Author Topic: Drivers AC Choices  (Read 9761 times)

Offline Zeroclearance

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Re: Drivers AC Choices
« Reply #15 on: December 08, 2010, 10:18:59 AM »
Does anyone know of any used CruiseAir takeouts?

Offline luvrbus

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Re: Drivers AC Choices
« Reply #16 on: December 08, 2010, 10:33:33 AM »
Zero, Jim Smith has 3 he took his out because the so called Pro converter ran the copper where you could not repair lines he never said but I believe he drilled holes in the lines lol Jim Smith (Smiths Ultimate Linings) 1- 505-332-1403 Alb NM 

good luck
Life is short drink the good wine first

Offline Zeroclearance

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Re: Drivers AC Choices
« Reply #17 on: December 08, 2010, 12:32:00 PM »
Clifford  :)  Thanks for the leed.    Jim has two!

Offline scanzel

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Re: Drivers AC Choices
« Reply #18 on: December 08, 2010, 02:04:36 PM »
I choose to keep the otr air because a few years ago after stopping at a Lowes to pick up a few items I came out and the coach was probably 100 plus degrees inside, started up, hit the otr switch to find out it wasn't coming on. Compressor clutch not engaging because of low pressure of freon. Was not fun driving home. With 680,000 miles on the coach I figured it had finally needed updating. Sure there are other alternatives but after checking on prices and options, it was the lesser to just update the system already in place. Because I work with computers and telecom systems I like a redundant system in case a processor fails the other takes it's place. Some day when possible I would like to have the driver air on a separate compressor. Until then to each his own way. That's why we are the way we are. Unique !
Steve Canzellarini
Berlin, CT
1989 Prevost XL

Offline busnut104

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Re: Drivers AC Choices
« Reply #19 on: December 08, 2010, 02:28:26 PM »
I installed a Welsh unite. used the org. dash coil and I added on mid ship for other cooling.

Offline Sean

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Re: Drivers AC Choices
« Reply #20 on: December 08, 2010, 04:58:42 PM »
The factory otr compressor for ours is a 6cyl, 3 head, 10 ton 75000btu monster

FWIW, Joe, it's got to be either 10 tons, or 75,000 BTU/hr -- it can't be both.

10 tons is 120,000 BTU/hr.  75,000 BTU/hr is 6.25 tons.

In A/C circles, it takes about one HP per ton of cooling, so a 10 ton unit would require about 10 hp.  However bus systems are a little different and there are more losses; I would figure twice that.  Also remember that OTR air has enormous electric evaporator and condenser fans, which use up a good deal of the 270-amp 50DN alternator; that, itself, uses 10 HP or so.

None of which matters to the OP, who states that he has already removed the OTR air.

Again FWIW, our bus had driver-only compressors and condensers when we got it.  Both compressors seized and we ripped it all out.  Since roof air is not an option in our "downstairs" driver area, we coupled a 120-vac Copeland refrigeration compressor to Red Dot evaporator and condenser units, each with 24-volt fans.  Works great, but the roughly 15,000 BTU/hr it provides is barely adequate in such a poorly insulated, glass-intensive area, especially when driving into the sun.  We chose R134 for the charge.  We also had to have all the hoses custom made, since refrigeration and automotive components use different couplings.

This unit pulls a good 15 amps when it's running, and occasionally trips the 20-amp breaker when starting.  Probably I need a breaker with a longer delay, but it's not enough of a nuisance to bother.  Our 4kW inverter easily runs both this unit plus one of the three roof airs while running down the road, and the alternator still has power to spare to charge the batteries.

Full-timing in a 1985 Neoplan Spaceliner since 2004.
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Offline gus

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Re: Drivers AC Choices
« Reply #21 on: December 08, 2010, 05:28:21 PM »
I solved a lot of the inefficiency of my front rooftop by cutting a hole in the ceiling housing so the air blows straight down to the floor. Blowing it out the side and diffusing it does not work!!


Sometimes I can make Search work by going to Profile first.

Otherwise it gives me fits!!

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Offline jbnewman

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Re: Drivers AC Choices
« Reply #22 on: December 08, 2010, 06:27:35 PM »
I am curious: How much horsepower does  typical OTR air conditioning system steal from your engine? I know on a typical automotive system, it can run from 10-25 horsepower.

For the MC-9, per its maintenance manual:

  • The system is designed to provide a nominal 7 1/2 tons main A/C and 1 ton driver's A/C of refrigeration or 90,000 Btu per hour heat removal.
  • The current draw from the engine for the evaporator blowers should be 48-52 amps at 27.2 VDC

  • Manufacturer: Carrier
  • No. of Cylinders: 6
  • Horsepower: 25, nominal
  • Weight: 142 lb.

Condensor Fan and Motor:
  • Manufacturer: Ohio Electric
  • Type: 24 V, 2 hp continuous duty
  • Amperage Draw: Rated 71 Amp, Average 52 Amp

Evaporator Fans and Motor:
  • Manufacturer: Reliance Electric
  • Horsepower: 1 1/2 hp
  • Volt: 24-28 Volts
  • Amperage Draw: Start-Up 70 amps, Running 53 amps


« Last Edit: December 08, 2010, 06:29:21 PM by jbnewman »
Chicago, Illinois

No bus.

