Death by Electric Fan?!

Here in Korea there is an urban legend(?) that operating an electric fan in a closed room will leave you dead. Many expatriots here scoff at the idea and attribute it to the backwardness of the locals. I read the owner’s manual for my new Samsung electric fan and it does have a warning about using an electric fan in a closed room. It says that leaving a fan on in a closed room for a number of hours can affect the air to a point where it might be dangerous for infants and old people. This sounds reasonable and scientific and not the product of a ‘backward’ culture’s ignorance. Has anybody heard about this?

The Straight Dope.

Your first sentence is almost the same as this guys.

Here you go.

On a side note, according to backwards culture, I’ve been getting on-and-off visits from the “sitting ghost.”

I can’t imagine how it could affect the air, other than a slight heating effect by dissipating the 30-40 watts a fan typically draws. They run on brushless AC motors and don’t have the arcing found in some power tools and vacuum cleaners that use brushed motors and can produce some ozone as a consequence. Other than that, there isn’t any mechanism for causing any change in the air.

Oops, I should have done a search first. :o

The great thing about the idea of it causing the body temp to lower is that having the window open would not effect this at all.

And to say that 10 people die like this in a year is crazy. When I lived there(Korea), I learned the Koreans believe this as fact, they do not run a fan with the window closed. No way 10 people die a year with fans on and windows closed because they don’t do it(in my experience, I don’t all of them).

I asked many Koreans(college students) about this belief of theirs, with an open mind thinking I might learn something. Not one ever came up with anything making any sense at all.

My belief is that the police perpetuate the myth to save the work of actually having to find out what killed someone. That or the myth has become a surefire way of making murder look like an accident. Smother someone with a pillow, turn on the fan, close the window. Police show up when the body is found. See window and fan, and they take the afternoon off after filing the one line report.

My guess is that many of the deaths are caused by alcohol poisoning. I saw some strange reactions while there when students were confronted with an unconscious classmate. The worst was one night about 9:00PM, january, well below freezing, student passed out on sidewalk in jeans and teeshirt, with friends pouring bottled water on him trying to wake him up. Now I’m not painting the entire popluation with that brush as there are many intelligent people there as well as misinformed people about alcohol but when they were doing dumb things involving drinking, they put the American students to shame.

If the above statements offended anyone, I apologize. My impressons of Koreans were formed by my personal experiences while living in Pusan. I certainly don’t have a clear view of the country as a whole but I have Hadan-dong pretty much nailed.

Actually, there are conditions in which a fan can speed your death. Those conditions are high humidity and air temperatures above body temperature.

My impression (from watching reruns of MASH, so take it with a BIG grain of salt) is that Korean summers can provide these conditions quite easily.

Under these conditions - which are not good for you anyway - the evaporation of sweat (which is what cools you when the fan blows) either doesn’t take place (too much humidity) or else it can’t provide enough cooling to cool the air from the breeze to body temperature or below.

When you hit these conditions, you must turn off the fan. These conditions are bad enough alone, but the fan then continues to blow warm, humid air onto you that only contributes to a rise in your body temperature. If your body temperature rises enough, you will die.

In the conditions I’ve laid out above, you need to find a cooler place to be anyway. If you can’t, then in all events turn off the fan. You will last longer (maybe long enough for it to cool off) without the fan.

All right Mort Furd, lets help contribute to the spreading of ignorance.

Mort Furd: I sincerely doubt that’s a factor. The human body has very low surface area, and skin is rather non-conductive. The difference between forced air conduction of heat with a 10C or so temperature difference compared to normal convective warming is, methinks, minimal on a human. Besides, you’re supposing ACTUAL 100% humidity, which you don’t get in real life.

uhh… Mort - where I am, we have the conditions you envision a lot of the time. Airconditioning is prohibitively expensive, so we all have ceiling fans.

By your theory, we should all be dead, but we are not. Wanted to say this in the thread about the heat wave deaths in France, but somehow never got around to it.

Mort, I call BS on two points.

