3 ms·

It isn't. It's just warmer than air in winter

• alextingle 11mo ago
  The air temperature isn't relevant.
  • pbmonster 11mo ago
    It is, since the obvious alternative to taking the heat from water would be taking the heat from the air or from the ground. The air is colder in winter than the water, and the ground only provides a limited amount of heat before you can't extract any more. So water beats both.
  • georgefrowny 11mo ago
    It is a bit relevant because if the air was warm enough you would be better building huge air source heat pumps. And if it was really warm enough you wouldn't need heating in the first place.
• deleted 11mo ago
  [deleted]