How to keep cool while saving energy

As summer heats up, we often crank the air conditioning, which uses a lot of energy. NPR's Climate Solutions Correspondent Julia Simon has five simple and affordable tips to save electricity without sacrificing comfort. We'll cover the science behind the open window versus AC debate, "night flushing" your home and cost-saving home improvement projects to help keep you cool. Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

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• 0:17Marielle Segarra?

  You're listening to Life Kit from NPR. Hey, it's Marielle. Summer is finally and officially here. It's going to be 98 degrees in New York for the next couple of days. So you'll find me hiding inside with the air conditioner blasting. But, OK, let's talk about that for a second. That impulse to crank up the AC. Of course, if it's an unbearably hot day, we're going to want to do that, and that's understandable. But air conditioning systems do use a lot of electricity. So when we use them, we are unfortunately contributing to climate change. NPR's climate solutions correspondent, Julia Simon, has been covering this.

• 0:58Marielle Segarra?

  And on this episode of Life Kit, she shares five ways to use less energy at home this summer. The tips are pretty easy, and they can help you save on energy bills.

• 1:10Speaker 00

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• 2:12Marielle Segarra?

  Julia, the first tip you have to help us use less energy at home is a simple one, right?

• 2:16Speaker 06

  It's very simple. I kind of love it. The tip is, open a window. To explain why, I talked to Dorit Aviv.

• 2:24Speaker 07

  And I'm an assistant professor of architecture at the Weizmann School of Design in the University of Pennsylvania. What people don't realize is that the inside temperature is sometimes hotter than it is outside because people inside of buildings produce heat constantly.

• 2:41Speaker 06

  Things like our computers, or cooking, or other devices, all of those increase the indoor air temperature. So Dorit says...

• 2:51Speaker 07

  Instead of going to the thermostat and lowering your air temperature on your air conditioner system, you can just open the window.

• 3:00Marielle Segarra?

  Yeah, it sounds like this advice might work better in some climates than others, more temperate climates, more temperate seasons.

• 3:07Speaker 06

  Yeah, I mean, but this actually often works. You know, early in the morning, this makes a lot of sense. At night, there's even this expression called "night flushing", when you open the windows to let out all the heat from the day. So, the tip is, open a window. Bonus points if you can open up two windows on opposite sides of your space to get a nice cross breeze.

• 3:29Marielle Segarra?

  All right, what's your second tip?

• 3:31Speaker 06

  Second tip, if you are needing to cool down your house, instead of turning on that air conditioner, try turning on a ceiling fan, if you have one.

• 3:41Marielle Segarra?

  Ceiling fans, I actually should get one.

• 3:43Speaker 06

  I'm a big fan of ceiling fans. Dorit is also a big fan.

• 3:47Speaker 07

  They're so much more energy efficient than air conditioners.

• 3:52Speaker 06

  A group of researchers in Australia found that using fans compared to air conditioners can reduce energy use and related greenhouse gases by 76%.

• 4:03Marielle Segarra?

  And do they actually... Keep you cool.

• 4:05Speaker 06

  Well, ceiling fans don't lower the air temperature in the same way ACs do. They can provide increased cooling by moving the air around. If you are in extreme heat and need an air conditioner, of course, turn it on. But if you can turn on a ceiling fan or open up a window and still be comfortable, then you can really help the climate and your pocketbook by doing those things first. Tip number three, this one has to do with shades. I'm curious, Marielle, do you have shades in your apartment?

• 4:38Marielle Segarra?

  I do. I have some shades and some curtains.

• 4:41Speaker 06

  Are they on the inside or on the outside of your windows?

• 4:45Marielle Segarra?

  See, that's a funny question because I never knew they could be on the outside of my windows.

• 4:49Speaker 06

  Well, here's the thing. While here in America, a lot of us have shades or curtains on the inside of the window pane. If you're trying to stay cool, that doesn't always make sense. And Daniel Barber at Eindhoven University of Technology in the Netherlands says, you might want to think about what that sunlight is also bringing in.

• 5:11Speaker 05

  The sunlight that's coming in, that is bringing in light, is also bringing in heat.

• 5:15Speaker 06

  And I feel like we know what he's talking about, right? The heat comes in with the sun, it stays inside, it heats our space. But there's another option, Marielle. Recently, I was in Vienna, Austria, and I met Sebastian Schubla. He has something called external shading. This is basically a shade that's outside the house going down vertically. You can make it unfold using a switch, or it can be automated. So these are your external shading. Do you mind showing us?

• 5:46Speaker 06

  Like a curtain outside of your window. Obviously, it makes sense because the heat doesn't go in, it stays out.

