a/c and energy consumption

<div class='quotetop'>QUOTE(poodlemaster @ Feb 10 2007, 04:29 PM) [snapback]388200[/snapback]</div>

The AC compressor is electrically driven and does not depend on the ICE running. If you've used defrost, then you've already used the AC compressor. I can definitely hear it I've got defrost on and I'm pulling into the garage w/ICE off. If it's running (can be off due to cycling), it shuts off the moment I press OFF on the HVAC screen.

 

Another thing about the great Prius climate control system is that the compressor and cabin air control system work together for your comfort. Set the temp where you are comfortable and forget it. Also note that in very hot weather, you should use the climate control system because the High Voltage traction battery is cooled with air from the cabin. If you are comfortable, the battery will be too.

There are a couple of currently or recently active threads about the air conditioning system. It heats, cools, reduces humidity, senses solar load, and doesn't use that much power.

 

Prius uses a relatively efficient scroll compressor. In the new model it is electrically driven and thus its speed control can also add to efficiency. It can also keep cooling with the ICE switched of, unlike the classic Prius system.

All that said, an added load of a kilowatt is still considerable. Using A/C a lot in the summer might cost you on the order of a couple of mpg.

The competitive fuel efficiency drivers sometimes wear vests with ice packs, to avoid A/C use.

 

if you're using the AC at a prolonged stop or while parked, you'll eventually drain your SOC, then it would still depend on the ICE to get your SOC back up to have juice to run

 

<div class='quotetop'>QUOTE(tochatihu @ Feb 11 2007, 09:45 AM) [snapback]388471[/snapback]</div>

Denso says "Air-conditioning systems should not rob torque from hybrid powertrains on hot summer days. And they need to be able to heat interiors on cold days with little help from engine heat. For the Toyota Prius hybrid car, we developed an ultraefficient air-conditioning system that consumes minimal power.

Our new subcool condenser and scroll compressor, equipped with oil separators, allow the air-conditioning system to run on 30% less power than conventional systems. And a two-layer flow heating, ventilating, air conditioning (HVAC) unit saves energy by recirculating heat already in the cabin. "

I find that any MPG lost due to air conditioning is more than made up for by the increased summer MPG.

Just set it to a comfortable temperature in Auto AC and forget it.

 

One thing you can do with the electric air conditioner is to run it while you're in the store shopping.

In order to leave the car locked with the air conditioning running, you have to use the mechanical key. The Smart key system will not allow you to lock the doors with the engine enabled. Just be sure to shift into PARK as well as setting the parking brake. I also set the display to OFF. Sure seems crude when I have to use the mechanical key to get back into the car.

I've only done this a few times, but it was really nice to come back to a car that was already cool. The ICE does cycle on occasionally, but not enough for me to notice any change in mileage.