Hey gang, has anybody here figured out if it's more efficient to use HVAC to heat the cabin in manual mode, with the fan only, or in auto mode? I use manual mode (A/C off), and the cabin heats fine to my 69/70 setting. As soon as I put it in 'auto', I can hear more racket. It sounds like an A/C compressor kicks in, but with the heatpump, doesn't a 'compressor' has to be running all the time??? At least that was my understanding after watching a not-very-well-done video of the system.
A more pointed question: If I'm using just the fan in manual mode, what's exactly happening with the heatpump? And does the heatpump have its own compressor, besides the A/C one? Thanks gang. Just want to understand the system better. Thank you.
You most probable can not change the way the heat pump works. Dont know about differen sounds but that is how it should be.
As in all other cars with HVAC the difference between Auto and Manual is that in Auto the software controlls the fan speed and from which outlets the air is coming. In manual you control these.
By the way, I have that problem with the heatpump( probably that/those pressure sensors). Lost heat once completely about new year. Havent had a complete loss since then but I hade bad heating capacity early in january. (1000km to the Sercivecenter so I wait until I know a trip will fix the issue.)
Anyway, after any of the software updates I dont loose heating capability. But sometimes I feel vibrations in the steering wheel, and if driving really slow or out of the car I can hear the heatpump work in a very angry noisy mode. Most probable this is the direct heat mode, where it isnt working as a heatpump but produces heat by direct 1:1 ( like the older hair dryer heater).
I now have seen this enough times to have reilable data of the consumption. Seen it about 1/2 to 1/3 of all trips lately so I have trips both with the heatpump working as it should and int the driect 1:1 mode.
Same drive, same speed same temps the consumption driving to work is like this( example with cirka -10C)
Heatpump works: 165-170Wh/km
heatpump dont: 235-240Wh/Km
This is a 40% increase in consumption.
I see the battery power parked/heating on goes to 6kw instead of about 1.5 or so. Also, it gets way hotter inside with the same temps setting and its fairly hot around the feets.
Maybe this is the difference we would se between a heatpump m3p and a non heatpump m3p in the same conditions.