Fans don't make the air cooler! They work by blowing away the envelope of warm air that surrounds your body.
As a living creature, you generate heat. A lot of it. As that heat slowly radiates away from your body, it creates a pocket of hot air that surrounds you. It's like you're being insulated by an invisible bubble of heat. What fans do is to push that hot surrounding air out of the way.
This is why blowing on hot food cools it off. It's not that your breath is especially cool, it's that you're blowing the heat off the food.
If you're sweating at all then the fan also cools you by speeding up the evaporation.
So now that you know that fans don't make the air cooler, you can see that there's no advantage to leaving the fan on when you leave the room. Fans don't lower the temperature in the room at all.
By the way, a typical 36" / 48" / 52" ceiling fan uses about 55 / 75 / 90 watts of electricity respectively (less on slower speeds).
No comments:
Post a Comment