The Difference Between AC Fans & DC Fans

Direct current fans, or DC fans, have a variable, uneven flow. In contrast, alternating current fans, or AC fans, change direction 50 times a second in order to provide a constant flow.

Historically speaking, AC fans were typically less expensive than DC fans. Today, however, the price difference is negligible, which means you need to weigh the pros and cons of each fan type carefully when making a purchasing decision.

The Pros and Cons of DC fans

DC technology has become much more sophisticated in recent years, and it can now be applied to both residential and industrial ceiling fans. DC fans have motors that rely on permanent, built-in magnets in order to attract and repel a rotor around an axis joined with invertors. DC technology is much newer than AC technology, which means there are fewer options available.

PRO: Minimal electromagnetic interference

Because the electromagnetic interference of DC fans is minimal, sensitive electronic devices often use DC fans to prevent electromagnetic interference. For example, computer applications and equipment rely on DC fans, as they prevent overheating while still minimizing electromagnetic interference that could negatively affect sensitive applications.

PRO: Consumes less power

DC fans are widely regarded as the most efficient type of fan. They consume significantly less power than AC fans. In fact, DC fans consume up to 70 percent less energy to produce the same output as other fan types. For example, that means that a 25-watt DC-driven fan uses the same power as a 100-watt AC-driven fan. This is ideal for commercial settings, like restaurants, allowing you to keep fans running all day without incurring astronomical electric bills.

PRO: Quieter

DC fans make use of a new type of electrically commutated motor (ECM). Not only are these motors ultra-efficient, they are also incredibly quiet. Because they are so quiet, DC fans are an excellent option for applications such as medical instruments, telecom switches, or car entertainment systems, where noise could be a nuisance.

PRO: Lower voltage

DC fans generally use less voltage than AC fans. The majority of DC fans are low-voltage fans. For example, you can typically find 5V, 12V, and 24V versions of DC fans. Larger models of DC fans, such as 119mm to 172mm fan models, are typically available in 48V. In comparison, most AC cooling fan models are available in 115V, a much higher voltage. Lower voltage also makes DC fans potentially less dangerous.

CON: Variable uneven flow

The major drawback of DC fans is that they don’t provide a direct, constant flow. Rather, they provide a variable, uneven flow.

CON: May require a transformer

While AC fans use an alternating current, which reverses direction, DC fans use a direct current, which means the current only flows in one direction. Unlike AC fans, DC fans cannot be connected directly to a DC power source, such as solar panels or batteries. That means that DC fans must use a transformer to convert AC to DC so that the fan can be powered.

The Pros and Cons of AC fans

AC fans are commonly used when consistent and even airflow is required. These fans are commonly used in domestic appliances.

PRO: Provides constant, even flow

The major advantage of AC fans is that they provide an even, constant flow. An AC fan will move warmer air away from the components of the fan and then draw cooler air over them.

CON: More energy consumption

AC fans do consume more energy than DC fans. However, it should be noted that AC fans are still energy efficient. In fact, a standard AC model will use no more than 100 watts on high speed.

CON: Louder

AC fans generate much more noise than DC fans, which can be a nuisance.

CON: More electromagnetic interference

AC fans have more electromagnetic interference than DC fans, which means they can’t be used in applications that might be sensitive to such interference.

AC vs. DC: Which Fan Is Right for You?

Now that you know which one is right for you, click below for a guide on how to select the right cooling fan for you.

Download How to Select a Cooling Fan

The bottom line is that the right fan for you will depend on your specific needs. Prior to deciding between an AC and DC fan, you will need to carefully weigh the pros and cons of each type of fan. If you need further assistance in choosing the right fan for your project and/or application, don't hesitate to reach out the Pelonis Technologies team and we'll be more than happy to assist you!

Topics: dc fans, ac fans