Factory Heat and A/C Systems

arutkow · March 01, 2018, 01:16:11 PM

Has anyone used the engine coolant to heat a coach with radiant floor tubes, like in a house?

Is the coolant too hot? would the loops be to long for the pump?

scanzel · March 02, 2018, 04:06:36 AM

You could probably use engine coolant but would probably need an additional pump that you could turn on when needed. Best solution would be a heat exchanger and have it a separate filled system in case something happened. I think Pex radiant floor tubing is only rated for 180 unless there is something else higher, 180 is probably the max you would want to go anyway. The engine system would only give heat while traveling, you would still need something when stopped then a Webasto or Proheat diesel unit may be needed to heat the floor system liquid. Our coach has the original bus heat and air, three 1500 watt built in electric heaters when on a pole. One in front, bathroom and bedroom area. I have a Proheat X45 unit but have not decided how I want to use that yet.

PNWorBUST72 · March 03, 2018, 05:58:14 AM

I will soon be at a point where I will need to decide what do with this OTR heat/ac.

Do I keep the side returns? Do I level and cover the ramp intakes?

Can you convert these AC systems to R134 like you can a car?

buswarrior · March 03, 2018, 06:22:36 AM

Yes, they can be converted.

MCI used to sell a kit of hoses, o-rings and the other kind of compressor oil. Back when the r12 was banned. What is in it now?

As for the rest, each busnut makes their choices in how to climate control their conversion.

The successful ones are comfortable.

The ones who aren't, are broke, divorced and unhappy.

Air, heat and cooling has to circulate somehow, both on the road, camping in a field and camping at a power pole. There are laws of physics that cannot be bent,no matter what a busnut wants...

The coach has an existing system. Whether to adapt, keep, remove is every busnut's dilemma. How much work, how much cash, how much risk of failure?

You will get better advice if you work up a design theory and float that on here for fine tuning?

Happy coaching!
Buswarrior

PNWorBUST72 · March 03, 2018, 06:58:52 AM

Oh I will...I need the communities help.

I would think converting it to R134, if its like a car, is just doing a full evac and changing the fittings/oil etc? That would be cheaper to fill and test the AC. I just got the feeling from the original AC guy that he was just, "its old and leaks so its not worth it".

My problem is still my lack of understanding how the returns/intake systems work. I need to get in there an figure it out.

buswarrior · March 03, 2018, 07:28:23 AM

R12 has been outlawed for 20 years or so... the coach will already have something else in it...

There i$ a very $mall hand full of bu$nut$ who maintain their coach AC, and for good rea$on....

How many thousands can you afford to spend trying to fix it, and then lose, when it still leaks off 25 lbs of gas every 2 weeks?

If you have lots of ca$h to risk wasting, go for it!

The coach AC doesn't work without the big engine running, so you still have to duplicate for camping cooling for the field and the power pole.

Keep the stock heat, dump the stock AC is a VERY common design for funds conservation reasons.

The air distribution, sucks air in from all over, blows air out all over. Carelessly make either opening too small, you got trouble circulating to all parts of the coach. Beware the previous owners and employees who may have bastardized stuff. You have to compare what you find to the maintenance and parts manuals to be sure you are learning "right".

As with most things in life, straying from the religious documentation leads to a sorry path...

Far more conversion attempts end up in the scrap yard, than on the road, and the posters never heard from again

happy coaching!
buswarrior

PNWorBUST72 · March 03, 2018, 09:27:14 AM

Yeah, I dont got it like THAT but I dont mind spending a few hundred to save the AC if there is a chance of it working.

I guess my problem is I still dont understand the "flow" of air through the floor returns/intake. Maybe it will become clear when I pull my subfloor...

richard5933 · March 03, 2018, 03:35:48 PM

Quote from: PNWorBUST72 on March 03, 2018, 09:27:14 AM
Yeah, I dont got it like THAT but I dont mind spending a few hundred to save the AC if there is a chance of it working.

I guess my problem is I still dont understand the "flow" of air through the floor returns/intake. Maybe it will become clear when I pull my subfloor...

Do you have a manual for the bus? Not sure how it is in the MCI manual, but the GM manual for our coach shows the flow from intake vents to heated air.

My recommendation on the a/c system is to have a shop that works on bus units do a leak check and evaluation before spending any money. If they determine it's repairable then you have choices. If they tell you it's not, then you have other choices.