Driver's A/C questions

[Skykingrob]

Hi All
More driver's a/c questions. I started a blog on this question last week and several of you replied with information. The blog is here: http://www.busconversions.com/bbs/index.php?action=profile;u=31;sa=showPosts
Thanks for that help but I did not get all the answers to everything and I have new questions based on new information I obtained.
I finally got a reply from Mobile Climate Control (MCC) in Indiana about my evaporator unit. As you will read in the blog above, I removed the OTR a/c system from the coach when I got it because it was not working except for the factory under dash driver's evaporator. I learned today from MCC that this evaporator is 46.5K BTU for heat and 27.5K BTU for air conditioning. If possible, I had planned to keep the factory evaporator and simply add a new smaller compressor/condenser to run it since it is still useable and made for the coach. If possible, I would prefer a dc or 110 volt compressor/condeser that could be installed in the spare tire compartment under the driver. I would prefer a 24 volt dc unit.
I was told by one a/c man I talked to today that I needed to find a compressor that 33-40% bigger in tonnage than the evaporator. Is he right? That would mean a compressor about a 35K BTU or 3 ton. He did not have a 3 ton dc compressor/condenser unit, a 110 volt unit compressor/consenser unit or an engine driven compressor to put with my evaporator in this size. So the second question is does anyone know of a source for any of the above? I have been doing lots or research and the most often recommended compressors are sanden and danfoss but I am sure there are varied opinions. Third question. This man said if I chose to go with an engine driven compressor, that I should put a fan dc driven condenser in the spare tire compartment to keep the liquid line as short as possible. Is this correct also?
I appreciate your help.

Rob
91 Prevost LeMirage
Hot Missouri-109 degrees today

[robertglines1]

Ok to really add to the confusion. 3ton at 110 volt probably not.  ck out mini split on E-bay for ideas. I use these in my conversion and put a 12000BTU condensor in the spare tire compartment of my 98 XLE stood upright. 110 volt cooled bus by itself today to 72 inside. You could locate inside unit above box for drivers air/heat on the 98 I thought about it but put it in cabinet above driver instead. I also have two 9000 btu units in for rest of bus.  I thought you were going with the engine driven drivers AC compressor? (the small one)?? still in design stage?   Bob  PS like Steve posted below the long hose hasn't posed a problem. the book just says add 6-ounces extra oil for the line length.

[stevet903]

Here's a chart with the BTUs of various engine driven compressors - http://www.heco.net/maincat/compressors.pdf

Prevost installed drivers air used the engine driven York compressor and had the condenser in front of the radiator in the rear - it seems to work fine.  I guess that having the liquid line as short as possible is a good idea, but it will work with the compressor and the condenser in the rear.  I replaced my York with a Sanden SD510, mainly because my York clutch failed and Prevost wanted over $400 for it.  A new Sanden with clutch and pulley was less than half.

Steve

[Skykingrob]

Bob
Yes I am still in the design phase, evaluating all the options. Since it is driver's air, I don't think I need 3 ton but if I am to use the stock Prevost evaporator, I will have to find a 3 ton compressor to use. The reason I want to go with dc or electric is because the back 20' of copper is gone since it was inside the passenger compartment and was removed with the other various a/c parts when I got rid of them. The front 20' is still there but I would have to solder new line to it if I planned to use it. I don't know what hose would cost for this part or if it is a good idea to run that long with hose rather than soldered copper tubing. Reading your post, you say the long hose length hasn't been a problem, so I can assume that it is not a problem to run hose 20' if the 40' hasn't been a problem, right?
I have found several places on the internet that sell complete systems, like Vintageair, Antique air, etc. for around $1,500 but they are only about 1.25 ton and I am not sure they would be of much value given all the glass enclosed area to cool. One system from vintageair is 1.5 ton for $1,900.
Steve
Thanks for the chart, I just found this site yesterday and hadn't had time to look through it to see what they had.

Rob
91 Prevost LeMirage XL
Missouri

[robertglines1]

Just behind the front step landing there is several   3inch PVC that runs all the way to the rear bulk head : in front of rear differential. accessible from spare tire compartment. Flexible Ac hoses can be  run thru them. or separate.

