This is awesome! No wait, helium would cause this super-efficient heat pump to cost more than it is worth and put a strain on areas where helium is needed, like

This is awesome! No wait, helium would cause this super-efficient heat pump to cost more than it is worth and put a strain on areas where helium is needed, like MRI machines, which are already having issues due to the increasing rarity of helium. Couldn't they have used argon or nitrogen instead of helium?