Coach a/c repair or . . .

[Steve102C3]

For adequate cooling during the summer in hot climates while traveling on the road, what would you do and why? What are the pros and cons?

1989 MCI 102C3 with 3 roof airs and an 8kw generator. I can only run 2 airs at a time.

(1)  I can repair my coach a/c for a minimum of $3800 (estimate from a reputable bus shop). This includes converting to 134a and replacing the condenser fan. More expense can be expected right off the bat; the question is how much. When I bought the coach 2 years ago, I had the a/c charged up and the system worked, but it leaked down within 2 days.

(2) Upgrade to a larger generator and add a roof a/c if necessary. Minimum is the cost of the a/c (approx. $750 for what I would install) and the generator which would be $8500 or so, plus my labor to soundproof and install. I could sell my current quiet diesel and offset some of this cost.

(3) Travel only in the cooler months.

Of course, (3) is not a viable option.

What do you think?

Steve

[Nick Badame Refrig/ACC]

Hi Steve,

I'm assumeing you expierenced your coach air for 2 days. That should have been enough to tell ya that the coach air is powerful....

You can run 4 roof airs and still wont match the Coach air's ability while in motion. Given your presant setup, I would repair the coach air.

Call me sometime, I can guide you through the repairs!

Nick Badame

[TomC]

Course Nick will always suggest you keep the coach A/C since he is in the business.  While Nick doesn't believe me, this is how my coach performs.  I have 3 Coleman 13,500btu A/C's with the front one close to the driver's seat.  Also have a 10kw that comfortably runs all three with room left over.  In any weather up to 100 degrees, two works fine.  If overly humid or hotter than 100, kick in the third.  Mind you I have 6 large windows (76x28) plus two smaller and the huge transit windshield.  My wife especially hates hot weather and hasn't ever complained about it being to hot-on the other hand usually have to turn up the thermostat so the compressor kicks off around 72 to keep from chilling to much.  I have 2.25" of sprayed in foam that helps.  Now here's the most important part.  In the 12 years that the 3 Colemans have been on the roof with averaging 30 days a year using them and every time I work on the bus, I have had ZERO problems with them!  I don't think even Nick can say that about his own A/C system.  So an initial outlay of $1,500 (a bit more now) and that's that.  Spend a little now on the bigger gen and the third or even fourth roof top and you'll be set for years.  Stay with the bus A/C and you'll have a genuine land yacht-a black hole you'll be thowing money into and never get it to be as reliable as a roof air.  Plus if a roof air does go down, another $600 or so and about 2 hours of your time to replace it.  How much to dip into the bus A/C?  And Nick, I mean no disrespect to either you, your bus, or your business.  Thank you, Good Luck, TomC

[niles500]

Though there is no question that older OTR A/C systems improperly maintained - are  a bottomless pit - there is no evidence that a reasonably sound OTR system properly maintained is not an ASSET - to each his own - YMMV and all that chit - why are you denigrating the contributor and NOT the facts? - many of us have OTR Air - Are we all idiots? - I think not - I've never condemned anyone for scrapping their OTR - don't denigrate anyone for keeping it - Live and let live - FWIW

[Beatenbo]

Just rode this train yhe other day. Went yesterday and picked up a new compressor. Hate being without bus air. 90,000btu cooling.I have an almost new gen that just happened to quit one day. Got running in a few hrs didn't take but about 5 mintes of 95 temp to smother. I don't like heading out just depending on a gen set. Fat boys sweat a lot!

[JackConrad]

How do you use your coach? How much of the time in your coach is spent on the road? In our case, most of the use of our coach is 3 day weekend trips with no more then 2 hours travel time each way. So out of approx 72 hours in the bus, no more then 4 hours of usable bus AC time. For us this small amount of bus AC time was not worth the expense and space required the the bus AC.  If we spent more time on the road, our plans might have been different.  Hope this helps, Jack

[DrivingMissLazy]

Have you had your genset checked? How many actual amps does each A/C unit draw? I would have thought that an 8 kw unit would run three roof air units, but really do not know.
Richard

1989 MCI 102C3 with 3 roof airs and an 8kw generator. I can only run 2 airs at a time.

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[Stan]

When I bought a bus from a company with over a hundred buses for sale (out of 1400 buses on the road) I developed a relationship with the shop foreman by going to him to see the maintenance records.

After the sale, and before I started the conversion, I asked hime two questions. What is the most frequent maintenance problem and what is the most expensive maintenance problem? His answer to both questions was the air conditioning. On that basis, I removed it and went to basement air on that bus and roof airs on a subsequent bus. Removing the air ducts along the walls made the interior construction simpler and made the bus interior six inches wider at floor level.

The size of the original system probably makes it a superior system if cost and locating maintenance are not considerations.

