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Aftermarket a/c?

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NutmegCT

NutmegCT

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Does anyone have experience with adding aftermarket *all electric* air conditioning to your older car?

I've seen several websites describing their systems as "all electric", but when I click the "more info", it says something like "air handling unit only".

Then click the "other hardware" and see "choose your compressor type, engine size, fan belt size", etc. Sure sounds like those parts still use the engine for compressor power.

Are there really such critters are *all electric* vehicle a/c units? So the blower, the compressor and the condenser run under vehicle 12 volt direct current?

thanks.
Tom
 
Simple physics says to me that it is unlikely. Takes a lot of power to turn even a small AC compressor. Tough to get much power out of a 12v DC system.

Car AC systems are way oversized compared to house units, for several reasons (like rapid pull-down, no insulation, higher heat load and much higher air infiltration rate). Typical car AC is around 5 tons or so; which means about 5 horsepower to turn the compressor, which is roughly 5kW of electrical power. That's roughly 400 amps at 12 volts! (All conversions very approximate, and in particular the hp to watts conversion includes a "typical" efficiency factor.)

Prius and all-electric cars do have an all-electric AC system (so it can work with the internal combustion engine not running), but they pull high voltage DC off the big battery, not 12v from the secondary battery (if it even has a 12v battery).

It also doesn't make much sense, IMO. You already have kinetic energy (in the form of a belt drive off the engine); why convert that to electricity (and lose a large part of it), then convert that back to kinetic energy and lose even more of it? Got to be more practical to add a belt drive, even to a TR3 (or MB 190).
 
Most newer small cars have electric power steering and A/C systems. You will have to upgrade generator to alternater and a minimum 85 amps. Very feasible as powerlite makes the generator conversion to alternater and then you would convert to neg ground if not already. A single wire altenator hook up will work too. If room needed find a new style toyota or honda alternater that is small for mounting.
 
In theory (!) you can always get something to work. But I'm tending toward Randall's line of thought where the car would have to have a *mighty* battery and alternator, to support the current draw an electric a/c compressor would need.

Wonder if anyone knows a website that actually lists a fully electric auto a/c system? and the electric supply requirements.

Thanks.
Tom
 
Like Randall said, I've always heard that the auto a/c drains about 5 hp off your engine. And even at an impossible 100% efficiency that's over 300 amps. If you could get by with an 85 amp alternator then that's under 1 hp to drive the compressor still leaving nothing to run the rest of the electrical system. That would have to be one extremely efficient compressor.

Of course, this is still speculation or calculation. I too would like to see some actual facts.
 
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actual facts - same here.

The EVs can use it, because they have massive batteries.

But I can't see pulling a trailer with a gigantic LiOn battery pack running a window a/c ...
 
Vintage Air
 
Larry - I just took a look at VA's online catalogue. Can't find any reference to all electric vehicle a/c systems. All their compressors seem to require a belt hookup - not an electric hookup.

Did you find an all-electric system on the VA site?

Thanks.
Tom
 
No. My brother-in-law put air in an Aurora Cobra and used vintage air. XKs sell a/c by pro air but do not know if electric powered. Has to be somewhere as all the new electric cars have the system. I'll start research when on computer next time.
 
Masterflux.com, Rigidauto.com, Denso Corporation, Electriccarparts.com, Alibaba.com***, all have 12VDC electric compressors. Alibaba actually have one shown. Did not go through specs but they do subtract 5HP as believed.
 
Thanks Larry. They definitely supply VDC compressors. I'd still like to find a company that actually makes the "whole unit" for providing a/c to a passenger car. It's probably the electric compressor's high current draw that keeps this a rare critter.

Tom
 
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Use 4/60 air-conditioning!

(4 windows down at 60 mph!) :smile:
 
Since the idea was brought up, got to thinking of A/C in my MKI, which is limited in engine room. Saw the Alibaba compressor and am now looking into restoring a rear A/C unit out of a MKII and replumbing to a electric compressor that will not have to be in compartment and install in the MKI. Just have to add a condenser in front and an electric fan. Will have either Powerlite or XKs convert old generator into an alternator. Only need 85 amps but they do up to 100 amps.
 
Larry - if you proceed on that idea, please document your research, as well as the step by step design and build. Seems lots of guys talk about doing that, but few complete the process.

I'd guess that a big issue is keeping the current draw from burning up the electrical system, as the alternator is continually trying to keep up with the draw from the compressor. And of course, you'd have to "match" the compressor with the rest of the components, regarding BTU need.

Thanks.
Tom
 
I'll see what comes up. I am in teardown mode at this time and have given a 3 yr. build time (hopefully), but have race duty in summer and the usual yard stuff and house remodel. First time I rebuilt engine and got to drive 500 miles and parked because of work. Second time I actually started stripping parts and interior and had to stop for a family funeral. Starting again, only have wife's Mom to upset schedule. Hopefully I can have metal all done and prepped and painted by fall next year. Interior will be most costly as I will buy a kit and install. Painting and mechanicals are done by me, so technically only other drawback is plating of chrome. Also need to find a fuel tank restorer. Have a good tank, just needs cleaned and a mount rewelded on. Still de iding what route to take. Rearend gears, auto vs stick etc.
 
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