Your weather when it really mattersTM


Please choose your default site


Asia - Pacific


Are electric fans friends or foes during extreme heat?

Tuesday, July 28th 2020, 11:24 am - Rumour has it (and some studies do too), electric fans aren't effective for cooling in extreme heat. Experts suggest that their effectiveness is based on environmental and geographical variables, this is what they have to say about using them in Canada.

Canada is known for being freezing. We know better. Right now, parts of Canada are going through a marathon heatwave. Other parts of Canada are just starting to pick up heat momentum. Whether you're in the midst of unbearable heat or preparing for what's to come, it's nice to know what the experts have to say about the effectiveness of electric fans.

With every weather article, there are two approaches; the scientific approach or the "what does this mean for me" approach. Attempting to turn the latter into the former, we've reached out to Dr. Robin Stoodley, a chemistry professor at the University of British Columbia, to help navigate the best cooling systems for our Canadian summer.

Many Canadians have the luxury of air conditioning. A lot of us don't have air conditioning. And even if we do, it could be broken, or maybe we want to give our air conditioning bills a break. So, a lot of us turn to electric fans. Some research shows that electric fans aren't the best solution for cooling us, and perhaps could even be dangerous. So, are fans friends or foes? Dr. Stoodley says, overall, friends. This is why:

As promised, going into the science of the "why," Dr. Stoodley says the effectiveness of fans depends on "the air temperature and how much water is in the air (the humidity). Fans mostly cool you by making your sweat evaporate faster. If the air is below your skin temperature, then there is a convection effect too. But most of the heat is carried away from your body by the water evaporating."

SEE ALSO: Can COVID-19 spread through air conditioning?

Going even deeper into the science, a small Australian study illustrates that fans are not great to use in arid (relative humidity <10%) regions of the world that experience heat waves ≥45 °C. But it's okay to use fans in areas with high humidity (relative humidity >30% to 40%) that rarely experience heat greater than 40 °C.

Basically, if you're in a hot, dry environment where your body isn't sweating, don't use a fan. It's that combination of factors that can lead to fans being harmful. Dr. Stoodley illustrates this reverse-effect of a fan by explaining it's "like the opposite of flowing water over ice-cubes to make them melt faster than if they sat in a cup of water; the rate of heat transfer into you is increased by the flowing hot air."

If you're not feeling the mini wind farm approach, what's your next-best solution? A single fan could do the trick. Dr. Stoodley explains that your fan should be blowing air across your body.

If you're a fan(atic) of the splash seats at amusement parks or the theatre, Stoodley suggests the even-better short-term cooling method of placing "a bowl of ice-cubes can be placed between the fan and yourself. While it isn't comfortable, getting yourself and/or your clothes wet while in the path of the fan's air will also help cool you."

And with every science-practical mash-up article, there comes an aha moment. Do you know when you're getting out of a lake/ocean and the air feels colder than you remember? That's why Dr. Stoodley recommends the ice-fan combo, he explains "the air blowing across your wet skin increases the rate of cooling on your skin."

Also, if you're currently dealing with extreme heat, drink plenty of water, find shade, avoid exertion, stay safe, and be glad we're not shovelling snow.



Thumbnail image source: Enrique Zafra/PEXELS

Default saved

Search Location


Sign In

Please sign in to use this feature.