Nashua_Night_Hawk

What is a peltier cooler and how does it work?
A peltier cooler is a cooler that uses a peltier element ;-). A peltier element can be described as a "heat pump" - it will pump the heat from one side the other. This means that a peltier element has a hot side and a cool side. To do this, the peltier element uses electricity - quite a lot. This also means that in addition to pumping heat, the peltier element will actually produce heat - overall, the system will run hotter, but the peltier element will cool there were it is needed - on the CPU.
Usually, the temperature difference between the hot and the cold side is of about 70 degrees, with some high performance peltiers reaching up to 120 degrees.

More: http://www.heatsink-guide.com/peltier.htm

TheModMole

Uhhmnnnnnn thanks for the lesson but that much I already know as well lol hahahahahha j/k

Nashua_Night_Hawk

Here's a complete Integrated Guy: 12V, 36Watts, 6 Amps and almost 3 lbs (1.5Kg) weight Size 101 mm x 91mm x 80mm Cost $192 each



http://www.tetech.com

Seems expensive?, here is a used one... ripped from an application but cheap at just $26



http://www.allelectronics.com/cgi-bi...C-1&type=store

Here is another source of ripped items: http://www.meci.com/default.asp?mode...ms&category=80

Davediego

and you plan on using this HOW in your car people use this in computers to overclock, but im just not seeing a car application. most peltiers are only a couple square inches

Nashua_Night_Hawk

Basically cooling the 3" CAI Alum. Tube.. Those modules would drop Temp by -70C... small but they have a cooling power of 40 Watts Example this guy, DA-041 (middle left):



You should custom design a 3" thremel sleeve that mates to the DA-041 module as each draw only 5Amps you can use 4 if you want... and then you would have a 160W cooling device...

allmotor_2000

I don't think cooling the CAI piping is going to do much! The Peltier coolers require a hefty power supply

EricL

They have a long way to go for larger applications. The efficiency is rather low at this time...

LINK:
http://www.tinaja.com/glib/hack68.pdf

Excerpt:

"The module data sheets carefully bury their efficiency figures for most normal operating points. Often, three watts of energy are required to move one. For an EER Energy Efficiency Rating of a laughable 0.33. Compare this against an air conditioner having
an EER of 15....

http://www.tetech.com/publications/pubs/1995RJB1.pdf

chizad1980

Hey Nashua_Night_Hawk: That is only 36 watts? And it's $192.00!

Check out http://<br /> <a href="http://www.s...462ut.html</a>

It's only $34.95!! It's 226 watts. You can get it for $110 with a water block. But the only drawback (If you can call it that) it that you need a pretty hefty power supply. They have one there specially for it for $114. And, since it gets so cold, it causes condensation. So it includes two pieces of foam to seal it form air getting in.

A little note about the Peltiers is that they really don't work well with air cooled products. However, they work awesome with water coolers. Which is why I need to get one.

1 question about them. How do you pronounce the name?
Is it pel-ter, pel-tey(a), pel-t-i-ey(a) or what?

EricL

pélt yay

Pel-ti-yay effect

They work great for cooling kegs of beer. We had one of the 1970 vintage beer-on-tap coolers and it used a Peltier device...

Nashua_Night_Hawk

Thanks for the link... There is a Direct Air Cooling model here: http://www.sidewindercomputers.com/swiftechmcx4621.html It needs a additional fan. It is 12V DC that can sustain 70-100 Watts at 24 Amps, not bad...it cost $90...

By the way, the engine battery can supply those 24 Amps with no problem at all.. A switch next to the VSA switch would turn on/off this cooler..

edgalang

ha...i used to used those to overclock my CPU's way back in the days where I still cared. There was one point where my CPU was sealed because whenever I turned it off, the ice that condenses around it would melt and get everything wet.

As for cooling anything in the car...hmm...I dont know. I think the performance that you MIGHT get from it would easily be overshadowed from the power loss that you get from running the alternator on all the time.