Offline Skykingrob

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Re: Drivers AC Choices
« Reply #23 on: December 08, 2010, 07:00:32 PM »
Hi Guys
I was suprised to see the amount of response. Yes, Jim, I know this is discussed alot but as you already found, the search function, at least in my hands, doesn't work well so it really does not help me.
No, Robert, my unit was one huge engine drivver Carrier compressor for the drivers A/C, the coach OTR and an auxilary unit at the back of the coach. I know I can put an engine driven compressor and run all the lines but I was exploring the options that would allow me not to have to do that.
I have cabinets covering the entire front of my conversion down to the level of the windshield top so there will be some help but with all the glass I am sure there will be a need for more A/C that is upplied by the 4 basement units. I may be wrong but I don't think so.
I do still have the dash coil which I keept because of the heat it will produce when supplied with hot antifreeze. All I need to solve is to get freon moving to it the easiest, least expensive and most effecient way for dash air.
Doug, I am with you, I too thought the Prius system would be sorely lacking given the green house effect of the area in question.
I am going to look at the suggestions made here but it looks like the best so far is to simply let the SW 4024 inverter run one of the basement units, close off all the rearward vent outlets, open only the very front outlets and run dash fans to circulate the green house air.
I have an aquahot and the front dash coil hooked up to coolant from the engine which will supply defrost and drivers heat so I am not concerned about heat.
Sean is right, I do not have the engine driven compressor, the condenser or evaporator coil, their fans or the copper tubing from the front of the engine compartment to below the mid part of the coach. As I said, I could put those items back in but in smaller versions to handle only the drivers area but wanted to see if anyone solved the problem satisfactorily without doing all that work. It appears some have, that's what I am looking for.
Thanks for your responses and I welcome any more ideas.

91 Prevost LeMirage XL

Offline luvrbus

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Re: Drivers AC Choices
« Reply #24 on: December 09, 2010, 10:39:20 AM »
Rob, I have a friend that uses the Red Dot hydraulic driven system on his Eagle seems to work good for him

good luck
Life is short drink the good wine first

Offline Ericbsc

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Re: Drivers AC Choices
« Reply #25 on: December 09, 2010, 06:28:13 PM »
I bought an air, heat, defrost unit from Ron the bus nut. I used a std gm compressor  mounted on the engine. Works great. Cost for unit was about $350.00 best I remember. Everything less than 1k.
(Didn't have lines run when pic. was made)

Offline Joe Camper

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Re: Drivers AC Choices
« Reply #26 on: December 10, 2010, 03:20:38 AM »
I once thought I knew a few things.

After buying this camper the amount of knowledge that I have acquired in the relatively short period of time since we purchased it is ...........cant even find a word to define it, for me, it has been and continues to be that large.

Sooooooooooo I have and will continue to spout out some very ignorant things from time to time LOL Thank you for that correction.

For the record what is the correct spec for this compressor we have.

JB newman GREAT first post thank you for that.

Signing off from Cook County Ill. where the dead vote, frequently.

Offline Mex-Busnut

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Re: Drivers AC Choices
« Reply #27 on: December 12, 2010, 08:07:52 PM »
Thanks to all for posting your educational replies.

How many of you have tried the ceramic roof paint to lower the temperature inside the bus? How much did it help?

I am supposing the inside of the roof can also be improved with better insulation?

Thanks in advance!
Dr. Steve, San Juan del Río, Querétaro, Mexico, North America, Planet Earth, Milky Way.
1981 Dina Olímpico (Flxible Flxliner clone), 6V92TA Detroit Diesel
Rockwell model RM135A 9-speed manual tranny.
Jake brakes
100 miles North West of Mexico City, Mexico. 6,800 feet altitude.

Offline Lin

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Re: Drivers AC Choices
« Reply #28 on: December 13, 2010, 10:53:51 PM »
We use the front rooftop powered by the generator while on the road.  Our problem is that the unit is installed in the middle of the living area.  It really should be as far front as possible.  We also have cut a hole in the bottom of the unit, but instead of letting the air drop downward, we installed an adjustable flap that sends the air up front.  Aside from closing off the rear vents, I adjust the flap so that it is closed enough to give the air some velocity but not create enough internal pressure to send any air backwards.  It has worked okay with just closing the door to the bed/bath area, but we are generally happy at around 80 degrees.  If I wanted it to work better, we have a curtain to hang just behind the unit to make the cooled area smaller.  I have thought of putting some sort of unit in the spare tire compartment, but the easiest thing to do would be just to install another roof unit way up front.  This would give us some backup as far as the AC units go, but the weak link for redundancy would be the generator itself.
You don't have to believe everything you think.

Offline kingfa39

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Re: Drivers AC Choices
« Reply #29 on: December 15, 2010, 05:44:24 PM »
have a automobile a/c compresser, a condenser over part of radiator and two evaporators in my 06, for several yrs always works great and that 8/71 dont even know when it turns on
Frank Allen   4106