Last week I wrote about “How Much Does It Cost To Keep The Lights On?”  I discovered that we were burning a lot of extra money every year with standard incandescent lights.  As I was installing the new CFL lights I got to thinking about our ceiling fans and how much it costs to run the fan and how much money it was saving.  I learned some pretty interesting things…and found out I was wasting more money.

Ceiling Fans Are Low Cost

I had always assumed the motor in a ceiling fan consumed a fair amount of energy.  Turns out the motors in most of our fans consume about the same amount of electricity as a standard light bulb.  Our fans are rated at 60 watts per hour when operating at medium speed.  They only consume 90 watts per hour when going full speed.

Using the same calculation as last week, we can figure out what it costs to run our fans overnight.  We have 3 fans running (180 watts total) at night for 8 hours.  Remember to divide watts by 1,000 to get it into kW:

(180 / 1000) * 8 hours * $0.09 per kWh = $0.13 per night

At a cost of $0.13 per night, ceiling fans cost less to operate than I had imagined.  Even if we cranked the fans up to max speed (90 watts) it would only cost $0.19.  This is a pretty good deal.

Ceiling Fans Cool People, Not Rooms

Perhaps I am the only person who thought that ceiling fans helped to reduce the temperature of the room.  They don’t…at all.  Ceiling fans use evaporative cooling to reduce the perceived temperature for people.  They do not impact the actual temperature of a room.

I didn’t believe this, so I did a quick experiment.  Our guest room stays a bit stuffy so I had always used a ceiling fan in an effort to keep the air moving and the room cooler.  Using a wireless thermometer I monitored the temp in the room for two hours at night.  For the first hour I ran the ceiling fan and the temp fluctuated between 80 and 81 degrees.  For the second hour I left the ceiling fan off.  The experts were right since the temp stayed between 80 and 81 degrees with the fan off.

Lesson learned!  Turn off ceiling fans when you are leaving a room, unless you like wasting money.  Ceiling fans cool people.  I had been running an additional 3 fans overnight to “keep the air moving.”  I have been wasting approximately $20-$30 a year due to my misunderstanding.

Turn the Fans Up and Save Your AC Bill

Ceiling fans and your air conditioner make a great team on hot summer days.  Opinions and findings about perceived temperature reduction from ceiling fans vary greatly.  As we’ve already figured out, ceiling fans use evaporative cooling to reduce the perceived temperature on the surface of your skin.  This effect varies per person but can feel like anywhere between 2 and 8 degrees in temperature reduction.

You can use that to your advantage and raise the speed on your ceiling fan and bump up your AC a few degrees.  Ceiling fans cost $0.02 to $0.03 per hour to operate while central air conditioning costs between $0.50 and $0.75 per hour to operate.  Raising the thermostat a few degrees can lead to some HUGE savings on your air conditioning bill during the summer months.

Which Direction?

I also learned that all of our ceiling fans were operating in the opposite direction.  Summer mode for almost all ceiling fans is counter-clockwise operation.  This circulates the air in the proper direction to cool the entire room.  Winter mode causes the fan to throw more air downward but it draws more of that air from the ceiling where the warm air hangs out.  Refer to the manual for your ceiling fans for your specific model.

Final Thought

I’ll keep working on whittling away at our electricity bill.  It is our largest utility bill by far.  I enjoyed putting together this post on ceiling fan savings and learned quite a bit.

Have any ideas for a ‘How much does it cost’ post?  I’ve been enjoying exploring these ideas and will really enjoy seeing the electricity bills getting lower.  Please leave any questions or comments below.