Davediego

i dont think air sits in the CAI pipe long enuf for having a supercooled pipe to have much of an affect. also you have to consider that for every watt the peltier absorbs, theres another watt of heat to dissapate on the hot plate. with air from the engine bay its going to be very difficult to cool off teh hot plate adequately

lrutt

you would also have to assess efficiency. I don't know he relative efficiency of these devices, but they are likely not very high. You should investigate the type of system being incorporated into the next gen Lightinings. They use excess HVAC capacity to super cool a tank of liquid. When activated, the intake charge is passed through this super cooled medium via intercooler and the intake charges drop an addition like 40 degrees or so. It's good for a couple minutes running I think. You then can work on recharging the reservoir again, takes 15 to 20 minutes I believe the article said. Doesn't take much in the way of new technology and parts, just makes use of existing systems. Helps put the new Lightning at 500hp/500tq. Impressive.

Nashua_Night_Hawk

As for efficiency.. the 45 Watts model had a DC current of 3 Amps at max load... It would draw a 2.5 Amps at no thermal load..

So It will disspate 25 Watts to 35 Watts by it is own and effectively pump ~40 watts at maximun Theraml load...

So, it's like 50% efficency at maximum cooling effect...

Finally, the CAI tube does become very hot in the summer.. It be effective the Cold plate of the thermal unit should be attached to a kind a heat sink (collector) inside the CAI tube..that would absorve the heat..

EricL

You can't ignore thermodynamics...

If you don't design ANY system that will STORE energy from a vehicle that would normally be consider "wasted" (during idling/braking), you need to figure how much power you are gaining vs. the amount you are losing. For example, if a supercharger used 30HP from the engine to drive it and only produced a gain of 30HP, the net gain would be zero. With a S/C, this is not the case.

You would need to actually figure out how much lower the actual intake air temperature would be with a cooler on just the intake pipe or with a full blown cooling system -- think intercooler.

If you want to be "methodical", you need to figure how effectively you cool the intake charge, how much power you derive from the higher density, and how you supply the energy for the cooling device -- regardless of cooling type. You would need to insure that the power source would (1) increase the net HP output to HP input OR (2) design a system that used the waste energy from braking, idling, so on.

Here is a study on comparative cooling systems that compares "most" of the cooling devices and heat pumps available. The efficiency is rated in terms of coefficient of performance (COP).

The title of the following document is "Technical Assessment of Advanced Cooling Technologies in the Current Market", dated August 1997.

Here is the link:

http://www.cecer.army.mil/techreport...t.ULU.post.PDF

"Thermoelectric refrigeration has several disadvantages. Attainable COP are low for thermoelectric refrigeration. The performance of a thermoelectric cooler depends on the figure of merit of the semiconductor materials composing the p-n junctions. Typical n-type compounds are 75 percent Bi 2 Te 3 and 25 percent Bi 2 Se 3. Typical p-type compounds are 75 percent Sb 2 Te 3 and 25 percent Bi 2 Te 3 with about 2 percent excess Te or Se. At a temperature difference of 40 °F, COP c/ e ranges between 0.3 and 1.4. Cascading with up to three stages helps somewhat, but COP c/e remains low compared to the vapor cycle..."

There is also the assumption that you are going to be able to get rid of the hot side energy!


Heat pumps, like a very high efficiency room or car unit would have COPs in the 3 range. A typical A/C has an EER from 9 - 12.0 and the conversion to COP is: COP = EER/3.413. So, a “typical” A/C unit has a COP close 3 (it moves 3 times as much heat as is input/consumed).

If you have an efficiency of 50%, you are going to use twice as much energy from the engine’s electrical source for a given amount of cooling. And that does not include any hot side losses (you need a fan, heat pipe, whatever to remove even MORE heat from that incoming intake air). If need to get that hot side energy to a cooling source, and if it's a fan, its going to use a LOT of power to move that heat load of the thermoelectric cooler AND the intake charge. (Whatever the situation/solution, you need to figure this out too...)

The point I'm trying to make here is: you would be better off taping into the A/C.

