Lots of colleges have steam tunnels too. With individual heat pumps you probably lose some efficiency but the source doesn't have to get as hot or as cold. Doin

Lots of colleges have steam tunnels too. With individual heat pumps you probably lose some efficiency but the source doesn't have to get as hot or as cold. Doing a residential retrofit sounds like herding cats but in somewhere like Phoenix or Tucson the efficiency gains might be worth it.