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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: musicman on August 30, 2006, 10:25:04 PM

Title: roof air or basement
Post by: musicman on August 30, 2006, 10:25:04 PM
Thanks to this board I solved the Eagles problem with shaking it was as simple as replacing the front rims,The previous owner must have beat the inside of the rims with a sledge hammer..Now In the next day or 2 Im going to order my air and I like the basement air but I want to hear from you guys and gals the pros and cons of both and which type to get and where..Looks like Im going to be living in it full time since my employer isnt going to be touring as much next year..When Im needed Im just going to drive my coach right up next to her lavender prevost like a big dawg

Title: Re: roof air or basement
Post by: TomC on August 30, 2006, 11:44:08 PM
On my 40ft transit with very big windows, I have three Coleman 13,500btu roof tops since I don't have dash air.  I usually run the front and rear going down the road with the third available when it gets over 100 degrees.  I use the middle one in camp.  The Colemans are good units-have had no problems with them.  It's just that they have only a two speed fan-like high and medium- and their low is still to loud for quiet night time use, if you need it.  If I did it again, I'd use the DuoTherm Penquins since they are low profile and have three speeds.  Carrier makes thee lowest profile A/C, but don't know how noisy it is.
Reasons to go with the roof top-cheap to buy, work very well-you don't have to deal with ducts if you don't want to, if they do break everyone carries them so you can replace one in less than two hours, they are on the roof not taking up valuable basement space.
Reasons to go with basement air-you don't have those roof top A/C's to look at, get 100lbs each off the roof, usually quieter.  Reasons not to go with basement air-harder to service, not carried everywhere, takes up space in the basement, usually costs three times what the same size roof top would have.  But then you probably knew all this already.  Good Luck, TomC

Title: Re: roof air or basement
Post by: Nick Badame Refrig/ACC on August 31, 2006, 01:49:34 AM

Tom is correct on a lot of points. I just want to add that the basements are almost silent, run more efficient in the bay, [no sun to battle],

and you can design where the vents are placed for maxium cooling where you need it the most.


Title: Re: roof air or basement
Post by: Len Silva on August 31, 2006, 05:26:42 AM
In my coach with roof air, we cannot run the bedroom A/C becuase of the noise.  We use the front at night with a box fan to move the air to the back.  Definitely some kine of basement air for me.


Title: Re: roof air or basement
Post by: JackConrad on August 31, 2006, 05:40:01 AM
Like everything else, there are trade-offs. Basement airs are quieter, get better distribution of the air, and provide a cleaner roofline with better overhead clearance. Roof tops are easier to install, quicker to repair or replace (should that be neccessary) and do not use up baggage space. It depends on which is more important to you. We prefer the basement ACs for the reasons listed above and can live without the baggage space required by the AC unit.  YMMV  Jack

Title: Re: roof air or basement
Post by: Ross on August 31, 2006, 05:44:50 AM
I prefer roof air for a few reasons, but mostly because of redundency.  I have 3.  If one goes out, I have two more and I can get the bad one replaced or repaired at my leasure.  I the basement air goes out, I'm hunting for an HVAC guy to fix it and there are plenty out there who won't go near a motorhome.  Roof airs are noisier but not excessively noisy.  I have no problem sleeping with the bedroom air and genset running, bit if you're the type the needs absolute dead silence to sleep, that may be an issue.  I also think thet roof air may be a bit more efficient since there is no ductwork...IE: No cooling loss and no loss in air volume due to ducting.


Title: Re: roof air or basement
Post by: FloridaCliff on August 31, 2006, 06:13:54 AM
I have the roof airs, but if I was starting over I could go either way....

Good and valid reasons given by all above.

One other thought....It depends on where you live and what your demand for A/C is.

Do you still have the bus air for traveling?   Can you get by with one a/c on your inverter on the road or would running

a generator be OK during the hotter months to run several or a basement unit?

I have the ducted roof tops and they are 100% quieter than the non ducted.

And last, some form off dash air is a must, the driver has the best view, but the most heat and cold to contend with.

No wrong choice, just YOUR choice.


Title: Re: roof air or basement
Post by: Kristinsgrandpa on August 31, 2006, 07:32:43 AM
  The one unit that hasn't been mentioned is the mini-split.  They install like a basement, with the condenser in the basement, or the spare tire compartment like mine, and the evaporator is a small unit that hangs on the wall inside the coach. They are also available in ceiling  mounted models.
   The  advantage over the standard basement units is a smaller unit and no ductwork to install. The mini-splits, like the basement air units, can be bought in A/C, or A/C and heat pumps either one.  The disadvantage would be the evaporator fan is nolsier than a basement unit, but not much.


