AC refrigerant advice

[salvageV6]

I get between 45 and 48 degrees out of the vents middle fan position after about 5 minutes of cooldown on a 92 degree day in salvageV6 with the R134a.

Using my EGT meter second thermocouple wrapped around the plastic fins at the outlet of the center vent.

My GN is colder with the R12 but the 134a is definately livable.

Plus it's more fun to drive salvageV6.

Slow leak over the winter with the 134a too, just tune it up with a couple of cans and the gauges and she's good to go until the winter.

 

[Wicked]

Originally posted by 49-blues
Wicked-call any manurfacturer of 134a and they will tell you 134a is 10% less effecient than r-12. At work we converted a 1000 ton ac chiller originally r-12 to 134a, after the change in refrigerant the machine now only will do 900 tons of refrigeration.FYI

Just going by my expience and what I was taught.

 

[Chris Cornett]

I guess every car is different. I am just not impressed with the 134a even in new cars. My parents Trailblazer has the worst AC I have ever seen in a new car. Although, my Impala SS AC is like a meat locker. I think I might give the Freeze12 a try.

 

[Evans Ward]

Freeze 12

Would anyone be willing to help me and answer some questions I have on a R-12 to Freeze 12 conversion for my 70 GS455? I have the Freeze 12 conversion kit but have several questions that the directions didn't cover very well. PM me or reply here and we could PM off list. Thanks!

 

[Louie L.]

Ok now im confused ...is R 12a the same as freeze 12?

Also what is this more efficient condensor everyone speaks of?
My buddy who does lots of side AC side work and is familiar ith G bodys couldnt find such a condensor.

 

[peterkin]

yes R12a is pretty much the same as freeze 12, or a replacement if you will. i recently did it in my car, well i added a can to whatever R12 was left in my system because i was lazy. the pipes instantly frosted up and now i just about freeze to death in the car.

 

[HouseofSpeed]

Just swapped compressors / accumulator / orifice tube and did a 134 conversion last week on my GN.

For the record...Houston is friggin' miserable right now in terms of temps and humidity.

48 degrees on high fan at the center vent after about a 5 minute cool down.

Lower fan settings will also drop the reading at the thermometer.

It also takes less 134 to charge the Regal system....3Lbs 4Ozs of R12 and about 2Lbs 8Ozs of 134.

Real R12 is about 70 bucks a pound here in the big city.

 

[granatl]

Originally posted by Louie L.
Also what is this more efficient condensor everyone speaks of?
My buddy who does lots of side AC side work and is familiar ith G bodys couldnt find such a condensor.

It's a parallel flow condensor. I bought one, but my car isn't on the road quite yet, so I can't give you personal experience. There's a guy from Georgia on this board that sells them. (Search the tech area for high efficiency condensor). I think in the post he mentions a % for how much better it is supposed to be than stock.
Downfalls are the plumbing required to get it to fit.

I want to add that it's important to remember that A/C is a heat exchanger. So if you have 2 giant fans pulling the heat off the condensor, you'll have colder air inside the car.

Also, I've done the R134a conversion in the SW desert. NEVER again.

 

[chevyII]

ac guru

the difference between r12 and 134 is the pressure is higher for the 134 compared to r12. pressure for r12 is a direct ratio to temperature. 32psi 32degrees. the 134 has higher stagnant pressure,ie not as efficent. to make 134 cool as well as r12 lower the pressure. 3 ways- bigger condenser,lower the cycling switch on off points,switch is on the accumulator sloted screw under plug,or if the car takes 3lbs use 2.5. one other point i would like to clear up when134 hit the market in about 90 I think,the manufactures wanted to replace parts like the compressor,accumulator,and all the oil. You do not need to replace anything including the oil. we even went as far as mixing r12 and 134 worrked just fine on my suburban and the shop owners olds. the key is to vaccum the system for at least 45 to an hour this boils any moisture,air has moisture in it. water boils very easy in a vaccum. always add oil to the system when charging the oil suspends in the freon,loose the freon you lost some oil. A/C is very very simple. one problem is most gn are black,ever been in a black limo with good A/C?

 

[norbs]

STAY away from Duracool and r-12a they contain propellents that are flammable. Not sure how they can sell them to the general public. read below:


Another class of alternative refrigerants has also appeared on the scene: illegal refrigerants. Some products that have been introduced (OZ-12, HC-12a, R-176 and R-405a) do not meet the EPA’s criteria for environmental acceptability or safety. Flammable refrigerants such as OZ-12 and HC-12a that contain large quantities of hydrocarbons (propane, butane, isobutane, etc.) have been declared illegal for use in mobile A/C applications, but are still turning up in vehicle systems anyway because of their cheap price.

Flammable refrigerants pose a significant danger to a vehicle’s occupants should a leak occur. A spark from a cigarette or a switch can ignite the leaking refrigerant causing an explosion and turning the vehicle’s interior into an inferno. It only takes about four ounces of a flammable hydrocarbon refrigerant such as propane or butane to create an explosive mixture inside a typical automobile passenger compartment.

Frontal collisions can also release the refrigerant if the condenser is damaged, which could result in a severe underhood fire causing extensive damage to the vehicle.

 

[norbs]

Here's some more info i found.



