Hello amigos,
Just passing along my findings in hopes to help anyone looking to add air condition to their vehicle without robbing HP. I found an affordable 12 volt AC compressor on Amazon.


Here the link:
https://www.amazon.com/gp/product/B09661D1ZY/ref

This looks like the one I bought for my car.

I will let you know how it works once it is in.

Clay

what is the alternator requirement for this, i dont see listed what the amp draw is, but i would assume we would still need a 150amp alternator, then other needed parts like
condenser dryer etc., Clay where are you going to mount the compressor, in spare tire location ? would save running any coolant lines front to back. could it fit where the washer bottle is?
@ClayPerrine

It does list the current requirements.
10.5VDC～15VDC / Current: 45A+-2
Pretty low cost compared to Benling.

Any electric driven compressor will draw additional energy (amps) from the alternator, which in turn requires more energy (HP) from the engine to spin the alternator. There is no "free" horsepower.

lol...my response was going to be, 'figure out some way to make the compressor drive the wheels and it'll make "free" horsepower!!'

45 amps, that's a chunk. # 6 copper should do. 45 amps will not be free, but one way or another it will be driven off the engine. What will end up the most cost effective will be the question. I ran a 200 amp alt with a bunch of offroad lights, it worked well but it worked hard and didn't last. I need to do one or the other

I took the plunge and ordered one. I will document the installation when I put AC in my 914. I already bought a hi-amp alternator kit from a 914 World Vendor a while back, so it’s time to get busy installing it to handle the current draw from this compressor. I plan on mounting the electric compressor in the frunk to avoid cutting holes in the longs and engine bay.
Mike D.

The only way you could possibly get something "free" out of this is to manage the alternator charge during specific periods, by recovering energy in a different way.

For example, you could install a big-ass battery and a total discharge controller such as at the below link, allowing your battery to be deep-cycled during normal use, then design a system such that it will only high-charge the battery during off-throttle loads such as deceleration. In this manner, you maintain battery voltage to drive the car without loading it, and then use the alternator to recover that energy during off-throttle instead of wasting heat energy from the brakes. It's the same idea that "hybrid" cars use to recoer energy and get better fuel economy.

https://raceenergyperformance.com/collectio...products/tdc-30

But let's face reality here: we're talking half-century old vintage cars, used for fun and part-time pleasure, and by the time you engineer and install these systems you may want to take a step back and think to yourself "why...?"

But to each his own.

Greg

P.S. that system is used often in our race cars to manage voltage in EFI systems when you don't want to run an alternator. Even basic EFI/ignition/pump loads will take 3-5 hp from a typical engine; I can't imagine what 45A would do.

I don't know what output is available from special 4 cyl. alternators but there are 150 amp units available for 911 engines.....is that enough to support a 45 amp draw ?

Lots of variables... What is the total draw of everything running at the same time? i.e. lights, stereo, etc. Plus for instance the 3.2 six has a 90 amp alternator, but at idle while stuck in traffic, it does not put out 90 amps, so you could be draining the battery. Classic Retrofit recommends the 175 amp alternator, since it can supply high current at idle. https://www.pelicanparts.com/More_Info/WSPL...SI=804&fs=0

I think it would be wise to note that typically the Compressor isn't on 100% of the time. Once the cabin is cool, and we have a tiny cabin, it gets under 50%. So you won't need 100% of the amps 100% of the time.

They seem to say this comp is designed for RV refrigerators, so it might be inadequate for the heat load of the cabin. So it might be on all the time anyways.

Also, alternators are rated at a high RPM. So 90a at say 5000 rpm but only 20a at idle. There is a chart for the 914 alternator in the brochure.

Might want to plug in an old school amp meter from the days before the volt meter became standard.

The AC compressor is going in the right rear corner of the front trunk. The lines from the evaporator and condenser are already setup to go there. I will be using hard metal lines instead of flex lines to hook it all up. The compressor control unit will go under the gas tank on the left side. I will run a dedicated electrical line from the battery positive to the control unit so I know I have enough amps.

And I have a 964 engine with a 180Amp alternator in it. So I am not worried about available amps. Yes, it will make an additional load on the engine, but it beats trying to find a place to mount an AC compressor on the engine.

Clay

I'll be watching
Very interested in what you are doing.

