Alternative AC refrigerant experiment --

[goodfellow]

After almost four years of service with this refrigerant, I just added a half a can of this air duster refrigerant to my old truck's system. It's still the coldest AC system in the entire family "fleet".

Here's the background info that I posted about 4 years ago.

This is my old '88 Mazda B2600 4x4 with the 2.6L Mitsubishi carbureted engine. I converted it to a Weber several years ago and really want to get this back on the road as an everyday driver. To do that I had to fix the AC system. The original R12 charge had leaked out years ago due to a faulty Schrader valve, and since R12 is so hard to come by these days, and R134a is not compatible with the old mineral oil based R12 systems, I decided to try the following --- Electronic Keyboard Duster!!

That's right -- the electronic keboard duster kits are nothing more than a refrigerant -- namely difluoroethane; which is R152A -- it's cheap enough at Wallmart $11 for three 10oz cans. That's quite a savings over the cost of R12. BUT what's even better is that the R152A has most all of the heat transfer and compression characteristics of old R12.

First thing to do is purchase a side-tap can dispenser because the Duster cans don't have a standard R12 or R134a Schrader fitting. Also, you must tap these cans at the strongest point -- about 1/2" up from the bottom, or you'll crush the can and get a massive leak. Be gentle when tapping and don't force it.



You will also need an R12 gauge set -- or a modern set that read multiple refrigerant types. I attached my set as usual -- low side on the compressor -- high side by the receiver/dryer. Then I replaced the faulty Schrader valve on the low side and pulled a vacuum for an hour.





After the vacuum, the system held 30 inHG vacuum for 1 hour and I was pretty confident that it was air tight.



I then tapped my can and proceeded to fill the system with the 152a air duster refrigerant. First without the engine running, and then after the system equalized a bit, I turned the AC on high and recirculation on internal (no external air flow).  I put a thermometer in the vent and proceeded to turn on the AC switch. The compressor instantly kicked in and the pressure dropped to 22psi on the low side. I opened up the gauge and added the 152A slowly to increase pressure 10psi at a clip and then shut the gauge valve off to let high side pressure stabilize and to check internal temps.

I did this procedure about three/four times until the low side had stabilized on 42-45 psi and the high side at 200-235 psi. I used about 1.5 cans -- or about 1lb of refrigerant to get the inside temp down to about 54F. Then I revved the engine for a few minutes and the gauge dropped just below 50F. I thought that was enough and unhooked all my gauges and took the car for a spin around the block. Within minutes the temp was in the 44-46F range -- PERFECT!!



At this point I would have to say that we have a success, BUT only time will tell. I'm not recommending anyone to do this to their car. This is an experiment to see what works and what pressures are viable for this type of refrigerant. One thing is for sure, it definitely does not behave exactly the same (pressure and volume wise) as standard R12. My system required less R152a than R12 -- I filled the original Mazda system back in the day with 20-22oz of R12 (a bit less than 1.5lbs.). This 152A takes less -- about four-six ounces less.

Let's wait and see what the long term implications are in this experiment -- I'll keep you posted.

BTW -- I'll debunk the myth right off the bat. This stuff is NOT flammable to any high degree. I tried spraying it across an open propane torch flame and it did not ignite -- in fact it extinguished my propane flame every time I tried to do this experiment. That doesn't mean it will never flame -- but it doesn't seem to be explosive.


Addendum -- Here is a Korean Advanced Institute of Science and Technology report about the efficacy of using R152a as an automotive refrigerant. Very interesting conclusions.

http://www.sae.org/events/aars/presentations/2008/manhoekim.pdf

[TexasT]

Do you have a better link? That one just goes to the sae website.

Also, did you change the oil you are using or stay with the stuff that goes with the r12? I was made to under stand I would need some different oil like the stuff used with the 134a other wise the 152a wouldn't circulate it.

I ended up getting some cans of r12 substitute off the ebay. My friend in Toronto sez it works goods for him as he cant buy the 134a like we can here in the us. And the r12 substitute sez i can use the mineral oil. I got one can in and got the compressor to cycle but ran out of the stuff as I had wasted it on the car before I realized the compressor wasn't working. Swapped compressor and now have one can in.