COP NOTES:

COP == 0.5: delivers 0.5 watt for every watt of energy consumed
COP == 1: delivers 1 watt for every watt of energy consumed.
COP == 3: delivers three times more energy than it consumes.

If a S/C or turbo consumed 2 watts for every watt they helped an engine produce, they wouldn't be used as they are today.

If you are considering adding an alternator -- or other electric generation system -- that only kicks in during deceleration or idling, enjoy.

Gas Turbine Inlet Air-cooling System link:
http://www.mhi.co.jp/tech/pdf/e392/S1-392_0705.pdf

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(I would just leave the next link, but it would bug you for registration.)
And a full thread on this topic on the www.eng-tips.com site:


73nova (Mechanical) Mar 14, 2002
Would cooling incoming air by way of flowing it through dry ice on a naturally aspirated engine give any kind of noticable power gains?thank you,73nova

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PoeAruzdnav (Electrical) Mar 15, 2002
They tried methods like it in racing and in hot rods from the 20's through the 50's. Normally the gas flowing into the carb was cooled by wrapping copper tubing around a coffee can full of dry ice. The air was cooled when the gas was introduced. Killed carbs and not sure if it accually gave any noticable improvements.

evelrod (Automotive) Mar 15, 2002
From one who actually did these crazy stunts---The dry ice in the intake system did not seem to work, but the dry ice cooling the incoming fuel did, but not to any great degree(in hindsight). It was as much psychological as anything. The 50's were times when we were trying just anything DIFFERENT in search of an advantage on the drag strip. One thing that did work was putting ice on the intake manifold before a run. Messy and outlawed after a time.Rod

carnage (Electrical) Mar 27, 2002
If Ice did work then what about a finned alluminum manifold?(fins on the outside of cource) could it work like a giant heat sink?

GregLocock (Automotive) Mar 27, 2002
Not really. The underbonnet temperature is typically 60-120 degrees C, dpeending where you are, at full throttle. The incoming air in the manifold is maybe 60 C worst case (assuming no turbocharger or supercharger).Good idea tho. CheersGreg Locock

GregLocock (Automotive) Apr 1, 2002
Many cars have problems with fuel temperature - the stuff going back to the fuel tank is at 60 or 70 degrees, this warms the tank up, so your evaporative emissions go way up, in practice, if not during the emissions test itself.I can't see any subtle advantage to cooling the fuel rail itself (rather than the return line). I wouldn't have thought the density would vary by enough to matter, maybe they had probs with vapour locks?CheersGreg Locock

Aljohn (Visitor) May 16, 2002
I don't think you would want to let the air flow over the dry Ice. This would be introducing more CO2 into the engine but the engine really wants more O2. I think cooling the intake would work better if there were fins inside the intake to take the heat out of the incoming air. Without fins the air won't be cooled enough to make a noticable difference. Maybe you cound do some experiments and see how mouch the air is being cooled by placeing a thermocouple down stream of the point of cooling.................have fun

dragdude (Visitor) May 16, 2002
73nova,I wouldn't waste my time arguing with any of the people responding so far...they are right way too often! You are correct in thinking that cooling the incoming air will increase power. You may not want to draw the air over the dry ice itself, but you could use it to cool the incoming air in a heat exchanger (think intercooler as seen on most turbocharged race vehicles) of some sort, so long as it's not a restriction. (I've never seen it on a N/A car though) Cooling the intake, as evelrod pointed out, is also of value. You didn't state your application, but long term cooling is difficult on a street car. For racing, again as evelrod pointed out, you can't contaminate the track surface in the process. Any cold-air intake system should help if it can get cool, clean air from outside the engine bay.

butelja (Mechanical) May 17, 2002
Here's a thought that I'd be happy for others to comment on. This setup could only work for offroad applications of short endurance, such as drag racing.If a heat exchanger coil was placed in the air inlet duct and used as a propane vaporizer, the latent heat of the vaporizing propane could be used to cool the air charge. I havent't looked at the thermodynamics in detail to see how much propane would be required, but I would think a 20 lb cylinder should surely be good for a run or two down the 1/4 mile strip. All of the vaporized propane has to go somewhere. For dramatic effect, pipe in into the exhaust and run an auxillary spark plug near the end of the pipe. Along with your inlet air cooling, you would have a pretty impressive flamethrower coming out the end of the exhaust.