• 5:54Marielle Segarra?

  Exactly. Okay, and is this available in the US too?

• 5:58Speaker 06

  Yes, 100%. External shades aren't just in Austria. I called up some of the big name shade stores. They sell them here in the US. Many of the prices are comparable to indoor shades, sometimes a bit more expensive, but you can find them here.

• 6:11Marielle Segarra?

  Nice. Yeah, some of my favorite things to do is to bring back inspiration from how other countries do things.

• 6:19Speaker 06

  That's what we're all about on the climate desk.

• 6:22Marielle Segarra?

  All right, well, tip number four involves a little physics lesson, I hear.

• 6:26Speaker 06

  It's true. The lesson goes like this. Heat will always try to escape from a hotter region to a cooler region.

• 6:33Speaker 07

  That's actually part of the second law of thermodynamics.

• 6:35Speaker 06

  And this is a tip for summer and winter. Let's say it's winter times, you're heating your house and it's cooler outside. That heat on the inside will try to escape to the outside. The other way is true, too. Let's say it's summertime and you're cooling your home. That heat from outside might come in through the cracks when you don't want it to.

• 6:57Speaker 07

  If you have any cracks, any openings in your buildings, anywhere where it's an easy path for the heat to go through, that's where it will go.

• 7:06Speaker 06

  Those cracks are often near our windows, our doors. So here's the tip. Seal it up. Buy some tape or rubber. This is called weather stripping tape. You can put it around your window frame to seal the leaks. You can get these things at any hardware store. It's easy to find online and it's often very cheap.

• 7:25Marielle Segarra?

  So, all right, what's your fifth and final tip for us today?

• 7:27Speaker 06

  Okay, the last tip is the most ambitious, but if you want to make your home more energy efficient, Dorit says one of the best home improvements you can do is to make your roof reflective.

• 7:38Marielle Segarra?

  Because the roof gets a lot of sunlight.

• 7:40Speaker 06

  So much sunlight. The sunlight carries a ton of heat. And when the sun hits your roof, that heat is absorbed through the roof and gets translated into heat inside your home. And here's the thing. This is all made worse because a lot of roofs are covered with black or darker color finishes, which absorb and retain even more of the sun's heat.

• 8:03Speaker 06

  So Dorit says one of the easiest home retrofits to reduce energy use is to coat your roof with a white or silvery color, a reflective roof.

• 8:15Marielle Segarra?

  OK, so the heat from the sun gets reflected away from the house instead of absorbed inside.

• 8:20Speaker 06

  Exactly. And then you don't have to cool your house as much. This is all reducing the need for cooling with air conditioners, which means less money spent on your utility bills. Dorit suggests talking to a roofer. Who knows about different reflective paints that can help reflect sunlight?

• 8:41Marielle Segarra?

  All right, Julia, thank you so much for these tips.

• 8:43Speaker 06

  Thank you for having me.

• 8:46Marielle Segarra?

  That was NPR's Julia Simon. To find more stories about housing and climate change, you can go to npr.org/climateweek.

• 8:55Marielle Segarra?

  OK, time for a recap. Takeaway one, before turning on an air conditioner, try opening a window or two windows on opposite sides of the space to get a cross breeze. This works especially well in mornings and evenings when it's cooler outside than inside. Takeaway two, if you have a ceiling fan, turn it on before you try turning up the AC. They can help a lot. Takeaway three, look for shades that you can mount outside of your windows rather than inside. Takeaway four, seal up any cracks in your home around the windows or the doors where heat could be sneaking in when you're trying to cool the place down. And takeaway five, if you can, paint your roof with a reflective color like white or silver, so it absorbs less heat. For more Life Kit,

• 9:40Marielle Segarra?

  check out our other episodes. We have one on five big purchases you can make to lower your electricity bill and another all about electric cars. You can find those at npr.org/lifekit. And if you love Life Kit and want even more, subscribe to our newsletter at npr.org/lifekitnewsletter. Also, we love hearing from you. So if you have episode ideas or feedback you want to share, email us at [email protected].

• 10:06Marielle Segarra?

  This episode of Life Kit was produced by Sylvie Douglas and edited by Neela Bannery and Megan Cain. Our visuals editor is Beck Harlan and our digital editor is Malika Gharib. Beth Donovan is our executive producer. Our production team also includes Andy Tagel, Claire Marie Schneider, and Margaret Serino. Engineering support comes from Simon Laslow-Janson. I'm Marielle Segarra. Thanks for listening.

• 10:47Speaker 00

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