Electric A/C compressor
 

So I'm boosting my miata in the next few months and the manifold I have will require me to remove my belt driven A/C compressor and I'll most likely just remove everything associated with it. I have been thinking of possible ways to avoid this and after a little thinking and searching I realized hybrid vehicles have electric A/C compressors. I realize if I/anyone were to do this it's not the most pratical approach at this point in time(that I have found so far) but it's something that we might be able to do in the future.

I doubt anyone has tried or done this but I thought I would throw it out there to get the ideas rolling so maybe someone could source some cheap parts or make a kit or something.

The major problems I can see with this right now are:

1) Price. I randomly searched for a 2006 toyota prius electric compressor and fould it was in the neighborhood of $800.....schitty

2) Too much powa. I'm not sure of what kind of load this will place on the alternator given hybrids dont have alternators and I'm sure it's a lot.

3) Fabrication. This is something I dont think would be a big limiting factor because I would think you could place it basically anywhere in line with the A/C system but I could be wrong.

Like I said, just throwing this idea out there, please bring some positive feedback or lurk.

In for the out come. Sounds like a good idea but wouldn't it be cheaper to buy a new manifold?

I would agree but like I said, maybe someone knows something about this we don't??

Interesting.

I will admit that when I did the (completely custom) intercooler setup on my '92, I also removed the A/C compressor, however that was mostly because I am extremely lazy, the A/C system had never worked in the first place, and I live in SoCal, where A/C is kind of pointless.

That said, I would posit that the vast majority of those Miatas which started out with A/C and then received a turbocharger kept their A/C system during the process. Both Bell and FM's turbo systems require no modification of the A/C system whatsoever to accommodate them.

What I'm saying, essentially, is that if you desire to keep the A/C functionality of the car, redesigning the system to accommodate an electrically-operated compressor seems like the extremely hard way of doing things as compared to simply routing the plumbing in such a way as to allow it to be retained as-is.

What manifold and turbo are you planning to use for this build?



On topic, what little I can find on the Prius' AC compressor indicates that it is driven by a 3-phase AC motor, powered from the main inverter and operating at (or near) the "nominal" battery voltage of 200-270 volts (varies by year.) I found one fellow who measured the power consumption of the device, and found it to draw around 1,700 watts, which is over 2HP- well outside of the range of practicality for a small DC motor, and nearly double the output of the stock alternator.


The closest thing I could imagine to a practical solution would be something like this: http://www.masterflux.com/products/sierra/

There are a couple of products on that page rated for use at 12v, with current/power loads that fall nearer to the range of "not insane" within the context of a Miata (220-450 watts). Remember, of course, that cooling performance as measured in btu/hr is going to drop as a function of power consumed, so you'll have to determine whether an A/C system with roughly one-third of the capacity of a Toyota Prius, installed in an old, leaky convertible with much more heat penetration into the passenger compartment from the drivetrain, is going to be adequate.

Mr. Perez you have brought all my doubts to the surface, basically impossible with a hybrid's electric compressor and either way a lot of work for A/C. I am running a custom bottom mount ramhorm manifold and I'd rather have it than A/C, at least for most of the year. I will either get another one or tough it out depending on how I feel unless a better solution arises. Thanks for your help.

I hate to use words like "impossible", but attempting to use the specific compressor assembly from a Prius would definitely be pretty far out there near the extreme end of the "difficult" scale. You'd need to lug around a couple of extra batteries, an inverter, and an extra alternator or two.

The MasterFlux compressors, by comparison, would certainly be practical from a power-consumption standpoint, though you might need to re-route the freon lines into the trunk to find space to mount the compressor. The question would be whether the performance of such as system, in the context of a Miata, would be any better than being coughed on by a mouse.

Why not move the Miata compressor? You could go down an inch or two with brackets off the stock mounts or move it under the alternator if you want to make brackets and hoses. One of the local Red Dot brand air conditioning dealers here locally builds compressor brackets and hoses for machinery, heavy equipment, and vehicles that never had factory A/C as an option. We drop it off and they install everything. It really is no big deal for someone when that's what they do all day every day for a profession.

Wouldn't you run into an issue of finding a belt that fit? or would they most likely match it to the OEM belt?

I think you would need a custom belt. You would have to try and find one that the PS can tension enough to work. Probably best to find one off another car so you don't have to get one specially made everytime.

Either that, or just find a bloody exhaust manifold that doesn't park the turbo in the same space which the aircon compressor is trying to occupy. They're not difficult to come by.

But, that's no fun Joe.

Well obviously that is the best idea.

An issue? You mean like having to measure the distance around with a string and then going down to the auto parts store and spending $12.32 on another belt? Yes, then.