Increasing A/C Performance

[steppinthrax]

Assuming your car's AC is functioning properly and is running a proper charge etc... What are some "MODS" you could do to make it blow colder? I have a 1999 Camry. I notice during really hot days, esp once I step in the car after it's been in the parking lot the whole day. The A/C takes a few moments to get colder. I know it's running a proper charge and the condenser coil is clean. I was thinking of a few things.

1. Flushing and evacuating the system, replacing the TXV or office. Recharge with new clean oil and new refrigerant. (I have an assumption that over time the oil and refrigerant starts to break down and possibly even mixes with outside air).

2. Do number 1 but use a refrigerant additive as well.

3. Using alternative refrigerants (R-410a, R-22), might have to change the compressor.

4. Change the pulley size on the compressor to something smaller so it will spin faster (maybe with combination of mod 3)

5. I saw DIYs of people insulating the low pressure (suction) line of the A/C, one guy with a Subaru said he got a 4 degree drop.

6. Installing a switch that once pressed or flipped causes the compressor clutch to always stay engaged, effectively making the a/c run colder (just for those days), however that would turn the evaporator coil into a block of ice.

 

[LTC8K6]

Remote start.

 

[phucheneh]

7. None of those. They're all varying degrees of silly, with some I'd have to label outright retarded. Like trying to 'hotwire' the AC compressor to ignore the pressure switches.

Put some manifold gauges on it and see what's going on. There's no point in just doing any of those random things.

The weakest point is probably the cooling fans...they're quite underwhelming on those cars. Do you notice that the AC seems colder when you're moving?

 

[Zenmervolt]

1) Your assumption is ludicrously wrong. An A/C system is hermetically sealed and refrigerant and oil will NEVER mix with outside air (in a functioning system), nor do the refrigerant or oil break down.

2) Won't work for the same reasons as above.

3) Not worth the trouble and potential illegality. Also, R-22 will leak straight through automotive A/C hoses. R-22 requires barrier hoses that R-134a and R12 did not, so you'd need to replace almost all the lines, plus the receiver/drier to do this. Even then you would not have any change in performance.

4) The A/C pulley includes the compressor clutch. You're not going to find a smaller pulley for it because it's generally an integral part of the compressor. Simply not a viable option.

5) Insulating the cold side of the system can help, but not with what you describe. When a car has been sitting in the sun for a long time, there's a lot of thermal mass to cool down. The issue you're seeing isn't from the A/C not doing well, it's simply because the vents are full of hot air when you start and the dash itself is quire warm.

6) NO. Just plain no. The compressor cycles because of a SAFETY switch to prevent the system from reaching excessive high side pressures. Doing something like this would run a very real risk of blowing something up. Besides, it wouldn't help the system cool down the car any faster because it generally never comes into play, and even when it does on very hot days it doesn't start until a few minutes after you've first turned on the A/C because you don't see problematic pressures until the condenser has heated up.

In short, none of your ideas will work, some are simply foolish while others are downright dangerous.

If you really want to improve the system's performance, get a larger condenser and find a way to fit that to your car. That's the simplest way to get better performance, but, again, this won't help the initial cool-down issue you're talking about.

ZV

 

[T2urtle]

U want better a/c get a higher end car with like dual evapators and etc.

I don't have a high end car but my a/c works gets colder and stays colder than my friends 2013 civic. I own a 2005 g35, no mods done. I drive around on fan speeds on low all day.

Try a vw phateon. Its an ice box in there.


Seriously tho how about window tinting. Keeps a little heat out and a little inside. It MIGHT help.

 

[Bartman39]

Seriously tho how about window tinting. Keeps a little heat out and a little inside. It MIGHT help

This and get a sun shade for the front windshield it really helps as your dash gets very hot including the AC vents, they have to cool off first before you get true cold air... Hot plastic vents work just like a heater core till cooled off...

 

[Raizinman]

Modern refrigerants are just not as effective as the old R12 or others. I converted my 2005 Chrysler to propane and am getting great cooling as good if not better than R12. If interested, do a search on the Internet. Its worth looking at. It costs less. You use about 25% less refrigerant and it cools better.

