Half a croissant, on a plate, with a sign in front of it saying '50c'
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Super Inter-cooler

Cool the intake air with the A/C
  (+5, -2)
(+5, -2)
  [vote for,

Cooling the intake air charge is a know way to increase the power of any engine, but it is especially useful in supercharged or turbocharged engines. Most supercharger intercoolers use engine coolant (at probly close to 200 degrees F), while units for turbo cars generally use air-to-air. Why not have the air flow through a condenser from an air conditioning unit into the engine? It would be the same principal as a normal A/C unit, but without the fans blowing the air into the passenger compartment. It would just go directly into the throttle body.

I realize that the compressor reduces useable engine power, but since there is a direct inverse link between intake air temps and horsepower, I think that the extra power would be more than what is taken to drive the compressor. According to Gale Banks Engineering, the ratio is 1.8% HP gain for every 10 deg. F drop. I have heard that the average A/C compressor takes 5 HP, so on a 300 HP engine, a 10 deg drop would already produce 5.4 HP more than before. If an air to air intercooler can trop temps by 20-40 deg, how much more could some type of refrigerant reduce the temp? (R-134a may not be the best, but would be practical given its availability).

This system would most likely be used only on high performance race engines, not neccesarily grandma's supercharged Buick.

OK, A/C experts, let me have it: why won't it work?

Hunter79764, Jun 27 2006

Bank's Engineering http://www.bankspow...om/tech_coolair.cfm
Interesting site for diesel power, as well. [Hunter79764, Jun 27 2006]


       this sounds like an attempt at perpepual motion. you forget to factor in that the A.C. would have to work harder to cool the intake and the interior of the car because once the air passes through the engine it's not cool anymore.
tcarson, Jun 27 2006

       I'm croissanting this for creativity, and because it looks like [tcarson] fishboned while really confused. It can be considered an odd type of supercharger, but it isn't perpetual motion.
baconbrain, Jun 27 2006

       yea, because it has an external fuel source, which is the combustable gas.
BJS, Jun 27 2006

       i didn't actually bone it. i was confused so i with held my vote.
tcarson, Jun 27 2006

       It should work, as long as you can get rid of the excess heat being generated. Really what you're describing is a air-to-water intercooler with a refrigeration unit in the water.   

       The problem is managing the extra heat generated--you've still got to dump the intake heat somewhere, and you're adding onto that the heat of the refrigeration unit. In the end, the only option is a radiator cooled by atmospheric air, which will have to be sufficiently larger to accomodate the extra heat. Is the extra weight/drag worth it? I dunno.
5th Earth, Jun 27 2006

       5th has the right idea. If a stock water to air intercooler could handle the pressure, it would be an ideal starting point, but considering the pressure involved in an A/C system, i think you would blow something. And car A/C systems already have a radiator (possibly goes by a different name, its just not coming to me at the moment) built in, usually located just in front of the engine radiator. An oversized unit would be beneficial, but not neccesary. (my best idea was to take an A/C system from an SUV (since they generally have better cooling systems to cool a much larger space than a car) and modifying it for use in a high performance car of some sort. While putting it in the intake itself, such as GM does with its Roots-type supercharged/intercooled 4 and 6 cyls, may have some benefits, I think the easiest way would be to fab up a box, post-turbo, pre-intake, with the stock condenser in it, forcing the air to pass over as many of the fins as possible. As far as having too much heat to dissapate, it would not be all that much more than your factory unit has to dissapate. It may put a strain on the system to work hard enough to cool 200+ deg air, but the system could easily have a switch to turn on and off, just like your regular unit. And its not going to cool the air to a comfortable 72 deg. All that you need is enough to allow more boost without getting detonation. Next time you get in your car, think about how hot the ambient air is outside (easily 110 where I live) and think about how cold the air coming out of vents is, then think about all that heat dissipating right in front of your radiator. But it still works decently enough, right?   

       And just to clarify, the system would not be used to cool the passenger compartment any longer. Independant second system? Should work, given an engine bay large enough.
Hunter79764, Jun 28 2006

       You said it would most likely be used in high-performance race engines. When was the last time you saw a race car with air con?
methinksnot, Jun 28 2006

       Many of them that I've seen around HAD air con, they just cut the belt, unbolted the compressor, and used the A/C radiator (still can't think of a special name for it) as an engine oil cooler or aux. transmission cooler. OK, so my definition of a race/high performance car isn't a Le'Mans car, its an old beat up Chevy. But it should still work on your average weekend drag racer or stoplight machine.
Hunter79764, Jun 28 2006

       Don't pay much attention to my ramblings. I fall squarely in the latter half of the balance you have insightfully alluded to in your profile page.
methinksnot, Jun 28 2006

       /A/C radiator (still can't think of a special name for it)/   

Texticle, Jun 28 2006

       OK, sounds right. Then what's the other half called? Maybe evaporator? I don't know. Most of the time I'm on here, it's already too late at night and I'm constantly short on sleep. So if thats it, sorry for any confusion I caused.
Hunter79764, Jun 28 2006

       Hey hunter, I tried to email you about an Idea of mine you liked, but it didn't work. See if you can send me a line... or just check my idea for a new link.
ye_river_xiv, Jul 12 2007

       Have none of you thought about cooling the water-air intercooler coolant with the a/c? Doesn't add any pressure to any sytem and it doesn't need to cool in real-time because of the huge thermal 'bank' a water reservior provides.   

       Ford have since laid a patent down on what I have just mentioned
BLSTIC, Aug 27 2009

       To get more heat out of the intake air (which is the point of intercooling) you can either use a bigger intercooler radiator or increase the temperature difference between the hot, compressed charge and the outside air.   

       If I understand correctly, you are proposing to use an A/C unit to add cooling by reducing the temperature of the air 'outside' the intercooler.   

       The 3HP A/C pump is capable of reducing the temperature of the air in the cabin by a few degrees (say 40° outside, 15° inside = 25°) and it does this at a relatively low rate of flow.   

       The flow rate from the supercharger or turbo is much higher (just look at the power drawn by a supercharger - up to a third of the engine's output in drag cars!) so your 3HP A/C pump would create a proportionally smaller temperature drop in the intake air.   

       Since the supercharger or turbo is already pressurising air, one approach might be to increase pressure from the charger. This will also increase the temperature of the intake air which will increase heat exchange at the intercooler.   

       A pressure regulator between the intercooler and engine would reduce pressure back down to the required boost.   

       As a bonus, this gives a reservoir of pre-pressurised air in the intercooler, giving instant throttle response and the ability to lunch the clutch, gearbox, propshaft, diff, half shafts and/or tyres :-)
Twizz, Aug 28 2009

       it does work, with the caveat that it only works if the engine is capable of utilizing the extra thermal efficiency via high compression or forced induction. In addition it causes a dramatic penalty in efficiency so it is no replacement for simple displacement. If you have a direct air/water intercooler of the reservoir type (thermal buffer, meaning lacking a radiator) then you could chill with an AC unit, otherwise it makes very little sense.
WcW, Aug 28 2009


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