Electric aircon pump
Discussion
Does anyone know if is possible to run the aircon pump off an electric motor. I would like to move mine and ideally run it from a motor. I know the pump takes a lot of power at high engine RPM but the airconditioning still works at tickover so I would presume the pump does not need to rotate that fast and a high quality brushless motor may well be sufficient to work the aircon?
Is it worth the hassle? The reason it 'robs' a bit of engine power is because the compressor needs quite a bot of power to function, that's why it is driven by the engine. Some Hybrid vehicles use electric A/C, but they use a lot of power, you'd probably need the equivalent of a 240v battery to run it, and you'd have to install a seperate petrol powered engine to run an uprated alternator to keep the this battery charged.
If you are driving along with the aircon on, and suddenly find you need a bit of extra power - just reach out your finger and switch the A/C off.
If you are driving along with the aircon on, and suddenly find you need a bit of extra power - just reach out your finger and switch the A/C off.
Edited by JensenA on Saturday 20th February 12:07
The reason I might want to move it is because its fitted right where I would like to possibly mount a supercharger. I can of course remove the aircon compressor completely but then the Cerb does get very hot in the summer so it would be nice to keep it. I'm just considering different options and thought this might be a possible one.
^ 
I Understand that an air conditioning compressor saps at least 15HP from the engine.
If you think that 1HP is roughly the same as a 750w electric motor then you would be looking at needing a motor of around 11.25Kw, at 12 volts this would have a power draw of around 937Amps. Just think of the alternater you would need to power this and the batteries you would need to smooth the supply to the motor.
I don't think that an electric pump would work, can you see if there is any way you can just mount it else where and leave it engine driven?
Easiest way round this is to leave the windows open and revel in the whine from the front and the growl from the back!!
If you think that 1HP is roughly the same as a 750w electric motor then you would be looking at needing a motor of around 11.25Kw, at 12 volts this would have a power draw of around 937Amps. Just think of the alternater you would need to power this and the batteries you would need to smooth the supply to the motor.
I don't think that an electric pump would work, can you see if there is any way you can just mount it else where and leave it engine driven?
Easiest way round this is to leave the windows open and revel in the whine from the front and the growl from the back!!
gruffalo said:
I Understand that an air conditioning compressor saps at least 15HP from the engine.
If you think that 1HP is roughly the same as a 750w electric motor then you would be looking at needing a motor of around 11.25Kw, at 12 volts this would have a power draw of around 937Amps. Just think of the alternater you would need to power this and the batteries you would need to smooth the supply to the motor.
I don't think that an electric pump would work, can you see if there is any way you can just mount it else where and leave it engine driven?
Easiest way round this is to leave the windows open and revel in the whine from the front and the growl from the back!!
Although I don't think an electric air con compressor is viable on a 12v system, I think you are over egging the motor size a little as a standard room compressor pulls about 8 amps on 230v ac which equates to about 2kW.If you think that 1HP is roughly the same as a 750w electric motor then you would be looking at needing a motor of around 11.25Kw, at 12 volts this would have a power draw of around 937Amps. Just think of the alternater you would need to power this and the batteries you would need to smooth the supply to the motor.
I don't think that an electric pump would work, can you see if there is any way you can just mount it else where and leave it engine driven?
Easiest way round this is to leave the windows open and revel in the whine from the front and the growl from the back!!
On a 12v supply this is around 160 amps which is double a standard alternator output.
Due to the thermal loads placed on most vehicle ac systems, the power drawn from the engine is around 3 to 5 hp with the comp turning at around 1200 to 2000 rpm to give an ok output.
The transport refrigeration industry have tried to get 12v electrical compressor's or motor driven compressor's for many years with little success. I see many with faults and when I do get them to run they tend to be noisy and high maintainence.
Maybe you could fit a comp driven off the rear of the alternator (jeep's cherokee used this system on it's diesel) if there is enough space?
Ade
The transport refrigeration industry have tried to get 12v electrical compressor's or motor driven compressor's for many years with little success. I see many with faults and when I do get them to run they tend to be noisy and high maintainence.
Maybe you could fit a comp driven off the rear of the alternator (jeep's cherokee used this system on it's diesel) if there is enough space?
Ade
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