[Carl Thomas]

Pioneer minisplit 12000 btu going into my 90 LeMirage.. Mounting inside unit above driver near upper windshields.. Outside unit headed for bay 1.
If anybody, especially Bob glines wants to call me, I'd be thrilled! 813854carl Tampa fl

[Nick Badame Refrig/ACC]

Hi Rob,

Many of us over the years have tried to reinvent the wheels if air conditioning.. All those ideas came with a price!!

If you want to use your dash evaporator, just hook up to an automotive a/c compressor (engine driven) most
of them are 4 to 5 tons capacity. And do what your guy said, install a condenser coil in the spare tire comp.

For stationary comfort, use either roof units, mini splits, or a basement type.

Keep it simple! Simple works!

Nick-

[mikelutestanski]

Hello.   Try welch industries.  Stockbridge ga.      They do this all the time...hoses are fine running the length of the bus .   If you have to convert from hose to copper it requires modified fittings..When I installed my dash air I used standard copper hose supplemented by ac hoses.   My compressor is mounted on top of the fan  gearbox located over the engine. The condensor is on the roof near the rear. My system is split because the fron dash unit only provides approx 9k btu of cooling with 134A.so I added a 38k evap in the kitchen... you have options but as nick says the simplest  is best.

     Regards and happy bussin
       Mike

[scanzel]

Red Dot is another one that has aftermarket ac/heat systems or just ac.

[Oonrahnjay]

Red Dot is another one that has aftermarket ac/heat systems or just ac. 

      I looked at Red Dot stuff a while back.  After I got my breath back after I saw the prices, I realized that the didn't seem to offer a compressor (for DC) that was more than 9K to 12K BTU and that was 24V and the Amp draw was ferocious.  I'm sure that their stuff is good for a small and isolated truck cab or sleeper enclosure, but it didn't look to me like they had anything that was nearly big enough for the front end of a bus.
      Their components look good, the styling is nice, and the quality and specs appear really good, it's just that it takes a lot of power to run a system like we'd need and the number just seem wrong for DC.

[TomC]

My driver's air is a forward mount 13,500btu Coleman roof top air aimed at the driver's seat. Technically, I have only about 3,300btu blowing on me since I only have 1/2 of one side aimed at me. With the dash fan also blowing on me, stay cool even in 108 degree weather (hottest I've been in). Good Luck, TomC

[robertglines1]

for some reason this old subject keeps coming up. My split install is doing great. Hardheaded ken used the stock Freon lines on his prevost and a different compressor for dash air. It was 97 yesterday with bus sitting in sun. We had just returned from great adventure and didn't put in barn.(broken garage door opener). left one  9000 split on and late yesterday pm had gotten up to 77 in bus. This am it was 70 that it was set on. Cable fixed and bus back in it's bay.  Will call interested party and try to answer his questions.

[Iceni John]

While we're talking about minisplits, has anyone here mounted a 12K minisplit's condenser (outdoor) unit either canted over at an angle or even flat?   I know the compressor will be starved of oil unless it's vertical  -  how easy would it be to remount the compressor so it's vertical?   The reason I'm asking is because I don't have space to mount a 12K's condenser upright, but I can find a home for it either tilted 45 degrees or even flat (facing down to the road).

John

[Oonrahnjay]

... has anyone here mounted a 12K minisplit's condenser (outdoor) unit either canted over at an angle or even flat?  ...

    Yeah, I'd like to know that, too. 

[J_E]

Mounting the condenser at an angle shouldn't hurt anything.  The condensers for large units are typically at a 45* angle to minimize the footprint of the unit.  You will need a good path for condenser airflow, the compressor should be the low point in the refrigerant loop, and you should run the lines in a path that minimizes or prevents oil catches.

You would void the warranty, but you could look at repackaging the condenser unit if you have the fabrication skills and need to reconfigure the unit.  Also, air is not required to flow through the condenser in a particular direction, so long at it flows through the condenser.  The direction is usually set by the direction that the fan spins.  Depending on the fan controller, you can usually swap polarity on the leads and make the fan spin the opposite direction.  This is true for both, AC and DC, motor types.  A more complex fan controller controller, may have a setting that allows reversing the fan direction.  Heat pumps are not a strength of mine, so if you go with one of those, there may be other things to take into consideration. HTH


Regards,