carnage (Electrical) May 18, 2002
I suggest to effectively coolincoming air in your motor that you first take off your hood to prevent temp buildup and then do all your racing in alaska in the winter time.

mgithens (Mechanical) May 19, 2002
Heat exchange requires a difference of temperature - so you can throw that idea out. Incoming air is ambient temperature, so today let's say 60 degrees. If you were to measure the temperature under the hood, the temp would be higher due to all the engine heat. So through the ducting the air will be slightly heated maybe 70 degrees, maybe more, which is opposite of the desired effect. So instead of trying to make a difference applying a small amount of ice, why not focus on insulating the ducting so that engine intake temp is at least as close to ambient temp as possible.Any system which requires constant attention in order to be effective is just a pain in the long run. So insulating the intake will be the most affordable, long term solution that will require no attention in the future.

Whittey (Automotive) May 20, 2002
Has anyone ever used peltiers in an automotive manner? I'm thinking 4 of these little baddies in a square as part of your air intake would work well, though it would draw 24 amps. Perhaps using one as a fuel cooler instead of cooling intake air would work better?-=Whittey=-P.S. http://www.allelectronics.com/cgi-bi...5&type=storeIf you click on them and download the pdf, they give an explanation if you are not familiar with them.

dragdude (Visitor) May 20, 2002
butelja,If we assume your predictions of 2 runs per cylinder are correct, it would seem quite expensive to gain 5 hp or less at a cost of $10(USD) per run. For that price you can get 200 HP worth of nitrous. Interesting idea though.Isn't that called snowmobiling Carnage? Whittey,Since the peltiers require a heat sink to disipate the heat, they would have to be on the outsides of the duct, thus allowing very little contact area. I still agree with Greg also: unless you have vapor lock problems, cooling the fuel is probably not necessary.Just my thoughts....

Whittey (Automotive) May 20, 2002
I would imagine a style of 'coolsink' on the inside and heatsink on the outside... A spare benefit of the 'coolsink' on the inside would be to straighten the airflow (or if you're a tornado lover, possily spin it).-=Whittey=-

carnage (Electrical) May 21, 2002
the general electric transortation system (gets) is a nifty computer box that goes in trains. To Isolate them from the envireoment they were put in a big metal box. to keep them cool there was a big heatsink on the outside a big "coolsink" on the inside and a thermal transducer (I think that is what they called it) inbetween that would heat up on one side and cool down on the other when electric current was passed through it. a setup like that might be kindof interesting to see on a manifold. (they ended up taking out the thermal transducers because they cused lots of condensation inside the metal box.)

ivymike (Mechanical) May 21, 2002
whittey, last summer I tried to use some of those peltiers, with a small water circulation system, to make a in-seat cooling system for my otherwise uncomfortably hot vehicle. I used a couple of those little 75W Peltiers (approx 2" sq). My "cooling seat" kept leaking, so eventually I gave up on it (I was trying to finish before starting a road trip). As I recall, those Peltiers are not capable of removing much heat (less than 1W for every 1W consumed)...

wpluim (Mechanical) May 21, 2002
As long as we're looking at cooling, try passing air through a bit of this material. ( www.pocofoam.com ) It's decently permeable. Or maybe setting a bit of it on top of your intake. This stuff has around five times the thermal conductivity of pure copper, close to that of diamond or better. it's fully machinable, though a not quite as hard as I'd like. Oh yeah, and it's almost a complete RF shield.Will

ivymike (Mechanical) May 21, 2002
Maybe I missed something... how does having a thermally conductive intake duct help keep the charge air cool? Are we talking about a pressurized intake?

