A/C Evaporator to cool intake charge?
Yeah, that sucks. How hot is it where you live?
09-27-2005, 09:05 PM
#13
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Originally Posted by vanillagorilla
It's hard to say, but I'm extremely motivated seeing as I saw this today while driving through traffic:
Check it out.
http://www.jegs.com/cgi-bin/ncommerc...83&prmenbr=361
09-27-2005, 09:25 PM
#14
Vanilla, you use all the right words and put them in the right order, but that doesn't hide the fact that your facts aren't factual. Cfm are cfm. The air pressure does not matter unless you plan on changing it, and I don't think you are going to put it through another compressor, or lower it back to atmospheric. It will take the same amount of BTUs to lower the temp of 750 cfm of air from 200+ degrees to whatever, as it will to get the same delta T with 750 cfm of 15psi air. My point was that an automotive air conditioner doesn't have the capacity, and I don't think that four air conditioners would be enough.
The 18 degree TD is standard for room air conditioning regardless of what gas is used. Automotive A/C TD is much higher, because the system is sized to cool your 140 degree interior quickly, not for economy. They are way oversized. There is more tonnage in car A/Cs than most home A/Cs. Yes, you'll get even colder air than 40 out of your vent, as long as the entering air temp is at the design TD (which I am guessing to be 30 or so degrees).
You are right about the lower pressure of 134A, that's the only reason it is used in cars. R22 has a much higher condensing temp, this combined with heat from the radiator would cause explosive pressures.
R22 has a much higher cooling capacity, and will run much colder at practicle pressures. For example, at 9 psi, 22 is at -22 degrees. At 9.6 psi (the closest my chart comes to 9psi) 134A is at +6 degrees.
My only reason for comparing a home A/C to a car A/C was to show that a similar sized compressor will give a low TD with a high cfm (a house, or a FI engine), or a high TD with low cfm (car A/C).
Again, my point was that there is not enough capacity in a stock air conditioner.
Thanks, you're a good audience.
P.S., I'm fighting the same problem, I parked my truck and began working on an intercooler setup after I learned that my lack of power came from IATs as high as 205 degrees.
The 18 degree TD is standard for room air conditioning regardless of what gas is used. Automotive A/C TD is much higher, because the system is sized to cool your 140 degree interior quickly, not for economy. They are way oversized. There is more tonnage in car A/Cs than most home A/Cs. Yes, you'll get even colder air than 40 out of your vent, as long as the entering air temp is at the design TD (which I am guessing to be 30 or so degrees).
You are right about the lower pressure of 134A, that's the only reason it is used in cars. R22 has a much higher condensing temp, this combined with heat from the radiator would cause explosive pressures.
R22 has a much higher cooling capacity, and will run much colder at practicle pressures. For example, at 9 psi, 22 is at -22 degrees. At 9.6 psi (the closest my chart comes to 9psi) 134A is at +6 degrees.
My only reason for comparing a home A/C to a car A/C was to show that a similar sized compressor will give a low TD with a high cfm (a house, or a FI engine), or a high TD with low cfm (car A/C).
Again, my point was that there is not enough capacity in a stock air conditioner.
Thanks, you're a good audience.
P.S., I'm fighting the same problem, I parked my truck and began working on an intercooler setup after I learned that my lack of power came from IATs as high as 205 degrees.
Last edited by Mikegyver; 09-27-2005 at 09:34 PM.
09-27-2005, 10:30 PM
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Cfm is not a good means of seeing if this is possible. You need to look at mass flow rate, not volumetric flow rate. The air we are talking about here is compressed. Sure it might displace the same volume, but it sure as hell doesn't have the same mass. It's much more dense, even though its heated. That is a fact! This is the FI section which means the air is compressed around here. 
You might not be finding pressure in your heat transfer formulas, but you will find density. That DOES affect the dT and the amount BTU's that need to be extracted. If cfm is what matters, then I'd have a squirrell cage blower on my car and be running 9's.
As far as your temp/press. numbers go: I don't know where you got 9psi?
What kind of cycle are you talking about. I've never seen any refer system operate at that low of a pressure. And besides, R22 at 9psi and -22*F is at about 104Btu/lb, which is well outside of the vapor dome. What compressor and TXV are you using? Did you buy it from the same guy that sold Jack his beanstalk beans? 
Comparing the two refrigerants is comparing apples to oranges. They just have too many differences...which is why cfm per ton rules of thumb don't apply here. Especially when the air is compressed.
I couldn't agree with you more that the vehicles AC system isn't going to cut it. In fact, I said that. Neither R22 nor R134a will suffice here. But there are refrigerants that will.
You might not be finding pressure in your heat transfer formulas, but you will find density. That DOES affect the dT and the amount BTU's that need to be extracted. If cfm is what matters, then I'd have a squirrell cage blower on my car and be running 9's.As far as your temp/press. numbers go: I don't know where you got 9psi?
What kind of cycle are you talking about. I've never seen any refer system operate at that low of a pressure. And besides, R22 at 9psi and -22*F is at about 104Btu/lb, which is well outside of the vapor dome. What compressor and TXV are you using? Did you buy it from the same guy that sold Jack his beanstalk beans? Comparing the two refrigerants is comparing apples to oranges. They just have too many differences...which is why cfm per ton rules of thumb don't apply here. Especially when the air is compressed.I couldn't agree with you more that the vehicles AC system isn't going to cut it. In fact, I said that. Neither R22 nor R134a will suffice here. But there are refrigerants that will.
09-27-2005, 11:17 PM
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Come to the Truckin' Nationals and I'll show you guys how to use the A/C system to chill the intercooler. No need for wrapping tubing or running dryer hose ducts. Just plumb the intercooler water thru the heater core and turn the A/C on.
09-27-2005, 11:26 PM
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Originally Posted by duner
Come to the Truckin' Nationals and I'll show you guys how to use the A/C system to chill the intercooler. No need for wrapping tubing or running dryer hose ducts. Just plumb the intercooler water thru the heater core and turn the A/C on.
If you live in Pheonix! I'd have to be buying way too many new shirts in January because my nipples would be cutting holes in them!
09-28-2005, 02:13 AM
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You can rest assured I'll be there duner. I wanna see you're handy work.
Seriously though I'll be looking for you. Will you be racing your white or black one?
Seriously though I'll be looking for you.
Will you be racing your white or black one?
