Do you use a fan to sleep? Here’s what to know

Is it true that a fan can help you sleep?

Fans may help you sleep better for a couple of reasons: They can provide a cooling breeze and soothing white noise, sleep experts said. It is not, however, a one-size-fits-all approach; its success can depend on various factors, including how hot it is, the type of fan, and whether a person has certain health conditions.

While fans cannot lower the temperature in a room, they can create a breeze that can help cool you.

As the Energy Department points out, fans “cool people, not rooms” through the wind chill effect, in which wind displaces warmer air and helps evaporate sweat from the skin, making people feel cooler. This may be especially helpful for people who run hot at night, including those who are going through menopause or taking selective serotonin reuptake inhibitors, or SSRIs.

But there are caveats.

First, fans work best when indoor temperatures are below 90 degrees. Above that, fans can increase body temperature, according to the Centers for Disease Control and Prevention.

Second, the type of fan matters. Ceiling fans and oscillating fans work well for air circulation, helping to create the wind chill effect, but they have some drawbacks. When people want the added benefit of white noise, ceiling fans have less to offer because they tend to be quiet. And oscillating fans can sometimes disrupt sleep by creating fluctuations in air flow and noise, said Norah Simpson, a clinical professor of psychiatry and behavioral sciences at Stanford University.

Third, how we use fans is important. Since we breathe out carbon dioxide, it can build up, particularly in poorly ventilated rooms, said John Saito, a spokesperson for the American Academy of Sleep Medicine. “If you’re blowing a fan on you to help you cool, that’s great. But if you’re in a stuffy room, you actually want the fan to blow out all the CO2 that has built up in the room,” meaning you should angle it to blow out an open door or window, he said.

Additionally, fans that provide a constant drone such as box fans — or even white noise machines — can “mask some of the lower-level fluctuations in background noise so that you’re not alerted to those signals,” said Simpson, also the associate director of the Sleep Health and Insomnia Program at Stanford Medicine.

This can be especially helpful for people who are light sleepers or live in noisy households or areas. A small study of 10 adults from a New York City-based sleep clinic reported that white noise improves sleep, though a systematic review on the topic did not find convincing evidence.

And for those who have auditory issues such as tinnitus, which causes ringing in the ears, white noise can make the ringing “less noticeable and easier to ignore, especially when trying to sleep,” said Michelle Drerup, director of behavioral sleep medicine at the Cleveland Clinic Sleep Disorders Center.

Fans — whether used for cooling or white noise — are not likely to help with sleep disorders such as insomnia or sleep apnea and should not replace physician-prescribed treatments, experts said.

Also, with consistent fan use, there is a risk that some people may get habituated and find it difficult to sleep without one, Simpson said.

While fans may help some people sleep better, others may not like or be able to use them.

Some people cannot consistently use fans because of allergies, asthma, or dry eyes, since fans can pick up and blow around dust and other allergens. Others may be hypersensitive to stimuli, and the added wind may irritate their nervous system, Saito said.

Here are some ideas:

The cool breeze and hum from a fan may help many people sleep, but a fan may not work for everyone and should not be used to treat sleep disorders, experts said.