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As you might have guessed, the answer can vary from person to person, depending on several factors. To understand this—and to determine which cooling solution is best for you—we first need to look at how each technology works.
The tech that keeps you cool
While fans and air conditioners help you stay cool in very different ways, they’re both primarily leveraging the cooling power of evaporation.
Fans blow air over your skin, which promotes moisture evaporation. Evaporation is an endothermic process, meaning the moisture absorbs heat from its surroundings as it turns into vapor. Part of what makes fans so efficient is they aren’t cooling down the whole room, just you.
Air conditioners utilize the same mechanism, but in a far more complex way. Inside your air conditioner is a coil of coolant that’s continuously undergoing evaporation and condensation. Air is pulled into the air conditioner and cooled by the evaporation process. The condensation process happens elsewhere in the unit, allowing the heat to be radiated outside your home.
The cost of cooling
It takes significantly more energy for an air conditioner to move heat around than it takes a fan to blow air onto your skin. As a result, parking yourself in front of a fan is significantly more energy efficient. Fans use around 1% of the electricity consumed by air conditioners. You could leave a fan running for a full 24 hours and still use less energy than 15 minutes of air conditioning.
While there are ways to minimize how much energy your home A/C is using, fans should be the go-to cooling option for the environmentally-conscious.
That being said, they aren’t ideal in every situation.
When fans just can't cut it
While ideal in many circumstances, you should avoid using a fan when things really start to heat up.
By speeding up the rate at which moisture evaporates from your skin, fans are also increasing your rate of dehydration and electrolyte imbalance. This is why the CDC only recommends using fans at temperatures below 95°F. Increasing hot-air circulation and sweat evaporation can actually speed up heat-related illnesses, like heat exhaustion. Unless you're able to use the fan to pull in cooler air from outside, it's best to leave it off.
Fans don’t lower the overall humidity, either. And humidity can make you feel hotter. On humid days, sweat will evaporate off your skin more slowly, which further limits the effectiveness of a fan.
Fans are best when used at close range, so they don’t do much for you if you’re sitting more than a few feet away.
When air conditioning is a good option
While air conditioners use lots of energy, they’re the most comfortable cooling option when temperatures start to rise. Since they reduce the ambient heat in your environment, they’re much better at cooling larger areas. And air conditioners also help to remove moisture from the air, reducing humidity and letting your body dissipate heat more efficiently. If it’s above 95°F, air conditioners are your best bet for cooling.
Which option is best for you?
A direct comparison between fans and air conditioners is unfair since they're good at different things. Determining which one is better for you depends on current conditions.
Use a fan if:
- It’s less than 95°F
- It’s not very humid
- You can position yourself close to the fan
- You want to use less electricity
Use an air conditioner if:
- It’s over 95°F
- It’s humid
- You’re looking to cool a large area
- You can afford a higher electrical bill
Whatever you decide, we’ve got you covered: We've lab tested the best fans, desk fans, air conditioners, and portable air conditioners available (and can explain what the difference is between those last two), so you can figure out the best fan or A/C to suit your needs.
During a heatwave, you don’t have time to mess around with products that don’t get the job done, so shop smart and keep yourself cool!
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