 

[steppinthrax]

Modern refrigerants are just not as effective as the old R12 or others. I converted my 2005 Chrysler to propane and am getting great cooling as good if not better than R12. If interested, do a search on the Internet. Its worth looking at. It costs less. You use about 25% less refrigerant and it cools better.

This is the 2nd time I've heard about this. I'm a little dubious on doing it. So what was the process? Did you have to change out any of the oils? How did you find your final charges?

 

[slag]

Modern refrigerants are just not as effective as the old R12 or others. I converted my 2005 Chrysler to propane and am getting great cooling as good if not better than R12. If interested, do a search on the Internet. Its worth looking at. It costs less. You use about 25% less refrigerant and it cools better.

And in the event of a front end collision, the propane will explode and most assuredly total the vehicle.

Great idea.

:whiste:

http://forums.anandtech.com/showthread.php?t=164250

 

[Raizinman]

This is the 2nd time I've heard about this. I'm a little dubious on doing it. So what was the process? Did you have to change out any of the oils? How did you find your final charges?

I vacuumed out the system, added about 75% of the OEM charge of Propane and it has been great since. Another advantage of Propane is that the pressures are lower and propane is a 'thicker' gas, meaning it won't leak out as quick as other refrigerants. There is lots on the internet about this. I suggest that you look around and research it instead of believing wild myths about collisions causing your car to explode. You'll also a OEM truck manufacturer using propane as OEM in their new trucks in Australia.

 

[Raizinman]

And in the event of a front end collision, the propane will explode and most assuredly total the vehicle.

Great idea.

:whiste:

http://forums.anandtech.com/showthread.php?t=164250

You left out the world will end too. Keep in mind many of the current refrigerants are extremely dangerous when mixed with flames, some even flammable. But you don't see anybody getting hurt.

Sorry, it just doesn't happen. Take your propane torch and direct propane anywhere in the engine compartment (without lighting the torch). It won't light. The 1.8 lbs of propane in your HVAC system is no more dangerous that gasoline at 60 PSI in your fuel injection system. Even with that, you don't see cars exploding left and right. I'll bet you had this same argument when they started putting natural gas inside homes for heating. Houses will explode and the world will end. Hmmmm.......

 

[drnickriviera]

Install a water misting system to the condensor

 

[drnickriviera]

You left out the world will end too. Keep in mind many of the current refrigerants are extremely dangerous when mixed with flames, some even flammable. But you don't see anybody getting hurt.

Sorry, it just doesn't happen. Take your propane torch and direct propane anywhere in the engine compartment (without lighting the torch). It won't light. The 1.8 lbs of propane in your HVAC system is no more dangerous that gasoline at 60 PSI in your fuel injection system. Even with that, you don't see cars exploding left and right. I'll bet you had this same argument when they started putting natural gas inside homes for heating. Houses will explode and the world will end. Hmmmm.......

No way man. when all these vehicles running CNG and LPG get in accidents, they have to rebuild the road. The crater they make when they explode is that big!

On a serious note, I wonder how strong CNG tanks are? I know the metal ones are stupid strong, but what about the carbon fiber/ fiberglass ones? Very strong, but they are brittle.

 

[slag]

No way man. when all these vehicles running CNG and LPG get in accidents, they have to rebuild the road. The crater they make when they explode is that big!

On a serious note, I wonder how strong CNG tanks are? I know the metal ones are stupid strong, but what about the carbon fiber/ fiberglass ones? Very strong, but they are brittle.

Laugh about it all you want, but the threat is real and propane is not run straight 100%, its mixed with other highly flammable gases. Its no wonder many states outlaw using propane as a refrigerant replacement.. But then again, you guys already knew that and definitely know more than everyone else..:whiste::whiste:

 

[slag]

You left out the world will end too. Keep in mind many of the current refrigerants are extremely dangerous when mixed with flames, some even flammable. But you don't see anybody getting hurt.

Sorry, it just doesn't happen. Take your propane torch and direct propane anywhere in the engine compartment (without lighting the torch). It won't light. The 1.8 lbs of propane in your HVAC system is no more dangerous that gasoline at 60 PSI in your fuel injection system. Even with that, you don't see cars exploding left and right. I'll bet you had this same argument when they started putting natural gas inside homes for heating. Houses will explode and the world will end. Hmmmm.......

