Heat pumps of the 1800s are becoming the technology of the future

> heat pumps: electrical devices

Just to be pedantic, but not exactly. The typical design in a domestic heating unit, or refrigerator is mechanical. A fluid is pumped and cyclically compressed/expanded. While electric motors are usually used, they can be driven by any source of mechanical energy; driven directly by a combustion engine is not too unusual.

There are also heat pump cycles that can be driven directly with heat. Refrigerators based on that are relatively common here in Canada in areas without reliable grid electricity. Usually a propane or natural gas flame.

Thermoelectric coolers are actual electric heat pumps; directly moving heat across a semiconductor junction. Not very efficient and quite expensive practically. They're used in those USB drink coolers and to cool down lab equipment. Finding a high-efficiency thermoelectric material that works at normal temperatures and pressures is nearly as much of a Holy Grail as finding a high temperature superconductor.

Why can’t my whole home participate in this technology? It would seem an ok fit for things like freezers, refrigerators, hot water heaters, etc.

When it’s freezing cold outside, it seems crazy that I warm the air of my house and then use electricity to keep the fridge cooler than the air I just heated.

Someone needs to make a standard for moving heat/cool through all appliances in a house…

> Finding a high-efficiency thermoelectric material that works at normal temperatures and pressures is nearly as much of a Holy Grail as finding a high temperature superconductor.

Are they two sides of the same problem?

I had a similar idea when I was designing a heating system for a mountain house I was planning on building. I was planning on primarily heating with an oversized wood stove. The excess heat the wood stove would produce would be captured by a heat pump inside the house with its coils in a 500 gallon tank of water that was well insulated. When the house needed heat you could run the heat pump in reverse or make a system that removed the insulation around the tank of water letting the heat out. I had a spreadsheet with the heat calculations. I think the water at 150F degrees had around a megawatt of energy stored in it and that could have heated the house for a couple weeks. I never ended building that house, but would love to build a system like this in the future.

> it seems crazy that I warm the air of my house and then use electricity to keep the fridge cooler than the air I just heated

The fridge is simply moving a little of the warmth in your room out of its box, and adding a little more warmth to the room in the process. You lose no heat from the room, which is what matters, really. It would be worse to dump the heat outside! At least in winter. The heat has to be removed in summer if you have air conditioning.

In any case, an exterior heat exchanger and heat pump that can handle a wide exterior temperature is much more heavy duty. This could all end up being less efficient, in practice. House-scale heat pumps can efficiently move heat even from a freezing cold outside into a warm interior. Just as fridges can efficiently move heat from their cold interiors to a warm room.