Tesla has unveiled Megamanifold, their next-generation heat pump. It runs cabin HVAC and powertrain heating and cooling at the same time, and the Tesla Semi can draw excess heat from the powertrain and use that to heat the driver's cabin.

I know @elonmusk has a lot on his plate but I really hope he can put some engineers into home hvac and water heaters. It would make a lot of sense to dump the heat from air into a hot shower.