View Full Version : A/C and intake question
Vandal21
12-02-2006, 08:12 AM
I was thinking about 'testing' this idea and seeing if it would work, but just thought I would ask before I went down this path. I searched the forum and didnt see any one else post this idea.
When you turn on your A/C unit it takes somewhere between 10-15HP from the motor to turn the compressor. This is a reason why a lot of people just pull their A/C units out, it lightens the vehicle and dont have to worry about that power loss. What I want to do is run a line from the Evaporator Low Pressure/Low Temp Vapor line into my Intake. My plan is to counter act the HP loss (and hopefully see some gain) while continuing to stay cool in my vehicle. It wouldnt require much work and may just be worth it. Any thoughts or opinions on this? Also, I'm open to be hazed since this is my first post.
sittinsideways
12-02-2006, 10:16 AM
do u know if the a/c vacume is needed for the car to run? my ac doesnt work anyways so.
Vandal21
12-02-2006, 01:06 PM
a/c vacuum should not be required for the car to run, but is obviously required for the a/c system to work.
projectRDM
12-02-2006, 04:24 PM
The compressor does not pull that much power, it's *maybe* 5HP.
The A/C system is sealed for a reason, introducing the intake charge into it would blow all kinds of shit from the crankcase breather, carbon canister, fuel vapor purge line, and PCV into the A/C and trash the compressor, condensor, and evaporator, not to mention you'd intake a good amount of oil from the compressor and burn it in the engine. Plus, unless you plumbed it in before the MAF, you'd be doing nothing but leaning out the engine heavily as there'd be a large amount of unmetered air entering the engine.
In other words, that's one of the dumbest fucking ideas yet.
Vandal21
12-02-2006, 05:10 PM
How would you blow anything? Do you even know how A/C systems work? The only thing that would happen from adding another line from your low side low vapor evaporator would do is add more area, which in turn would add lower pressure. The whole oil thing is a complete falacy, since if you have oil in your system by the time it is leaving the evaporator and going back to the compressor your system is already fucked anyways. And unmonitored air flow? All I'm talking about is cooling the air that is already being pulled in with your refrigeration system. Kinda similar to spraying your intercooler. Your the fuckin reason why so many sites have bad information. You dont fully know how things work and pretend you do. Do some research on refrigeration systems before you start posting stupid fucking answers. Also, the average pull for an A/C compressor is about 10hp, at least on high, although 5hp is more reasonable, so I'll give you that. Do your fuckin research! I dont have a problem if its a dumb idea but I have a problem with ignorant dicks that dont know what they're talking about, at least in this instance. You might be knowledgable in some areas R240NA but obviously not this one.
cmcdougle
12-02-2006, 10:41 PM
Ok, neither of you know what you're talking about. First of all, there is a refridgerant that runs through the air pump. It condenses the R12, giving off heat. The R12 runs through the condenser, cooling it. It then runs through the AC box, which expands it, absorbing heat, then runs it through the heat exchanger. Air blows through the heat exchanger, cooling the air and heating the R12, and then runs back to the air pump.
What exactly do you want to do by running it through the intake? All that would do is spill R12 into the atmosphere and kill your lungs and your engine.
Vandal21
12-03-2006, 07:05 AM
Ok, neither of you know what you're talking about. First of all, there is a refridgerant that runs through the air pump. It condenses the R12, giving off heat. The R12 runs through the condenser, cooling it. It then runs through the AC box, which expands it, absorbing heat, then runs it through the heat exchanger. Air blows through the heat exchanger, cooling the air and heating the R12, and then runs back to the air pump.
lets go on a lesson in A/C systems, heres what I know to be certain: the condensor doesnt necesarilly cool the r12, all it does is change the latent heat of the refrigerant, so it takes the form of a liquid. It can still be the same temperature but in another form (remember your 3 forms-liquid, solid, vapor). Its still on the high side of the A/C system, meaning it is still hot. Depending on your system the refrigerent leaves the Condensor in the form of a High Pressure/High Heat liquid and 'may' travel to a thermo expansion valve also known as a 'TXV'. If it is on the High side of the system it is called a Reciever/Dryer. It uses a desicant to prevent any unwanted refrigerant and oil from continuing in the system. It boils it off back into a vapor form changing the latent heat using pressure. It now leaves the TXV (if this is where yours is located) and continues through a metering device and into the evaporator. The Evaporator then changes the refrigerant into a Low Pressure/Low Temperature Vapor. If your 'TXV' is located on the low side it is called an accumalator and functions the exact same way as a Reciever/Dryer only on the low side. It prevents any liquid from being pulled back into the A/C compressor. The compressor pulls in the Low Temperature/Low pressure Vapor and then, guess what, compresses the Vapor, changing its pressure, back into a High Temperature/High pressure Vapor. Thats how a A/C system works. All it does is change the pressure of the refrigerant by transfering the latent heat allowing it to take new forms. Now, it cools by tranfering the heat from a hot spot to a less hot spot, making the air feel cooler. The Heat Exchanger your talking about is more of a suction device, removing the air (lack of a better word) from the Passenger compartment. In turn, again, it transfers from hot air to less hot air. The blower motor just blows that less hot air around. If I am wrong on any of this, tell me where your getting your information from so I can read it.
