI, there are hundreds of Vantare coaches on the street that run 2 Cruise Airs (some run 4 off the inverter with the new 500a Niehoff alt...) while traveling at highway speeds with out the unit shutting down.

jack14r
06-19-2010, 09:47 PM
Donnie,I hope that you agree that roof airs increase the center of gravity and that as a result of increased weight on the roof the coaches drive worse.I am using the Liberty panel,but I could use a Fluke amp probe if it will make you feel better.

Donnie_M
06-19-2010, 10:12 PM
I don't know...but if 4 roof airs cause a Prevost to drive worse than having 4 Cruise Airs, I think I would "re think" my purchase of a Prevost. Roof airs are the LEAST of your worries of the "driveability" of a converted coach. So I guess I'm saying no, I don't agree. The only thing roof airs take away from a coach (in some peoples eyes) is aesthetics.

rbeecher
06-19-2010, 11:26 PM
That is true with the traditional method of installing roof airs. There are some very unique ways of installing the units and routing the return air, which yield a "quieter than a Cruise Air" result. Again, remember, ALMOST every RV service center in the US has access to a replacement roof unit! The same cannot be said about the others....

Donnie, can you further explain the installation procedure that produces a "quieter than Cruise Air" result? Do you know if this can be done on a Marathon with the a/c and heat pump combination? I am about to replace a unit so I am curious.
Also, are you familiar with Marathons new very quiet roof airs, good bad or other wise?

Thanks,
Richard Beecher
2002 Marathon XLII 45
2010 Mini Cooper S

Larry W
06-19-2010, 11:54 PM
We try to avoid 95 plus temps. Our Royale has 3 roof airs, Prevost dash air plus a second Pro-air Royale installed that uses the dash air compressor also.Two summers back we did travel across I-70 across KS and MO on on to NC. Day time temps climbed to over 100. We stayed cool but found we could not get outside much when we parked for the night because of the heat. We made a promise to each other that we will stay away from hot places not because of the bus but because it was awful to us to try to see the sights. We stay cool here in the Colorado mountains during the summer.

jack14r
06-20-2010, 01:42 PM
Donnie,I can't disagree more about the weight on the roof changing the center of gravity of a coach,I am a pilot and anything loaded into an airplane has an effect,I am glad that you do not work for NASA with statements like that.The engineering school at the University of Central Florida would like for you to apply,their summer school starts next Monday,I think that you should start with physics 101.I have seen numerous post of roof airs failing and being replaced but not any on cruise airs failing,I am sure that they do but I think that roof airs keep many technicians in business,maybe that is why you are partial to an inferior product.

Donnie_M
06-20-2010, 02:51 PM
Donnie,I can't disagree more about the weight on the roof changing the center of gravity of a coach,I am a pilot and anything loaded into an airplane has an effect,I am glad that you do not work for NASA with statements like that.The engineering school at the University of Central Florida would like for you to apply,their summer school starts next Monday,I think that you should start with physics 101.I have seen numerous post of roof airs failing and being replaced but not any on cruise airs failing,I am sure that they do but I think that roof airs keep many technicians in business,maybe that is why you are partial to an inferior product.Jack, I appreciate your expertise as a pilot and value your opinion. My statement, "Roof airs are the LEAST of your worries of the "driveability" of a converted coach" comes from years of watching converters build coaches with the latest and greatest while trying to be the "fanciest" or "the most expensive" coach. Alot of people would be shocked if they were to weigh each tire position individually. I see no need for personal insults. I'm trying to answer questions with "factual" information. My ratio of Cruise Air to roof air repairs is 100 to 1! And more often than not the main problem with roof airs is poor installation, causing drain pans to crack and leak into the coach. A Dometic 15k roof top a/c unit weighs 100-115lbs, the entire unit. You are correct, I'm no rocket scientist, but please come up with a stronger argument against roof airs other than driveabilityb due to adding 400lbs spread out over the roof of a 40-45' vehicle weighing 54k. I find it hard to believe you have never heard of a Cruise Air failing, or the wonderful message that pops up on the SMX display "LO...P5" which actually means "LO..PS" for low pressure. Since it is a split system, you are relying on the "non rocket scientist" type to run the lines and make the proper connections. All the while preventing line damage from the constant movement of the vehicle and the need to make sure all lines are insulated properly. As I said..It's a no brainer...you can buy 4 roof airs for the cost of 1 Cruise Air. You can get the unit worked on any where you travel. Try finding a competant service center to work on your Cruis Air while traveling and then get back to me. Until the, have a good day!