The first is the logic that temps above body temp will always increase body temperature. Doesn’t work that way if you sweat due to the evaporative cooling effect. Try this on a 110 degree day. Soak yourself with water and see if you feel cooler in front of a fan or in still air. Then talk to anyone who has lived in the desert and ask them how “swamp coolers” work.

Second - your MASH rerun research comes up short. I live in Seoul and have for 6 of the last 15 years. The summers are hot, humid and miserable but no place in Korea is all that far from the ocean. It essentially never gets to 100 deg F. Temperature at night almost always gets down into the 70’s. Due to the monsoon season, humidity is the problem, not temperature.

ah, it’s a 1920s style death fan…

Before any more of you give Mort a hard time, realize the conditions that have to be present in order to make a fan a hindrance rather than a help are pretty extreme. We’re talking temps of over a 100 degrees F coupled with nearly 100 percent relative humidity. When those conditions exist, two things occur: First, the ambient temperature exceeds your body temperature so even in the shade, your body is gaining heat from the environment. Second, sweating has little or no effect on the ability to cool off you body since the cooling only occurs when the sweat evaporates from your skin (100% relative humidity means the air is holding all the moisture that it can, the sweat has nowhere to evaporate to). Add a fan to this combination and what do you get? More hot air blowing over your body, speeding the rate at which your body accumulates heat from the environment.

If you need some anecdotal evidence: Think about the reason that convection ovens cook items faster than a conventional oven: the moving air in a convection oven speeds the heat transference to the item being cooked. Think about how wind chill works to make you feel colder in a stiff breeze. Same thing is happening with a fan in a hot room, except you’re speeding heat gain instead of heat loss.

Now it’s true that the rate of heat gain is comparatively slower than the rate of heat loss due to wind chill (because the difference between your body temp and the ambient temp is not as great- perhaps only a 10 degree difference on the hottest days versus a 100 degree difference on the coldest days), but that’s why heat related deaths require a long exposure to extreme temperatures and can usually be prevented by only an hour or two a day in an air conditioned environment.

And the reasons that the ‘swamp coolers’ or other misting type coolers work in the desert is that, despite the very high temperatures, the humidity is very low and therefore allows substantial evaporative cooling to occur.

Damn, I feel educated.

To address Mort Furd’s point, here’s a CDC report that I posted in a thread here about the heat deaths in Paris. It refers to the heat wave in Chicago, July 1995, that killed hundreds of people.

Relevant quote:

I note, however, that the temperature range mentioned is well above what was cited in Cecil’s article (~85 F), and does not address closed rooms per se. It does, however, give support to the statement that fans do not help above a certain temperature/humidity combination, and can in fact make the situation worse.

Just as anecdotal evidence, I’ve been sleeping with a fan blowing on me in closed rooms for a good chunk of my life, including the last 6-8 years about 6 months out of the year. Last I checked I’m not a ghost, so I’d say it can’t be all that lethal.

Ok, now back to our regularly scheduled factual responses.

I’m not saying that sleeping in a room with a fan on will cause your death.

I’m just saying that there are conditions under which a fan will not help, and may in fact hasten death. Those conditions would probably kill you any way - the fan just helps it along.

Cite Mort Furd? The cite that Ferret Herder provided from the CDC says fans should not be used for preventing heat-related illness in areas with high humidity. I’m assuming that means that one should find better preventative measures, not that fans will speed up your death.

In the minds of the Koreans I knew, it didn’t matter if the fan was blowing on you. It didn’t matter how hot it was. It was just the idea of, “fan on/ window closed = death” No one ever mentioned anything about heat and the fan affects you discuss make no mention of why closing the window would make this worse. I can however extrapolate that closing the window will prevent the room from cooling during the night. That may be it…actually, maybe we are learning something here.

Now I buy the part about, above a certain temp amd humidity, that a fan will speed your demise, but that doesn’t seem to address the fears the Koreans have of closed windows.

I just called wife at work (She’s Korean, as it grew up there), she doesn’t seem to think the temp matters.