Title: Re: roof air or basement
Post by: j_wilson on August 31, 2006, 08:41:07 AM
This is just a question.  But I've noticed that a lot of the newer entertainer coaches such as the XLII.  Have 3,4 or even 5 roof mounted units.  Is there a new technology out there that makes these new units quiet?  Or are these just off the shelf low profile units?

J. Wilson

Title: Re: roof air or basement
Post by: cjm on August 31, 2006, 01:37:13 PM
I have 2 Carrier Air V's on my MCI-8.  They are much quieter than the Coleman or Dometic units.  You can get them ducted or with the standard air box.  http://www.airv.carrier.com/cac/home/0,1334,CLI1_DIV46_ETI1977,00.html  HTH, John

Title: Re: roof air or basement
Post by: jjrbus on August 31, 2006, 05:53:28 PM
I have 2 rootop units, If I knew then what I know now, I would go with the mini splits. A large BTUin the front, medium in the middle and small in the bedroom One thing I have not seen mentioned here and I may be wrong, is with the basement air  even on road you have to run noisemaker, becuse of amperage draw of the unit!
                                                                                Work?/Play safely Jim

Title: Re: roof air or basement
Post by: Nick Badame Refrig/ACC on August 31, 2006, 07:04:05 PM
Hi Jim,

I just run the road air not the gen.  ;D

The biggest problem with the mini splits is exhausting the condencer air. Because of their design, it's difficult to keep them from overheating in

the bay of a bus. It's natural design is to be in the open air of your back yard or busisness. But their close proxcimity of the inlet and outlet

of the condencer fan causes big headachs when you are trying to get rid of all that heat. Iv'e installed enough of them to tell you they don't always

fit into the design of a bus bay.


Title: Re: roof air or basement
Post by: jjrbus on September 02, 2006, 03:34:35 PM
Thanks Nick
 After checking I decided I did not want too maintaine the road air. I've seen the condencer located outside the bays. One was in the area between the friont tires. I think the spare tire compartment area on an MCI could be utilized, maybe the area around the rear tires/transmission? Different buses have different options. I like to keep energy usage to a minimum. I like the idea of being able to use a small, med or large unit as conditions require. None of this is a suggestion, Nick has forgot more about AC than I will ever know!

Title: Re: roof air or basement
Post by: mc8 tin tent on September 02, 2006, 08:36:22 PM
Hope this helps!
 I used two ductless split systs.HP@9000btu each.In 95+ temps each unit would cycle at any temp I set them to.This has worked well for us In so. Indiana. So far I havent had any problems with unit overheating( or dropping out on high head pres.),the condensersdis.air is vented downout the bottom of the bay/with the inlet air from the side.noise is not a prob.(on low fan we would get up to see if unit was operating!!!very quiet) This system works well for us(better than expected)

  Be Safe &thank a vet!!!!!!

Title: Re: roof air or basement
Post by: Dirtball on September 03, 2006, 12:56:29 PM
I have 4 Cruise Airs with bsmt compressors by Copeland. 12,000btu each.  At 9 yrs old now , I have had to rebuild one compressor, replace 2 fan motors, one relay, capacitor  and an occassional charge adjustment. They pull almost 20 amps each , (comp-14 amps, condensor 3-4 amps).  Two compressors are in the spare tire compartment and two in the engine compartment C/S forward of the fuel filter and battery jump posts.  The forward compressors like for the flip down front bumper to be in the down position for good air flow.  The rears have grates over holes cut into the access door and each unit has it's own aluminum box to keep it clean. SO they can suck lots of air through the rearmost C/S access door.  They all cool great, no heat strips installed.  The Cruise Air controllers have about 8 speeds.  They are pretty quiet on the slower speeds.  I also have OTR air and I am a big fan of the big fan.  j Wilson above asked about  Entertainer coaches.  Many Entertainer delete Bus Air to pick up storage bays for equiptment and supplies. 5 roof units allow them to cool 12+ passengers almost as well as 12 tons of BusAir.   Some use two 20kw gensets that are given alternating duty cycles like a yacht.  They may not see a 50amp plug for weeks. ...........