Need A/C help

[Dr_Snooz]

I just filled the system with Duracool (propane). Vitals are:

Hi = 150 psi
Lo = 32 psi
Ambient temp = 90*
Humidity = 17%
Vent temps are running between 42* on the highway and 59* at idle.

Everything looks perfect, right? My question is, why doesn't my compressor cycle? It just runs constantly and the evaporator isn't icing over. Do I need to add more? Am I overcharged?

[RobDirt89]

I've never heard of propane in a mobile air conditioning system and I've been in the business almost 5 yrs.
Anyways, do you know how much you put in? The high side pressure seems a little low should be up around 200 psi. Alot ofcompressors don't kick off and on, but I doubt your Honda has a variable displacement compressor.
They are mainly on newer vehicles.
I charged air on a 99 civic today,(should be simmalar setup) the compressor only kicked off when I revved it and the pressure got to about 300 psi.

I think you may be slightly oncer charged. And did you add any oil?

[88Accord-DX]

Nevermind.

[Dr_Snooz]

I think you may be slightly oncer charged. And did you add any oil?

I think you mean "under charged"? Yes, I added all kinds of oil. And not PAG 150 like I did last time. :uh: This is 134 oil (Ester).

You should totally look into propane. It's compatible with mineral and ester oil. It doesn't react with water and turn into acid, so you don't have to pump down the system as much. It is more efficient than 134. It is non-toxic, non-greenhouse gas, non-ozone layer reactive. You don't need thousands of dollars of recovery equipment. I can't believe anyone bothers with anything else. I'll never use freon again for anything.

[Oldblueaccord]

Mine cycles of course my humidity is like 70% today :uh:

Try for a low side of 40 psi.Aim for a lower vent temp. I don't think the high will get to 200. I thought the head pressure was lower with propane.

wp

[ShyBoyCA6]

My compressor doesnt even turn on? does it mean i have no oil in there?

[Pnem3]

First of all, welcome to the wonderful world of hydrocarbon refrigerants.

To answer your question, it is not cycling because your vent temperatures aren't low enough. Why aren't they low enough? First I'd look at the ambient temperature. In 90 degree weather, most ACs don't cycle. In fact, in 90 degree weather, you don't want the AC to cycle because that reduces cooling. In order for your unit to cycle, the low temperature sensor in the evaporator has to reach the turn off temperature. This temp should be above freezing. You might find that this sensor is either faulty or set too high but that is not why your car isn't cycling right now. If I were you and happy with your vent temps and pressures, I wouldn't do a thing. Your car will cycle when the vent temps get near freezing. If it doesn't then check the low temp sensor in the evap. If you want lower vent temps, you might add more but try to keep your low side where it is around 36psi. Your vent temps should go down. Your high side might climb some but don't raise your low side because higher low side pressures lead to higher vent temps.

My system has hydrocarbons in it. Yesterday, 97 degree ambient temps and 25-45 mph driving, I got vent temps in the low 40's in a hot car with the fan on high. I got temps in the mid to hi 30's with the fans on 3rd highest setting and temps in the low 30's (31.1 degrees, yes I know it shouldn't be set that low) with the fans on the 2nd lowest setting. I screw around with my propane / isobutane blend and with my current blend, I am running 36psi low side, 265 high side at 91 degrees ambient with blowers on high. I'd like to play around some more and get my high side lower because that saves gasoline and puts less stress on the compressor but since it is going to be 100 today and it works, I will leave it alone for now. Like I said, I like to play with the blend and since it is so cheap to use hydrocarbons, I can do that.

This is my general charging method. First check to see that the car is in good shape. By that I mean check to see that your condenser is clean and not clogged with leaves and such. 2nd, make sure that both of your fans come on and blow strong. 3rd, clean the fan cage inside the car. It usually has lots of leaves in it. 4th, clean the evap box and get the leaves and crap out of it and then make sure that the drain works. 5th, get yourself a good digital thermometer with a long sensor wire so that you can read the vent temps while you are charging the system. 6th , get dual gauges so you can read both hi and low pressures.

Charge the car with the car in a shady spot, windows up and the blower on high, re-circ off. Watch the pressures but more so the vent temps. When the vent temps stop going down, then stop adding refrigerant. If the high side gets too high then stop adding. Charge slowly and let the system stabilize temps and pressures. In these cars, if you find that your unit is cycling with vent temps in the upper 30's or 40's then look to your low temp sensor which might be set too high.

Have fun and enjoy your cool ride.

[Pnem3]

My compressor doesnt even turn on? does it mean i have no oil in there?

Your compressor not turning on is not an indication of whether it has or does not have oil. Not turning on could mean that it does not have enough refrigerant, but not necessarily.

