hmx

I finished the conversion of my system to R-406a or autofrost. All the stories Reid and the others have been telling is true. It's unbelievable. My A/C was never this cold before and definitely wasn't this cold when I converted it to R-134a initially. So, for anyone wanting to make the conversion, don't waste your time with the R-134a: get some autofrost and do it right the first time.

I took an infrared thermometer and shot it at the vent, where it said the temp was 17.2 °F. I don't believe that for a second, but it is definitely cold, probably around freezing temp; I'll try and get a picture of a regular thermometer after I scrounge one up.

3rd gen Will

iTrader: (8)

That's awesome! Where did you pick up the R406a?

I have found the R134a conversion to work pretty good, but colder is always better!

Does that thing shoot out ice cubes? if the temps that cold you can bring along syrups and sell slushes at the car show!

Reid Fleming

iTrader: (2)

It works great doesn't it?

The laser temperature guns for some reason don't give accurate numbers. Digital thermometers do though.

Last month, I had been throwing around the idea of putting in a parallel flow condenser with Autofrost to see what kind of "maximum cooling" situation I could get. They're advertised as being 30% more efficient than our tube and fin style condensers. But before doing that, I wanted to try out how well the stuff worked with just the stock condenser, stock fans etc.

I adjusted the low pressure cycle switch down to the 6 o'clock position on my car (aprox 18 psi which would give a min temp of 20°F before cycling off)

With 83°/53% outdoor conditions, I went for a drive. Ohhhh brother. It went down to the 27°F zone and hung around there for awhile. Turning the fan speed down, it went down to 24.7°F .......At that point, I pulled over and popped the hood. Who wants a slushy?


There are a few things wrong with running the A/C this cold:

• The hood insulation will stick to the iced up accumulator. Not a lot. Just a little black fluff that will wipe off with your finger.
• Turning around and driving home with it blowing 25° air on me, I started to shake from the cold.
• It will fog up the outside of your windshield, requiring you to either turn up the temperature or turn on the windshield wipers. This is due to the interior of the window being colder than the outdoor dew point. (this only happens in hot-humid climates)
• Bright white glowing layer of snow on the suction line running from the accumulator to the compressor.
• Why waste fuel running the compressor when it's unneeded?

I'm sure it probably could run even colder if I really wanted it to. But at 24°, I was shivering. It was rare for the outside air to get that cold during the wintertime when I lived in Canada never mind having a "windchill" blowing on me in the car in Texas in September.

I now understand why the creator of R-406a used to get kidded for creating pneumonia in Florida during the summertime back when he had the stronger version of Autofrost. That stuff would blow 25° at the stock low pressure cycle point.

Driving on the highway at 60 mph, my car would sit at 29-30° duct temps. Below 40 mph (when the radiator fans turn back on), it would go down to the obscenely low temperatures mentioned above. So it appears that the stock condenser is maxed out on it's own around 30° or so. I do have a fairly large 11" x 12" transmission cooler in front of the condenser (not touching it). Without that, it may run cooler. Who knows.....

I decided against going for the parallel flow condenser. Quite honestly, I just don't need it. I can live with 30° on the highway and as cold as I want around town. Putting the parallel condenser in would just result in faster cooling and more cycling.

I turned the low pressure cycle switch up to around 24 psi so that it would shut off the compressor around 27°F. But after a few days of that, I decided to just put it back to where I had it before. (stock 26 psi giving a low temp compressor off point of 30-31°) With the stock pressure/temperature point, the car will drip mammoth amounts of water. When I was running at 24°, not much would drip until you went to VENT or shut the car off. At that point it would literally spray water onto the ground.

