How much HP does A/C take?
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Car: 84' Monte
Engine: 350
Transmission: 700-r4
Axle/Gears: ferd 9" posi 3.50 gears
How much HP does A/C take?
I'm doing a little research for a school project. How much hp does A/C take to run? Also do any of you know what pressure the high and low side run at? COPr and high and low temperatures would also be nice, but not necesary.
This is for my heat transfer class, we're learning about refrigeration cycles, and I'm going to map out the average automotive A/C system to see just how much heat it's capable of moving.
This is for my heat transfer class, we're learning about refrigeration cycles, and I'm going to map out the average automotive A/C system to see just how much heat it's capable of moving.
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Car: 84' Monte
Engine: 350
Transmission: 700-r4
Axle/Gears: ferd 9" posi 3.50 gears
That makes sense to me considering all the ecm has to do when it kicks on is add a few IAC counts to maintain idle. The way people make such a big deal of making sure the A/C is off when they race, you'd think it was like 50 hp, well maybe thats just the excuse the Honda guys make when ever I beat them by 20 car lengths.
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Car: 89 Formula 350 (x 2)
Engine: L98
Transmission: 700R4
Axle/Gears: BW 3.27
I don't know the power numbers, but I keep the A/C off at the track because I get worried when the Mrs says the guys with the mops were wiping the track after my pass! (Condensation).
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Car: 84' Monte
Engine: 350
Transmission: 700-r4
Axle/Gears: ferd 9" posi 3.50 gears
Most a/c systems shut themself's off at WOT. Yeah my track makes sure the street guys turn theirs off. I'm just looking for some numbers to play with.
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Car: Different One Every Day
Engine: LS1,LS6,L98,L83
Transmission: 700R4, 4060E,Turbo 350, Turbo 400
A lot of folks say you can't feel 5 or 6 horsepower INCREASE.
I CAN FEEL a big DECREASE in power when I turn on the AC.
So, I'm going to guess closer to 7-8 HP to turn the AC compressor when it's engaged.
I CAN FEEL a big DECREASE in power when I turn on the AC.
So, I'm going to guess closer to 7-8 HP to turn the AC compressor when it's engaged.
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Car: Camaro RS/SS
Engine: 5.7 LS1
Transmission: 4L60E Transgo shift kit, 3500 stall
Axle/Gears: 4th Gen Rear 3:42
i think its more like 15 hp. i can feel my car run harder when the AC is on. i always have it off except when its about 95-110 out side.
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Car: Different One Every Day
Engine: LS1,LS6,L98,L83
Transmission: 700R4, 4060E,Turbo 350, Turbo 400
I agree but figured the 1-2 hp guys would flame me outta here.
It's a LOT, that's for sure.
A little 2-3 horse Briggs & Stratton won't run it, that's for sure.
Mine is like setting the parking brake on "drag".
It's a LOT, that's for sure.
A little 2-3 horse Briggs & Stratton won't run it, that's for sure.
Mine is like setting the parking brake on "drag".
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Car: 84' Monte
Engine: 350
Transmission: 700-r4
Axle/Gears: ferd 9" posi 3.50 gears
I was thinking more like 1-3 at idle, but I'm positive that would go up with rpm. Wish there was a way to really find out, I have a g-tech pro, but all of the vehicles I have available for testing turn the a/c off at full throttle.
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Car: C-20
Engine: 260 boat anchor Mexican 350 (crate) TPI (MAF)
Transmission: THM-400 I turn 3500 (which is where my pos engine's power starts droping off) at 80 I need a 4L80-E
Mine is like setting the parking brake on "drag".
I figure that an R-4 compressor takes 30% of your total power.
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Car: '86 Berlinetta
Engine: 350
Transmission: 700R4
Are we talking a 20 yr old a/c setup? Or when it was fresh from the factory? Because our cars took like .1hp when they were fresh out of the factory. The more wear, the more it takes to move it.
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Car: 1985 Firebird
Engine: 3.1L (planning for a turbo)
Transmission: 700R4
Axle/Gears: 3.42
I always though people took their AC out to save weight & free up "some" HP. lower weight = faster times.
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Car: 93 GM300 platforms
Engine: LO3, LO5
Transmission: MD8 x2
The AC in a car has the compressor turned by the engine, via the v/serp belt. From the viewpoint of the compressor, it doesn't care if the compressor is turned by an electric motor or by an internal combustion engine.
So, IMO you should be able to match the automotive AC unit (incl the volume of the cabin, and the potential for having 5 occupants plus the Florida/TX sun baking into the interior) to a small home electric-motor powered AC unit. For those units you can look up the electrical Watt consumption. From there 745 W = 1 hp..... so you should have a better estimate for the engine power load of the AC unit than just swagging it, by equating it to a small AC unit for home use. IMS you can also match the BTU (assuming they still use those units) of the home AC unit to the one *you* can estimate that's needed for the car interior.
Hints: avg person dumps 100 thermal watts into a car interior (1 person = 1 lightbulb model), and you need to assume worst-case southern summer weather, and the solar heating into the interior. That will tell you what the capacity is needed for the auto AC system.
I bet there are also numerous SAE articles on AC for automotive use, but I'll leave that search, and the nosediving into Thermo & Heat Xfer tables to you. I already did my time in those areas. HTH.
EDIT: FWIW I believe the high- and low-side pressures are printed in the FSM..... at least IIRC they are for the GM Bcars that I've had.
So, IMO you should be able to match the automotive AC unit (incl the volume of the cabin, and the potential for having 5 occupants plus the Florida/TX sun baking into the interior) to a small home electric-motor powered AC unit. For those units you can look up the electrical Watt consumption. From there 745 W = 1 hp..... so you should have a better estimate for the engine power load of the AC unit than just swagging it, by equating it to a small AC unit for home use. IMS you can also match the BTU (assuming they still use those units) of the home AC unit to the one *you* can estimate that's needed for the car interior.
Hints: avg person dumps 100 thermal watts into a car interior (1 person = 1 lightbulb model), and you need to assume worst-case southern summer weather, and the solar heating into the interior. That will tell you what the capacity is needed for the auto AC system.
I bet there are also numerous SAE articles on AC for automotive use, but I'll leave that search, and the nosediving into Thermo & Heat Xfer tables to you. I already did my time in those areas. HTH.
EDIT: FWIW I believe the high- and low-side pressures are printed in the FSM..... at least IIRC they are for the GM Bcars that I've had.
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Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
How many BTUs are the older a/c units? About 6-10,000 BTU? If you know the BTU rating you can use a conservative coeff. of performance to estimate the nominal power draw.
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Car: 1987 Trans Am
Engine: tree-fiddy
Transmission: 700r4
HA, I used to call the A/C button on my truck my NOS button. I'd turn off the AC for a boost of power.lol damn 4 banger trucks.
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Car: 84' Monte
Engine: 350
Transmission: 700-r4
Axle/Gears: ferd 9" posi 3.50 gears
I totally forgot about the SAE papers. I just got my membership to SAE a couple of months ago, I should go check out the website.
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Car: Badass 1991 Firebird
Engine: Screamin' 305 TBI
Transmission: 700R4
Axle/Gears: 2.73, 3.42's waiting to go in!
My .02 here, don't notice any diff with AC on or off. Would like to remove it, though, just because I never use it, and all its hoses and whatnot take up space. I like the look of the AC delete pulley too. That's gotta free up a bit of power.
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