wpluim (Mechanical) May 21, 2002
I don't think you missed anything. I was just throwing it out with all the heat sink talk, is all. IF you have this stuff in contact with a cooler surface (peltier?) and pass air through it, the exiting air will be just about the temperature as the cooler surface. Sorry if that was confusing! Just throwing out ideas without actually thinking about application.Will

Chumley (Visitor) May 21, 2002
Hi Guys, I'm new here. Over the last 100 years engine designers have determined that automotive intake systems on NA internal combustion engines require "heated" intake air under many conditions so they provide a thermostatic tempered (heated) intake air system for most applications except turbos. In most NA applications except at wide open throttle, the ambient air temperature is not what the engine sees. Because of the pressure loss across the throttle body at all positions except at, or close to, wide open throttle, there is a drop in intake air temperature in the intake manifold. The heat of vaporization of the gasoline also reduces the intake air temperature (now considered to be called the charge temperature) which is what you need to pay attention to. The charge temperature can quickly vary from below freezing to above ambient temperature depending on the throttle body position, the current stoichiometry, and convective heating due to the current power setting.If the ambient air temperature and the fuel are too cold, the fuel won't have time to fully vaporize and the engine will run lean just like in a cold start condition without substantial fuel enrichment. That happens at low power settings on cold days without tempered intake air. Remember carburetor ice before the days of port fuel injection? That's why the injectors spray the fuel at the back side of the hot intake valves instead of dumping it on the throttle body in the carburetor. Keep in mind that with a low manifold pressure, the effective compression ratio is MUCH LESS because you are starting with only 7 or 8 psi in the intake manifold so you don't get as much temperature rise in the combustion chamber as the mixture compresses. Everything changes drastically though when you crack the throttle wide open. Why don't most compression ignition (diesel) engines have a throttle body? Answer, because the combustion chamber temperatures would drop too much at idle to support combustion. That's why diesels run with excess air. Certainly, under some contditions, cold dense intake air is a good thing, but, it would be overly simplistic to say that if cold is good, then colder air is always better. Not so! With racing engines it may be true but not with daily drivers! Tempered(heated) intake air, when necessary, improves gas mileage and drivability while reducing warm up time and exhaust emissions, because it improves the fuel vaporization characteristics. That's why those cheap dummy engineers (I'm one) spend the money to install tempered intake air systems on many NA automotive gas engines! If you live in a colder climate, and your auto is equipped, remove the warm air hose and see what happens. Chumley

evelrod (Automotive) May 22, 2002
Chumley----Of course you are correct in what you post. The discussion up to this point has been 'tilted' toward WOT and the attempt to achieve max power in a gasoline fueled car, a la dragracing etc. In the past I have had a few cars that would not run without heated air but, they were not performance types. On the methonol powered cars I have had to route heated air to the intake to keep it from icing up! (even on warm days).I must admit that some of the ideas in this thread ARE rather 'far out', eh?Rod

Chumley (Visitor) May 22, 2002
Rod:Yeah,. . . . I realize the discussion is mostly about getting the maximum performance out of an engine.I guess my point was just that the fuel vaporization characteristics usually far out weigh any possible gains by small density improvements due to the temperature of the air/fuel mixture in a NA engine below certain well established limits.Knowing (not guessing) which condition governs in any application is the key to performance.For years engine designers have experimented (with valid tests to justify what they build) with ram air, polarized air/fuel, turbulent air, super cooled air/fuel and in all but the most limited applications (specialty racing) the systems end up in the garbage can or on TV in an infomercial. Not to say they don't work, when properly designed they clearly do, but, they also come with other drawbacks that reduce their widespread use. Even in racing, practicality and reliability have their applications!Have a great day!Chumley

carnage (Electrical) May 22, 2002
see a gasoline powered xx cooler is very possible. now to figure out how to have the other side of the manifold heat the burritos maybe just use a heat plate on the exahust manifold for that. perfect now you have everything you need to make lunch right there with you. and it is a lot eisier that carrying arround a barbeQ'r and a can of 1,1,1,2 thetrafloralethane (probibly spelled that wrong)

Lonx (Visitor) May 30, 2002
How about adding methanol injection pre-throttle body? I've considered doing this with my 1.8litre NA as the testing ground. The system would consist of a washer bottle & water spray pump, mist spray nozzles and a little bit of piping. Anyone have opinions on this? If this doesn't cool the charge air, then possibly it could be sprayed onto your air filter - meaning the evaporation is more efficient, but increases potential for engine fires.

