In-dash air conditioner - Worth converting or fixing?

[DaHose]

I have an older Jamboree I am breathing new life into and cost is a concern. Our in-dash air conditioner is dead and I am mulling over converting it to R134A. However, I have seen some posts comment that the dash A/C is nowhere near enough to cool the RV on hot days and that it makes more sense to just run the gen. set and rooftop A/C.

If you had a 1983 Jamboree (26'), would you bother to repair/convert the in-dash A/C to R134A, or just forget about it and use the rooftop any time you wanted to cool the rig down?

Jose

[Matt_Colie]

J-D,

That is one of the beauties of HC-12a, it compatible with mineral, PAG and Ester oils and all the rubber hoses and o-rings. I can put it in an old R-12 system and it will work and it won't tear-up things that were just fine.

Yes, it is a mixture of pure propane (not fuel gas) and isobutane. If you are afraid of less than 3 pounds of that in the engine box, remember that if it gets released, it is gone in a moment. Compare this to gasoline or diesel fuel......

You do know that the ignition by-products of 134 are extremely toxic as is 134 as it is. It never was a good idea.

I don't know what Maxfrig is, the charts read a lot like HC-12a. I have never used it.

No matter what you use as charge, you still need to evacuate the system even if you are not using a refrigerant like 134 that can become corrosive with exposure to moisture. The problem is that the non-condensable gasses (air stuff) gets in the way and the moisture will freeze and plug important parts.

Matt

[DaHose]

I hear that, j-d. I am always dubious of anything that says it has seemingly magical properties.

I will be looking around quite a bit more to see if I can find science or practial studies about HC-12a and that Maxi Frig stuff.

Jose

[j-d]

Propane will work as a refrigerant. Just don't have a leak near an ignition source...

I've met many mechanics and they didn't have that much in common. Some good, some bad, large, small, old, young etc. etc. But they had ONE thing in common. Nobody came in a can.

[DaHose]

Hmmmmm.... I was looking around for some HC-12a and came across this.

Maxi Frig Refrigerant

If you look at their published charts, their product looks to consistently out perform R12 in a variety of A/C equipment. Is their printed material legit or bogus? Is their stuff just HC-12a by a different name?

Based on what I am seeing, their product looks like a magic bullet. Moisture and oxygen don't make it caustic. You shouldn't even need to vacuum. You can just top off your oil level on your compressor and refill.

Jose

[j-d]

Which OIL should be used with HC-12A, Matt?

[Matt_Colie]

Do not convert to R-134a. The change is fraught with pit-falls and traps and the system will be a disappointment when it is done. R-134a is a good an idea as alcohol in motor fuel. (Yes, it is that bad.)

Do you have a good friend that can deal with A/C?
Buy him:
A case of HC-12a (Duracool)
2 cans of leak trace HC-12a
1 - Cheap LED UV ligtht and a pair of yellow glasses.

Have him put in the leak trace and enough HC-12a so the compressor runs and then run it for a while. When the dye shows up, fix that part and now suck down and recharge with HC-12a. This will take some calculation as it takes much less of the HC than it did of any prior.

I sold off my last big can of R-12 years ago. I will never buy R-134a again. HC-12a works better, is compatible with everything (none of the oil and seal issues as with 134), and it is Cheaper.

The only issue is locating it, but it can be found on the web without much difficulty.

Matt

[rvten]

Use our dash A/C all the time.
Keeps most oh MH cool enough. Unless in very high heat.

[snowdance]

The in dash AC will cool the complete motorhome if you open a rear vent in the coach. Even in 110 degree F temps our complete motorhome is cool using the indash AC or warm using indash heat. To make the indash heat and cooling work the air must have some place to go and if the only exit is at the other end of the rig it goes there cooling or heating every thing along the way. If you close up the coach then it just stays in the driver area. One of the hardest things to do is to get people to open a rear vent in the heat or cold..

[j-d]

Unless you can find a serpentine crankshaft pulley and maybe idler pulley, that eBay compressor with a serp pulley's gonna be hard to drive. Or, you'd have to change the clutch/pulley assembly to go V-Belt like the rest of your pulleys. It's also a "cross bolt" mount design. If you're fabbing your own bracket, you can probably get away with that. Pricing is good since it includes a lot of what you'd need.