See my other post right above this one. Glad we have an expert on this forum to negate research and common sense. WHEW!

 

[LTC8K6]

Laugh about it all you want, but the threat is real and propane is not run straight 100%, its mixed with other highly flammable gases. Its no wonder many states outlaw using propane as a refrigerant replacement.. But then again, you guys already knew that and definitely know more than everyone else..:whiste::whiste:

IIRC, RV refrigerators use propane. As do many other things like vending machines.

There have to be millions of them out there.

http://www.lindeus.com/internet.lg....e R290 Refrigerant Grade Propane138_11493.pdf

 

[Raizinman]

Laugh about it all you want, but the threat is real and propane is not run straight 100%, its mixed with other highly flammable gases. Its no wonder many states outlaw using propane as a refrigerant replacement.. But then again, you guys already knew that and definitely know more than everyone else..:whiste::whiste:

I wonder if the states will also ban R1234 which is in about every new car. Yep, its flammable.

 

[steppinthrax]

Laugh about it all you want, but the threat is real and propane is not run straight 100%, its mixed with other highly flammable gases. Its no wonder many states outlaw using propane as a refrigerant replacement.. But then again, you guys already knew that and definitely know more than everyone else..:whiste::whiste:

I was reading that the refrigerant form of propane is r-12a, it comes in a cylinder specifically designed for HVAC techs to charge a system. It is a pure form and is not mixed with other gasses like BBQ propane. Also from my research the quantity of R-12a in a system is so small even if it were to all leak out at the same time and ignite, the worse you would get is a flash flame. Almost like a really intense flame all over the place that would quickly dissapear.

 

[LTC8K6]

I was reading that the refrigerant form of propane is r-12a, it comes in a cylinder specifically designed for HVAC techs to charge a system. It is a pure form and is not mixed with other gasses like BBQ propane. Also from my research the quantity of R-12a in a system is so small even if it were to all leak out at the same time and ignite, the worse you would get is a flash flame. Almost like a really intense flame all over the place that would quickly dissapear.

Propane is R-290

R-12a is a blend.

http://en.wikipedia.org/wiki/HC-12a

 

[phucheneh]

R12 is not propane. R12 is not flammable. R134 is not flammable.

I believe R22 is flammable, but I'm not sure under what kind of conditions. Assuming a general label of 'yes, it burns,' you can take that in one of two ways: flammability is not of great concern, as R22 is/was used as a household refrigerant, among other applications. Or you could say, hey, I bet I know why they came up with R12 instead of putting R22 in cars; someone thought flammability was a real concern.

Also of note, R12 and/or R22 (I know they're pretty similar, but I'm not a chemist) can produce phosgene gas. Now THAT is bad shit. I remember reading about how they used to leak test with a torch by looking for a green flame. People subsequently inhaled nerve gas. Now, this isn't saying that the gas is flammable; the fuel for the torch is what was maintaining the flame. With just refrigerant plus spark, there would have been no ignition. The color change was due to a chemical reaction, that, AFAIK, was not actually combustion (again, not a chemist).

Thinking about leak testing brings up a relevant point, though. For the same reason that a can of propane with a torch end on it does not explode, your A/C system would not magically combust. Pressurized gas stored in a container, without an oxidizer, will not do anything. The gas has to come out and mix with oxygen. So under normal 'leak' circumstances, propane refrigerant would not explode. But it could certainly cause a sustained flame.

To the comment about the amount of refrigerant being 'so small,' though...uh, go get a propane torch with a standard cylinder, and see how long the flame lasts. Prepare to get very bored while you wait. A pound (IIRC the size of 'camp stove' cylinders; not sure how much the skinnier ones hold) of propane goes a long way. I would mostly worry about a worst case scenario where a leak is ignited, manages to sustain a flame, and then causes something else to be lit. Like fuel vapors.

