AC compressor ideas

Richard454

Well-known member
Joined
May 6, 2008
Messages
153
Location
Atlanta, GA
OK...on my project I have no room left on the front of the motor for an AC compressor....
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I do want AC though- and here's a solution I found that might just work.

It's a DC 12V brushless motor driven AC compressor- it's not that big- about 8" x 6" and variable speed- draws between 18 and 36 AMPS. I have a alt capable of 125A- with the smallest pulley I could find.

I was thinking of a Classic Auto Air system and just running this compressor.
It's rated at 6000BTUs.

What do you guys think? It's used on Truck Cabs thanks to the no idling laws in some states and also in marine applications....


Product INFO-

http://www.masterflux.com/products/sierra/?pid=22


THANKS-

Richard


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I've been dealing with the same issue in a Search and Rescue car - need A/C for cooling/heating/moisture removal.... at this point, I've been considering using the evap cooling unit from a rv refrigerator because 6000btu is a lot for a small car.
 
The current draw at startup is considerably more than what it's rated at. Marine applications are made to run off banks of several deep cycle batteries. I would seriously consider some innovative engine run compressor mounting solutions before going in that direction.
 
I've been dealing with the same issue in a Search and Rescue car - need A/C for cooling/heating/moisture removal.... at this point, I've been considering using the evap cooling unit from a rv refrigerator because 6000btu is a lot for a small car.

NOT for a dark color car/roof/convertible in FLORIDA....in your town you maybe well be correct, I give you that.... I have a 8000 btu unit in the motor home, and it white almost all over, and barely able to keep up, with the unit setting at a camp sight all closed up.....it's only 15' of aluminum behind the seats.....:evil:
 
That compressor realistically is probably way more efficient than the original A6, even though it was around 12000 btu. Remember that was at peak rpm. It is also hermetically sealed, so there will be no shaft leakage whatsoever.

This will depend a lot on your driving style, whether at idle or above for battery and alt requirements. You can probably upgrade the alternator, usually the higher the rating, the more output at idle. I believe some BMW even had water cooled alternators. Check the performance curve on different models.
At max input, it doesn't seem to require more juice than good cooling fans do.

If you do go with a recirculating air system like Classic Auto Air, it should work extremely well.
You may want to check what the new elec and hybrid cars to see what models they use. Trade mags all predict this is the new wave and being implemented largely in Europe first.


Post your progress, sounds interesting.
 
I've been dealing with the same issue in a Search and Rescue car - need A/C for cooling/heating/moisture removal.... at this point, I've been considering using the evap cooling unit from a rv refrigerator because 6000btu is a lot for a small car.

NOT for a dark color car/roof/convertible in FLORIDA....in your town you maybe well be correct, I give you that.... I have a 8000 btu unit in the motor home, and it white almost all over, and barely able to keep up, with the unit setting at a camp sight all closed up.....it's only 15' of aluminum behind the seats.....:evil:

okay so why would a small car have the same btu requirements as a mobile mansion? I'm sure you're comparing the same to the same - but I don't see it; if anything, it appears from what you said that I'm right on the money -my hypothesis: a small car with perhaps 16 cubic feet of volume can be cooled with a 6000btu cooler. Your statement that an aluminum box of 768 cubic feet can be cooled with merely ~30% more capacity would add a proof to my assertion.... but you put your statement in the negative, so you don't believe so.... what am I missing?
 
I've been dealing with the same issue in a Search and Rescue car - need A/C for cooling/heating/moisture removal.... at this point, I've been considering using the evap cooling unit from a rv refrigerator because 6000btu is a lot for a small car.

NOT for a dark color car/roof/convertible in FLORIDA....in your town you maybe well be correct, I give you that.... I have a 8000 btu unit in the motor home, and it white almost all over, and barely able to keep up, with the unit setting at a camp sight all closed up.....it's only 15' of aluminum behind the seats.....:evil:

okay so why would a small car have the same btu requirements as a mobile mansion? I'm sure you're comparing the same to the same - but I don't see it; if anything, it appears from what you said that I'm right on the money -my hypothesis: a small car with perhaps 16 cubic feet of volume can be cooled with a 6000btu cooler. Your statement that an aluminum box of 768 cubic feet can be cooled with merely ~30% more capacity would add a proof to my assertion.... but you put your statement in the negative, so you don't believe so.... what am I missing?

I"m just saying a poor insulated shark convertible in 130f road heat tarmac traffic in FLORIDA with our humidity loading, and even on a freeway, the temps are damn nearly the same, plus we get all that air leakage on the rag tops that never seal good as a modern sedan, now MY vette has a white top, so much cooler, wife's Miata has a black top, and I can feel that heat much greater in the sunlight......

but the motor home running the A/C is plugged into a camp ground, so no intrusive air, and of course primarily white all over and well insulated with 1.5" of foam all around, except the driving cab, of course, and we curtain that off for privacy and airflow anyway.....

