Ways to cool or Heat the home

Just trying to think of ideas that would counter act the high bill situation of the central heat/air from the thermostat. If there are others ways in the game that can warm your sims during the winter or cool them off during the summer (other than swimming) please let me know.

Working Space Heaters would be nice, specially for those that don't have fire places.
Standing or desk fans.
Open the windows for natural breeze.

What might be some other ideas?