Ceiling Fans

The first ceiling fans appeared in the United States in the 1860s and 70s, powered by a stream of water that turned a turbine and the fans via a series of belts rather than electricity. Examples of this approach can still be seen in some parts of the South where they first saw widespread use. In 1882, Philip Diehl modified his Singer sewing machine motor to drive a fan.

Today, ceiling fans are a common fixture in American homes. Their use in businesses has dwindled as advances in air conditioning have made them unnecessary. Yet, the ceiling fan does not get the credit it deserves when it comes to enhancing comfort.

Ceiling fans do not change the temperature of the air they move like air conditioners. It is the movement of the air that affects the comfort of occupants in the space. Who hasn’t enjoyed the cooling sensation of sitting under a fan on a hot day? The wash of air over your body makes you feel much cooler. This movement of air over our hot skin causes convective heat loss, or wind chill in weatherman parlance. This is especially true when we are sweating. As the air moves over us, the sweat evaporates and cools us down. No AC required.

On cold days when the heat is running, the last thing you want to do is increase wind chill. What you do want is to move all that lovely warm air from the ceiling back down to the floor where people can enjoy it. To do this, your fan must blow up (clockwise) rather than down (counter clockwise)1. All ceiling fans worth their salt have a directional switch for this purpose. The fan now pushes the cooler air towards the ceiling, forcing the warm air out and down the walls. No drafts for people, nice warm air where it is needed.

Fans make you feel more comfortable and have the possibility of reducing your energy use because of it. Keeping the conditioned air closer to floor level can make your thermostat think that it has satisfied the call for heating or cooling and it won’t run as often. In fact, you may get away with turning your temperature settings up or down a couple of degrees. That does save energy.

Okay, how about some tips on proper ceiling fan use? Here goes.

If you are installing a ceiling fan for the first time, be sure to attach it to a joist or get a bracket that spans two joists. Ceiling fans can be heavy and when spinning, put a lot of pressure on the mounting. Nothing will sour a nice evening at home like a ceiling fan crashing down.

I was asked to calculate the cost of operation of a house full of ceiling fans one time to compare against the cost of a central air system. The hopeful inquirer wanted to show the AC was cheaper. They lost, by a big margin. The cost to run a ceiling fan pales in comparison. If you want to see how much it costs, here is the formula using 75 watts (average for a 48” fan on high) 8 hours per day at $0.125 per kWh for cost:

(watts of the fan x hours of operation)/1000 = kilowatt hours (kWh) of electricity used

kWh used x cost per kWh = cost of operation

((75watts x 8 hours)/1000) x .125) = $.075 per day, a very affordable cooling solution!

While they don’t use a huge amount of energy, there are Energy Star models available so go with those whenever possible. And turn them off when you are not in the room…just like lights. Ceiling fans can help increase comfort and reduce energy use when used the right way.

1 Most references say a clockwise direction blows upwards, counter clockwise blows down. Not a bad idea to check your fan in case someone got their “wires crossed” in manufacturing!