Why Reverse Direction On a Ceiling Fan?

I recently read an article on a green building web site that said ceiling fans are a waste of energy, and of course, I strongly disagree with the author’s conclusions. Here’s the truth. If fans are used wisely, they can reduce the amount of time that your air conditioning and heating need to be used and they can allow you to keep the AC or heat at a lower setting, too. That saves both money and energy, because ceiling fans use far less power than air conditioners, furnaces and boilers. In fact, some of our modern fans, like our Aeratron two and three blade fans and our Hunter Pacific Typhoon 316 fans, are incredibly energy efficient.

It’s all a matter of understanding when to run the fans and whether or not to put them into reverse. It’s common sense, but a lot of people just never stop to think about it. Remember: ceiling fans in standard mode blow air down and ceiling fans in reverse move air upward.

Ceiling Fan Standard Operation: Blowing Air Down

When do you want to blow air down from the ceiling? Usually, it’s going to be when you need air to cool your skin on a hot day. Blowing air downward can also draw air indoors from transom windows, operable skylights or the tops of double-hung windows. That can help keep the air in the space near the floor fresher and cooler. This is what people usually use ceiling fans for: cooling and air circulation. Never run outdoor fans unless someone’s there to benefit from the cooling effect of the moving air.

Ceiling Fans in Reverse: Drawing Air Up

When you put the fan into reverse, it draws air upward. Most people think of this as a way to bring the warmer air near the ceiling back down into lower half of the room, where the people are. That’s a great way to use the reverse function in the winter. However, it’s not the only way to use it. If your air conditioning vents are near the floor, then putting the fan into reverse can draw the cool air upward and circulate it around the room so that you can really feel it. It can help you to maximise the effectiveness of your AC, and that will allow you to keep it at a lower setting.

The reverse setting can also blow warm out of high windows, creating negative air pressure that will draw in cooler air from lower windows. Sometimes, it’s possible to blow warm air out on the hot side of the house and draw cooler air in on the side that doesn’t get direct sunlight.

So, next time you turn on a ceiling fan, give a little thought to what it’s supposed to be doing. Are you blowing air onto your skin so that you’ll cool down? Are you trying to draw cool air upward so that the warm air circulates back into the space you’re occupying? Are you using the fan to pull in outdoor air or to push indoor air out an open window? Next time, give it some thought – and be conscious about using your fans rather than cranking up the heat or AC.