| Author |
Message |
Robert MC-9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 12:29 am: | |
Hi Guys
We own a 1980 MC-9, We need to know what is everyone doing out there with their factory heating and a/c unit? I don't know if we should keep it or remove it. The system works great,so I would hate to remove it, but I'm confused on how to keep all the duct work in place without losing space and efficiency of the unit? Please help, all suggestions needed. Thanks |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 12:52 am: | |
Another opinion?
My MC9 unit put ice on the windows at time of purchase.
Shortly thereafter, it ceased to function.
For commercial operation, the OE should remain operable,
but for private use, convert it to the standard rv type
(overhead AC units, or ducted air).
Heat can be obtained via the engine heat, and through the
piping that goes from front to rear. Just add convection radiators.
The Welch System a can also be of great benefit. |
James Maxwell (Jmaxwell)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 3:11 am: | |
I'm a retired refrigeration fitter/mechanic. Up until a yr. ago I would have said leave it in if it is working and appears to be well maintained and in good condition. Then I started hearing more and more adventures like John mentions. Given the extremely high costs of refrigerant now, I have to hedge my previous recommendation. Buses, and I don't care what make or model, have always been high maintenance concerning the a/c. They are very prone to leaks. They are also notorious for eating compressors. Loose a compressor seal or develop a hose leak or broken line, there went 3-500 for new regrigerant alone, not counting the other parts costs and labor if u can't do it yourself.
They are so prone to failure, and your system is now 25 yrs. old, unless it shows good evidence of having been completely refurbished at some point, I would abandon it. If u do use it, I would not rely on it, and that being the case, why have it.
The alternative is not cheap either. 2 15k roof airs, a good large ah battery bank to drive a good high capacity sine wave inverter, and a good dsl. genset. However, u now have air on the road and parked. It won't equal that 10 ton u have in the central system, but then, you won't need that capacity if u do at least average reasonable insulating when u convert. Just my modified opinion. |
Bob Vandawalker (Rav221)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 6:45 am: | |
Since you can't always leave your bus running you'll likely be installing other types of heat/air units anyways. You will also likely be installing a genset, so you'll have power.
We gained quite a bit of space by ditching the unit and compressor. Of course by removing the compressor your also reducing engine load.
Like John said, when they work, they work well. Before our was removed it was ice cold inside, however the complexity and access to these units makes them extremely expensive to maintain. One repair would likey easily pay for all of the new roof units you wanted.
Besides after seeing what collected in the duct work over 18 years, I wouldn't want to be breathing it. |
bruce knee (Bruceknee)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 7:15 am: | |
Well, so far that is 4 against keeping it. Who still has bus air? My system was completly refurbished 4 years ago, compressor, condenser, hoses, everything. It does not work though. The bus has been sitting for 3 years. Should I fix it? |
Jack Conrad (Jackconrad)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 7:55 am: | |
If it is not working, I would guess the freon leaked out, which means there has to be a leak (or more than one). Depending on where the leak is, it could be a very expensive system to maintain.
When we made the decision to remove our non working bus air, these are the factors we considered.
1. Of the time you spend in the bus, what percentage of that time will the bus engine be running? For us, we do mostly weekend trips whith a travel time of approx. 2 hours each way. So in a 48 hour weekend, the bus air can be used less than 10% of the time.
2. I have heard that the AC compressor requires about 15-20 horsepower. If 1 gallon of diesel fuel will produce 17 HP for 1 hour, then we are using approx. 1 gallon per hour for the AC (our generator, running our basement air uses about .7 gallon per hour). AND we have approx. 15-20 additional HP available to the rear wheels to climb hills.
3. We felt that space used by the bus AC was more useful for other purposes. Depending on how you use your bus, YMMV. Jack |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 8:12 am: | |
I have to respectfully disagree with Mr. Maxwell about the requirement for a large bank of batteries and a sine wave inverter.
If you have a generator, then you can eliminate the requirement for a large inverter for running it. Although I am sure you will need an inverter, there is no requirement, in my opinion, to have this large an inverter or large battery bank, just for A/C while going down the road. |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 8:14 am: | |
When I bought a MC-5 the shop foreman told me that the most frequent and also the most expensive (when Freon was $1.00/pound) maintenance item on the bus was the a/c.
I gave him the entire heat/ac system which he removed and in exchange he removed the seats, overhead racks, bathroom and put in two new windshields.