One of the most common questions people ask me is doesn't the system turn into a giant ball of ice? No. Ironically the duct temperatures will drop faster from 30 to 25° than they will from 35 to 30°. Once you get it down to super cold levels, the low side pressure drops like a stone. It would sit blowing 26-27° air on me at stop lights with traffic in front of me. Yet if it was at 33° at that same stop light, it would tend to rise up to maybe 35-37°......Now that fast drop in temperature (and low side pressure) is what causes the compressor to cycle off and melt any ice. Of course if you've got it intentionally set so that it won't cycle off, well yeah the system will ice up.

I can see why it's recommended that you have antifreeze in your coolant system. The heater core would freeze. When I was running at 24°, my dashboard on the passenger side was very cold to the touch. Oh yeah, one more thing. With the stock low pressure setting, I don't get any ice or snow on the accumulator. It will be dripping wet and just a tiny teeny bit of frost on there. But no ice. No insulation fluff on the accumulator either.

Fun stuff.

3rd gen Will

iTrader: (8)

When I went to automotive air conditioning repair school, the "general" specification for system effeciency was air 30* cooler than the ambient temp's. Getting nearly 60* cooler is damn impressive!

Reid Fleming

iTrader: (2)

30° delta temps may be fine for northern climates. But in Arizona when it's 115° outside, I sure as heck don't want 85° air coming out the ducts. That 30° figure probably represents inside cabin temps. Most cars run around 80° inside during the summer with A/C running. That would mean a 50° duct temp or better.

I prefer low low LOW temperatures in order to increase the dehumidification aspect. (More important in humid areas of course)

3rd gen Will

iTrader: (8)

HAHA, yea when I was visiting my grandpa in IL a few months ago there was misty air coming coming out of the vents, it made me chuckle.

3rd gen Will

iTrader: (8)

You are probably correct on it being the cabin temp not ambien temps. I went to A/C school in 03' and have been out of the air force since 06' which was when my being a mechanic for someone else ended and I know work in the medical field so my automotive knowledge has kind of laxed on me.

84 1LE

iTrader: (9)

So where can one get this 406a stuff.I used to run freeze12, but havent recharged the system in a while.
Is there a retrofit kit available?
How much?

thegooseman

Where do you get this stuff?

I posted a little too late.

PURPLEFORMULA

iTrader: (1)

Where and is there a kit for our cars still running R-12?

tazextreme3

http://www.cooltop.net/autofrost.html

84 1LE

iTrader: (9)

So did you guys that purchased this.Buy the kit?Will the R134 adapters work or do you need to buy 406 fittings.

arrowcamaro

iTrader: (2)

Actually, the original r12 fittings will work, but by law (EPA) you're supposed to have unique fittings for each refrigerant.

84 1LE

iTrader: (9)

It seems you need to be certified to buy this crap.Is this the case?

arrowcamaro

iTrader: (2)

yes.

84 1LE

iTrader: (9)

Well ****!

arrowcamaro

iTrader: (2)

I think its $20 and a couple hours of reading. Its not a big deal.

EDIT- just looked, and its even an open book test lol

http://www.epatest.com/609/

84 1LE

iTrader: (9)

yeah, i saw that, but whats with giving them your SS# !

arrowcamaro

iTrader: (2)

How would you like them to track it? Its the Govt.

Reid Fleming

iTrader: (2)

http://refrigerantsales.net/shop/

You can buy Autofrost at the above place. Yes, you need the EPA 609 card. Price of the stuff is pretty good. Cheaper than R-12. As long as you're not leaking, the system will run for a long time. Autofrost has the same long life span as R-12 and mineral oil.

As far as retrofit kits go, there's not much to retrofit. A "kit" is an R-12 style can tap, the refrigerant, a sticker, and some unique service port caps. The unique service port caps have an R-12 connection on top. It's just that they're a different colour than the original service cap already on our cars. Personally, I would use a different R-12 can tap than the one in their kit. I use this one:

The best R-12 can tap

As far as switching from Freeze12 to Autofrost, it really depends on what oil you're running. Freeze12 says it works fine in mineral oil or POE oil. But Freeze12 also recommends switching to POE oil for best results......Since Freeze12 is 80% R-134a, I can't see it working too well in mineral oil at all.

