Cooling
Fans work in basically two ways. One, they are often used to move air around
within the house making occupants feel cooler. In this mode of
operation, they do not actually cool the air. In fact, a fan operating in a
"closed" room will increase air temperature, because of electrical losses
from the motor. However, they make occupants feel cooler by moving
air across their skin. The moving air causes moisture on the skin to evaporate
taking heat with it. The cooling effect of moving air is directly related to
the speed of the air, which increases the body's evaporative
cooling. You have probably heard about "wind chill" in winter making it
feel colder outside than it really is. Fans are accomplishing the same effect
in your home by increasing the wind speed across your skin.
The second way fans are use to cool is by moving hot "inside" air out of the home, so it can be replaced with cooler, "outside" air. In this use, fans make you feel cooler because the air really is cooler. Whereas with the first cooling method, the air is getting warmer from using the fan to cool the body.
Compared
to refrigeration units, fans are much less expensive to purchase and
use very little energy. For these reasons, most homes in this country
use of some form of fan cooling. Even homes that use air-conditioning during
the hottest months of the year, usually use fans to reduce the amount of time
(or number of months) the air conditioner must operate. Systems that rely on
the movement of air include: natural ventilation through
"open" windows, window fans, portable fans, ceiling fans, whole-house fans,
attic vents, and passive ventilation.
And Furthermore . . .
| Window
Fans Portable Fans |
Ceiling
Fans Whole-house Fans |
