Electric A/C install on my 328

Any Update on warm weather performance?

I've done a LOT of research/reading about this subject (electric compressor) since this thread originated and everything I've read so far from AC tech companies that deal in car AC, including those that make electric compressors for cars, indicates that a 12V electric compressor cannot provide sufficient cooling in a car, even the smallest cabin.

At higher voltages, of course, they can. I figured, heck, they cool Teslas with electric compressors so what's the big deal? Well, the 'big deal' is the voltage available. I (erroneously) thought and stated earlier that the Tesla AC was powered by 48v...it's powered by 400, yep, you read that right, FOUR HUNDRED volts!

The only way - per several companies - that a 12v system could spin a compressor to cool the car equal to what an engine-driven compressor can do would be with battery cable-sized connectors to the compressor and an electrical system capable of delivering around 200 amps to the compressor, plus the other electrical needs of the vehicle.

SO...again I am (we are) very interested to see if the compressor in this thread employs new technology that overcomes the limitations that have existed up to now. I sure hope so!

Pleas keep us updated!!

 

Heck - maybe this will eliminate the need to worry about the car's AC - https://www.engadget.com/2019/07/28/sony-reon-pocket-wearable-air-conditioner/

 

C'mon Tony, update!

I'm concerned this thread is going to go the way of the Fabspeed guy's (absurd) claim a couple of years ago that they were developing an exhaust system that would add 30+ HP to a 3x8. He, of course, never returned because the claim was impossible by any know physical laws (at least in this universe). But the newest technology MIGHT make the 12V electric compressor workable! What's happening?

 

i think what is happening is the air flow has found another way to make it through. Not sure but it looks like about 10 degrees cooler than before...Maybe because no spare tire in there to block air flow??? good question and i am keeping an eye on it as i am not sure why it is running cooler...

 

We have determined to put in the next level up of the compressor....6000 BTU.... I am comfortable with the way things are but my wife runs hot any way so going to make it a meat locker in there.... swap out will be easy as the replacement parts are identical to existing..... no draw down on the battery and car is running great..

 

you are spot on but i am putting the high output one one that does 130 amps...more power arugh

 

UPDATE... Took the 1500 mile trip and it is official 3000 btu cooling a/c is not enough cooling. Next week will swap out for same system but with 6000 Btu and see where we are at.... The realization that i may need to do a complete over haul of cooling system is starting to look real. Because my primary focus is on cooling and not heating we may consider what modifications can be made to the ducting to increase cold a/c. I need to find a way to completely block off all esternal heat entering cabin.... will advise

 

Out of interest are you just running the electric compressor or are you still using the engine driven compressor in parallel

 

Just the electric compressor.... took the York (original) out and sealed all the hoses up.

 

Reason i ask , i was wondering if you could run both with non return suction and discharge valves in the line. Run the engine unit as primary and have electric one cut in and out on a danfoss pressure switch with a differential . As long as your condenser and the rest of the system can handle the volume i would think it might work. Are you still using the same expansion valve , i seem to recall from my refrigeration days that these have an inlet orifice to limit the freon flow rate, so u could change this to get a bigger flow if the evap could cope with it.

 

got a new expansion valve put in but your thoughts on this are most interesting.... My primary reason for doing this was two fold. first to not risk catastrpohic failure with the a/c belt letting go... and to see if all electric is good enough to do the job..... however your thoughts pose a third option i had not considered... thanks

 

Have a look at the liquid freon inlet connection to the expansion valve, if it is like some i have seen you will find a brass cone with a mesh filter attached to it, lift this out and see if there is a top hat with a tiny hole in the base of it. If this will lift out it will have numbers stamped on the outside, this tells you the max liquid freon flow. You can fit a huge compressor but this controls the flow rate in the system, so a big compressor is not going to help if the max flow is already fixed by this hole size.
If you go bigger you have to be sure the evap and fan can handle it- if you find that the suction is getting too cold ( due to too much flow) you risk getting liquid freon back to the compressor and damaging the compressor bearings or the compressor itself.
The fix is to increase the airflow over the evap with a better fan
The liquid freon gets compressed with the gas and boils off in the oil- the discharge gauge will be fluctuating . If your compressor had an oil pressure gauge you would see the oil pressure all over the place .
If u had the 2 comps in use, the electric one would be No2 and as the suction pressure increased your pressure switch would cut it in until it dropped enough to cut out. Hence a danfoss pressure switch with a differential setting

 

nice explanation and this is an option i will now consider..... after the results come back for the new unit I will consider this as an option... very nice explanation thank you

 

Tony, is the electric compressor you have is the same electric compressor use on the new electric cars now like Tesla and other electric cars like BMW I8?

 

No.

Electric cars generally use compressors that operate at the car's battery voltage. In the Tesla and the the Leaf, that's approx 400 volts. Don't know about the BMW but it's probably in the same range.

 

https://www.ebay.com/itm/24V-DC-Refrigeration-Compressor-AC-Air-Conditionner-Reefer-Solar-6000btu-R134a/183418056585?hash=item2ab4916f89:g:chwAAOSwCmZZOBxg

 

https://www.ebay.com/itm/24V-DC-Refrigeration-Compressor-AC-Air-Conditionner-Reefer-Solar-6000btu-R134a/183418056585?hash=item2ab4916f89:g:chwAAOSwCmZZOBxg

 

Are you getting anywhere ?

 

new system is in and seems to be doing the job.... getting a lot of condensation water that some times over flows into the lower vents. Waiting on new expansion valve so make final tweak.... not gonna change it back at this point. the 6000 btu unit did the trick and only needs a can and a half of R134a to fill it... easy to maintain and no risk of belt failure. will advise

 

So the update is that the 6000 btu unit does the trick. We are still tweaking it with new expansion valve but other than that it does the job. With the top on and windows up the temp inside stays low 70 when it is 95 outside. Once I get on the highway it runs cooler. i would suggest any owner to consider this alternative as long as it is done right. i will not go to the vintage air replacement system nor put back the york compressor. This new system shich is all electric and allows me to control the compressor directly through the pediiometer. (controll more or less cold) My fans are more than enough and the evaporator and condensor are just fine to handle the load. It make a big difference when all the correct5 vents are opened or closed to maximize the a/c. no small feat on this car as the center consol controls are digital and rarely work properly. i had them all resodered and then shut all vents from the outside since the a/c is an automatic recirculation type system in this car. (keep all hot air out)
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I do like to see a man enjoying himself- any thoughts about fitting a CAT diesel geny in a spare bit of space so you have enough volts !!

 

That is funny right there..... thank you for the thought... Gonna tweak it this week and take a ride to Texas nice and cool....

 

Where does the 24V to run that compressor come from, is there a 12 to 24VDC voltage converter included as part of the unit? What is the specified amp draw at 12V (or 24V) to operate the unit? I tried to find that info on the link page but that link page won't fully load for me for some reason...

 

converter takes care of volts and amps. 50 amps is the draw and it puts no electrical issues on the car... works great