Alternative refrigerants that have been found acceptable for automotive applications or are currently being reviewed by the EPA include the following blends:

Free Zone (RB-276). Supplied by Refrigerant Gases, this blend contains 79% R-134a, 19% HCFC-142b and 2% lubricant.
Freeze 12. Supplied by Technical Chemical, this blend contains 80% R-134a and 20% HCFC-142b.
FRIGC (FR-12). Made by Intermagnetics General and marketed by Pennzoil, this blend contains 59% R-134a, 39% HCFC-124 and 2% butane.
GHG-X4 (Autofrost & McCool Chill-It). This blend is supplied by Peoples Welding Supply and contains 51% R-22, 28.5% HCFC-124, 16.5% HCFC-142b and 4% isobutane (R-600a).
GHG-HP. Also supplied by Peoples Welding Supply, this blend contains 65% R-22, 31% HCFC-142b and 4% isobutane (R-600a).
Hot Shot\Kar Kool. Supplied by ICOR, this blend contains 50% R-22, 39% HCFC-124, 9.5% HCFC-142b and 1.5% isobutane (R-600a).
The suppliers of the alternative blends say their products typically cool better than straight R-134a in systems designed for R-12, and do not require changing the compressor oil or desiccant in some cases. Changing the desiccant to XH-7 is usually recommended if an R-12 system is converted to R-134a. The desiccant should also be replaced if a blend contains R-22 because R-22 is not compatible with XH-5 or XH-7 desiccant. The recommended desiccant in this case would be XH-9.

 

[49-blues]

Wicked- someone taught you wrong.

 

[ijames]

Norbs, your second post may have come from the EPA web site (the one that lists approved replacements for R12 for auto use), but your first had to have come from some company or industry group. If you read the EPA site, they say that flammability in and of itself is not an automatic bar to SNAP approval for auto use, and the ones that are flammable such as R12a, Duracool 12, and OZ-12, have not been tested and found wanting, they have never been submitted for testing in the first place. It may seem a pedantic semantic point, but they have not been declared illegal, they have not been approved.

 

[petesgn]

Originally posted by granatl
It's a parallel flow condensor. I bought one, but my car isn't on the road quite yet, so I can't give you personal experience. There's a guy from Georgia on this board that sells them. (Search the tech area for high efficiency condensor). I think in the post he mentions a % for how much better it is supposed to be than stock.
Downfalls are the plumbing required to get it to fit.

I want to add that it's important to remember that A/C is a heat exchanger. So if you have 2 giant fans pulling the heat off the condensor, you'll have colder air inside the car.

Also, I've done the R134a conversion in the SW desert. NEVER again.

What size parallel flow condensor did you get ?

 

[Lhorn]

FWIW,
ACkits.com sells parallel flow condensors that they say are 1/3 more efficient than the old condensor. Prices seem pretty good. Depends on size but seems most are around 70 bucks or so. My only concern would be how much fabrication would be required to install this thing. Might be just what the doctor ordered though. That plus a RC dual fan kit and you might be able to make some money renting out your back seat as a meat locker.

 

[granatl]

Originally posted by petesgn
What size parallel flow condensor did you get ?

I don't know the dimensions, since the car is at a buddy's house getting the engine put in. It's really big (LxW). The input/output nipples are almost right against the core support; that's going to make plumbing even trickier. If you've noticed my signature, you can tell from the A/C cooler intracooler why I'm going all out for A/C this time around.

 

[ijames]

Oops, forgot to add that R12a is not the same as Freeze-12. R12a is a mix of propane and butanes and is not EPA approved (I'm sure it cools well and works well with the mineral oil in a R12 system, but those pesky legal liabilities if anything ever happened ... ). Also, it is a brand name, unlike R12, R134a, etc, which are part of a standardized naming system for all HCFC's. Freeze-12 is a mix of R134a and R141b and is EPA approved but I was told by a parts guy that FourSeasons and the other compressor manufacturers that they sell will not warranty it but he couldn't tell me why. Personally I think it must do a poor job of oil return with mineral oil but I have no testing to back that up.

 

[petesgn]

Originally posted by granatl
I don't know the dimensions, since the car is at a buddy's house getting the engine put in. It's really big (LxW). The input/output nipples are almost right against the core support; that's going to make plumbing even trickier. If you've noticed my signature, you can tell from the A/C cooler intracooler why I'm going all out for A/C this time around.

If you find outthe size let me know .

Thanks

 

[1970gsx]

STAY away from Duracool and r-12a they contain propellents that are flammable.

So is that 18 gallons of gasoline in back of the car.
www.freeze12.com

 

[87GN_70GS]

Looking through the Modine catalog for condensors, looks like the stock one (1K200035) has a 26-3/4" x 16-1/8" x 1-1/4" core with 3/4-16 UNF-2A and 5/8-18 UNF-2A fittings. Scanning the catalog for larger cores I come up with:
1K200038: 28-1/2" x 16" x 1-7/16" core with 3/4-16 male tube-o and 5/8-18 male tube-o fittings.
1K200066: 28-3/4" x 16" x 1-7/16" core with 3/4-16 male tube-o and 5/8-18 male tube-o fittings.
1K200026: 30" x 16" x 1-7/16" with 3/4-16 male tube-o and 5/8-18 male tube-o fittings.

Fittings are in the same general location and orientation as stock. Cores are bigger but I'm not sure about the fitting compatability, maybe there's an adaptor?