Autofrost works great in mineral oil. In fact it's designed specifically for mineral oil. It "will" run in POE. But long life is not guaranteed. POE oil will thin out over time when combined with Autofrost......Do not run it in PAG oil or else your A/C will be dead in less than a month. As a matter of fact, don't run anything with HCFC in PAG oil or else you'll have a dead A/C system.

For you R-134a people, your best bet is to get a can of Tune Air from Cryo Chem and put it in your system. It's a 4 oz can, so shouldn't be a problem of overcharging. If you combine it with their Cryo-Seal, you'll have colder air and be great as far as stopping potential future leaks as well as current leaks. Tune Air and Cryo-Seal are compatible with Autofrost as well.

Simply adding Tune Air to an R-134a system can give you 7-9°F colder duct temps than what you currently have.

84 1LE

iTrader: (9)

Thanks for the info.

Justin89Formy

iTrader: (26)

OK. Its about 90 degrees here and high humidity. This is the first time I've tried the autofrost in my car. I have to say, the AC has never worked this good! Its not like a meat locker, but its definitely cold enough. After about 5 minutes on high I can increase the temperature and lower the fan speed to maintain the cabin temp.

Very happy, and best "modification" I've done to my car in the last couple years

Reid Fleming

iTrader: (2)

You'll probably find that it works better after a couple days of driving with the A/C on. It has to blend together. My 1st day driving, it only went down to 35°. After that, it went down to 30-31° (or wherever I wanted to cut it off at).

Regardless, stop by the grocery store and buy a temperature probe and throw it in the duct. See how it does. I prefer the digital ones. But an analog one will work too.

Bullydawg

iTrader: (7)

Gah... I need to get my car dialed in so I can put the AC back in!

I am going to be home in June with around 100* weather, with no AC AND Black leather seats...

And a side note... I just got EPA 609 certified... Boo ya! I will be ordering some Autofrost for my 5.0...

PaulSwany

The AC in my son's 89 camaro just took a dump... Of course I had to converted it to R134 a while back when he accidently vented the system. The R134 performed pretty marginally and eventually the compressor failed....

I bought a new compressor and I flushed the evaporator. I'm thinking about having the condenser boiled out and using AutoFrost. The stuff sounds amazing... Is it still available? I've found a lot of sites that offer the cooltop, but from what I've read, that's just an enhanced R134 product, not the R406a....

JimRockford

What exactly is involved in converting a car to autofrost? I still have r-12 in my car,but the a/c needs to be charged as it doesn't cool anymore.

Can autofrost be used to charge the system or does the system need to be completely refilled with autofrost?

Beater79TA

Or if you have an AC license you could just recharge with R12. I did this about a year ago and the small cans are readily available, just not cheap at $40 a can.

LarryD

The main thing is to make sure there are no leaks and that the compressor is in good shape first.

My parts are all factory original so I am nervous about something going wrong after I spend money charging it. For example, I am doing mine right now but when I tried to pull the orifice tube out of the evaporator to change it, it broke off inside... So, properly evacuated, a new evaporator on the way, new accumulator in hand (I always replace this due to the dessicant inside being used up to remove moisture), and new compressor in hand (mine was making noises). Ok, now that I am this far, new condenser on the way... The only thing left, I flushed the lines with A/C flush.. I am still nervous about my lines but they are no longer available it seems. So, new O Rings all around including the low pressure cutoff on the accumulator.

Replacing it all means I added 4 oz of mineral oil in the compressor and rotated the compressor shaft 10 turns plus 4 oz of mineral oil in the accumulator. Once started I try to put it together quickly (same day) to reduce the moisture in the system. Once together, I draw vacuum for 1 hour and charge with R406a.. The quantity must be adjusted per the documents on R406a.

