The difference between DC and AC ceiling fans is a matter of electrical current and the motor rather than the design of the more recognizable part of the fan, but that doesn't make the difference negligible.
AC vs. DC Power Sources
AC (alternating current) motors primarily differ from DC (direct current) motors in the way their names suggest: AC motors convert electrical energy to mechanical energy using alternating current while DC motors use
direct current. But, what does that mean?
Direct current is supplied by batteries, fuel cells and other power sources that provide current that travels in one direction. Alternating current, on the other hand, is the kind of current provided from an outside
source (like a power plant) via a wall outlet.
These power source and motor differences, which can also come in the third form of an AC-to-DC power converter, can indeed impact the performance properties of a ceiling fan.
AC Ceiling Fans vs. DC Ceiling Fans
A DC ceiling fan motor passes its current through a series of magnets with opposing polarity, the resistance between which creates torque that powers the fan rotor. This results in higher torque, better speed
control, lighter fan weight and quieter operation between the two fan types.
Combine these benefits together and you have a fan that can also last longer and is more energy efficient than its AC counterpart. So, why buy an AC ceiling fan?
AC ceiling fans are less expensive, still reliable and still relatively energy efficient. AC ceiling fans also have an advantage in that they can be powered with a standard wall switch and power source, whereas DC
ceiling fans require a remote control (although remote control units can also be mounted on the wall along with the traditional switches).
It's true that DC ceiling fans may use as much as 70% less energy than a standard AC ceiling fan, but it must be noted that neither requires much energy at all. It's also true that the way DC motors operate lends
them to a longer and quieter life, but those benefits typically come at a higher cost.
As with most products, it will always depend on what suits your home and your budget best when it comes to choosing an AC or DC ceiling fan.
Visit the Ceiling Fan Info Center