August 2014 US-spec BEV with standard heat pump question:
OK, so the first really cold weather has arrived in my part of the world and I'm starting to have doubts about my heat pump. Certainly when the A/C is working hard, the compressor is fairly noisy, and from outside the car it can be heard from the rear left underneath the car, and sometimes even from inside the car with the windows closed. Now that I've run the heat in cold weather, the range has dropped off more than expected (and this is not my first EV), but I never hear the compressor running. I can confirm that the heat exchanger fans are running up front despite the cold conditions (which suggests that it's trying to use the heat pump), and the heating itself is working fine, but I'm starting to wonder if my heat pump is actually working or if it's just using resistance heat.
Is the heat pump heating using the same compressor as AC cooling? Any reason it should be freakishly quiet in heating mode? In my experience with residential heat pumps, they are usually noisier in heating mode than in cooling mode. Is there any good way to confirm heat pump operation/performance, or any known method of heating system operation that would fit the pattern I'm seeing?
By the way, my definition of "cold" is 20-50 degrees F or roughly -5 to 10 degrees C. I park the car in an enclosed garage that doesn't get very cold, charge overnight, pre-condition based on set departure time, drive efficiently (I get an indicated 5.0 miles/kWh when the weather is mild and I'm not on the occasional high-speed highway trip), and left the house this morning with a full battery and an indicated 56 miles of range.
OK, so the first really cold weather has arrived in my part of the world and I'm starting to have doubts about my heat pump. Certainly when the A/C is working hard, the compressor is fairly noisy, and from outside the car it can be heard from the rear left underneath the car, and sometimes even from inside the car with the windows closed. Now that I've run the heat in cold weather, the range has dropped off more than expected (and this is not my first EV), but I never hear the compressor running. I can confirm that the heat exchanger fans are running up front despite the cold conditions (which suggests that it's trying to use the heat pump), and the heating itself is working fine, but I'm starting to wonder if my heat pump is actually working or if it's just using resistance heat.
Is the heat pump heating using the same compressor as AC cooling? Any reason it should be freakishly quiet in heating mode? In my experience with residential heat pumps, they are usually noisier in heating mode than in cooling mode. Is there any good way to confirm heat pump operation/performance, or any known method of heating system operation that would fit the pattern I'm seeing?
By the way, my definition of "cold" is 20-50 degrees F or roughly -5 to 10 degrees C. I park the car in an enclosed garage that doesn't get very cold, charge overnight, pre-condition based on set departure time, drive efficiently (I get an indicated 5.0 miles/kWh when the weather is mild and I'm not on the occasional high-speed highway trip), and left the house this morning with a full battery and an indicated 56 miles of range.