If you know the amount of labor required to strip the inside, that will give you an idea of the cost of the a/c system parts if you have to replace them. He mentioned a few numbers, like $2k for a condensor and 2k for a rebuilt compressor. |
John MC9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 9:10 am: | |
Bruce-
Re:
"My system was completly refurbished 4 years ago, compressor,
condenser, hoses, everything. It does not work though."
That pretty much sums it all up. "It doesn't work now". So now,
you're left with a major decision. You're either going to dump
some heavy bucks into a system that may or may not have
some major problems after sitting for 3 years (dried seals, etc),
or you're going to have to buy new air conditioning.
As everyone's noted, the OE system is a monster that eats
cash. Unless you're going to carry a busload of people, it's
overkill for a family trip. Actually, it's overkill even for full-timing.
The OE system is difficult to service, costly, and limited to
operation only via the bus engine.
You may be able to sell the system (parts) and use that cash
towards replacement system. RV type roof air conditioners
are about the least expensive way to do it. You can even buy them
used for less than 1/2 of the new price, they're easily repaired
or replaced. And since they're 110v, you can use almost any
genset to run them, the shore power when camping, or an
inverter powered by your alternator, while driving.
They make a neat automatic switching device, that allows
you to run two AC units from any power supply that will run
at least one of them, so a 4kw genset can suffice!
About a year ago, this board tried to convince me to get rid
of my then operational OE system, . It was only until it failed
to cool (after sitting for a few months), and after I got a quote
for a freon re-charge from a local bus outfit, that I realized that
I should have just followed the advice here. The freon re-charge
costs almost as much as a new rooftop AC unit.
I gave my system to the guy that took it all out for me as
payment for taking it out. I bought two used 6 month old roof air
conditioners (with heat strips) for under $500 for the pair. |
Jim Shepherd (Rv_safetyman)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 10:16 am: | |
Has anyone, who removed the OEM AC, used the front evaporator with an engine mounted automotive compressor/condenser as a dash air? Seems like a good idea, but I would guess that a new expansion valve would be needed.
Jim |
RJL
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 10:29 am: | |
Jim -
The answer to your question is yes. I know of at least two coaches that have had this done, one a GMC 4905 and the other an MC-9.
HTH,
RJ
PD4106-2784
Fresno CA |
Jim Stewart (H3jim)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 10:54 am: | |
I have a 1995 coach, and I still have the 9 tons of bus air. I live in San Diego area, and if I go east or north, I am still in hot country. I really hate being hot, and that system works so well at keeping the inside nice and cool. No noise when its working, and it can cool a hot bus down faster than my car can cool itself down. I have had the bus for 1 3/4 years, so far so good. The dealer did replace several expensive refrigerant hoses and recharged it just before I bought the bus.
It has been a pain to work around the ducts, but still worth it, they make good wire and plumbing runs too. Plenty large enough that I am not significantly impeding air flow by using some of that space.
I do not yet have the roof airs in and working. My plan is to get them in, see how the generator and that all works, and if it works well enough, I may remove the bus air. It will be hard to equal though. |
john w. roan (Chessie4905)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 11:57 am: | |
If you leave it in, you will need to work your conversion around all of the components to access and maintain them. Could waste a lot of the space you will use. Also it will be more difficult to remove it later. If you keep the coach long enough, they are talking about phasing out r22 down the road 2019? May not be a problem. Also some of the parts of the system may be more difficult to obtain after several years.How much will it cost to fix it now.....maybe the cost of one of the roof or basement airs? A few services and you've spent most of the cost of alternative AC. |
Ed Jewett (Kristinsgrandpa)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 12:04 pm: | |
If the system is still working, now would be a good time to peddle the parts to a bus/tour company. If you can show them a good working system they will pay pretty good prices for used parts, and remove the system. My compressor was locked up and I only got $150 for the rest, and kept the relays, breakers and a few misc. items maybe worth another $50.
That would make a down payment on a good heat pump/ac sys. or whatever you decide on.
I personally am going with 2 mini-splits, one front and one rear.
Do it your way.
Ed |
Robert MC-9
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, August 20, 2005 - 3:00 pm: | |
Wow, by everyones response I guess we should remove it now before we start the conversion. At least now I don't have to worry about working around the duct work. Thanks for the help guys. |
bruce knee (Bruceknee)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, August 23, 2005 - 1:03 pm: | |
I added 1.5 lb of r22 and the compressor clutch locked in. That was all of the r22 that I had.
I got another can $77.00. and added about5 lbs.
Air temp is 41 coming out of main vents and 33 coming out of defrost vents. Could not find any leaks yet, I guess I will see how long it stays cold. I'm glad (for now) that I didn't just tear out the whole system |
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