Resurrect old A/C?

[TruckerJoe28]

Hi everyone,
I have a '78 Piper Turbo Lance with factory A/C. I bought it about 2 years ago, and the PO disabled the A/C system because of "weak flow." He never got more specific than that (didn't seem like he took much interest in the workings of his plane). I'm not convinced the real issue wasn't just the blower motor, but the point is, I have no idea why it wasn't working.

I would love to have A/C working again for those deep south summers, but am not sure it's worth it. The engine is getting re-installed after an overhaul, so now's the time to try to get the A/C up and running if I'm going to do it. My shop does not specialize in A/C and doesn't have a lot of experience working on the system, but are able/willing to do a basic inspection/troubleshoot of the system.

I'd love your opinion on it. It seems most factory A/C units on the market are inop or removed, which tells me most people don't think it's worth it to keep it alive. What would you do?

I'm not going to own the airplane forever (at most another 4 years), is there any relevance in resale value to keep the system intact in the plane even if I don't re-activate it? It's a lot of dead-weight to be carrying around. Is there a market for original factory A/C parts out there? I'm always surprised what pulls top dollar on the salvage market.

If I do get the A/C working again, is it typically a mx-intensive system that will likely require a fair amount of attention to keep running?

Thanks for your perspectives!

-Joe

 

[Hang 4]

Are all the parts still installed? How was it disabled? I have an Archer that had AC, but all was removed except the blower motor. It still works and blows air into the cabin. My understanding is that many of the Piper systems were removed for weight savings and limited performance. I suspect a qualified automotive AC tech might be helpful to work with your A&P to check the basics of the system.

 

[JOhnH]

Hi everyone,
I have a '78 Piper Turbo Lance with factory A/C. I bought it about 2 years ago, and the PO disabled the A/C system because of "weak flow." He never got more specific than that (didn't seem like he took much interest in the workings of his plane). I'm not convinced the real issue wasn't just the blower motor, but the point is, I have no idea why it wasn't working.

I would love to have A/C working again for those deep south summers, but am not sure it's worth it.

.
.
.

Thanks for your perspectives!

-Joe

IMHO, It's worth it!

 

[Jim K]

How much air does your blower fan move? The fan in my 76 (non a/c) is so anemic I'm considering taking it out for the weight savings. If your fan is like mine i can't imagine the a/c being worth spending any money on.

 

[Salty]

How much air does your blower fan move? The fan in my 76 (non a/c) is so anemic I'm considering taking it out for the weight savings. If your fan is like mine i can't imagine the a/c being worth spending any money on.

Ask your kids first. People in the back of mine said it made a big difference back there even though I couldn't feel anything up front.

 

[Bell206]

If I do get the A/C working again, is it typically a mx-intensive system that will likely require a fair amount of attention to keep running?

Most aircraft A/C systems do require regular maintenance but I would call it intensive. To get your existing system working again will depend on its current condition, ie., how long its been inop. So depending on that condition will dictate how many components will need to be replaced, however, I do not know the current availability of those items. Perhaps start first with a parts catalog and check part availability for the compressor, evaporator(s), condenser, and dryer. Once you have that info then discuss with your mechanic the labor involved to bring the system up to speed.

 

[TruckerJoe28]

Are all the parts still installed? How was it disabled? I have an Archer that had AC, but all was removed except the blower motor. It still works and blows air into the cabin. My understanding is that many of the Piper systems were removed for weight savings and limited performance. I suspect a qualified automotive AC tech might be helpful to work with your A&P to check the basics of the system.

Yep, all parts are installed and intact except for the compressor belt. As far as I can tell, it was disabled by just cutting the belt off. By visual inspection, all components seem to be in decent shape.

How much air does your blower fan move? The fan in my 76 (non a/c) is so anemic I'm considering taking it out for the weight savings. If your fan is like mine i can't imagine the a/c being worth spending any money on.

Not a lot, but certainly noticeable. I would definitely try to get a better functioning blower before I removed the thing entirely. That’s the only thing keeping the back end from being a stale sweatbox on the ground (with the blower running it’s just a sweatbox).

Appreciate the replies, y’all.

 

[3393RP]

All I can add is that the Texas summer I had access to an air conditioned 182 was wonderful.

 

[Lndwarrior]

Pressure test the system (piping, Evap coil, condenser coil) verify compressor bearings and cylinder are functional, verify blower fan, new air filter, refill refrigerant and bob's your uncle. None of this is complex for a refrigerant guy. No idea if finding someone to work on a plane is a challenge or not. If the compressor is fried the cost of replacement may be the determing factor. Other items may not be prohibitively expensive.

 

[WDD]

Can you even get the old style refrigerant / Freon that it was designed to use?

 

[3393RP]

Can you even get the old style refrigerant / Freon that it was designed to use?

