As I said, I already have GPUs. If you don't think mining has been profitable for me and others during e.g. the last year then you need a reality check, cause it has been profitable.

> If you're already spending 1J of energy to get 1J of heat, a heat pump is not going to turn that 1J of heat into 2-3J of heat, nor is it going to recover any of the Joules you've spent to generate that heat.

It's not magic, or complicated. The energy spent is used multiple times, as I said. You can save energy using a heat pump both by using it for initial heating, or transferring existing heat that would otherwise be thrown away.

So no, I'm not misunderstanding anything. If you think it's not possible then you too can get this "magic" using e.g. Nibe F750 + SAM40. Check their documentation, it even has charts for everything!