Good stuff either way. Thanks for posting it up. and what is the deal with the three things at the bottom so I can post? Did I do something wrong?

[bonneyman]

In a chlorine-free refrigerant there's always the concern of oil return being less than optimal in a system, as chlorine atoms help with wetting of metal surfaces and miscibility of the freon and oil. It's one of the reasons the original freons worke so well and were so durable - the presence of the chlorine. of course, it's the chlorine that destroys the ozone (if you buy that bull), so all replacements for r12 and R22 are chlorine free. But then you have other problems.

So I'd say if you're getting trouble-free operation of the compressor then you're getting enough oil back to it. You should be GTG. But I would refrain from advertizing this, as IIRC the EPA has laws against mixing refrigerant gases and switching to "unapproved" refrigerant into a system designed for something else.

[gtermini]

Rumor has it that plain old propane (R290) will make the AC on your POS jalopy blow colder than Shillary's heart... I would never suggest or condone trying this at home.



It has some issues, the biggest being the liquid volume change with temperature is a lot more than 12/134. So if you let the low side at the optimal 55psi at 70 deg, you'll be over pressure and freeze up at 100+ ambient. BBQ grade propane isn't always moisture free either. The price makes it no big deal if you can't get the leaks buttoned up and it is compatible with most oils.

Greyson

[bonneyman]

Yeah, I've heard that R-22 residential units will run great on propane - though like you I wouldn't risk it. 

[goodfellow]

The previously mentioned SAE link is dead, but there is a journal article that addresses the issue in using 152a over 134a

https://www.researchgate.net/publication/282563215_Experimental_comparison_between_R152a_and_R134a_working_in_a_refrigeration_facility_equipped_with_a_hermetic_compressor

[nonhog]

I'm interested in all this. Having 4 cars with A/C issues (one is my boys) 2 of I want to sell and selling with working A/C is always good. Yet I have never done A/C work nor do I have the tools (yet)
I'll probably use standard refrigerant but find this fascinating thanks for posting!   

[bonneyman]

This whole globull warming/ozone depletion thing has turned the AC industry onto it's heads. What once used to be a profitable and fun job has become a mess of constantly changing regulations, compatibility issues, and profit margins.

R-12 is hands down the best refrigerant ever. Safe, decent heat absorption, miscibility is par excellance, excels in low temp situations, has low flow requirements, non-toxic, non-flammable, etc. When the EPA banned it I knew the industry was in for an upheaval. And I've been right.  They finally got the R-134a stuff to work OK, now they're going to ban and replace it!

I don't know how you classic car guys deal with it. I can't see you having an all-original restored 1960's beauty and then convert it to R-134a. Just doesn't compute. But R-12 is rare as gold. Unless you've found an alternative.

[DeadNutz]

This whole globull warming/ozone depletion thing has turned the AC industry onto it's heads. What once used to be a profitable and fun job has become a mess of constantly changing regulations, compatibility issues, and profit margins.

R-12 is hands down the best refrigerant ever. Safe, decent heat absorption, miscibility is par excellance, excels in low temp situations, has low flow requirements, non-toxic, non-flammable, etc. When the EPA banned it I knew the industry was in for an upheaval. And I've been right.  They finally got the R-134a stuff to work OK, now they're going to ban and replace it!

I don't know how you classic car guys deal with it. I can't see you having an all-original restored 1960's beauty and then convert it to R-134a. Just doesn't compute. But R-12 is rare as gold. Unless you've found an alternative.

Unless you have a stash of R-12 cans just hanging out on a shelf.

[gtermini]

This whole globull warming/ozone depletion thing has turned the AC industry onto it's heads. What once used to be a profitable and fun job has become a mess of constantly changing regulations, compatibility issues, and profit margins.

R-12 is hands down the best refrigerant ever. Safe, decent heat absorption, miscibility is par excellance, excels in low temp situations, has low flow requirements, non-toxic, non-flammable, etc. When the EPA banned it I knew the industry was in for an upheaval. And I've been right.  They finally got the R-134a stuff to work OK, now they're going to ban and replace it!