Whittey (Automotive) May 30, 2002
Last night I was thinking about this whole cooling of N/A engines. The Ford 300cid inline six (and most old american i-sixes for that matter) all had non-crossflow heads. This meant you could cant the valves which is all well and good but it is a Bad Thing (tm) because of the intake and exhaust manifolds next to eachother. This sounded ok a bit ago, but now that I get to think about it, the only way for it to transfer heat would be along the outer layer. Whats the scoop? It works for heating but not for cooling?-=Whittey=-

evelrod (Automotive) May 30, 2002
OK---Let's cut to the chase here. The only viable intake air cooling that I see with a chance of production, even aftermarket, is the water mist system for intercoolers on supercharged engine applications. While all sorts of scoops and ducts are seen on production cars, most are located by STYLISTS! Get real, guys. The last time I saw a car designed by engineers, while it worked well, IT WAS VERY UGLY! You could not have sold it to an Iowa farmer with a death wish! The mist system, a la the system for the Subaru WRX intercooler(claimed to increase hp in normal AND part throttle(???) use), are currently on the market. These systems may be duplicated by the DIYer with little effort. Windshield washer motor, water source, garden misters, etc. is all it takes.If you think I am wrong about the scoop deal, check out the REAL race cars for their air intake systems in relation to the production cars they are supposed to represent. (Rear wheel drive V-8 Taurus??? ---WRC cars, especially the Subaru WRX---good example as they are about as close to production as pro racing gets!!!)Rod

Whittey (Automotive) May 30, 2002
Rod,I was perusing the 'net the other day in search for performance mods to be done to my buddies 2.9L V6 Ford (wow, noone likes that engine). This guy had a neat idea of running some flexible plastic ducting to draw air from the actual cowl itself. Would that work as well as a regular cowl induction (ala Winston Cup) without an actual hood cowl?-=Whittey=-

evelrod (Automotive) May 30, 2002
That is without a doubt the best place to pick up outside air for the intake or, anything else, heater, ac, anything. A lot of the scoop placement you see on production (street) performance(?) cars are located by the stylists, not the engineers!Rod

bundski (Visitor) Jun 6, 2002
Hi,How about a thermal barrier between the head and the intake-manifold. I can have, if I've got a template, cut 6.4mm thick special gaskets. The cost about NZ$250,- + shipp.c.B---------------------------------

TheBlacksmith (Mechanical) Jun 6, 2002
You also need to provide a thermal barrier between the hot oil in the lifter valley and the bottom of the manifold on a V engine. There was a "plastic" intake maniflod marketed for the Corvette engine a few years ago that claimed 20-30 hp due to a cooler intake mixture. I believe Chevrolet later make the plastic manifold standard on Vettes, at least for a couple of years. Blacksmith

Whittey (Automotive) Jun 6, 2002
Aren't the newer mustangs using a plastic intake?-=Whittey=-

butelja (Mechanical) Jun 6, 2002
Pop a few hoods on new 2002 cars. It seems nearly everything is using plastic intakes, and more than a few valve covers as well. I would imagine most of the use is to have lighter weight and more flexibility in manufacturing obscure shapes. Also, the plastic intake will have a smoother interior for less airflow resistance.