Donnie_M
06-20-2010, 05:23 PM
To add to this, and I will quit!! My expectations of the acquisition of Cruise Air by Dometic Corp (you know that company that makes some of those EVIL roof airs that cause people to loose control of their Prevost while banking hard right or left...lol) have been disheartening at best! Dometic understands air flow and "theory", something Cruise Air never applied to their air cooled unit. I have been hoping Dometic engineers, some I know personally, would re-design the Cruise Air (air cooled) platform. They said in this economy "not a chance"! Also Dometic changed the warranty period, two years from the date of mfg, not the date it was put in service. Before Dometic bought Cruise Air, we could get evaporators, condensing units and whatever else we needed. Not now! Don't get me started on "inferior"!!!! Don't take my word for it call AAP tomorrow!

"I have seen numerous post of roof airs failing and being replaced but not any on cruise airs failing,I am sure that they do but I think that roof airs keep many technicians in business,maybe that is why you are partial to an inferior product."

Before you assume to know any thing about me, please take some time and do some research. I do not deal with INFERIOR...PERIOD!

The "perfect coach" would have five roof airs and Prevost installed OTR. Of course I am probably focusing more on a "H" series as that is the primary vehicle we see. An XLII would be "perfect" with 4 roof airs and Prevost OTR. The reason is, roof airs can be ducted as to eliminate the "hot spots" Jon was speaking of. Cruise Air efficiency drops with every 5 foot of ducting.

Roof airs can be made quieter by relocating the return air away from the unit and by mounting the unit on an "isolated" plate on the roof, which will also allow the unit to be removed and replaced with another one without having to touch the inside of the coach. I designed one of these systems a couple years ago and have never had a chance to actually do it. Certain people at certain company took my idea and tried something like it but totally effed it up. Right now my focus is trying to keep my Cruise Air customers cool since that is their only source of a/c while traveling.

Jon Wehrenberg
06-20-2010, 08:29 PM
I'm with Jack. I not only want to minimize weight, but I want that weight as low as possible. I don't know how much driving of coaches you have done Donnie, but up here in the area around the Smokies the roads wind and curve, and while you may not think so, sticking 400 pounds of roof airs on a coach as opposed to the weight of the Cruise Airs almost below the centerline of the axle will have a profound impact on an air bag suspension and how it controls the coach. That 400 pounds 12 feet above the road, and 10 feet above the air bags is a huge lever arm that forces the air bags (and the ride height valves) to have considerably higher internal pressures to resist leaning in a curve. Further, if the curves are spaced such that the coach ride height system gets behind the "curve" you have the leans counter to the way the coach would be expected to lean through the curve. The only difference is the frequency and spacing of the road curves will have a different effect on slow acting or fast acting ride height vales, but they will both be affected by that high mounted weight.

I'm a pilot also.