I did a simple recharge once by; properly evacuating the system, changing to a new orifice tube and accumulator, changing the valves to the correct R406a schrader valves (different size and used to be available on the internet), drawing a vacuum for 1 hour and then charging with R406a.

I believe 525 viscosity mineral oil is correct for R406a. It must be mineral oil that is used because it is compatible with R12 or R406a. PAG Oil cannot be used. On a recharge it is always hard to decide if there is enough mineral oil in the system. When I changed my accumulator on the recharge, I did add 4 oz of mineral oil and it seemed to be ok.

This is not advice on how to do it, it is just a dissertation on what I did. So, educate yourself before doing this and you need certification as mentioned above to buy and install it properly. Make sure you read all the stuff about R406a. Hope this helps....

Reid Fleming

iTrader: (2)

The above is really good advice. I would also recommend using Nylog "Red" on all threads and O-rings when you put the system together. It will keep the fittings from seizing together should you need to change stuff out later. It works good for sealing. And it keeps O-rings in a forever wet state. The stuff is sort of like sperm and crazy glue rolled into one.

http://www.refrigtech.com/Product/Se...nylog_red.html

For R-134a people, use the Nylog "blue"

blackjack12982

Has anyone had problems with not replacing the hoses when using Autofrost. I had planned on doing it, and thought I had a new set, but alas, no such luck. I'm just trying to minimize my chances of having the investment go up in smoke. I'm going to see if my system will hold a vacuum, so that should answer this, but I didn't know if anyone is having any leaks.

LarryD

I had done it once before and now again last month... This time I put in dye but haven't checked them yet. I might check them this weekend to see if there are any leaks.. I couldn't find any place to buy new ones.. It looks like the biggest issue is finding the right O Rings.. I used Dark Green this time.. The Light Green apparently breakdown...

blackjack12982

I was looking today at the parts store, and saw AC "sealer", and didn't know if I wanted to put that garbage in my system in the chance that it would gum up an 20 year old compressor.

LarryD

If you are going to use R12 or R406a, don't use the leak sealer.. It is generally PAG oil based and not compatible with R12 or R406a.. I have heard that a lot of people have had trouble with it plugging up.. Just about anything you buy at most auto parts stores is for R134a... That's why it is almost impossible to get the right O Rings (deer in the headlights look when you say R12 anymore).. R12 and R406a use 525 viscosity mineral oil.. I bought some of the mineral oil on Ebay..

I originally drew a vacuum on my system and then left the gauges attached to monitor it for a few days to see if it lost vacuum (drove my other rig and left the Camaro parked while I waited).. No guarantees that you won't have a leak even if it doesn't lose vacuum but at least one level of test short of putting in the dye and pressurizing the system..

blackjack12982

That's what I wondered about, was the sealer possibly gunking up my system, or not being compatible with R406a. When I was at Advanced (for something else), the guy kept questioning why I wouldn't just go with R134a, and kept trying to push the PAG oil. I had to flatly refuse, telling him it would send my compressor to the graveyard if I used it.

I guess I'll have the system evac'd, pull a vacuum on it for a day or so to see if there's any apparent leaks, then I'll install the new drier/o-rings, and fill it. Here's hoping this turns out good like everybody else's.

LarryD

A big problem with PAG oil is that it obsorbs moisture easily and carries it into your system. If you use anything other than mineral oil, use POE.. Not as long lasting as mineral oil but will work somewhat with R406a.. I just ran out and checked my hoses for any dye and didn't see any so appears the hoses are good and the dark green ORings are working... By the way, make sure you change the orifice tube or at least check it for metal shavings.. Any metal found in it and you can expect your compressor is on its last legs...

blackjack12982

I just found out that getting all of this might not be the hardest hurdle to overcome. I was at my base's Skills Center, and they aren't able to evac my system because is still original R12. They said they didn't know of any places around here that would do it either. I'm going to make a few calls around, but it looks like I may need to buy the equipment to do it myself.