Bundski (Automotive) Jun 7, 2002
Hi,A friend of mine who did all the development and testing with these gaskets is also making gaskets for late model BMW's who have plastic inlet manifolds, these ran pretty hot when heaksoaked. The only advantage of them is that they are black and get rid of the heat fairly quickly.B------------------------------

carnage (Electrical) Jun 8, 2002
I would still preferr an extrude honed cast aluminum manifold over plastic. The thick gaskets is a neat idea.If you are after good thermal isolation then how about this stuff:http://www.3m.com/market/industrial/...s/nextel.jhtml

Bundski (Automotive) Jun 8, 2002
Hi,The gaskets are made of some kind of (glass?)fibre mixed in some kind of resin (epoxy?).I've also seen piping from airbox to manifold being insulated by some kind of material that one would use for insulation heater/cooler pipes with some kind of rockwool I think it was, with an alu- foil around it. It looked pretty neat too!B----------------------------

highlandsun (Computer) Jul 4, 2002
Funny, I just found this thread while searching for "peltier intercoolers" - but I'm thinking about a turbocharger setup, not normally aspirated. Unfortunately, I went thru some coarse estimates and it appears the heat content of the compressed air is beyond the capacity of a typical car's electrical system for peltier cooling to have a significant effect.I.e., I calculated about 11kW of added heat content in the compressed air exiting the turbo (and I could be way off, because the input numbers were rough estimates), and even with an ultra-efficient Peltier you'd need 13-15kW of electricity to suck that heat out. In combination with a standard intercooler, with say 80% efficiency, you'd still need 3-4kW of electricity to extract the last 20% of added heat. (Assuming 77F ambient temp, 10psi boost, 200F compressed temp.)If anyone else has gone thru this exercise for a turbo intercooler and come up with a more favorable answer, I'd love to hear it.

carnage (Electrical) Jul 8, 2002
peltier intercoolers?

highlandsun (Computer) Jul 8, 2002
Yes. There was a '98 issue of Turbo magazine describing a Dodge Ram with twin-turbos, and peltier-assisted intercoolers. But in that case, they used an air-to-water intercooler, and the plumbing went to a 12-gallon ice-chest that had integrated Peltier coolers. (A PolaPak or somesuch, off the shelf ice chest.) Kept the water around 40F. I would imagine this kind of setup can really only help a drag-racer, since if you're constantly dumping heat into it it will eventually max out. But I suppose it might be worth the slight weight penalty.

Islander (Mechanical) Jul 8, 2002
someone explain why vehicles run much faster track times during the winter than during summer...such as the Ford Lightening or the Dodge Dakota RT...it's cause the cold air is DENSER air.I fail to beleive that you would only get a nominal gain by utilizing "cold air".RT's and Lightenings often run nearly a full second faster in cold weather...Why not cool the fuel also...the fuel rails on my RT in 92degree weather are probably near 150+ degrees...i could feel the truck bog in the heat. So I put some radiant barrier on them...it helped.my only issue is how cold is too cold.

highlandsun (Computer) Jul 8, 2002
"Too cold" would be the point where the fuel no longer vaporizes when it hits the back of the intake valve. And I suppose that depends on the combustion temperature and how much heat gets absorbed by the valves. Also it depends on the fuel and time of year when you purchased it, since the winter blend is more volatile than the summer blend.The rule of thumb I've seen is that power changes 1% for every 10 degree change in temperature, and stock engine ratings are usually measured at 77F ambient. Certainly running at the track in 20F dry weather gives a stronger pull than in 90F humid weather...

Chumley (Visitor) Jul 8, 2002
Islander:Cooler air is not only denser but the relative humidity, the amount of water(water vapor is a gas) the air will hold drops considerably. It's contrary to intuition, but, fully saturated humid air is actually lighter than dry air at the same temperature. Water vapor in the atmosphere displaces(reduces) oxygen(21%), nitrogen(78%), and, all other gaseous components of the atmosphere. Oxygen is involved in the combustion of fuel and the production of heat. Water is not. Additionally, water vapor in the charge mixture will reduce the amount of power available because of its high specific heat and high heat of vaporization as long as its not needed to retard detonation.As the air cools, not only does it become denser but the much of the water condenses out allowing more room for oxygen. We're talking fractions of a percent here, but, remember that the atmosphere is only 21% oxygen on a good day. Most of the nitrogen(78%)is in the way. Now, if you could figure out a cheap fast way to dehumidify the air, and, cool it before it enters the intake system, and, keep combustion chamber temperatures within critical limits, you might have something.Give up on the idea that if cool is good, cooler is always better. Engines in automobiles are complex systems with hundreds variables that change second to second.Think about it. Cooler is denser but more difficult to drive through. At what point does the additional friction on the body out weigh the additional power generated?Will that occur at the speeds normally encountered while driving? All you pilots will know the answer to that! Chumley