[Dr_Snooz]

Good stuff. Thanks everyone. In the instructions I have, Duracool says to aim for low side pressures of 30-38 but I just saw another place where they say to shoot for 28-45. I think I'll put more in and see what happens.

Thanks!

[DBMaster]

As you may recall, I replaced my compressor and drier last year. I went with a brand new Denso compressor from Rock Auto. I had my favorite shop do the work because I figured since they use a replacement refrigerant if I had any issues with it they would make good. They use Freeze 12. I have to say that I have been pleasantly surprised. The vent temps are only 2-3 degrees higher than they were with R12 and I have not had to add any refrigerant in a year. Previously, the system needed about one half to one can of R12 per year. That was even after replacing the hoses, schraeder valves and compressor in 1999.

As long as the system cools I would shoot for the least compressor cycling possible. Old cars like my 72 Pontiac used to see compressors lasting forever partially because the lack of cycling eliminated the wear and tear that entails. The clutches and shaft seals seem to be the point of failure with compressors like ours and that is a direct result of the cycling. I noticed that as an issue on GM cars starting around 1980 when they switched from the A-6 to the R-4 compressors. The A-6's didn't cycle and the R-4's did.

[Pnem3]

Good stuff. Thanks everyone. In the instructions I have, Duracool says to aim for low side pressures of 30-38 but I just saw another place where they say to shoot for 28-45. I think I'll put more in and see what happens.

Thanks!

Focus more on the vent temps than the pressures and you will be fine.

I hope this helps.

[Dr_Snooz]

I added another 1/4 can or so today. I got the low side up to 38 and the high side up to 151. Vent temps actually went up (59*), so I think I'm done. I filled up the 4g with 134 last month and the head pressures were almost exactly the same (35/147) with vent temps at 62*. In this weather, the 4g compressor isn't cycling either. My 3g vent temps are cooler and I did notice the compressor cycling today while I was driving down the freeway.

Duracool should probably change their charging instructions. They say to fill until the compressor starts cycling. That may be great for an American car with a V8 driven, 80 lb., cast-iron compressor, but a Japanese econo-car with a lightweight aluminum compressor just isn't going to get there. Propane might be too easy really. You don't even need gauges. You can just fill up the low side to 35 or so (check it with a tire gauge) and go.

What a brilliant refrigerant!

[DBMaster]

With a 100 degree ambient temperature I am getting 45 degrees from the center vents. That is in-town driving, not highway. If memory serves correctly, I get about 42-43 at highway speeds. Doesn't sound like the HC blend does any better than the R134a blend (Freeze 12). I wish R12 were more readily available.

[Oldblueaccord]

Run it around some and let it stabilize.


wp

[Dr_Snooz]

It does seem to be working better the longer I run it. I had to pull the system completely apart and flush it because I put the wrong oil in last year. :duh: When I put the new oil in, I just dumped a few ounces in the evaporator, drier and compressor. Its all real lumpy right now and needs to smooth out.

Are our blower fans really anemic or do I have a problem? Mine just doesn't seem to blow out much air. I might have a door problem too.

[Pnem3]

With a 100 degree ambient temperature I am getting 45 degrees from the center vents. That is in-town driving, not highway. If memory serves correctly, I get about 42-43 at highway speeds. Doesn't sound like the HC blend does any better than the R134a blend (Freeze 12). I wish R12 were more readily available.

It can be misleading to judge just based on the vent temps people post. Everything is relative when it comes to vent temps. Some of the variables that matter: Does the blower blow hard or weak? Are the windows tinted? Is the compressor 20+ years old or a newer? Do the radiator fans work well? Are the blower housing and evap housing clean? Is the thermometer reliable and calibrated? Was the system charged to it's maximum efficiency?

That's way too many variables to form an informed opinion. In the end though it doesn't matter. What matters is that people are cool and comfortable and happy with the car they drive.:D

[Dr_Snooz]

Propane is failing then for me. For the last couple days, I've been driving with the thing blowing flat out (recirc on, fan on high) and am only just staying cool. The 4g is an entirely different story. It cools the car down relatively quickly and once cool, we can turn the fan down to low and stay comfortable for the entire trip. I need to keep investigating. The 3g AC was always a little wimpy, but it's really wimpy now. The 4g was also wimpy, but it kicks butt now.

[DBMaster]

That's way too many variables to form an informed opinion. In the end though it doesn't matter. What matters is that people are cool and comfortable and happy with the car they drive.:D

I more or less agree with that. The HC refrigerant *SHOULD* do better than the R134 or Freeze 12. From the research I have done in the past I think it should actually work better than R12. There must be something else going on here.

Living where I live I have had tinted windows almost since the car was new. Blocking the UV has kept the seats, door panels, etc. looking new. It sure helps with the A/C as well, as you mentioned. I still get a very strong airflow from the vents and my compressor is a one-year-old Denso.

