Auris Hybrid Aircon

[Jonmartin]

Can anyone tell me how the aircon is driven. Is the compressor belt driven from the engine or is it electrical, like a domestic fridge ? And is a buzzing noise normal, or do i get it looked at by an expert ? And not necessarily my toyota dealer, but an aircon specialist.

[Gerg]

Our Auris Hybrid aircon is noisier than I expected too, but then the lack of other noises to mask it means it is the only 'engine' noise sometimes.

The aircon compressor is electrically driven (from a high-voltage supply, I believe).  There are no belts on this model of engine, the engine coolant (water) pump, inverter coolant pump and A/C compressor are all electric, as is the brake booster pump, the function of which used to be operated by engine vacuum/servo combination (on a conventional petrol engine, anyway). 

There is a crankshaft drive pulley visible on the driver's side of the engine, it drives nothing.

[Jonmartin]

1 minute ago, Gerg said:

Our Auris Hybrid aircon is noisier than I expected too, but then the lack of other noises to mask it means it is the only 'engine' noise sometimes.

The aircon compressor is electrically driven (from a high-voltage supply, I believe).  There are no belts on this model of engine, the engine coolant pump, inverter coolant pump and A/C compressor are all electric, as is the brake booster pump, the function of which used to be operated by engine vacuum/servo combination (on a conventional petrol engine, anyway). 

There is a crankshaft drive pulley visible on the driver's side of the engine, it drives nothing.

Thanks for the info.

I don’t use aircon much, only when it’s really hot in the car. So no belts, mean no drag on the engine so it shouldn’t increase fuel use. Maybe ? It is a very noticeable buzzing when stationary or running on EV. The car is due a service in a month or so, I’ll perhaps mention it.

[Gerg]

The HV (traction) Battery will discharge faster with the aircon in use.

As a perverse side note, if you google 'Prius car camping', in the US there some folk who have tried sleeping/camping in their gen 3 Prius (so same engine) for practical reasons, or just to see what happens.  If the 'engine' is left on through the night then the car reliably kept them at the specified temperature, the engine (ICE) cutting in from time to time to recharge the HV Battery.

IIRC, a car used about two US gallons of fuel per night in the rather warm US temperatures.  Those that have tried it considered it a very useful feature.

Maybe you have room to do this in the Auris estate? It wasn't mentioned in the brochure...

In a similar spirit, some US owners experiment with the car's inverter output (12v, I think) to attempt to turn the Prius into a standby mains supply (via another inverter?, I can't remember), for powering their house during power cuts etc. Again, 'engine' is left on, the car sorts the rest out.

[Mike J.]

1 hour ago, Jonmartin said:

It is a very noticeable buzzing when stationary or running on EV.

Could this just be the aircon fan at the front of the car. My Yaris Hybrid fan is noisy (buzzy rather than whooshy), but I checked against a new one and sounds were similar. Been the same for 2 years so far.

[ArranB]

Yes it’s noisy and the buzzing is normal, it’s the electric compressor and/or twin fans running on the condenser