Ceiling fans can be set to push air up… or run in reverse to push air down.
Here’s the question… which direction should you use in summer and which direction should you use in winter to get the most efficiency from you AC/heat system? I’ve heard lots of differing opinions… I’m turning to GQ/SDMB for the fact of the matter! Thanks!
The ceiling fan is intended to circulate air within a room, in order to accomplish two objectives:
- This prevents “stale air” from accumulating in areas which would otherwise have poor natural ventilation, and
- This helps to achieve a consistent temperature throughout the room, by reducing the significance of natural convection (i.e. eliminating the natural floor-to-ceiling temperature gradient which would otherwise exist, and eliminating cold spots adjacent to windows, etc.)
The actual airflow direction is not significant, provided the fan is effective enough to create circulation within the room, and promote mixing. Here is where the functional difference might lie, as with the fan pushing air to the ceiling, you automatically create an airflow that spreads radially outward from the fan until hitting the walls and moving to the floor. With the fan pushing air in the other direction (toward the floor), circulation at the far edges of the room may be less significant. This will depend greatly on the amount of air moved by the fan, and the size and geometry of the room in question.
winter: clockwise to push the warm air down
summer: counter-clockwise to force the hot air up against the ceiling and doewn the walls to create a cooling effect
A recent, related thread:
Help for the ceiling fan illiterate
don’t ask, as noted in the discussion in the thread to which squink linked, there are differences of opinion regrding the winter setting, but in the summer, one direct cooling effect of a fan is to have moving air passing directly over one’s body and a fan that pulls air upward cannot generate that effect.
(And while the winter setting does get generate some controversy, fan manufacturers recomend the exact opposite of your statements.)