The only problem I seem to have is internal. I keep my house at 72 degrees in the summer and I'm barely comfortable while everyone else grabs for the blankets I keep around. The car A/C does OK, but I have never been 100% satisfied with its performance since the car was brand new. It doesn't blow air so cold you can see your breath in the car like my old Pontiac. I doubt any A/C does that anymore.

[DBMaster]

It was 106 here yesterday. When it gets that hot I can detect the small, but noticeable, difference in performance of Freeze-12 v. R-12. When idling at traffic lights and relying on only the electric fans for air flow across the condenser the output is not quite as cool as it was with Freon. I haven't taken any measurements, though. It is satisfactory.

[Dr_Snooz]

Propane is failing then for me.

Okay, the problem is me. I have a leak. The propane is all gone now. :(

I will fix the leak, but it's a slow one and I need a sniffer. I don't have a propane sniffer, but I do have a 134 sniffer. If I have to fill it with 134 to find the leak, then I'll probably just go with 134.

Duracool says propane is "extremely better" (sic) than 134. My experience is different. I found propane to be roughly equivalent with 134 in terms of head pressures and vent temps. There are other reasons to go with propane, of course. It's easy to use, doesn't require certification to buy and is more environmentally friendly than anything else. I'll probably use it later, but not because it's a better refrigerant.

[Oldblueaccord]

Big lots had cans again on sale for 8$ a can. I dunno if that's good for your area or not.

We had some hot days with low humidity 96 wit h44% at about 4 pm. I was still getting compressor cycles with the fan on speed 2. I'm just saying I think you can get there. Everything in my car is original but the compressor I got out of a junkyard in 1995.

wp

[2drSE-i]

Okay, the problem is me. I have a leak. The propane is all gone now. :(

I will fix the leak, but it's a slow one and I need a sniffer. I don't have a propane sniffer, but I do have a 134 sniffer. If I have to fill it with 134 to find the leak, then I'll probably just go with 134.

Duracool says propane is "extremely better" (sic) than 134. My experience is different. I found propane to be roughly equivalent with 134 in terms of head pressures and vent temps. There are other reasons to go with propane, of course. It's easy to use, doesn't require certification to buy and is more environmentally friendly than anything else. I'll probably use it later, but not because it's a better refrigerant.


I found my leak in the high side compressor line, the line that goes from the condensor to the compressor, but it was leaking out almost as fast as I was putting it in.

I will probably flush my system next year, put a new dryer on it, new oil all around and run propane or a propane blend. But for now, 59F is pretty nice compared to the 110F ambient

[Dr_Snooz]

My AC came back on today! And then it went away again. Soooooo I have some more troubleshooting to do. Stupid Honda ACs are nearly impossible to keep running after 20 years.

[Oldblueaccord]

Now im thinking you got to much oil in the system. When I did mine I only added to the compressor like 23/4 oz Im guessing. I never put any in any lines or anywhere else.

Can you vacuum it down?

wp

[Pnem3]

My AC came back on today! And then it went away again. Soooooo I have some more troubleshooting to do. Stupid Honda ACs are nearly impossible to keep running after 20 years.

What do you mean it came back on? Didn't you say all of the refrigerant leaked out? If it did, get yourself some dye and add that before you fill it again so you can find the leak.


Now im thinking you got to much oil in the system. When I did mine I only added to the compressor like 23/4 oz Im guessing. I never put any in any lines or anywhere else.

Can you vacuum it down?

wp

Too much oil = poor cooling. Did you get all of that other oil out or did you just add new oil?

How much refrigerant did you put in the system? I think you would be better going by weight of refrigerant (in grams) than by some arbitrary standard of when it cycles. I think you were probably over-charged. You should be able to get good results with the hydro-carbon blend but it has to be done right.

[Dr_Snooz]

Here's the long version of the story. I did the conversion to 134 in 2004. At that time, I completely flushed the system, pulled out each component and blew Napa's flush through it. I also replaced the compressor. I added 3 oz. of Ester oil to the system and charged with 134. I came up with 3 oz. by adding up the amounts of oil listed on p. 23-19 of the manual. It's a chart that lists how much oil you should add if you replace a given part of the system. That seemed to work well enough. The car was Mom's at the time and she subsequently "lent" it to someone who mistreated it badly for some months. Very badly and I'm still mad at him for it. One casualty of that experience was the AC, along with most of the car. I resurrected the AC when I was restoring the car. When I got it running again, I noticed some slight compressor chatter. I added a small can of oil through the gauge set. By some miracle of stupidity, the oil I used was PAG 150, which is way too heavy. The compressor really chattered then. When I posted about the chatter here, I was told by others on this board that I should have added closer to 6 oz. of oil when I did the conversion according to Napa. I don't know AC super well, so I deferred to them. I tore the system apart and completely flushed everything again. This time I added 5.75 oz., per their recommendations. It seemed like a lot to me, but I don't want chatter again.