As to the assertion the Cruise airs are troublesome I have to disagree. Admittedly I don't have Cruise Airs Dometic has dumbed down to equal the quality of roof airs, but unless Dometic has completely redesigned them my 20 years experience with them has been very good. The biggest problem I see are technicians that do not clearly understand the operating pressure charts and as a result under or over charge the units. My first coach was 17 years old when I replaced all three condenser units, and I did that because one of the compressors locked up, and when I opened up the unit I saw how driving the coach for years in the snow belt during the winter had compromised the coils. I have four in the present coach which has a 14 year old chassis and so far I have not done a thing to them except clean the coiuld on occasion.

jack14r
06-20-2010, 08:39 PM
Donnie,We appreciate your experience and knowledge of Prevost and various conversions.I have had 3 coaches all with cruise airs and I have a Renegade Toter home for a tow truck,my experience has been that the roof air last 5 years on the toater home and the cruise airs do not fail(this is my experience).I see many post by others who have or are going to replace their roof airs at 5-8 years but not post of problems with cruise airs.You state that cruise airs fail 100-1 verses roof airs,why don't we see this on this site,maybe there is a problem with the installation in the type of coach that you are servicing.POG members might service their cruise airs better than the rest,I don't think so.If I were looking to purchase a new coach I would want OTR and 4 cruise airs,this has worked for me.

truk4u
06-20-2010, 08:47 PM
I've had both and for my part, I prefer the Cruisairs due to ease of maintenance and less noise than the roof airs. I would much rather stand on the terra firma and fix the cruiseairs instead of getting on the roof. Your worst nightmare is some bozo with work boots stomping around your roof, dropping tools and only putting half the screws back on the cover and then the leaks start to surface.

Oh by the way, I'm a Pilot also and 400 lbs on top of a 13' 4" bus would certainly have an effect on side to side stability in the extreme. In addition, I hate roof penetrations and there's nothing nicer than a clean uncluttered roof, not to mention less chances of water leaks.

I have never had any work done on the Cruisairs, whether busing or boating!

Donnie_M
06-20-2010, 09:47 PM
"why don't we see this on this site"

"I'm a Pilot"


"I'm a pilot also."

Jack, my neighbor has a 1971 Airstream with original roof a/c's so leave that 5 yr crap at the door!

Ya see, I said I was done with this thread, but I will add one more piece of info...I was involved in the design of the original "mister system" and the original "pressure equalization valve" (which now is incorporated in the programming of the SMX controls of the heat pump and opens the reversing valve 3 tenths of a second at start up to prevent cb tripping) that prevented circuit breaker tripping when the Cruise Air was "short cycled". The one thing I have noticed is the "pattern" here at POG. Basically..well...I will just leave it at that! This site has the wrong name! I think this site should be called LOG! I have not only seen this movie, I have the DVD and it is printed on the back of my work shirt!!! The attached is not to offend or to advertise, simply to make a point! Happy travels guys, if y'all wind up needing help, I'm a phone call away, and unlike others, I actually ANSWER my phone.

Donnie_M
06-20-2010, 09:51 PM
I'm with Jack. I not only want to minimize weight, but I want that weight as low as possible. I don't know how much driving of coaches you have done Donnie, but up here in the area around the Smokies the roads wind and curve, and while you may not think so, sticking 400 pounds of roof airs on a coach as opposed to the weight of the Cruise Airs almost below the centerline of the axle will have a profound impact on an air bag suspension and how it controls the coach. That 400 pounds 12 feet above the road, and 10 feet above the air bags is a huge lever arm that forces the air bags (and the ride height valves) to have considerably higher internal pressures to resist leaning in a curve. Further, if the curves are spaced such that the coach ride height system gets behind the "curve" you have the leans counter to the way the coach would be expected to lean through the curve. The only difference is the frequency and spacing of the road curves will have a different effect on slow acting or fast acting ride height vales, but they will both be affected by that high mounted weight.

I'm a pilot also.

As to the assertion the Cruise airs are troublesome I have to disagree. Admittedly I don't have Cruise Airs Dometic has dumbed down to equal the quality of roof airs, but unless Dometic has completely redesigned them my 20 years experience with them has been very good. The biggest problem I see are technicians that do not clearly understand the operating pressure charts and as a result under or over charge the units. My first coach was 17 years old when I replaced all three condenser units, and I did that because one of the compressors locked up, and when I opened up the unit I saw how driving the coach for years in the snow belt during the winter had compromised the coils. I have four in the present coach which has a 14 year old chassis and so far I have not done a thing to them except clean the coiuld on occasion.
Jon, I have many hours of windshield time. Way more than you would expect!

