Sometimes, the quickest way to cool off during the summer is via a fan. Sure, air conditioners are lovely, but to be effective, you must run them for a while to get that comfortable temperature. However, while ACs cool indoor temperature, what’s interesting is that even the best fans technically don’t lower the temperature of a room. This fact leaves many wondering, “How do fans work?” For the quick answer: Fans use rotating blades powered by electricity to draw in air and create airflow. And if you are curious about how much electricity they use, we have a page explaining ceiling fan power usage.
The gentle cool breeze a fan creates provides significant benefits to your home or office. Not only will it keep you cool in the summertime, but it also helps to reduce energy costs. Air flow from a fan circulates the air throughout a room, which evenly distributes heat and coolness while also keeping stagnant air from building up. This keeps you comfortable and helps extend the life of your air conditioning system.
KEY TAKEAWAYS:
- Fans work using a motor that rotates a set of fan blades, which circulate the air.
- While fans produce a cooling effect via evaporation, they don’t lower a room’s temperature.
- A fan’s power is measured by how many cubic feet of air it can move per minute, which takes into account the power of the fan’s motor and the diameter of the fan blades.
And for anyone with a fan that isn’t working correctly, we have a great article explaining how to fix a fan that won’t spin.
How Does a Fan Move Air?
Fans aren’t wizardry. Humans first harnessed wind power thousands of years ago, and modern electric fans are only one of the most recent developments, although not quite as recent as you might think. The first electric fan ran on a DC current and was invented in 1886 by Dr. Schuyler Wheeler.
Insider Tip
Remember to keep noise levels in mind when choosing a fan. In smaller rooms, the noise of a fan motor will be much more noticeable.
That means reading about the loudness of fan noise for the fans you’re looking at. Look for fans that offer a quiet operation, as well as those with low energy consumption. For an added bonus, consider some of the newer cleaning methods, like fan cleaning hacks and deep cleaning, to keep your fan in top condition.
The basic science behind cooling with fans is this: Humans generate body heat, and bodies generate sweat to create a healthy body temperature (known as thermoregulation). So, air flowing across sweaty skin creates evaporation, which produces a cooling effect on the body. By speeding up the process of body heat evaporation, fans can help reduce the internal temperature in hot weather by several degrees. Additionally, circulating air also helps to move any other sources of degrees of heat away from the person.
Regarding how they work mechanically, it’s relatively simple. In an electric fan, an electric motor rotates a set of fan blades, creating air circulation. Check out our page on mechanical fan vs electric fan comparison to learn more about the difference between these fans. So, while fans don’t lower a room’s temperature, they do reduce body temperature through the power of evaporation. In fact, fans raise a room’s temperature slightly due to the heat radiated by the electric motor, but you’d never know it. And if you are curious about what uses more electricity between AC and a fan, we have a page explaining it.
Choosing a Fan
The scientific processes aside, it’s important to know how to purchase a fan that will create a suitable cooling effect for your particular space.
Fan power is calculated by how much air they move; the technical term for this is CFM (cubic feet per minute). CFM is determined by the motor’s power (speed) and the diameter of the fan blades.
Finding an exact CFM isn’t vital for most house fans, like box or tower fans, so it’s okay to select one without worrying about it. But for ceiling fans and larger industrial fans, this matters because CFM helps determine how often the air in a room is replaced by outside air, which can be necessary for meeting safety requirements. And, for those looking for additional ceiling fan resources, you can check out our article that shows you how to control ceiling fan speed. However, if you are looking at an option for the whole home, make sure you understand whole-house fan sizing for optimal performance and energy efficiency. If you are wondering what is a whole-house fan, we have a page explaining them and their use.
Warning
A running fan accomplishes nothing but wasted electricity. Therefore, ensure your fans are off if no one is occupying the room.
While fans are still widely used, the technology has evolved in recent decades. If you want to learn more about this, you can find our article explaining how bladeless fans work.