The outfit that had the "Sankyo" compressors now has one called "Alpha" that looks like this



It has the "mounting ears", 4 on the bottom, that would drop into a bracket made of angle or channel. Like the one you found, it DOES have the "O-Ring" hose connections. Many compressors use either what I'll call a Hose Manifold that tightens to the compressor with one bolt, or you have to find port adapters to connect to an O-Ring hose end. The 6P148A used port adapters but I had them (kick again!) and mounting ears like pictured above.

[DaHose]

Well j-d, now it sounds like the way to go is with a Nippondenso, stock condenser and a couple small 12v fans to move air around. Is the 6P148A the only one that will work, or could I source any Nippondenso from ebay or a local pick-n-pull?

How about this one I found on ebay? It's a rotary and designed for a Ford E350. Looks like it might even work well with the existing York mount.

http://www.ebay.com/itm/Universal-Air-Conditioning-CO101200C-New-A-C-Compressor-KIT-submit-vehicle-i...


Jose

[j-d]

If you have "dealer"...
That York is enough load to make a 460 hold back at idle. It also reduces MPG noticeably. Ours had a long single V-belt and we found that only top-quality belts like NAPA, Dayton, Gates, etc would last more than a few hundred miles.
It was when I tried to charge to normal low side spec with 134 that I found the high side pressure was climbing to over 300PSI and making the compressor balk, causing the belt or clutch to slip. I'd shift to N for traffic lights on hot days. For a fall "autumn leaves colors" trip, I took the belt OFF and gained nearly an MPG. When you go from 7 to 8, that's a lot.
I'd say try to leak test it. Ours chafed through a hose that was attached to the back side of the radiator shroud. The "dealer" installs are so sloppy that there are more opportunities for thins to rub on sharp edges than you get on "factory."
If you want, you can make a nice conversion with a Sankyo axial compressor. I say that one because it's available with mounts to replace York (an aluminum compressor) and Tecumseh (same thing in iron). You can also get a large parallel flow condenser, drier, TXV, and custom hoses to put it all together without hose clamps. I can send sources, but I'd guess that since the time I looked at it, the parts/supplies cost would be around $600, you providing all the labor. Go Axial and I don't think A/C would decrease your MPG by any amount you could measure.
Of course you can fab your own A-Dapter Kit for a Nippondenso compressor if you have one of those around and somebody who can fab it. I junked a perfectly good 6P148A by mistake thinking it was one of the junk FS6's I had. Then I really kicked myself when I realized I could have used it to replace the York.

[TyroneandGladys]

We do not use the dash AC we run the generator and the roof AC. Pull the curtains on the overhead and on HOT days close off the back end of the RV. We have a fan right behind the front seats to blow the air into the cab and have always been cool. We like it this way since it takes a huge heat load off of the engine and the back end is cool whenever we stop. Also when the boy is with us we would have to run the house AC for him so why run both.

[DaHose]

j-d : I have the "dealer" York compressor, not the factory cylindrical. I pushed the Schrader on the fill side and I get nothing. Seems like its totally empty.

The in-dash A/C is 20K BTU? Wow ......

Ok, then. It sounds like I should get hold of a vacuum pump and see if my R12 system holds vacuum. If so, then I will hot-wire the clutch so I can confirm it is working. If that is a go, then I will have my buddy (HVAC dude) get me some R12 and we will re-charge.

Thanks for the feedback folks. Will update this thread as I make progress.

Jose

[j-d]

Good point, paul. He'd have to get somebody with a license to evac and charge it, but the periperals to convert aren't cheap. There's a ton of R12 out there, and meanwhile the price of 134 has climbed. Diff might not be too bad. Just do something before the other shoe falls. R134A is "now" considered harmful. Gee wow. R12 banned then R22 was accused but never convicted. Banned anyway.

[pauldub]

I'd consider repairing it and recharging with R12. It should cool the cab fine, but asking it to cool the house is asking too much.