Donnie_M
06-20-2010, 09:53 PM
It's probably best that I say Good Bye, so, Good Bye POG, and happy travels!

Before I go here is a quote

"If you have not seen if discussed keep in mind that if you do not have OTR, do not plan on Cruise Airs as installed in our coaches to perform as well as they should as a substitute when traveling. They are best when the coach is not in motion. They require cool air passing through the bay mounted condensing units for maximum efficiency. When you need cooling the most the Cruise Airs are likely to let you down because the heated air radiating from a hot highway is likely to prove inadequate for cooling and the units will shut down unless the units have been modified by forcing additional air through the coils or by having a water misting system for cooling.

Roof airs are the best alternative to OTR when in motion"

and this one...

"but roof airs are a great backup if the OTR fails to work. I cannot say that about the Cruise Airs."

And this one...

"What has not been stated here and needs to be recognized is each system is likely ducted differently so in addition to being able to maintain a given temperature the AC system needs to be able to disperse its cooled air in such a manner as to not have hot or cold spots.

I have no clue whatsoever about how roof airs or installations other than my Liberty work, but I do know my OTR is superior to the Cruise Airs in cooling without having hot or cold spots in the coach. For example, my front Cruise Air moves a lot of air around the living room (salon for rich folks), but there is one spot on the passenger side sofa where the cold air blows directly on you. The other Cruise Airs and other places in the coach are OK, so give some thought to the cooling systems with respect to distribution but do not worry about having excess capacity"

CAPT MOGUL & Sandy
06-21-2010, 12:47 PM
We have 2 Prevosts and live in Key West,FLORIDA . We can't use our buses during the summer months because we have roof airs and We don't like driving in the snow, either!! ?????
Ed

jack14r
06-21-2010, 08:20 PM
Ed,I am surprised because the roof air that I have in my renegade really does perform quite well when it is new,it does only last so long but will work OK up to that point.Donnie's statement about a roof air on a 71 Airstream still working does not surprise me,in those days it was built totally different than the ones built today,I doubt that they cool any better just that the coils and condensers are much stronger,the motor will have bearings instead or bushings,etc..The units that I have replaced in the last 10 years are not really meant to be repaired,just replaced.They are so inexpensive that a diagnosis of the problem could cost 50% of the cost of a new unit.

Gary Carmichael
06-21-2010, 08:56 PM
Hey I am just glad to own a bus, roof air ,cruise air OTR, or no air, heck I believe i will open the windows and get a suntan on the left arm, remember? We are so fortunate!

garyde
06-21-2010, 10:13 PM
As usual, the great debate over A/C's has degenerated into a polarity of diverse opinions. As a famous person once said " why can't we all just get along?" I mean really, it just Air conditioners.

Jon Wehrenberg
06-22-2010, 06:51 AM
I'm with Gary, but I do think the discussion is helpful. We need to keep personalities out of these discussions, but I think we all learn from other's experiences.

While I like Cruise Airs for example, they are not acceptable in my opinion for cooling while driving down the road. Roof airs, by comparison are very good for cooling when driving, but as has been stated above they are also not without their weaker points, such as short life or greater noise within the coach.

Our discussions are likely not only going to help potential buyers formulate a list of their preferences for a coach, but are also likely noted by converters who may use that information to create better coaches. At least I would hope so.

I think we can get some very animated discussions going on a range of topics such as slides, driving speed, rivets, engines, converter, etc. and if we avoid getting personal we get a lot of good information from them.

Or we can have a dull forum.

Bill1170
06-22-2010, 07:37 AM
Mark, You certainly started a good discussion on AC systems. I have a question for you on slides,as you stated you were interested in a single slide coach. We have 2 slides and really like the extra room the bedroom slide gives us so I would encourage you to at least look at both 1 and 2 slide coaches.
Bill

Ray Davis
06-22-2010, 01:01 PM
It is highly unfortunate however that the discussion lead to a member leaving POG, one that had knowledge and was a valuable contributor.

