A DC ceiling fan uses a brushless DC motor fed by electronics inside the fan, while an AC ceiling fan runs its motor straight off the 230V supply. DC fans typically use around a third of the power, run quieter and offer more speeds. AC fans cost less to buy and work with a simple wall controller.
Both types hang from the same ceiling point and both need a licensed electrician to install in NSW. The differences show up once the fan is running: on the power bill, in the noise at night, and in what you use to control it.
What is a DC ceiling fan?
A DC ceiling fan has a brushless DC motor and a small electronic driver that converts the 230V mains supply to direct current before it reaches the motor. The driver sits in the canopy or the motor housing and controls the motor precisely. That precision is why DC fans offer five or six speeds, a reverse button on the remote, and a very low power draw at the slowest settings.
The "DC" describes the motor only. A DC fan needs no special supply or dedicated circuit, and connects to the same active, neutral and earth as any other ceiling fan.
What is an AC ceiling fan?
An AC ceiling fan runs an induction motor directly on the 230V mains supply, the design ceiling fans have used for decades. Speed is set by a wall controller that steps the motor through three or four speeds. Changing direction for winter usually means a slide switch on the motor housing.
The motor is heavier, with no electronics in it to fail, so a well made AC fan runs for many years.
DC vs AC ceiling fans, side by side
| Feature | DC ceiling fan | AC ceiling fan |
|---|---|---|
| Motor | Brushless DC motor with an electronic driver | Induction motor on mains power |
| Power at top speed | Roughly 20 to 35 W | Roughly 50 to 90 W |
| Speeds | Usually 5 or 6 | Usually 3 or 4 |
| Control | Remote, app, or the matching DC wall control | Wall controller, sometimes a remote |
| Reverse for winter | A button on the remote | A switch on the motor housing on most models |
| Noise | Very quiet, including at low speed | Some hum on certain controllers |
| Purchase price | Usually higher | Usually lower |
| Weak point | Driver electronics, which a power surge can damage | Very little to fail |
Wattage varies with the model and the blade span, so check the rating on the box before comparing two specific fans.
How much does it cost to run a ceiling fan?
Very little either way, and a DC fan costs roughly a third as much to run as an AC fan of the same size. To work out your own figure, multiply the fan's wattage by the hours it runs, divide by 1,000 to get kilowatt hours, then multiply by the rate per kWh printed on your bill.
Take a fan running eight hours a night for 120 nights over a Sydney summer. A 30 W DC fan uses about 29 kWh across the season. A 75 W AC fan uses about 72 kWh. The gap is widest at low speed, which is where a bedroom fan spends most of the night.
Either type is cheap next to air conditioning, which draws kilowatts where a fan draws watts. If your bill has jumped, a fan is almost never the reason. Our guide to why an electricity bill is so high covers the loads that usually are.
Swapping old fans for DC models?
DM Electrical removes the old controllers, checks each mounting point is fixed to the ceiling framing, and installs and tests the new fans with the right controls. Based in Brookvale, working across the Northern Beaches and wider Sydney.
Can you use a wall control with a DC ceiling fan?
Yes, as long as it is the wall control made for that fan, because a standard AC fan controller does not work on a DC fan and can damage its driver. Many DC fans come with a remote only. The manufacturer sells an optional wall control that pairs with the receiver inside the fan, and those controls are not interchangeable between brands.
When an AC fan is replaced with a DC fan, the old controller comes off the wall. It is replaced with a plain switch, so the fan can still be turned off at the wall, or with the DC fan's own wall control. Neither type of fan should ever go on a light dimmer. It is the same kind of mismatch that makes LED downlights flicker, except a fan motor can be damaged by it.
How do you tell if a ceiling fan is AC or DC?
Check the label on the motor housing or the original manual first, because it states the motor type and the wattage. If the label is gone, these clues are reliable:
- A rotary or push button wall controller with three or four speeds. Almost always AC.
- A remote with five or six speeds and a reverse button. Usually DC.
- A direction switch on the motor housing. Usually AC.
- A rating under about 40 W at top speed. Almost certainly DC.
- A slim, flat motor body. Common on DC fans, where AC motors are deeper and heavier.
Do not open the canopy to find out. The terminals inside are live unless the circuit is isolated at the switchboard.
Which type should you choose?
Choose DC for bedrooms and anywhere a fan runs for hours, and AC for rooms where it runs occasionally or the budget matters more than the running cost.
- Bedrooms. DC. Quiet low speeds and a remote beside the bed.
- Living areas used all summer. DC, for the running cost.
- Garages, studios and rental properties. AC is usually fine and cheaper to replace.
- Covered outdoor areas near the coast. Either type, as long as it is rated for outdoor use with a finish that handles salt air. An indoor fan on a Northern Beaches balcony corrodes quickly.
- Homes with automation. DC fans with app or smart home control are easier to bring into a system.
The electronics that make a DC fan efficient are also what a power surge damages, so whole-house surge protection at the switchboard is worth considering if you are fitting several DC fans.
Can you install or replace a ceiling fan yourself?
No. In NSW, installing or replacing a ceiling fan is electrical wiring work that needs a licensed electrician, even when the new fan goes on the existing point. A fan also has demands a light fitting does not. It moves and vibrates, so the mounting has to be fixed to the ceiling framing rather than hanging from plasterboard, and the blades have to sit high enough above the floor, generally at least 2.1 metres.
A residential electrician can confirm the existing wiring suits the new fan, remove any AC controller that would damage a DC unit, fit the correct switch or wall control, and test the circuit before handing it back.
Frequently asked questions
What is a DC ceiling fan?
A DC ceiling fan uses a brushless DC motor with a small electronic driver that converts the 230V mains supply to direct current. It connects to the same ceiling wiring as any other fan, but it typically uses about a third of the power of an AC fan and offers more speeds.
Are DC ceiling fans better than AC ceiling fans?
For bedrooms and living areas where a fan runs for hours, usually yes. DC fans use less power, run quieter and have more speed settings. AC fans cost less to buy, have fewer parts to fail and work with a simple wall controller, which suits rooms where a fan only runs now and then.
Can I use my old fan wall controller with a new DC fan?
No. A standard AC fan controller does not work with a DC fan and can damage the fan's driver. The old controller is replaced with a plain switch or with the wall control made for the new fan, and that control has to match the fan's brand.
How much does it cost to run a ceiling fan?
Very little. Multiply the fan's wattage by the hours it runs and divide by 1,000 to get kilowatt hours, then multiply by the rate on your bill. A 30 W DC fan running for eight hours uses about 0.24 kWh, and a 75 W AC fan uses about 0.6 kWh.
The bottom line
For a bedroom or a living area that runs a fan every summer night, a DC fan usually earns back its higher price. For a garage or a spare room, an AC fan does the job. If you are replacing fans and want the controls, mounting and wiring done properly, get in touch.