Hi I'm Elliot, and this is Mental­_ Floss on YouTube. And today I'm going to talk to you about some misconceptions about your house.

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Misconception number one: Ceiling fans only spin in one direction. Most ceiling fans are reversible. Generally people only put their fans on to counterclockwise, because that’s the direction that makes the room feel cooler. But if you set your fan to go clockwise, it can actually warm up a room in the wintertime. Warm air rises and stays near the ceiling, so a fan rotating clockwise can circulate that warm air through the room.

Misconception number two: If you set your thermostat really low, it’ll cool down faster. This isn’t the case in every house, but most cool down at a steady rate regardless of how low you set the temperature.

Misconception number three: A dish that goes through a dishwasher is completely disinfected. Over time, a dishwasher itself can actually build up food and grease and soap remains and other really gross things. This effects how clean it's able to make dishes. Luckily there are a few simple ways to clean a dishwasher, like with baking soda and vinegar.

Misconception number four: If you have a bathroom window, there’s no need for a fan. A window might due, but you’re probably not going to be opening it up as much as your should, especially during wintertime. Cause it’ll be freezing! So an exhaust fan is pretty necessary. Without one, moisture gets trapped in the walls, which puts your house at risk for mold and mildew. Those might sound like minor risks, but they can lead to drywall and wood damage. Plus mold is a health risk. It’s not worth it. Get a fan.

Misconception number five: Fireplaces cause you to lose heat. This is true, but it doesn’t have to be true because it's a fixable problem. For one, you can just get a fake fireplace. But things that might help with your real fireplace: installing a glass fireplace door, closing the damper when you’re not using the fireplace, and insulting the chimney. And if you never use your fireplace, you can just hire someone to plug and seal it for you. Don’t worry about Santa, he’ll find his way in. He’s the cleverest of home intruders.

Misconception number six: The more insulation in your attic, the better. Actually, once there’s a certain amount of inches of attic insulation it can’t help anymore. The exact number of inches depends on your personal situation, though. Basically insulation is measured by R values. The R value tells you how resistant the insulation is to heat flow. Every location requires a different R value of insulation. Adding more insulation than is necessary doesn’t actually help. Luckily The US Department of Energy has a website where you can plug in your zip code and it’ll tell you how much insulation they recommend. You can find that link in the video description.

Misconception number seven: Turning lights on and off takes up so much energy that you save money by keeping them on all the time. So this might be true, but it depends on two things: How much your electricity costs and what kind of light bulb you’re using. The idea that lights should always be kept on to save energy probably came from the fact that the operating life of a light bulb can change as it gets turned on and off a bunch of times. Here’s some general rules from the US Department of Energy: if you’re using compact florescent lamps, or CFLs, you should leave it on if you’ll only be gone for less than fifteen minutes. Otherwise, you should turn the light off. On the other hand, you should always turn off you halogen or incandescent bulbs when you don’t need them.

Misconception number eight: Electronics that are turned off aren’t using up energy. If your electronics are still plugged in, then they’re still using up energy thanks to something called “Standby Power”. According to our old friend, the US Department of Energy, Standby Power is responsible for five to ten percent of residential electricity use. That’s about a hundred dollars a year that could be cut out of your electricity bill if you really wanted it to be.  The worst offender is your cable box. So either unplug your electronics or invest in some power strips that you can turn on and off.

Misconception number nine: The way to test a smoke detector is by pressing the “test” button. You’d think. But all that button does is let you know that the sound is working. It doesn’t tell you whether that alarm can actually detect smoke. The best way to check that is to blow out a match directly under the smoke detector. It's also helpful to ask someone to stand at the point of your home furthest away from the detector to see if they can hear the alarm.

Misconception number ten: Basements get wet from below, not above. There might be a problem with the house’s foundation, but there are other possible causes of a damp basements. It could be something much simpler like maybe, I dunno, a leaking water pipe or high indoor humidity. A plumber can easily fix a pipe, toilet, or shower leak. Indoor humidity can be reduced with things like ventilation fans, sealed air leaks, and dehumidifiers. Look into those options before declaring that your foundation is awful, ok? How do you think it makes your foundation feel? Probably like dirt. Get it?

Thank you for watching misconception on Mental_Floss on YouTube, made with the help of these wonderful people. If you have a topic for an upcoming misconceptions episode that you would like to see please leave it in the comments. And I will see you next week. Bye!

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