Jon Wehrenberg
06-22-2010, 01:15 PM
Who left?????????

Ray Davis
06-22-2010, 01:50 PM
I'll refer to this specific post http://forum.prevostownersgroup.com/showthread.php?4794-New-member-from-Florida-with-questions&p=65152#post65152

Kenneth Brewer
06-22-2010, 02:33 PM
Hold the phone. If that is the case, it is very unfortunate. But, I don't think the level of passion in point/counterpoint in that thread rose to the level that should cause someone to leave. I think I have had my head handed to me twice already, at least, but I undoubtedly brought it on - and learned something. Hopefully, if indeed he left as a result of the thread battle, he will cool down and come back. I think many of us have retired from a lifetime of work and the high stress and/or blood pressure it generated, but miss lighting the fuse and having it lit under us at the lunchtable or coffee pot. Come on back please, Donnie, if this development is true, so we can find something else to fight about. I don't think any comment was meant to be personal, just heartfelt based on personal experience.

Jon Wehrenberg
06-22-2010, 03:49 PM
When we cannot debate a topic and make our true feelings known it will be a sad day. If everyone liked rivet coaches, with OTR and no slides and drove 62.5 MPH this would be one boring forum.

At the end of the day no matter how strongly I feel about slides, Libertys, OTR, rivets, Chinese Tires, driving speeds, etc. I still respect the folks on this forum, I like everyone and consider everyone my friend, and expect to get spanked if I cross a line. I hope the newer members who are sitting back watching this runaway freight train we call POG know and understand this is like a big family and while this bunch may argue, debate, discuss, or beat a topic to death, this bunch will stop the horseplay and get serious in a big hurry to help anyone that expressed a need for help.

This bunch also may intimidate people who have not yet seen and understood how we not only participate with one another on the forum, but we also take advantage of the friendships we developed here to get together on a spur of the moment, to visit with one another, to pick up the phone and call one another, or to help one another physically by working on someone else's coach. Because of those close relationships new members may not yet recognize there is a certain amount of ball breaking that when viewed out of context for the first time makes some of us look like nasty people and that may be intimidating. The truth is when we break someone's chops on the forum we are kidding around. (actually we are not, but we can pretend).

The only draw back to this site is if someone is not used to the discussions on the internet, and does not understand comments in the context in which they were made, because we cannot see facial expressions we sometimes fail to appreciate the intent of a post. I think Ken has said it well.

truk4u
06-22-2010, 05:12 PM
When you meet face to face, all this typing fades into the background and this is what it's really like:p

6738

Do you really think you'll get any respect here?:p;):D

Roadpilot
06-22-2010, 05:58 PM
I agree Ray.

dale farley
06-22-2010, 10:11 PM
I certainly hope Donnie comes back on the forum. I'm for anybody that can get all the Liberty guys stirred up about anything. It gets their minds off of bashing CC.

I had 3 cruise airs in my last Marathon and all three had been replaced. I now have three 10-year old roof airs and they are all still working and have never been replaced. Cruise airs or roof airs would not be a deal breaker for me if I were purchasing another coach.

While I agree that theory and common sense tells us that 400 lbs on the roof will impact the center of gravity from a laboratory perspective, I do not agree that it makes a noticeable difference in driving a 50K bus. "Never" have I heard of anyone with roof airs or cruise airs having problems with the handling of the bus that could be directly attributed to the placement of the AC units. Theory often has to be tempered with common sense. I'm a farmer. That should be close enough to being a pilot to get in this conversation.