How much should I have in there? It's easy enough to get it out. I've pulled the system apart enough times that it's second nature now. I'll probably remove the evaporator and dump out the oil that seems to like to accumulate at the expansion valve. That should get me where I need to be. Wherever that is.

Anyway, that's the whole sordid tale. I'm open to any thoughts or suggestions.

[Dr_Snooz]

Figured it out today. When I reconnected the compressor clutch, I didn't push the connector tight enough and it worked itself loose. Put it back together and it's up and running again.

I'm still mostly underwhelmed by propane though. Oh well. My brother is here this week so I'll have him look at it. He is wiser in the ways of car repair than this grasshopper.

[2drSE-i]

Don't give up on propane! Just a few posts back you were loving it! I'm thinking you have an underlying issue. According to what I read (somewhere, its been two years now...) on an R12 system you should be running 8oz of oil.
Have you replaced the drier recently? They REALLY don't like moisture, and having the a/c system open a few times for a few hours each can eat them up. I'm thinking this is what my problem is as well. Head pressures are great, but vent temps still aren't where i'd like them (then again, temps out here have been 110 and higher, today is an AWESOME high of 88! Barely used the a/c today lol)


Oh and I think our blower motors are really lame. I barely feel mine unless its on high

[Dr_Snooz]

I like the idea of propane, but my results have been less than stellar. Duracool is great if you are a propane newb and need a lot of handholding through your first propane conversion. After that, you start to realize that Duracool is $10 per 6 oz. can, whereas you can buy 5 gal. of bbq gas for $14. The cost equation is decidedly against using Duracool. So is convenience. You can't buy Duracool at the store, so you have to order it online and wait. Which sucks. Moreover, every can of Duracool comes with some A/C oil in it. That's the last thing I need because every time I remove my high side gauge hose, it blows A/C oil all over everything. I have plenty of oil and don't need a drop more. Long and short: no more Duracool.

With my brother's help, we made an adapter to connect a standard A/C gauge set to a bbq bottle of propane. It turns out I did have a leak in my system and it was very low on refrigerant. I found the leak (oil soaking around the high side entry to the evaporator) and fixed it (I hope), then topped off the system with standard bbq gas.

Here are the new numbers:

Hi = 200 psi
Lo = 34 psi
Vent temp = 49*
Ambient temp = 79*

On the road, it is pulling right down to 42* and cycling nicely. A better test is going to be when it's 105* here and the car has sat on a blacktop parking lot for a few hours.

For now, I'm very pleased. If all works out, I'll put up a how-to for the adapter I'm using and how I charged the system.

[2drSE-i]

Did you guys take any precautions to minimize the amount of moisture from the bbq propane? I figure its negligable and the dryer can probably handle it, but I've read of sticking the propane in the freezer for a few hours to freeze the water (obviously a smaller can, 1lb or so). Any reduction of moisture will only help performance, though.

[nswst8]

I'm against the use of propane in these cars for the simple reason, inability to secure the known leaks in these systems.

Of course I haven't had a leak in the 2007 return to R12 but the latest 2009 has a stubborn leak that I have to top off every 9-12 months.

It is the exact same denso conversion kit as the other. Leak is at the suction side of the compressor.

I'm surprised that you just haven't returned it to R12 like I did. there is plenty of it on the market, it will only cost you $25 to take the EPA test and then you can buy all you want.

[2drSE-i]

Edit, don't know what I'm talking about.

Propane is flammable above -150*F, whereas Freon (generally speaking) isn't. The concentration we are dealing with though is minimal. Unless you leak ALL of your propane out and light a match, I think your going to be fine.

[nswst8]

Who, stated that you don't know your talking about?

I hope that you are not thinking that is what I was saying. I just said that I was against using propane in these cars.

[2drSE-i]

Who, stated that you don't know your talking about?

I hope that you are not thinking that is what I was saying. I just said that I was against using propane in these cars.


No i had a long reply about Critical temperatures and flash points of refrigerants and how R12 and R134a are indeed flammable, but Propane is flammable at every conceivable temperature, and R12 and R134a are flammable at the point your car is already a fireball. Admittedly, propane won't release nerve gas if it catches on fire.


I'm still going to use propane, as your car needs less than a pound of it to have ice cold vent temps. Just be sure the sucker isn't leaking.

[nswst8]

Cool.

[lostforawhile]

I think you mean "under charged"? Yes, I added all kinds of oil. And not PAG 150 like I did last time. :uh: This is 134 oil (Ester).