I don't know how you classic car guys deal with it. I can't see you having an all-original restored 1960's beauty and then convert it to R-134a. Just doesn't compute. But R-12 is rare as gold. Unless you've found an alternative.

Unless you have a stash of R-12 cans just hanging out on a shelf.

Same kind of guys that probably polish their tools instead of use them 

Greyson

[bonneyman]

Sadly both of my AC vehicles are R-134a. So having a stash of R12 wouldn't help. But I've got some R-22 put away to keep the home unit going long after the cutoff in 2020. 

[goodfellow]

I've had this 152a gas in my 1988 Mazda truck for three years, and it's been doing great. A good R12 alternative for older vehicles, and it's cheap. I plan on putting it in my Jaguar when it's time to recharge the newly installed AC system. It seems to work well with old mineral oil-based R12 systems.

[stokester]

A very interesting experiment.

As mentioned in your earlier post, most customers are not aware of the new R1234YF refrigerant and the complications that come with it.

[bonneyman]

I've had this 152a gas in my 1988 Mazda truck for three years, and it's been doing great. A good R12 alternative for older vehicles, and it's cheap. I plan on putting it in my Jaguar when it's time to recharge the newly installed AC system. It seems to work well with old mineral oil-based R12 systems.

And I'm assuming you've had no problems with seal and gasket compatibility? That's the big one I hear about.

[goodfellow]

I've had this 152a gas in my 1988 Mazda truck for three years, and it's been doing great. A good R12 alternative for older vehicles, and it's cheap. I plan on putting it in my Jaguar when it's time to recharge the newly installed AC system. It seems to work well with old mineral oil-based R12 systems.

And I'm assuming you've had no problems with seal and gasket compatibility? That's the big one I hear about.

I only have one data point, and it's a 30 year old beater truck at that. The system is old, but it holds vacuum, and at this point it seems to be working fine.

[john k]

Glad it is working,  am in the same boat with older vehicles, or will be if I ever get some of them on the road again.  Since propane is very combustible,  wonder if any tests have been done with the vehicle in a front end crash?  Boom or fizzle?   Was thinking of this when before I quit work, we were being introduced to the new R-1234a stuff, and the instructor mentioned it was ((slightly)) combustible. 

[goodfellow]

Glad it is working,  am in the same boat with older vehicles, or will be if I ever get some of them on the road again.  Since propane is very combustible,  wonder if any tests have been done with the vehicle in a front end crash?  Boom or fizzle?   Was thinking of this when before I quit work, we were being introduced to the new R-1234a stuff, and the instructor mentioned it was ((slightly)) combustible. 

Bonneyman is our AC expert and a wealth of info on the properties of the various refrigerant gases in use. From my own limited research I've found that they are all combustible to a certain extent. I tested 152a by spraying it directly into the flame of a burning propane torch. It did nut flare or blow up like most aerosol propellants do. This stuff is used/sold as an alternative source for compressed air to clean keyboards and circuits -- hence I doubt it would be extremely flammable like propane or butane.

[bonneyman]

Thanks GF for the kind words. I've been around the block a few times - sad part is I'm starting to look it! 

The other "new" gas possibility for auto A/C is R-32. It, too, is slightly flammable - which has kept it out of the American market for refrigerant use in pure form. Europe is using it, and early indications are promising. But the flammability rules preclude its use here - which is why the manufacturers and enviros are pressuring the EPA to change their rules a little to permit a "slightly" flammable gas.

Personally, I am leary of anything flammable in an AC. In the old old days ammonia was the main refrigerant, and one of the main reasons it was replaced (with chlorinated hydrocarbons) was because of safety - as it was flammable!  So now we're coming full circle and pushing for a flammable (albeit slightly) gas?
People have said, "It's flammable - so what? There's gasoline in the car, and it's flammable!". Well, with the fuel it's outside of the passenger compartment. With AC, part of the system (i.e the evaporator) is INSIDE the passenger compartment. In a crash a leak in that coil could let flammable freon escape into the area where the people are. Not so sure the phrase "slightly flammable" is gonna be OK with people in that scenario.