Kenneth Brewer
06-22-2010, 10:14 PM
Here we go.

garyde
06-22-2010, 10:33 PM
I thought more about this last night . If we have owners who are tallking and discussing opinions its generally accepted everyone has their own opinion and they are welcome to it. But if we have a member who makes their living working on these Coaches and someone questions their ability, opinion, expertise it may not go over so well. I could see being sensitive to someone questioning my judgement or ability when it came to how I make my living. Just a thought.

billbunch47
06-22-2010, 11:22 PM
We can't afford to lose any one from these hollowed pages, especally a person with the hands on every day knowledge of a guy like Donnie. I have never had the pleasure of a face to face meeting with this guy but when the person I think knows as much as any one about our busses (Rick May) picks up the phone and calls Donnie to ask a stumping question that should tell ya'll something, the guy knows what he's telling us. Have a nice day

Ray Davis
06-23-2010, 11:12 AM
So, I may be completely wrong in these calculations, but I thought it would be fun to try to calculate the change in center of gravity of a 45,000 lb coach. So, my assumptions are this.

* 45,000 coach (that is without any A/C)
* assume that CG for that would be at 4 ft (the center of the engine is roughly up that high. it's a guess at best)

* adding 1000 # of A/C on the roof (estimate 12 ft) adds a 12,000 ft-lb torque which equates to a 4.17 ft CG (a raise of 2.087 inches)
* adding 1000 # of A/C at bay height (estimate 2 ft) adds 2,000 ft-lb torque, which lowers the CG to 3.96 ft CG (a lower of 0.5 inches)

So, it seems that a change from basement A/C to roof airs would raise the CG about 2.5 inches.

Does it make a difference. I don't have a clue, but I thought the numbers might be fun.

Ray

Sid Tuls
06-23-2010, 11:50 AM
Ray I think you have a little too much time on your hands :)

dale farley
06-23-2010, 11:55 AM
Thanks Ray. Based on your calculations, I think we could assume if you used the actual weight of the 3 roof AC units that most of us have, the figure would be about 1 inch.

Now, I've got to be especially careful with every corner I turn in the bus. If I ever run off the road, some are going to say, "We tried to tell him about those Roof Airs!"

Ray Davis
06-23-2010, 12:09 PM
Sid, actually if my boss found out that i spent 10 minutes on this on work time, he'd have my hide! I'm probably not supposed to read this forum on work hours either Oh well :)

grross
06-23-2010, 12:20 PM
Gary & Bill: You hit the nail right on the head...WELL SAID!!!
Ray: Your calculation puts the issue in perspective. On winding roads or while experiencing crosswinds I wouldn't notice the difference with or without roof a/cs at 65-70 mph.

Donnie_M
06-23-2010, 01:08 PM
What??? Did I miss something...lol :)

Sid Tuls
06-23-2010, 01:46 PM
Hey Donnie, Glad your back:)

HarborBus
06-23-2010, 01:52 PM
Welcome back Donnie:). I hope you can see from the recent posts that the group really appreciates your input and was disappointed that you may have left us. It's good get the prospective from you as someone that is out there in the trenches working on our bus systems every day.

Steve Mitchell
06-23-2010, 05:16 PM
Mark,
Your question regarding A/C's has been asked over the years almost as much as "Which came first, the chicken or the egg?" Marketing Prevost Conversions over 20 years, I can tell you from experience that "everyone" is different. What appears to be cold to one person, may still seem hot to the other person. I've been driving down the highway in about every conversion out there, and have been hot, look over at my wife, and she's covered up with a blanket. Now that we're getting older, she's hot (hot flashes) and I'm covered up with a blanket.

OTR A/C was developed by Prevost for a commercial application (seated buses) hauling a bunch of passengers that produce a lot of body heat. It's almost an overkill in a (2) person conversion, however, if you want to hang meat inside your coach in AZ. in the summertime, it'll get the job done.
It's wonderful, and if your generator fails, or A/C fails (roof or cruise), you have the OTR as a back up. Down side, it takes up storage and horse power (when running).

