In my list of stupid irritations, this ranks low on my list, but people keep posting it like it works. I keep running into it all over, but mostly from companies claiming it will save me money on my seasonal utilities bills.
In the winter, every time I log in to pay the bill, the "tip" claims I should keep my ceiling fan blowing air down into the room. It's supposed to warm me up.
In the summer, the advice changes to having the ceiling fans blow in the opposite direction, pulling air up to the ceiling and away from me.
These rank with the silly idea that keeping your very furry pet inside a long untrimmed coat in summer actually protects your pet from overheating, so don't bother trimming their coat. The same failure of the idea works in both situations.
Look, if our dogs need a lot of fur on a hot summer day to "protect" them from heat, we'd also be wearing heavy coats when thermometers soar, right? If you believe it's good for your dogs, go ahead and do it yourself and find out. "Protect yourself" from the heat by bundling up. Better have a friend nearby to call an ambulance for you.
If we - people and pets - were inanimate objects, the idea would have a point. AIR TEMPERATURE would change with the fan direction. We all know heat rises, or at least we do if we paid attention in, say, 2nd grade. Cool air sinks. But we are NOT inanimate objects. I'm not. You're not. Unless it's dead, stuffed, and posed in a corner, neither is your dog. (It might be a possibility if you left your furry dog with its long coat on in summer.)
So why are we different? As mammals, we all have something called a metabolism. It's the reason one way we measure our food is in units called calories, which are units of - ready? - HEAT! We take in food (potential heat) and our systems turn it into the warmth we need to keep alive. There's a very narrow range for body temperature that keeps us healthy, and the body has mechanisms for maintaining it. We find it so vital to life that we seldom give it much thought. When we are cold, we cover up. It might be with clothing, it might be under the blankets. We might even stand in front of a window with the sun pouring in. We also keep moving, when we can, to keep our internal engine processing calories, stored in fat, into the heat we need. If we don't, our body takes over with making us shiver, until it gives up and we stop. It's all but too late then.
When we get too warm, we feel desperately sick within a very few degrees of change. We excrete water from our skin to evaporate and cool us. We shed layers, avoid sun or other sources of heat, take a cool shower, jump in the pool. Whatever it takes.
Another thing we do to regulate our temperature is either find or avoid a breeze. Too hot? Turn on a fan to blow past you so evaporation works better. Too cold? Find ways to get out of moving air so it doesn't rob us of heat faster.
WE ALL KNOW THIS!
So why am I reminding you? Because stupid people are still claiming that blowing air at maybe 70 degrees on you in the winter is a good thing and taking it away when it's 90 degrees in summer is as well. The only way that works at all is if, in winter, the air blowing on you is realllllly warm. Not the degree or two higher temperature it is near the ceiling, but warmer than you are plus the heat loss from evaporation from your skin. All that does is cool you down even more. And summer? Sucking air away as passively as it would leave in order to head to the ceiling would not be fast enough to aid in the evaporation you need.
We are our own heat pumps. When that goes out of whack for us, we have to recall the methods that really work, kicking in or protecting from the cooling of evaporation. More wind on us = more evaporation. It's not what happens to the room temperature and where that matters. It's what happens to ours. Because we also are our own cooling pumps.
Got it?
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