What I had in mind was that heating and cooling using an air-conditioner, a fridge or a "heat pump" is fundamentally the same thing, and electricity is just one way of driving it. Ultimately you have a gas that you compress to release heat (outside for AC, inside for heat pump), which then expands (inside for A/C, outside for a heat pump). The compressor can run off a pedal bike for all it cares.