You should totally look into propane. It's compatible with mineral and ester oil. It doesn't react with water and turn into acid, so you don't have to pump down the system as much. It is more efficient than 134. It is non-toxic, non-greenhouse gas, non-ozone layer reactive. You don't need thousands of dollars of recovery equipment. I can't believe anyone bothers with anything else. I'll never use freon again for anything.

I have to chime in here, the reason people don't use it is it is extremely dangerous to fill your system with propane, you have a highly flammable gas circulating in your system, it's also heavier then air, it sinks, if you have a leak it's going to collect along the floor, one small spark and BOOM!!

[lostforawhile]

here you go, It's hard to tell but from the wheels but it looks like a burning three g ,due to a propane refrigerant explosion, that thread is 100 percent accurate, have a minor accident, the first thing to hit is the ac condenser full of high pressure extremely flammable propane, combine this with sparks from the accident or electrical shorts and your car becomes a barbecue grill. any accident that causes the radiator to be damaged will almost certainly ruin the ac condenser. I'm a licensed ac technician, believe me, you don't want to do this. it's not worth the risk
http://www.aa1car.com/library/flammable_refrigerants.htm

[gp02a0083]

I have to chime in here, the reason people don't use it is it is extremely dangerous to fill your system with propane, you have a highly flammable gas circulating in your system, it's also heavier then air, it sinks, if you have a leak it's going to collect along the floor, one small spark and BOOM!!

oh yah its dangerous, my father attends mechanic seminars to stay updated with new products and systems. They demonstrated the use of propane in a ford taurus, thing caught on fire from a small pin hole leak. Sames goes for my fathers friend / service manager. He was traveling south on vacation with his wife in his 70's trans am. He had a small leak and eventually he said it was like a grenade under the hood, not to mention the fire.

[DBMaster]

Lost's link is an interesting read. A lot of variables come into play when determining safety, apparently. I have found Freeze 12 to be an acceptable replacement refrigerant so far (it's been a year now), but only time will tell if the performance remains and if the system durability is maintained. I'm still hanging onto my three cans of R12, just in case.

[Pnem3]

This discussion has been played ad nauseum out all over the internet. What it comes down to is that in most States in the U.S., it is legal to use hydrocarbon refrigeration in automobiles. What I have said in the past is that it is not for everyone and everyone should research it and come to their own conclusions. For me, I have used hydrocarbons for several years now and have never had any issues whatsoever.

Back to the thread:



I like the idea of propane, but my results have been less than stellar. Duracool is great if you are a propane newb and need a lot of handholding through your first propane conversion. After that, you start to realize that Duracool is $10 per 6 oz. can, whereas you can buy 5 gal. of bbq gas for $14. The cost equation is decidedly against using Duracool. So is convenience. You can't buy Duracool at the store, so you have to order it online and wait. Which sucks. Moreover, every can of Duracool comes with some A/C oil in it. That's the last thing I need because every time I remove my high side gauge hose, it blows A/C oil all over everything. I have plenty of oil and don't need a drop more. Long and short: no more Duracool.

With my brother's help, we made an adapter to connect a standard A/C gauge set to a bbq bottle of propane. It turns out I did have a leak in my system and it was very low on refrigerant. I found the leak (oil soaking around the high side entry to the evaporator) and fixed it (I hope), then topped off the system with standard bbq gas.

Here are the new numbers:

Hi = 200 psi
Lo = 34 psi
Vent temp = 49*
Ambient temp = 79*

On the road, it is pulling right down to 42* and cycling nicely. A better test is going to be when it's 105* here and the car has sat on a blacktop parking lot for a few hours.

For now, I'm very pleased. If all works out, I'll put up a how-to for the adapter I'm using and how I charged the system.

Did you have all of your gas leak out? If so, then you might just be running propane and have no iso-butane in your system at all. IF you find a way to introduce iso-butane (I personally use a can side-tap I got from Napa) then you will be able to fully control your refrigerant needs. I'd personally like to see your vent temp lower at 79 degrees ambient but like you said, let's see how the system works when it gets hotter.

As always, best of luck to you.

[lostforawhile]

This discussion has been played ad nauseum out all over the internet. What it comes down to is that in most States in the U.S., it is legal to use hydrocarbon refrigeration in automobiles. What I have said in the past is that it is not for everyone and everyone should research it and come to their own conclusions. For me, I have used hydrocarbons for several years now and have never had any issues whatsoever.

Back to the thread:




Did you have all of your gas leak out? If so, then you might just be running propane and have no iso-butane in your system at all. IF you find a way to introduce iso-butane (I personally use a can side-tap I got from Napa) then you will be able to fully control your refrigerant needs. I'd personally like to see your vent temp lower at 79 degrees ambient but like you said, let's see how the system works when it gets hotter.