What exactly do you want to do by running it through the intake?
All I am saying is this-if you ran a line from your evaporator (or if your 'TXV' is on the low side, it would be after the accumalator) and had a line running into the intake, couldnt you transfer the heat from the air coming into the intake (cooler air means a more efficent engine, simply put) making it cooler. Hence, in theory, you would make up the difference in HP loss from running the A/C system in the first place and possibly see some gain. Of course it isnt as simple as just hooking one line and calling it done, there would be more to it. But the question is-does the theory seem sound? I realize that as it is stated, the refrigerant would damage the engine but thats why you test and experiment, and try to perfect the theory. Overcoming these obstacles.
All that would do is spill R12 into the atmosphere and kill your lungs and your engine.
Well, to set the system up, you would have to drain the R12 out, in turn do a retro fit to R-134A (which is less corrosive), which would mean changing your lines, and I would change most my components, anyways. And if your a tree hugger then yeah, there probably would be some leaking the first few goes at it. But I dont see any Federal regualtions placed on Third world countries or for that matter some 1st world countries that have laws governing their extraction and disposale of Refrigerants. So, really, whats one more car. How would you kill your lungs? How is the refrigerant getting back into the passenger compartment? And I agree, it would kill your engine unless that problem was overcome. So, cmcdougle, whats the problem with the theory other then possible engine corrosion and refrigerant leaking? Am I wrong, or wouldnt it still cool the air coming in through the intake. If I'm wrong on that then the idea is stupid and fine, but I have found no evidence to support that that isnt what would happen. Sorry for thinking outside the box.
wootwoot
12-03-2006, 07:59 AM
Dont compressors clutches generally disengage at full throttle to allow that hp loss to not exist?....
To do this right the line would either have to coil around the intake tube covering a large surface area or be inside of the intake. Placing this chilled line inside of the intake would be the most efficent way for heat transfer but you would be restricting the flow.
What you are suggesting sounds like a shit load of work for practically no power increase. Not only that, but you are doing a poor job communicating your thought and are getting mad when people are saying it is a stupid idea. Remember when you are speaking people dont know the idea you have.
This has been thought of before.
projectRDM
12-03-2006, 08:12 AM
How would you blow anything? Do you even know how A/C systems work? The only thing that would happen from adding another line from your low side low vapor evaporator would do is add more area, which in turn would add lower pressure. The whole oil thing is a complete falacy, since if you have oil in your system by the time it is leaving the evaporator and going back to the compressor your system is already fucked anyways. And unmonitored air flow? All I'm talking about is cooling the air that is already being pulled in with your refrigeration system. Kinda similar to spraying your intercooler. Your the fuckin reason why so many sites have bad information. You dont fully know how things work and pretend you do. Do some research on refrigeration systems before you start posting stupid fucking answers. Also, the average pull for an A/C compressor is about 10hp, at least on high, although 5hp is more reasonable, so I'll give you that. Do your fuckin research! I dont have a problem if its a dumb idea but I have a problem with ignorant dicks that dont know what they're talking about, at least in this instance. You might be knowledgable in some areas R240NA but obviously not this one.
Fuck you and your whole family, asshole. I have done A/C work on and off for years and know damn well how systems work. Oil in the A/C system is used to lubricate the compressor, guess you've never replaced one on a car since you'd know you pour a few drops into the compressor before final pressurizing. That oil is thinned out when charged and circulates through the system.
Secondly, your question stated that you wanted to use intake air to lower the pressure. By doing so, you're introducing whatever is in the intake into the A/C low pressure side. Again, PCV blowby, crankcase blowby, fuel vapors vented from the tank, all this is ported into the intake on a normal car. Unless you've removed all of that you're not filtering that air at all. Doing so after the mass airflow sensor would change the overall metering, since some of it would be displaced by channeling it elsewhere.
Lastly, piping anything into the engine means it's burned in the engine, so the R134a you'd be using would be mixed into the airstream and combusted with the fuel, and though I don't know if R134a is even flammable, I know the resulting byproduct coming out the exhaust would not be clean at all.
If that's not what you meant, learn how to form clearer thoughts and type them out so other people can know what's in your feeble little brain. Seems like your problem is that you're wanting to hear the answer you've already concluded to yourself, so why look for that answer knowing that you're just going to cry about it when you don't hear it?
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