<VV> 12V AC install

[James Davis]

70 amps @12 volts is 840 watts or about 9,000 btu asuning the condenser is
at 90 F degrees.with a relative humidity of 50% or less.  Typical
evaporator draws about 9 amps on medium or 12 on high. It is
usually necessary to mount an electric fan on the evaporator so add
another 10 amps  A140 amp Delco 12SI can be bought and modified to fit a
Corvair engine.  The alternator RPM to produce the 140 amps is 6,500 to
7,500 rpm.  The relationship of engine rpm and alternator RPM is 1.45:1.
For the alternator to produce the required 90 amps, it would be about 3,000
rpm.  So, it could work on the road if the conditions are favorable.  To
work around town you would need a large (300 AH) lithium battery to operate
the A/C when the was at a lower rpm.  A solution I have seen on the
Greenbriers is to use the A/C pull to drive a second alternator on a
custom mount.  Wiring the two alternators in parallel would allow the a/c
to be used around town with just a small battery (100 AH).

Based on my Rampside with A/C there is a 4-6 mpg reduction in mileage and a
50 t0 80 increase in cylinder  temperature and a 40 degree increase in oil
temperature.  Because of air dynamics  and condenser location, there will
be less heat and fuel mileage loss in a car.
Jim Davis

On Wed, Dec 3, 2025 at 1:07 PM Tim Frederick via VirtualVairs <
virtualvairs at corvair.org> wrote:

> Hello all,
> I was recently discussing auto AC with another car nut and I shared my
> desire to install AC into my 63 Monza. He said he had installed AC into one
> of his vehicles using an AC kit that came with a compressor that was
> powered by 12 volts and didn't need to be attached to the engine and run
> off a drive belt.
> Does anyone have experience and advice with this product installed in a
> Corvair? Below is a link to a system offered on Amazon that gets good
> reviews.
> Amazon.com: 12V 12000 BTU Under Dash Air Conditioner with Heating,
> Universal 12 Volt A/C Kit System, Electric 12V DC Underdash AC Unit Quiet,
> Fast Cooling for Classica Car, Automotive, Truck, ATV, Pickup,Tractor :
> Automotive
>
> Tim Frederick1963 Corvair Monza CoupeTampa, Fl
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