There's also the rapid release thing. First thing that comes to mind- I've seen driers rust from the inside out, and blow out the bottom when someone tries to charge the system. If the system gets close to fully charged before it happens, it is most certainly NOT an unsubstantial release. It will clear out an entire shop.

edit: and I am neither 'playing both sides' nor am I taking one. I'm simply sharing what I am pretty certain is good info (correct it if needed; just be damn sure of it) and someone considering an 'alternative' refrigerant can make up their own mind. My thoughts about what COULD happen with propane are 100% hypothetical, and I'm just comparing it to the many, many releases of R134 that I've seen.

 

[drnickriviera]

Laugh about it all you want, but the threat is real and propane is not run straight 100%, its mixed with other highly flammable gases. Its no wonder many states outlaw using propane as a refrigerant replacement.. But then again, you guys already knew that and definitely know more than everyone else..:whiste::whiste:

no just laughing at your ridiculous statement that the car will blow up. Can you point me to anything running a propane refrigerant blowing up? I don't think anyone doubts that there is a fire risk with propane.

Question is, will you buy a new vehicle that uses HFO-1234yf?

http://blog.caranddriver.com/daimle...loped-refrigerant-flammable-gm-continues-use/

 

[SparkyJJO]

You left out the world will end too. Keep in mind many of the current refrigerants are extremely dangerous when mixed with flames, some even flammable. But you don't see anybody getting hurt.

Sorry, it just doesn't happen. Take your propane torch and direct propane anywhere in the engine compartment (without lighting the torch). It won't light. The 1.8 lbs of propane in your HVAC system is no more dangerous that gasoline at 60 PSI in your fuel injection system. Even with that, you don't see cars exploding left and right. I'll bet you had this same argument when they started putting natural gas inside homes for heating. Houses will explode and the world will end. Hmmmm.......

You do realize that propane at 1 atmosphere is a very explosive gas, while gasoline at 1 atmosphere is a liquid, and gasoline as a liquid does not explode? Gasoline in a tank does not explode in a huge fireball like in the movies.

Propane is far more dangerous and explosive than gasoline.

Natural gas does occasionally blow up a house too, if there is a leak long enough to create a concentration of it and there is an ignition source. But, unlike cars, houses are not subjected to collisions like cars are. Well, aside from RVs

 

[phucheneh]

Thinking of a drier shitting itself and unleashing a rolling fog of propane that spreads through most of a shop is fucking scary to me. If I happened to be in the next bay using a welder, torch, grinder, ect...that would be a hell of a day.

 

[Raizinman]

The propane that is regularly used for barbecues, and general consumer or commercial use is a byproduct or derivative of the hydrocarbon manufacturing process (the production and refining of raw oil products). In order to utilize propane as "refrigerant grade" the product is further refined to render out methane gases and other impurities. The Auto ignition for regular grade propane is ~842 F., while the DURACOOL® products auto ignition is ~1635 F. There is nothing under the hood of your vehicle that gets this hot. You might be interested to know that R134a ignites at 1328 F. You must also keep in mind that charging your system with Duracool, because of its nature, you only need about 40% of the normal charge. So if your system held 1.5 pounds of R134a, you would only need approximately 0.60 pound charge of Duracool. For this you get colder temperature and a more efficient air conditioner.

Virtually all modern cars have exhaust shields covering the exhaust manifold. With the circulation of air under the hood, the exhaust shields dissipate heat quickly and don't get anywhere near even 400 degrees. Likewise, engine designers don't place Air conditioner hoses close to exhaust manifolds or even the exhaust shields. If an A/C hose with propane did burst it would be dissipated with the engine air and nothing would happen. That is part of the reason there has never been an engine fire from using propane. Again, the proof is in the torch. Take an unlit propane torch and turn on the gas and hold it next to your exhaust manifold. It won’t ignite. Heck, if you have used a propane torch much, you know the difficulty of lighting it with a strong spark right in front of it. Often, even with a lit match igniting the propane is difficult. Try it, I did. No need to guess or make assumptions.

Also remember the further the distance the propane must travel to a heat source, it is being dissipated with air lowering the level of the propane to air mixture. The lower and upper limits of flammability are the percentages of propane that must be present in an propane/air mixture. This means that between 2.15 and 9.6% of the total propane/air mixture must be propane in order for it to be combustible. If the mixture is 2% propane and 98% air, there will not be combustion. The more air that mixes with propane the more difficult for combustion.