Has anyone else had this problem? The shop I was at claimed to not even be able to hook their machine to it, because they don't have the fittings anymore.

LarryD

There are still some shops that will evac an R12 because they do conversions to R134.. I just bought myself a vacuum pump for AC systems from Harbor Freight.. You can get a cheap box that hooks to your air compressor and uses venturi effect to create a vacuum draw (also available at HF) but it takes longer to draw a vacuum... I also bought a Gauge set off of EBay but make sure you get a set that is compatible with R12 and R134a (has both readings on the gauges)...

tpi88camaro

iTrader: (7)

I wasn't aware it was adjustable. How do you do this?

82tarecaro

iTrader: (4)

There is an adjustment screw under the electrical connector inside the low pressure switch.

LarryD

Correct me if I am wrong but I think it is counter-clockwise to lower it and clockwise to raise it. Recommended that you go in quarter turn increments and check it again...

Birdstheword

So, in order for R406A to work in a R134A system i need to swap the PAG oil for Mineral oil ?
will the R134 seals work with R406A ?
thanks Reid for sharing your knowledge

LarryD

Is the R134a system one that used to be R12 or is it a new system that started out using R134a? That could make a difference. I would think an old R12 converted to R134a could be converted back if you flush all the old oil out, replace it with 525 viscosity mineral oil (Ebay source), replace some parts like the orifice tube, O Rings, and accumulator. You would have to pull the compressor off, drain it, flush it and put in the right amount of mineral oil..

As to the O Rings specifically, that can be a problem.. I couldn't find Neoprene O Rings which are recommended for R406a so I went with the dark green HNBR as they were suppose to be compatible. Mine just failed so both light and dark HNBR don't work (at least based upon my personal experience). So, I will be replacing mine with Neoprene O Rings and charging again with R406a. As an FYI, I found and got my Neoprene O Rings as a kit of 200 pieces in 12 different sizes from The O Ring Store on the internet.

fasteddi

iTrader: (2)

This is what I work with all day, now that cold!!

Problematic vapor barrior cause this.. snow.

Just wanted to show you what cold looks like.

-5 through -10 degree freezer

Birdstheword

original R134a with PAG oil

82tarecaro

iTrader: (4)

I can't believe there's an o ring store.

LarryD

R406a may not work if the system was designed for R134a originally... Somebody else know about that??? And yup, an O Ring store does exist... It was the only place I could find a good set of multiple sizes of Neoprene orings...

LarryD

My end results:

Ambient Temp: 65 degrees
Vent Temp: 42 degrees
Low Side Pressure: 25 psi steady
High Side Pressure: 170 psi (fan shut off) to 240 psi (fan turns on)
Compressor runs 100% with no cycling

Birdstheword

is the R134-A machine compatible with the R406 stuff ? OR is it just a hose from R406 container to service port ? i want to do this to two cars . one being my firebird (witch will be getting a brand new AC compressor , so no PAG oil or other stuff ) and two being my 2004 Audi A4 that runs on R134-A and PAG oil .

LarryD

If the cars are originally set up for R134a, the only thing I know for sure is that the o-rings are not compatible and would have to be changed to neoprene (that probably includes the schrader valves as well) and you would have to flush the system completely to get all of the PAG oil out (that would mean putting in a new accumulator since you can't really flush it). As to the size of the orifice tube, I just don't know. When I replaced my evaporator and condenser, they both said they were compatible with R12 and R134a (since R12, then compatible with R406a) so maybe the stock ones would be.

Maybe someone else on here has converted R134a system to R406a that can help.

mikebondi

hey guys.

im not surprised this stuff cools real well. but keep in mind it is a HIGHLY FLAMABLE option. its a mix of r600 which is butane hcfc-22 (r22) and r142b
using this stuff is similar to just charging the lines with propane.

not the safest way to go for a vehicle where the lines are exposed in an accident

didnt see this covered in the thread figured i would put it out there.