Ceiling Fans: Do The Blades Make A Difference?

Ceiling fans are much more than just a decorative element that hangs from the ceiling, yet appearance is the first thing you notice.  And since there are so many different styles to choose from, you might be tempted to just close your eyes and pick one.  But the purpose of a fan is to circulate air, without blades your fan would be useless.

When used properly a ceiling fan can help you save a substantial amount of money on your energy bills, all year round.  The average air condition costs 36 cents per hour to operate while a ceiling fan costs less than a penny.  And a fan allows you to set your air con thermostat a little higher and still be very comfortable.

But the key words are “when used properly.”  One of the biggest mistake homeowners often make is to install a ceiling fan that’s either too large or too small for the room.  If it’s too large the air actually bounces off the walls and back into the flow, essentially blocking air movement.  If the fan’s too small, no matter what speed you use or how long you run it, it’s not going to be able to circulate enough air to help cool the room.

Either way, too large or too small, you’re wasting money on operating costs and you wasted money on buying and installing the fan.

Length matters:  For a 15′ X 15′ room you’ll need a blade span of 50 to 56 inches.  For a 12′ X 12′ room you’ll need a span of 42 or 44 inches, and for an 8′ X 8′ room you’ll need 32 inches.

Placement matters:  To get the best circulation, hang you fan in the center of the room.  If you have a very large room, like a great room or a basement, you may need multiple fans centered over different areas of the room.

Height matters:  The optimum height to hang your fan is 7 to 9 feet from the floor.  For vaulted or extra high ceilings use an extender pole to bring the fan closer to the floor.

Width matters:  Don’t assume that a wider blade will move more air.  In fact, wider blades can sometimes be much less efficient.  For example, the popular palm frond blades are the least efficient of all because they’re not aerodynamic.  And when there are more than four of these wide blades they really don’t circulate the air at all.

Number matters:  You’ll find ceiling fans with two blades all the way up to seven.  Generally, more blades means more air movement.

Pitch matters:  The pitch of the blades is one of the most important things you need to look at.  A 15 degree pitch provides maximum airflow.  However, if you’re using wider blades, like the palm blades, then you’ll need a steeper pitch.  Keep in mind that a steeper pitch also puts a larger strain on the motor, so you’ll want to choose a fan that’s been specifically designed for a wider blade at a steeper pitch.

When choosing your fan the three most important blade features to consider are the length of the blades, the pitch and the number of blades.  These three elements, taken together, are what have the biggest effect on air movement, and the better the air movement the more efficient your fans and your air conditioning units will be.

3 thoughts on “Ceiling Fans: Do The Blades Make A Difference?

  1. hi, can I use a larger fan blade on a ceiling fan with a smaller blade. The problem I have is my kitchen fan, 42 in, has a smaller shaft iron that I cannot find. The larger shaft irons are easy to find. One of the smaller shafts broke, leaving me with an unbalanced fan. Since I cannot find these smaller shaft irons, I decided I would either replace all the remaining fans blades with the larger blades or simply replace the fan. Remember, the larger shaft irons do not fit the smaller blades. Holes are different. What can I do. The Kitchen is in an open kitchen adjacent to a much larger great room. Therefore there is a large area to circulate air. Thanks

  2. A number of … ceiling fan designs have three blades instead of the more usual five or four. This sometimes leads to the question: can ceiling fans with three blades match the air moving performance of ceiling fans with four or five blades?

    It’s a good question. Intuition and some ceiling fan websites may provide the wrong answer here by simply assuming the more blades the better.

    As a matter of fact, … research results that stated that three turns out to be the optimum number of blades for best air moving performance and efficiency. The research found that adding more blades does not improve performance and may actually make it worse by creating more aerodynamic drag on the motor. They stated that greater numbers of blades are usually added for styling purposes. I think that we see many fans with more blades also because many people have a feeling that more blades is better and might fear that a three bladed fan would prove inadequate. Well, it turns out that the opposite is true.

    Reflecting on this I realized that all commercial and industrial fans I’ve seen in warehouses, factories and similar settings, where performance and energy efficiency are primary considerations, have three blades.

    Returning to my designs for a moment, I know from both experience and testing that for instance the Artemis ceiling fan, a three bladed fan, has very high, and well above the average, performance.

    – See more at: http://g2art.com/2010/08/16/3-blade-versus-4-blade-ceiling-fan-efficiency/#sthash.NMQw1G7t.dpuf

  3. I recently purchased a ceiling fan which was way smaller then the one I already had, meaning the blades and Motor were smaller. Will I be able to switch the blades and still have a good circulation flow?

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