Brings to mind a old joke of mine from my year in DFW Tx region.....
How HOT does it get in Dallas?? Take a pitcher of icewater, pour it on the freeway, watch the ice melt and water evaporate before it his the ground'......:twitch::eek::cool:
 
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Aren't some of these new hybrids running an electric compressor too? With so many of the new cars coming with an engine start/stop function for fuel economy, I think there's bound to be a few OEMs out there with electric compressors. I'd say the Prius is out as a donor as it runs on high voltage (appx. 200V). Perhaps one of these start/stop engined gasoline cars. Wasn't there one in a Buick commercial? Here's a link to Denso's compressor: http://www.globaldensoproducts.com/hvc/electric_compressor.html
 
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Aren't some of these new hybrids running an electric compressor too? With so many of the new cars coming with an engine start/stop function for fuel economy, I think there's bound to be a few OEMs out there with electric compressors. I'd say the Prius is out as a donor as it runs on high voltage (appx. 200V). Perhaps one of these start/stop engined gasoline cars. Wasn't there one in a Buick commercial? Here's a link to Denso's compressor: http://www.globaldensoproducts.com/hvc/electric_compressor.html

there are, and I have first dibs on the one in a wrecked Volt :D
 
Clutchdust- the engine is a BMW v12- out of a late 90's 750/850. 328ci w/ 10:1 compression...replacing a LS5 that was originally in my 71 vert.

Here's the motor w/ the throttle bodies on it-

Picture016-1.jpg

I have looked at sleeper units- but the are too large and pull huge amounts of current-runs a fan for the evaporator and to circulate the air.

The electric car stuff-most run on three phase 208 volts and have a controller w/ them- that would be tough to integrate. Plus my GF said if I put ANYTHING from a Prius on my car - it would reject it!!!

That's interesting-1200BTUs for the OEM...I'm really just looking for some cool air-so it looks as it might just do it. If I want to be comfortable I'll drive my BMW...

I'm thinking my alt will be able to handle it- I had some guy in Texas rebuild it- does stuff for big car stereos- so it was test at 125A..I don;t remember the idle current- but I'm running a 30% smaller than stock pulley...Plus the car will be wired correctly- large gauge wire from alt to battery and the electronics powered off the battery.

The DC motor has a controller- so I'd be able to start it up slow and then ramp up- reducing the start up current surge....

I'm gonna email the compressor guys and classic auto air- so consensus is- it should work?

Richard
 
Clutchdust- the engine is a BMW v12- out of a late 90's 750/850. 328ci w/ 10:1 compression...replacing a LS5 that was originally in my 71 vert.

Here's the motor w/ the throttle bodies on it-

Picture016-1.jpg

I have looked at sleeper units- but the are too large and pull huge amounts of current-runs a fan for the evaporator and to circulate the air.

The electric car stuff-most run on three phase 208 volts and have a controller w/ them- that would be tough to integrate. Plus my GF said if I put ANYTHING from a Prius on my car - it would reject it!!!

That's interesting-1200BTUs for the OEM...I'm really just looking for some cool air-so it looks as it might just do it. If I want to be comfortable I'll drive my BMW...

I'm thinking my alt will be able to handle it- I had some guy in Texas rebuild it- does stuff for big car stereos- so it was test at 125A..I don;t remember the idle current- but I'm running a 30% smaller than stock pulley...Plus the car will be wired correctly- large gauge wire from alt to battery and the electronics powered off the battery.

The DC motor has a controller- so I'd be able to start it up slow and then ramp up- reducing the start up current surge....

I'm gonna email the compressor guys and classic auto air- so consensus is- it should work?

Richard

Richard, what sort of improvement are you expecting for the engine swap??? what about it that makes it better than the LS that was in there???

:crutches:
 
Yes- Jeff- it's a convertible- but I am working on the heat shielding on the firewall- less heat- less cooling requirement...

Gene-

"Better" is all relative to your viewpoint....

It was originally a Bigblock LS5- low compression 454 weighing in at over 685lbs and a Muncie 4 speed... Gross HP in the 365 range...

My V12 weighs in about 185lbs less- dry sumped- individual throttle bodies-no cats- Megasquirt ECU and coil near plug ignition system.
Originally it was 326HP NET-and 363 ft/lbs from 1800-5000RPM...It's 60degree v and fires every 60 degrees so it's incredible smooth...Hoping close to 400HP ...

Will it be faster than say a slightly warmed over new LS engine- no...but who cares- it'll look cool...

Richard
 
Well, I have to give you the COOL factor, just hope that can apply to the A/C also....it is a wild assed vettmod type project for sure....:bump::bounce:

this is one to follow, for sure.....

interested in how you work out the driveline issues....


:goodevil:
 
Have you looked into the AC units for kit planes. They might be 12vdc. Not sure how many BTUs, might be too small. My friend is building a plane and was considering one of these. It gets hot in those bubble canopies out on the tarmac in Arizona.
 
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