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Old 12-07-2014, 07:43 PM   #1385 (permalink)
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Originally Posted by e*clipse View Post
...Also, I'm looking at how to heat/cool my EV. The available options are pretty lousy, IMHO. There is no cooling option, and the heating option is expensive and totally not appropriate for a vehicle. The new technology is heat-pumps - yes, the EV1 had one, the new Leaf has one, and the Renault Zoe has one. I've been looking around, and found a pretty svelte one that uses a little BLDC motor for the compressor. - Hey! what about this controller??
I also am looking into eventually using a reverse cycle heat pump set up to heat and cool.
Initially i will use a ceramic heater element to replace the existing liquid heater core. That is a super cheap option. Ceramic heaters can be found for less than $20. Of course they are not as efficient as a heat pump but it will do the job initially.
And i will use the existing A/C compressor driven off of the non drive end of the traction motor. Again cheap and will get the job done.

I had thought of doing a heat pump with some sort of small electric motor to drive it.
But then i thought, why not just run the compressor off the traction motor?
As long as the traction motor has enough torque to spare then it means i save the weight of an additional motor for the compressor as well as the complexity and weight of a second controller. It is also very cheap as a standard ICE belt driven compressor can be used. Although i would like to get a nice efficent scroll compressor out of a modern split system set up.

The compressor wouldn't turn when the car was stationary but as long as it was just a brief pause like say, a set of traffic lights, the existing pressure in the system should keep it going for a little while and it will be re-pressurised as soon as the car takes off again.
Or if it was a longer stop than the car could be put in neutral and the and the motor brought up to a low RPM to operate the compressor. Much like an ICE vehicle idling.

Actually seeing as the compressor has an electrically activated clutch maybe it could be made to only activate when there was spare torque available. So not when the car was accelerating, only when it was cruising.

Actually another thought, for the guys that don't have a regen capable motor having the compressor engage on deceleration would be a way to recover some energy.

I am sure Paul's controller would be capable of running a small motor to drive the compressor but it may be a bit of overkill.
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