It's available but expensive. The buyer must have an EPA 609 certification. I still have that laminated card somewhere.

 

[JOhnH]

I can't imagine that fixing it would cost more than the value it would add to the plane.

I'm quite sure it would be much less than what it would cost me to add AC to my Bonanza, but I'm even considering that.

 

[WDD]

would cost me to add AC to my Bonanza, but I'm even considering that.

Ditto. Right now I’m spending unplanned sums of money to fix my great condition new to me plane for unplanned repairs.

Next year I’ll break down and spend an unplanned sum of money for an unplanned AC project in the 182.

 

[Dan Thomas]

I'd love your opinion on it. It seems most factory A/C units on the market are inop or removed, which tells me most people don't think it's worth it to keep it alive. What would you do?

Failure of the companies holding air conditioning STCs is one reason. We had to remove the compressor from a P210 because we couldn't get a new mounting bracket to replace the broken one. In Canada we could have had one made, at horrific expense. The laws here are tough on that stuff.

 

[Gary Ward]

First I would check to see if any pressure is in the system.
Once it is empty I would pull a vacuum and see if it holds.

 

[AV8R_87]

Can you even get the old style refrigerant / Freon that it was designed to use?

If it's R12, classic car owners have been quite successful at replacing it with propane. I understand no modifications are required, and you can get 15 lbs of it for a great price at your local gas station.

 

[WDD]

Heating a flammable gas on purpose through a compressor in a system that might leak? In an airplane?

 

[AV8R_87]

With the typical airflow under the cowling and in the cabin, a couple pounds of propane won't pose a problem, even if the leak is significant. The mixture will most likely not get in the combustible range.

 

[Bell206]

Heating a flammable gas on purpose through a compressor in a system that might leak? In an airplane?

FYI: This goes back decades as there is actually a refrigerante-grade propane with its own R number. However, anybody who substitutes a fuel-grade propane in an A/C system not designed for it are prime candidates for a Darwin award.

 

[AV8R_87]

Propane's ignition temperature is above 900 degrees, and it needs a concentration of about 2-10% to burn.
Do you really believe you can accomplish conditions that will trigger and sustain its ignition, with less than a pound of propane in the system, even if it gets released through a ruptured hose, under the typical cowling airflow?

Ballpark cowling airflow is about 3600 cubic feet per minute. Propane gas is about 8 cubic feet per pound. You'd have to release all the propane in the system in a couple seconds to get a mixture that's combustible under the cowling. And then you'd still need to find an ignition source that's above 900F (red heat) in the engine compartment.

I'd be more concerned with fuel leaking through overpriming and throttle pumping before engine start.

This is the same fearmongering that has been going on for years, first with people that were using propane conversions on their cars (not as common in the US, but quite common in other parts of the world), then with the people converting R-12 car AC systems to propane. All of them were predicted to die a fiery death. Doesn't seem to happen, and we're starting to see a lot more factory systems using hydrocarbon refrigerants, both in automotive and stationary applications.

As for the regulatory aspect of it, one could probably make the argument that replacing R-12 with propane is a minor alteration.

 

[WDD]

You learn something new every day in this place.

 

[Getonit]

I am in the HVAC business and we are being forced to go to a new refrigerant that has less GWP (global warming potential) and the new refrigerant is flammable, barely but it takes an act of Satan to get it to stay burning. The UL and ETL standards are laughable as they are not meant to be understood but it is for safety. The testing folks just want $30K to recertify the design. It is a definite S*** sandwich that the customer will have to pay for.

 

[WDD]

As I dig into options for putting AC in my 182 P with 12 volt system I finding few choices.

Can’t find anyone who makes an aftermarket engine driven compressor version, just electric. The nice installed looking option requires a 24 volt system and a lot of amps.

I think I may have found a 12 volt offering that is removable, and looks like a DIY cooler unit vs an installed look.

One more thing to spend money on.

 

[TruckerJoe28]

I can't imagine that fixing it would cost more than the value it would add to the plane.

I'm quite sure it would be much less than what it would cost me to add AC to my Bonanza, but I'm even considering that.

Interesting--you think working A/C adds that much value to the aircraft? I was wondering about that, but it's hard to isolate that variable looking at asking prices on the web.

 

[WDD]

Interesting--you think working A/C adds that much value to the aircraft? I was wondering about that, but it's hard to isolate that variable looking at asking prices on the web.

I just bought a 182 P in June. I would have paid more if it had AC, FWIW. More attractive than a P Ponk engine, etc.

 

[Dan Thomas]

And then you'd still need to find an ignition source that's above 900F (red heat) in the engine compartment.

The exhaust system glows red hot at high power settings. I have seen it. A ruptured oil line is every bit as dangerous as a propane leak.