[gtermini]

My take is there are so many other dangers on the road, a half pound of something flammable in your rig is a non issue. There are thousands of class 7 and 8 trucks running around on compressed natural gas or propane. I would expect one of these to be a much higher risk in a wreck than a small ac system. Life is full of risks, and I try not to worry too much about most of them.

Greyson

[TexasT]

This is the stuff I am trying out. I'm using it in my 1987 Regal to replace the r12. Just received three more cans.

I plan to use the 152a in our 1994 Suburban when I get that far. I'm goofing with the trans at this time and replacing the ball joints and calipers on the front end. Some of the clutches weren't in very good shape.

[goodfellow]

This is the stuff I am trying out. I'm using it in my 1987 Regal to replace the r12. Just received three more cans.

I plan to use the 152a in our 1994 Suburban when I get that far. I'm goofing with the trans at this time and replacing the ball joints and calipers on the front end. Some of the clutches weren't in very good shape.

What gas compound are they showing on the can label? For example 152a is Difluoroethane

[mikef2316]

The reason ammonia is not used in automotive A/C:  From https://www.osha.gov/SLTC/etools/ammonia_refrigeration/ammonia/index.html


Health Effects

...

Lungs

In the lungs, liquid anhydrous ammonia causes destruction of delicate respiratory tissue.
Exposure to ammonia vapor may cause:

    Convulsive coughing.
    Difficult or painful breathing.
    Pulmonary congestion.
    Death.

...

Occasionally you read about ammonia leaks in refrigerated warehouses or hockey arenas and the death of a person or two.  Plenty of examples if you google it.

[bonneyman]

Oh, ammonia has some definite nasty side-effects, no doubt about it. And for cars I don't think it's a viable option.

But for stationary refrigeration - especially large capacity - I think its advantages outweigh the drawbacks. It would take good design and alot of operational diligence, but - if we can deal with nuclear power and corrosive acids and explosives - I think we could build and maintain ammonia plants.

[coolmercury]

Is it true that the newest refrigerant in some Ram pickups costs big $ an ounce??

[bonneyman]

Don't know about auto A/C gases, but with residential freons the older ones (or to-be-banned ones) are going stratospheric!

R-410a is not too bad, but R-22 is going for anywhere from $100-$300 a pound, depending on your dealer. Which is outrageous!

[slip knot]

so what is R12 going for now? I ran across a couple of cans in the back of the shop.

[Matt_T]

Is it true that the newest refrigerant in some Ram pickups costs big $ an ounce??

Most manufacturers are transitioning to R1234yf. It's about $70 a pound, vs $5 a pound for R134a, which could easily be $10 an ounce or more with shop mark up.

R-22 is going for anywhere from $100-$300 a pound

Looks to be running around $15 a pound online.

[bonneyman]

Is it true that the newest refrigerant in some Ram pickups costs big $ an ounce??

Most manufacturers are transitioning to R1234yf. It's about $70 a pound, vs $5 a pound for R134a, which could easily be $10 an ounce or more with shop mark up.

R-22 is going for anywhere from $100-$300 a pound

Looks to be running around $15 a pound online.

Sorry, I misspoke. Dealers (as in service companies) are charging $100 or more a pound retail. Wholesale for me now is $500 for 30 pounds (i.e. about $17 a pound).

Considering R-22 is made from natural gas and sea water it shouldn't be that expensive.

[Matt_T]

Sorry, I misspoke. Dealers (as in service companies) are charging $100 or more a pound retail. Wholesale for me now is $500 for 30 pounds (i.e. about $17 a pound).

Considering R-22 is made from natural gas and sea water it shouldn't be that expensive.

That or I misread I've heard the interlink rumors about very high R22 costs at retail. Might be some compliance issues I'm unaware of but that kind of mark up seems excessive.

Regards the wholesale price I'm really not surprised R22 is running ~3x the price of R134A and R410A. Declining volume and the threatened phaseout are going to drive the cost up.