[busguy01]

If you want to pay for and maintain TWO A/C systems then go ahead and make the down payment on repairing the OTR system. If, however, you want to just enjoy the cool with NO easy payments get a larger Gen set. The cost of the gen set, less selling price of the old one will be a lot less. My Eagle gets along fine with two basement airs in all kinds of weather. Foam in the roof, fiberglass in the walls. Do about 15K miles a year and never have a problem.
Your mleage may vary.
JimH

[Steve102C3]

Nick - thanks for the offer. If I decide to keep the bus air, I'll take you up on it.

TomC - Thanks for the input. I didn't strip my ceiling down to the metal, so what I have is factory insulation. I also have 4 large windows in the front. It's a work in progress and will be for a while.

Niles500 - in our cars and trucks, we just get in and go, never thinking about the a/c until it doesn't work. In other words - zero maintenance. What do you do to keep your OTR a/c properly maintained?

Beatenbo - skinny guys sweat, too.

Jack - Good advice. We take several long trips a year (as long as we can afford diesel) that may require a couple of full days driving, plus many shorter trips. The long trips in hot weather are the main reason I have an interest in using the coach air.

DML - I thought an 8kw would run 3 airs as well,  provided they don't all cylce on at the same time. What I've found, though, is if I run 3 for very long, the 35 amp breaker on my generator trips. Each a/c draws under 15 amps if I recall correctly. They are Duo-Therm lo-profiles - one 15,000 and 2 13,500.

I have each 35 amp circuit from the generator feeding one leg of my breaker box, so when all 3 a/c's are on, 2 are being fee from one 35 amp circuit (of course). Maybe my genset circuit breaker is weak. Of course I'm careful of what is running at the same time. What do you think about the genset circuit breaker?

Stan - I've heard the same from several people, too.

JimH - I know I can make it work with the genset and 3 or 4 roof airs. I just trying to decide which way is better for me in the long run.

Thanks to all for your contributions. As one who reads more than I post, I can assure you what you put on here helps many more people than just the ones who participate in the discussion.

Thanks again.

Steve

[Nick Badame Refrig/ACC]

Hay,

We can all argue to no end about this subject... Huh!  LOl  

Everybody has a different outlook on this. But, That's good! That's life.....

Good luck Steve, If ya need to call me: 609-263-2296
Nick Badame

[DrivingMissLazy]

I have to assume a couple of things. If you have two 35 amp circuits, then the genset may be connected up for 240/120 volts. Or I seem to recall one of the Onans had a circuit like this with two separate 35 amp circuits.
If it is really a 240/120 volt connection, then I would suggest re-connecting it for straight 120 volts. That is unless you are using 240 volts for something.
Otherwise, I would have no hesitation of increasing the size of the Breakers 5 or even 10 amps. Just keep a close monitor on the actual amps and do not continuously exceed the specified rating. Momentary overload for starting current is not a problem to the genset and I suspect starting current is what is giving you a problem.
Richard

I have each 35 amp circuit from the generator feeding one leg of my breaker box, so when all 3 a/c's are on, 2 are being fee from one 35 amp circuit (of course). Maybe my genset circuit breaker is weak. Of course I'm careful of what is running at the same time. What do you think about the genset circuit breaker?

[Steve102C3]

DML - I've read my installation and owner's manual for this generator and I've seen nothing about 240/120, so I assume it's 120. The one breaker on the generator controls both circuits, so I guess it's a 35 amp 2 pole. It's probably a proprietary Onan part ($$$).

I'll research a little and see what I can come up with.

Thanks.
Steve

[DrivingMissLazy]

I would try a temporary 50 amp breaker and monitor what the amps are with both units running. As long as it stays below 35 amps in normal running mode it will be OK. The gennys are rated to handle the starting current overload and it will not hurt it.
Richard

In fact in some situations like this I have simply shorted out the circuit breaker to see what the actual running current was.

DML - I've read my installation and owner's manual for this generator and I've seen nothing about 240/120, so I assume it's 120. The one breaker on the generator controls both circuits, so I guess it's a 35 amp 2 pole. It's probably a proprietary Onan part ($$$).

I'll research a little and see what I can come up with.

Thanks.
Steve

[FloridaCliff]

Steve,

A couple thoughts on the Genset;

Verify that you are really on two poles.  I just found out on my 7KW that was tripping the generator breaker,

that the two 110 outputs were on the same pole(marked as seperate)I was using the 110's since I had an abundance of that flavor of twist locks.

My 220 output was correct and I switched to that.

Second, If your genset compartment/area is getting too hot it will make the breaker belieive it is paasing more current and cause the breaker to trip at at

lower amp draw.  If thats the case a simple fan added to the compartment may solve the issue.

Just a couple of ideas from my own adventures.

Best of luck

Cliff