[bryanlarsen]

The complexity and ingenuity in the Tesla heat pump system is the octovalve, not the heat pump. 8 different places to source/sink heat, with different set points. Keep the battery, motor, interior each at different optimal temperatures with a single heat pump.

[jjtheblunt]

Yep. the non octovalve complex of separate valves and tubes between is where the BMW outsourced design failed.