Thanks

George

Hi Clay, Please let us know how it all works out for you. I like your ideas for this type of ac system. Can you tell me where you sourced your A/C hard lines and line bender, i have only found rubber flex lines but I also prefer hard lines.

Thanks
Al

Al,
I am going to make the hard lines. I will get the fittings off the ends of the flexible lines, and Summit has the tool to make the o-ring flange.

Clay

This would be a great option for 914-6 conversions as there is little room for an AC compressor in the -6 engine compartment.

It does state 850 watts, which would be 70 amps at 12 volts by my calculation.

You are right 70.833 amps. Scratch that #6 copper, For spike safety I'd go #4 copper That is a lot of amps. Standard residential circuit is 20 amps, my stick welder uses 50 amps

Careful

Click to view attachment

[quote name='ClayPerrine' date='Jul 20 2021, 08:27 AM' post='2932046']
[quote name='DRPHIL914' post='2931867' date='Jul 19 2021, 01:24 PM']
[quote name='ClayPerrine' post='2931859' date='Jul 19 2021, 02:05 PM']
[quote name='ahycaramba' post='2931845' date='Jul 19 2021, 12:37 PM']
Hello amigos,
Just passing along my findings in hopes to help anyone looking to add air condition to their vehicle without robbing HP. I found an affordable 12 volt AC compressor on Amazon.


Here the link:
https://www.amazon.com/gp/product/B09661D1ZY/ref
[/quote]


This looks like the one I bought for my car.

I will let you know how it works once it is in.

Clay
[/quote]


what is the alternator requirement for this, i dont see listed what the amp draw is, but i would assume we would still need a 150amp alternator, then other needed parts like
condenser dryer etc., Clay where are you going to mount the compressor, in spare tire location ? would save running any coolant lines front to back. could it fit where the washer bottle is?
@ClayPerrine
[/quote]

The AC compressor is going in the right rear corner of the front trunk. The lines from the evaporator and condenser are already setup to go there. I will be using hard metal lines instead of flex lines to hook it all up. The compressor control unit will go under the gas tank on the left side. I will run a dedicated electrical line from the battery positive to the control unit so I know I have enough amps.

And I have a 964 engine with a 180Amp alternator in it. So I am not worried about available amps. Yes, it will make an additional load on the engine, but it beats trying to find a place to mount an AC compressor on the engine.

Clay

Great info Clay, my compressor plan is similar to yours.
I'll go with the high output UK alternator on my 3.0 SC engine
My two issues are placement of the condenser and creating an evaporator/dash
vents that look OEM
I'd like to use the void in front of the right rear tire for the condenser but making
it look 'right' on the GT quarter is a challenge.
As for the dash / evaporator a period 911 Behr under dash unit might work
.....I have one to size it up or
mount the evap toward the pass. footwell and plumb delivery to the center
floor and late dash end outlets.
I'm not a fan of the available aftermarket under dash outlets.

I was just reading that the Prius and other hybrids are using electric AC compressors

A Prius compressor won't work.

Most of the hybrid cars use a 440V AC compressor powered from the main battery pack. I know this is true of the Prius. I found it out when I was researching 12v AC compressors.

Clay

I just read that, I was looking at RV systems and a couple on board electronics cooling systems, but the BTU's on the latter were 1/3 of what you are looking at but the wattage was around half. Wrong direction.

The title on the thread gave me a chuckle:

1. I am old enough to remember the K-mart days and the gal with the microphone and flashing blue light.

2. The coorelation now with Amazon and K-mart with the blue light.


Maybe Mark can start making them?

Click to view attachment

This is the underdash evaporator I'm having installed.

https://www.vintageair.com/custom/product-pop.php?pn=674005

It will operate with a Sanden SD7H13 compressor. The engine mount and pulley are supplied by Gilmore Enterprises. They may have something suitable for the -6 engine.

There's nothing free with an electric compressor. 850 watts is just over 1hp. That power comes from the engine as well...

I know it's not free. But it is much easier to run heavy gauge wire than to make a compressor mount for the 4 litre engine.

Clay

I also looked at aviation systems, they were light but pricey.

How about one of these?

Not too effective in the Texas heat....... you just end up with hot water all over you.

Clay

PM'd you.