As always, best of luck to you.it's actually very illegal to use flammable gasses such as propane in automotive AC systems, I don't know where you get your ideas, but don't spread dangerous information on here, running this stuff can kill you, plain and simple, it's happened before, it will happen again, it can also very easily turn a minor accident into a totaled burned out car. You are also risking the lives of anyone who responds to the accident scene to help you, do you want to be responsible for the firefighter who is blown out from under your hood trying to disconnect your battery? Propane powered cars and trucks are designed to cut the gas in a wreck, rigged AC systems have no such safety protection.

[lostforawhile]

osted 02-21-10 05:08 PM
Hello Dr. G.

I just watched with horror, the episode that described the death of Robert Paul Terrible 1981-2004.

It is VERY common for people with leaking automotive air conditioning systems, in third world countries, to fill them with propane or butane instead of expensive factory replacement refrigerants. Rather than fix the leak they fill them with a few pennies of these fuels every few weeks when the air conditioning stops running cold.

An air conditioning system most commonly leaks refrigerant at the evaporator, located behind the glove box (it looks like a small radiator with an electric fan proximal to the unit).

If Robert Paul Terrible was running his air conditioning while sleeping off his alchohol intoxication, a small leak could have filled the cabin with propane or butane gas and then ignited as the compressor switch cycled on an off inside the cabin. The compressor switch is a high amperage switch and will commonly arc in older model automobiles.

Law enforcement in third world countries are most likely familiar with this cause of death and/or serious injury.

I am a tech on the lexus owners club site and we recently had a young man that immigrated from africa, post to our members that we were wasting our money recharging our lexus cars with u.s. sourced refrigerants and should just use propane like they do in his country.

He was chastised strongly for suggesting such a dangerous procedure and suggesting to the younger members that if they want to save money that using propane for a leaking system instead of fixing the leak, was the way they should proceed.

If anyone can forward this information to the proper authorities in the case or even the family of Robert Paul Terrible, it would be greatly appreciated.

His death was most likely a preventable accident.

Galahadthis brings up a good point, you have the evaporator right next to the fan in a closed box, plus a thermostat switch in there, the fan arcs when it's running, and the thermostat switch arcs when it's cycling the compressor clutch, all you need is a small leak in that evaporator box, and propane will collect in the lower part of it, the compressor to cycle, and half of your dash blows off going down the road.

[Pnem3]

it's actually very illegal to use flammable gasses such as propane in automotive AC systems, I don't know where you get your ideas, but don't spread dangerous information on here, running this stuff can kill you, plain and simple, it's happened before, it will happen again, it can also very easily turn a minor accident into a totaled burned out car. You are also risking the lives of anyone who responds to the accident scene to help you, do you want to be responsible for the firefighter who is blown out from under your hood trying to disconnect your battery? Propane powered cars and trucks are designed to cut the gas in a wreck, rigged AC systems have no such safety protection.

From a simple google search:

"Existing mobile air conditioning systems are not designed to use a hydrocarbon refrigerant that is highly flammable and similar to what supplies the fire in your back yard barbeque.” said Ward Atkinson, Chair of the SAE Interior Climate Control Standards Committee. Nineteen states and the District of Columbia have laws prohibiting the use of a flammable refrigerant in mobile air conditioning systems. (Arkansas, Arizona, Connecticut, Florida, Idaho, Iowa, Indiana, Kansas, Louisiana, Maryland, Montana, Nebraska, North Dakota, Oklahoma, Texas, Utah, Virginia, Washington, Wisconsin, and the District of Columbia).

I'd say 19 does not qualify as most so as I said, it is legal in most States. While I agree that the systems have not been designed to use hydrocarbon refrigerants, they certainly can, and can safely. I'd also add that our systems have not been designed to use R134a either.

From the article you posted:

EPA does not regulate the use of hydrocarbon refrigerants such as HC-12a® and DURACOOL 12a® as substitutes for HFC-134a in motor vehicles.

[lostforawhile]

From a simple google search:

"Existing mobile air conditioning systems are not designed to use a hydrocarbon refrigerant that is highly flammable and similar to what supplies the fire in your back yard barbeque.” said Ward Atkinson, Chair of the SAE Interior Climate Control Standards Committee. Nineteen states and the District of Columbia have laws prohibiting the use of a flammable refrigerant in mobile air conditioning systems. (Arkansas, Arizona, Connecticut, Florida, Idaho, Iowa, Indiana, Kansas, Louisiana, Maryland, Montana, Nebraska, North Dakota, Oklahoma, Texas, Utah, Virginia, Washington, Wisconsin, and the District of Columbia).

I'd say 19 does not qualify as most so as I said, it is legal in most States. While I agree that the systems have not been designed to use hydrocarbon refrigerants, they certainly can, and can safely. I'd also add that our systems have not been designed to use R134a either.

