Anyone tried an electric AC compressor yet?

[E9Wayne]

I was dropping my E9 at the local shop to get a new high pressure hose installed (previous one ruptured at the crimping between the compressor and condensor and caused quite a scene on the freeway drive home for me). One of their mechanics said an early 1970s Mercedes-Benz 280SE 3.5 was coming in also for some AC work - specifically to install an electric-powered AC compressor versus the previous hydraulic unit that we all have. This intrigued me what the reduced power consumption from the hydraulics (and one less belt) and freedom of location although a more powerful alternator would be necessary, I'm sure.

Anyone try this yet who can talk about the pros and cons?

Wayne

 

[Stevehose]

A mega alternator will drag more on your engine than a stock one so the efficiency gain minus an a/c belt with electric is not 100%. You'll be going from mechanical (belt driven alternator) to electrical (compressor motor) back to mechanical (the compressing).

Cost? A replacement compressor/hose/belt for our cars is simple, pretty cheap, and time-tested.

How often do you use a/c?

 

[lip277]

Also - Getting a high power alternator can be a bit of a problem (if you want to stick with OE looking Bosch ones).
I found that out when I asked Don to install one in the car he was working on for me.
They are available - but are a pretty penny.... (as I found out).

 

[E9Wayne]

A mega alternator will drag more on your engine than a stock one so the efficiency gain minus an a/c belt with electric is not 100%. You'll be going from mechanical (belt driven alternator) to electrical (compressor motor) back to mechanical (the compressing).

Cost? A replacement compressor/hose/belt for our cars is simple, pretty cheap, and time-tested.

How often do you use a/c?

Hey Steve, I've used AC about 15 minutes over the last 10 years due to various hardware failure issues! I'm hoping that this is the last hurdle to good AC for me during those frequent summer events I tend to go to out here. Compressor, condensor, dual fan, evaporator/condensor, switches and expansion valve all replaced...not much more to break other than another shoddy high pressure hose...

 

[jmackro]

Modern, Asian-made, rotary compressors are pretty efficient and easy to mount. Substituting one of those for the original, piston compressor would be a LOT simpler than installing an electric compressor (and new alternator, and new wiring, and ....). Plus, as others have written, a modern, mechanical compressor has to be more efficient than the mechanical --> electrical --> mechanical chain involved with an e-compressor. I wonder why the 1970s Mercedes-Benz 280SE 3.5 guy is going that route.

 

[Arde]

The main problem of an AC electric compressor is that the AC cable has to be pretty long...
Seriously, the advantage is that you can have Air Conditioner with the engine off, if you have a large battery.
I hate cars and busses that leave the engine running when parked as the fumes do not dissipate. Hospitals ask ambulances to shut off the engine when parked at the entrance.

 

[dang]

How about an RV AC system mounted on the roof. Simple and you'd be the only one!

 

[bmw2800cs]

How about an RV AC system mounted on the roof. Simple and you'd be the only one!

Great idea!

 

[Nicad]

I don't have AC in mine and really can't imagine ripping my interior apart, sourcing all the parts and installing them. The stock system is so heavy too. If going electric, perhaps a system could be cobbled together using junk yard Toyota Hybric AC parts.
Pretty interesting compressors in those.

 

[x_atlas0]

Howdy, Wayne.

I saw a Porsche 914 on BaT a while ago with a fully-electric system and I've been thinking about the same thing. (https://bringatrailer.com/listing/1976-porsche-914-75/) There's also some other Porsche kits that convert their system to electric, I thought it would be a nice thing to swap over to one of our cars.

Here's the kit I'm talking about: https://www.classicretrofit.com/en-us/products/air-conditioning-kit-for-classic-911-full-kit

As others have mentioned, you need a honking alternator. I was looking at one from WASP, outputs around 300A as a drop-in replacement. I'm not sure what you need to do in terms of the belt, though, as I'd expect you need a lot more torque to make that much more current/power at the same RPM. Then you'd need to use a 12/24V AC compressor. I've seen them mostly used in campers and RVs.

I was looking at this one:

DC 24V Air Conditioner Compressor| 24V AC Compressor

Small 24V DC electric air conditioner compressor for truck, van, construction machinery and agricultural vehicles etc. Widely-used 24 volt DC compressor.

www.guchen-eac.com