Lonx (Visitor) Jul 15, 2002
Nice explanation Chumley Thanks mate,

PJMT (Automotive) Jul 16, 2002
There is a wacky idea floating around the auto industry at the moment which involves using the aircon system to cool inlet air. It's mainly being linked with turbo engines, the idea being if you run the charge air cooler you can increase the compression ratio to improve part load fuel economy. If it allowed you to increase the compression ratio on your N/A car this could give you more power. Assuming it would run on the now freezing cold air and the engine could stand the increased stress!

highlandsun (Computer) Jul 16, 2002
Sounds like what these guys are doing:http://www.coolflow.com/prod1.htmImproving part-load fuel economy? Hm, losing 10-15hp to drive the A/C compressor; you need an extremely efficient heat exchanger to just to break even, let alone get any gains.

PJMT (Automotive) Jul 16, 2002
I didn't say it was a good idea. I agree with you personally. The actual idea involved using "excess aircon capacity" so it assumes you're already driving a compressor for the cabin cooling. This statement I fouund to be interesting since all the cars I've driven with aircon don't seem to have any excess capacity, in fact they struggle to cool the cabin on really hot days, even here in the UK! Also, the condition where max cooling is required i.e. WOT to avoid det (turbo engine) is where aircon compressors usually clutch out.

highlandsun (Computer) Jul 16, 2002
Yes, that's certainly a drawback. But assuming the power gain was worth it, you could reprogram the ECU to keep the A/C active at WOT.I found this link to be pretty fascinating:http://www.hi-z.com/websit07.htmA thermoelectric generator that produced 1kW of electricity from waste heat in diesel engine exhaust.The modules seem to work best with a delta-T (hot side to cold side) around 200C. It'd be interesting to see this find its way into automobile mufflers, assuming you could keep the cold side cold enough. (Yet another cooling problem...)

Civic_Sleeper (Visitor) Aug 21, 2002
I have built my own CAI(cold air intake for my civic). I used 3" aluminum (aluminum relects heat)house ventilation. It has a two ducts, one inside the other. The outer duct keeps the inner duct isolated...I've tested it with a propane torch against the outer duct...the inner duct was uneffected. I'm still working on a coil to run between them so I can run a refrigerant through it to cool the inner duct even more. My current design gave me an increase of about 5 hp..but it costs $60 vs. 200-300 for a name brand CAI. On a side note, what I did does not comply with CA smog regulations...I have to put my old airbox on when I get smogged.C_S

vicmax (Automotive) Oct 1, 2002
Hi, I am in JamaicaMy race car (Mini Cooper) had on a chrome steel intake manifold/SK Carb. with plenum and allum. air duct directing air from the front of the car to the carb.It was explained to me that the chrome would deflect the heat and help reduce intake air temp. It seems to work as I experience a lot of condensation from the intake manifold (none with allun. manifold) on a very hot day and 7hp increase. This is a engine making 159hp

Nashua_Night_Hawk

Now this 1KW alternator/Generator/DC Charger is very cool.... http://www.hi-z.com/websit07.htm

Imagine have such charger and the opposite as a cooler for the intake...!!!

EricL

AS long as you "grab" the power for cooling from "wasted energy" (heat, idling, stopping, etc, etc), you get a "free ride" (presuming you have a fat-enough wallet).

If you looked at the "chiller chest" in one of the other links the cooling had its greatest application in turbo & S/C applications.

In the other thread I mentioned the guy who used a freon based system to "harvest" the temp differential(exhaust waste energy) -- that exists from the large difference in temperature between a hot exhaust and ambient -- to store energy for a pneumatic assist that was one-way clutched into the ring gear on the flywheel during WOT runs...