From the article you posted:

EPA does not regulate the use of hydrocarbon refrigerants such as HC-12a® and DURACOOL 12a® as substitutes for HFC-134a in motor vehicles.
how long have you been a certified AC technician? putting this stuff in a system not designed for it is dangerous, plain and simple, I don't know any other way to put it, if you want proof, look south of the border, it's a common practice there to use propane because it's cheap, it's also common to have explosions and burns and deaths because of it.

[Pnem3]

I'm sure you can produce lots of evidence to support your statements but I personally have not heard of all of these "deaths" south of the border. I'm not a certified AC tech. I don't earn a living putting any type of refrigerant in anything. In short, I don't have a dog in the fight. I have always said that hydrocarbons aren't for everyone and that everyone should do their due diligence before making their own decisions. I stand by that.

[Dr_Snooz]

Wow Lost, that's some pretty scary stuff. You realize of course that every RV on the road comes with big bottles full of propane? Sometimes those bottles spring leaks too. And sometimes the people in those RVs fail to turn off the propane to their refrigerators, drain the system of all residual gases and then secure the propane bottles in bomb-proof bunkers before driving down the highway. It's a wonder anyone survives. And all those trucks converted to run on propane. My god. Terrifying.

Just to clarify, we're filling the A/C system with PROPANE. Not nitroglycerin. Because propane is so efficient, a typical system does not need a lot of it to work well. Even if there is a leak, there is a fairly limited amount of it to combust. The car is not going to be blown to smithereens in a Hollywood-style fireball. Sorry. What's more, there's a number of environmental factors that have to be just right to create the nightmare scenario you describe. Propane will only burn in concentrations of 4-9%. Outside of that range there will either be too much propane or too much air. So, IF you evacuate the entire charge of it inside the car and IF you somehow fail to smell any of it and IF you atomize all of it finely and prevent it from being blown out of the car by the blower fan and IF the concentration of vapor happens to be between 4% and 9% and IF it's right near an ignition source, THEN you might get a flameout. That's a lot of IFs. Of course, given the right conditions, you can get your gas tank to explode too. It's a lot more likely that any propane lost will disperse harmlessly into the atmosphere. Yes, there's a risk, but I'm a lot more worried about what Monsanto is doing to the food supply than I am about the propane in my A/C system.

Propane is already used as a refrigerant in non-mobile applications. So much so that it's known as R-290. Your blower fan example is completely ridiculous. The fan would be blowing the propane AWAY from the sparks.

The truth is that simply getting into your car in the morning is risky. There are all kinds of things that can go wrong, including death or maiming. That's just life. If you are too afraid of the risks, you'll never leave your house. Am I adding to my risk by running propane? Yes. But then I'm also adding to my risk by speeding or racing to make yellow lights or driving when I'm tired. It is what it is.

On the other hand, propane doesn't require a special license to use and it's dirt cheap. I don't need a lot of special equipment to use it and I can still have ice-cold vent temps. Nor do I have to worry about some regulatory change that prices it out of reach and requires me to spend a bundle converting my system to the next dumb refrigerant that will be outlawed again in a few years time. I'm done with that nonsense. Best of all, propane is non-toxic. It doesn't harm the ozone layer or cause global warming.

So in the end, I have a vanishingly small likelihood of burning myself. Everyone using R-12 or R-134 is rendering the planet uninhabitable. Which is the greater risk?

@2drSE-i, moisture really isn't a problem with propane. It diminishes the efficiency obviously, but it doesn't turn into acid and eat everything up like regular refrigerants. You don't even need to vacuum down the system really.

[lostforawhile]

Wow Lost, that's some pretty scary stuff. You realize of course that every RV on the road comes with big bottles full of propane? Sometimes those bottles spring leaks too. And sometimes the people in those RVs fail to turn off the propane to their refrigerators, drain the system of all residual gases and then secure the propane bottles in bomb-proof bunkers before driving down the highway. It's a wonder anyone survives. And all those trucks converted to run on propane. My god. Terrifying.

Just to clarify, we're filling the A/C system with PROPANE. Not nitroglycerin. Because propane is so efficient, a typical system does not need a lot of it to work well. Even if there is a leak, there is a fairly limited amount of it to combust. The car is not going to be blown to smithereens in a Hollywood-style fireball. Sorry. What's more, there's a number of environmental factors that have to be just right to create the nightmare scenario you describe. Propane will only burn in concentrations of 4-9%. Outside of that range there will either be too much propane or too much air. So, IF you evacuate the entire charge of it inside the car and IF you somehow fail to smell any of it and IF you atomize all of it finely and prevent it from being blown out of the car by the blower fan and IF the concentration of vapor happens to be between 4% and 9% and IF it's right near an ignition source, THEN you might get a flameout. That's a lot of IFs. Of course, given the right conditions, you can get your gas tank to explode too. It's a lot more likely that any propane lost will disperse harmlessly into the atmosphere. Yes, there's a risk, but I'm a lot more worried about what Monsanto is doing to the food supply than I am about the propane in my A/C system.

