In recent years, DC motor fans have become very popular and there is now a huge range available. What actually are the differences? And which is best? Read on to find out.
The Technical Talk:
There are two types of electric motors general, AC (Alternating Current), which is electrical current which reverses direction and DC (Direct Current), which, as its name suggests, electrical current which only flows in one direction. Most ceiling fans, as well as most household appliances, use AC motors, as AC is the type of current distributed by power companies.
AC motors function by being connected directly to a power source. This power source is what creates the moment of force required to rotate the motor’s rotor. With DC fans, the direct (AC) power source, connects to a transformer which converts the power to DC. The effect is that it decreases the amount of power used by only using a direct current instead of the alternating current. To then create the force needed to rotate the motor’s rotor, the DC motor uses a system of magnets of opposing polarity.
Please note that current models of ceiling fans with DC motors cannot be connected directly to a DC power source (like solar panels or batteries) and whilst that may change in the future, manufacturers do not seem to currently have plans to provide this facility.
AC vs DC:
The advantages of a DC motor ceiling fan over an AC motor ceiling fan:
- In most cases, they use less energy – up to 70% less than a standard AC fan.
- They are generally extremely quiet.
- They will often have more speed options, the reverse function on the remote, and are generally faster to start, stop and change speed.
- The motor is generally more compact and lighter, which allows for a slimmer motor design.
The advantages of an AC motor ceiling fan over a DC motor ceiling fan:
- DC ceiling fans tend to be more expensive when compared to an equivalent AC model. Although you do use less electricity and therefore save money there, it is minimal. For example, if a DC fan saves you 20W per hour of use, and you use it for 10 hrs per day, 100 days per year (all night, all of the summer, on low speed), you save about $3.50 per year (off peak rates).
- AC fans can be controlled from a wall control, pull cord or remote, while DC fans can generally only be controlled by remote (very few exceptions – see below*). Remotes are more likely to be lost, broken, run out of batteries. Some DC fans are available with an optional wall controller, at an extra charge.
- AC fans are still extremely energy efficient, a standard model will use no more than 100watts on high speed.
What is right for me?
As with anything, there are many factors that will determine your decision. Ultimately, what is most important to remember is that you can get great fans with either AC or DC motors. Fans which are extremely quiet, don’t wobble and create good air movement. And although AC motors may use more energy than DC motors, they nevertheless use very little energy, equivalent to one or two standard halogen light bulbs on high speed. Compared to most household appliances, especially air conditioners, this is nothing! So once you have worked out your style, budget and function needs, feel confident in going either AC or DC.