The bottom line is:

1) There has not been one attributable fire caused by using propane for a vehicle refrigerant.
2) Duracool (Propane) is non-global warming
3) Duracool is non-ozone depleting
4) Duracool is more efficient than R134a
5) Duracool has lower head pressures than R134a (similar to R12). R134a will often get to 300 psi pressure, whereas Duracool will rarely get to 150 psi.
6) Millions of vehicles have been converted to hydrocarbon refrigerants worldwide.
7) Duracool cools much better than R134a, and marginally better than R12.
8) Duracool is up to 35% more efficient than R134a and only marginally better than R12.
9) Duracool will make your A/C system last longer because it is non-corrosive. R134a breaks down into highly corrosive components.
10) Easy installation with simple high/low screw on fittings.
11) Compatible with mineral and synthetic oils, including PAG and Ester. No oil change is required.
12) No special tools required, you can use your R134 or R12 gauges and tools.
13) Requires only 40% of charge by weight for R134a usage and 35% of charge by weight for R12 systems.
14) Auto ignition of ~1635°F which is a higher auto ignition of R134a which is 1328°F
15) Totally non-toxic – 100% natural organic product.
16) It has been predicted by a risk assessor that, considering if all the cars in the US converted to Duracool (some 50 or 60 million vehicles) that one accident might occur every 50 years, and this accident would theoretically create a “flash” which would last 1 to 1.5 seconds.
17) Does Duracool Guarantee or Warrantee this product? Yes, with a written guarantee that Duracool will perform as efficient and will not harm any air conditioning part. Duracool does have good standing with the BBB with no complaints filed.
18) R134a is being phased out being replaced with R1234. The price of R134a will likely rise (like what happened with R12). Currently Duracool is about ½ the price of R134a. If R134a follows the same pattern like R12, the DYI cans of R134a will be first to be gone.

So there you have it. Some pro’s and con’s of using propane (Duracool) in your air conditioning system. I’m not advocating that everyone should remove their R134a and put in Duracool. Some people live in cool climates and some in hot. It also depends on the person. Some people need quick and colder A/C and some don’t mind waiting a bit longer and having warmer vent temperatures. Personally, having grown up with R12, I loved switching on the A/C and having virtually instant ice cold air. I also remember being able to see my breath mist when blowing into the vent duct due to the ice cold air. Those don’t have to be memories any longer. I converted my 2005 Chrysler Town & Country to Duracool about 3 years ago and really love it. It use to take 5 or 8 minutes for the van to cool down, but by then you are already sweating. Duracool has ice cold air blowing after about 30 seconds and the van cools down comfortable in 2 to 3 minutes or less. A can of Duracool costs $8.99 and you might need two cans to charge your A/C.

Reading this thread should give you enough information on whether to convert or not to a hydrocarbon based refrigerant.

Why doesn’t an OEM vehicle manufacturer use a hydrocarbon refrigerant?

Australian OKA trucks come factory equipped with HyChills Hydrocarbon (propane) Refrigerant as standard factory OEM equipment. Actually this has been happening for the last 5 years (without problems). Likewise, an entire line of European-Australian built AVIA trucks, distributed by Reymer Pty Ltd. the parent company of OKA Australia also benefits from HyChill factory OEM propane refrigerant.

Just do a Google search for OKA Propane refrigerant.

 

[Bartman39]

IIRC, RV refrigerators use propane. As do many other things like vending machines.

There have to be millions of them out there.

Uh no RV refrigerators do not use propane to cool they use ammonia that is heated to circulate by either propane or electric heating coil...

Also have to agree with phucheneh about the dangers of using hydrocarbon refrigerant in auto's or equipment... I sure do not want to work around that kind of stuff in my shop... If a 134a system is setup properly it will perform quite well and if its not working correctly then something is wrong from to small of a condenser to the wrong orifice tube or improper charge so fix the problem do not put a crutch on it and have issues that can be dangerous (like in your garage)...