Propane is already used as a refrigerant in non-mobile applications. So much so that it's known as R-290. Your blower fan example is completely ridiculous. The fan would be blowing the propane AWAY from the sparks.

The truth is that simply getting into your car in the morning is risky. There are all kinds of things that can go wrong, including death or maiming. That's just life. If you are too afraid of the risks, you'll never leave your house. Am I adding to my risk by running propane? Yes. But then I'm also adding to my risk by speeding or racing to make yellow lights or driving when I'm tired. It is what it is.

On the other hand, propane doesn't require a special license to use and it's dirt cheap. I don't need a lot of special equipment to use it and I can still have ice-cold vent temps. Nor do I have to worry about some regulatory change that prices it out of reach and requires me to spend a bundle converting my system to the next dumb refrigerant that will be outlawed again in a few years time. I'm done with that nonsense. Best of all, propane is non-toxic. It doesn't harm the ozone layer or cause global warming.

So in the end, I have a vanishingly small likelihood of burning myself. Everyone using R-12 or R-134 is rendering the planet uninhabitable. Which is the greater risk?

@2drSE-i, moisture really isn't a problem with propane. It diminishes the efficiency obviously, but it doesn't turn into acid and eat everything up like regular refrigerants. You don't even need to vacuum down the system really.

I just don't want you to blow yourself up snooze, people do get hurt trying to do this, as far as the rv's i agree with you on that, but they are designed to use the propane and are designed with being on the highway in mind, the same with propane powered cars and trucks, those tanks are designed to shut off in a wreck, I just would hate to see a post on here about your car exploding while driving down the road, I've been certified in refrigeration since 1992, I don't use it actively anymore, but I have heard many horror stories about explosions and fires. I think the idea might work, but the systems simply aren't designed to safely use it. even a small leak in your condenser behind the dash could blow it apart, releasing propane into the car and resulting in a huge fireball.

[gp02a0083]

its not that the car will become a rolling bomb, hell pinto's were good for that. Anyway the main issue here is overall safety with a viable alternative. I would worry more about a small leak and possibly causing a fire of any type in the engine bay.

as far as the refrigerant goes, they are totally different in physical properties. I am sure the phase transitions are similar to an extent. The system was designed for use with freon and it should be disposed of properly. If you are concerned from an environmental standpoint, CO2 refrigerants are being researched more often these days and are much safer

[lostforawhile]

its not that the car will become a rolling bomb, hell pinto's were good for that. Anyway the main issue here is overall safety with a viable alternative. I would worry more about a small leak and possibly causing a fire of any type in the engine bay.

as far as the refrigerant goes, they are totally different in physical properties. I am sure the phase transitions are similar to an extent. The system was designed for use with freon and it should be disposed of properly. If you are concerned from an environmental standpoint, CO2 refrigerants are being researched more often these days and are much safer

a small leak in the evaporator,which is the most common leak point, and the evaporator box filling up with propane with it's electrical switches and the blower, can very quickly become a disaster, if someone wants to do this,it's up to them, but I'm going to say my piece, the last thing I want to ever hear is someone died on here from bad advice. This is one of those instances where doing something you read on the net can be deadly.

[lostforawhile]

Did you guys yield any precautions to abbreviate the bulk of damp from the bbq propane? I amount its negligable and the dryer can apparently handle it, but I've apprehend of afraid the propane in the benumbr for a few hours to benumb the baptize (acutely a abate can, 1lb or so). Any abridgement of damp will alone advice achievement, admitting.

spammer reported, apparently he's been inhaling some propane

[Pnem3]

I think it is someone who doesn't speak English as a first language and is using some sort of translation program.

To answer the question, I've used the grill propane in the past and have never had a problem with the system freezing due to water in the system. I don't think the gas is wet enough or else on the times I have used it I haven't been affected. I prefer torch propane to the gas stuff because it should be all propane and not a mixture of something else and it should be higher quality.

Edit: on second thought, it's probably someone trying to get their links out there, borderline spamer.

[lostforawhile]

I think it is someone who doesn't speak English as a first language and is using some sort of translation program.

To answer the question, I've used the grill propane in the past and have never had a problem with the system freezing due to water in the system. I don't think the gas is wet enough or else on the times I have used it I haven't been affected. I prefer torch propane to the gas stuff because it should be all propane and not a mixture of something else and it should be higher quality.

Edit: on second thought, it's probably someone trying to get their links out there, borderline spamer.
all his posts are the same advertising links in his signature, and gibberish in his posts, bot reading the thread and trying to create a realistic post out of it