Three A/C's is "very marginal" in humid, southern climates. The technology of inverters in the newer coaches and battery power can allow you to run several a/c's without starting the generator. Then, you have some converters that do their own OTR system with an a/c compressor 1/4 the size of the Prevost OTR. Then, you can get into the cruise a/c's in comparison to the roof a/c's. All converters use to have cruise a/c's and I think it was Angola or American that put the first roof a/c on a Prevost in the early 90's. It was a slow evolution, but several other converters followed five to seven years later. Other converters opted to stay with the cruise a/c's. Then you get into serviceability, noise factors between each, etc. and so on and so forth. I agree with Donnie, (3) roof a/c's is not enough (at least in Florida this time of year).
Steve
Parliament

GDeen
06-23-2010, 05:38 PM
I love me some OTR.....Jennifer says I am obsessed with it. I like it frigid in the coach while driving and anyone who doesn't, may feel free to bust out the winter wardrobe or crawl in the bed situated over the big ole series 60 heater.

I honestly think the 3 cruiseairs are at their limit in keeping the coach cool (70) in the very hottest summer days unless the shades are drawn or the awnings out shading the sides and windows. I am guessing the Deuce is a little easier to maintain cool given the thermal pane glass. Have always been a little jealous of the 4 cruiseair setup in the Liberty, although I am not sure how they run all 4 with the other electrical demands on 50A. Don't know how to compare to roof air, but the cruiseairs do seem to work well for us although we never use them when driving. Just fire up the big boy. Still wouldn't mind have 4 of them rather than 3 though.

truk4u
06-23-2010, 06:52 PM
Thanks Steve, nice to have a Converters view!

Kenneth Brewer
06-23-2010, 08:40 PM
Have always been a little jealous of the 4 cruiseair setup in the Liberty, although I am not sure how they run all 4 with the other electrical demands on 50A.

They all (4) run on 50A, but additional loads such as the microwave will be powered through the inverter(s) pulling on the batteries. If the batteries are low and the inverter/chargers are charging them at the higher rates (the inverters not adjusted for a lower amp charge rate) it has been my experience that the total load will then often pop the pole breaker outside.

Kenneth Brewer
06-23-2010, 08:43 PM
I should add that in that case I turn off the charging function and watch/minimize the other loads carefully. My inverters have dual power inputs, the second is a separate supply for the charger(s).

rfoster
06-23-2010, 10:46 PM
The Center of Gravity on my bus with roof airs is offset by the additional cargo my wife has me carry in the bays of the bus. I would not have the ability to haul on that extra stuff unless I had roof airs. I have not rolled it over yet. So it worked out.

Plus I had a Liberty with 4 cruise airs and after experiencing a cruise air failure and getting blistered in more ways than one, I recalled that in a previous life on my plastic RVs - when the roof air died, I didn't have to rob the cookie jar to buy a new one.

So don't anybody get their panties in a wad, but roof airs ain't that bad and cruise airs ain't that good!!

Pete
06-24-2010, 04:30 PM
OH MAN! Roger, I wish you had posted earlier.....I just finished moving my roof airs to the side windows, (2 on each side), the air horns , light, and the sat dome to the front of the bus. And I thought......glad I didn't have a plastic shield on front.. Now I will feel much safer on those curves!

JIM KELLER
06-25-2010, 06:42 AM
Wow Pete, What a job that must have been. Although the visual I have of the finished product is pretty ugly I'm sure the weight transfer is significant. Too bad though you could only get those units as low as the windows. That won't compete with the Cruise Airs low mounting point. By the way, are you a pilot ? No comment about the " Plastic Shield. "

Pete
06-25-2010, 11:05 AM
Yes Jim, as a matter of fact, I am a pilot (though not current), but I failed to get the connection between the A/C issue and airplanes, so I didn't mention it in the post.....guess it was making reference to cooler air at altitude...maybe that is the reason roof airs work good they are higher up than the cruise airs.

dale farley
06-25-2010, 02:21 PM
Pete, You may have started a trend. f mine ever go bad, I may take it a step farther and just get me 3 of those portable units from WalMart and place one in the LR, DR, and bedroom. Simple installation.