How To Choose A Lightbulb: Life Kit What kind of lightbulb do you need? There are so many options when it comes to picking the right lightbulb: LED or incandescent? How many watts? What's a kelvin? We help focus your lightbulb search to make the decision easy.
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Picking A Lightbulb, Made Easy

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Picking A Lightbulb, Made Easy

Picking A Lightbulb, Made Easy

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This is NPR's LIFE KIT. I'm Jeff Brady. I've spent a lot of time in lightbulb aisles recently because I've been reporting on changes to energy efficiency regulations. And one thing I've noticed is a lot of confused people holding an old lightbulb and trying to find a new one just like it.

JOHN PENNICK: I'm looking for a bulb to go inside of my refrigerator.

BRADY: John Pennick (ph) is at a Home Depot in suburban Philadelphia.

PENNICK: This is a 40-watt. It's a 40-watt. The bulb seems to be the same. The only thing is, I don't want dimmable. I'm not going to be dimming inside the refrigerator so.

BRADY: Turns out, that means it's able to be dimmed, not that it has to be. This confusion is the result of a revolution in the lighting industry. The old energy-hogging incandescent lightbulb is going away, and new LED or light-emitting diode bulbs are taking over.


BRADY: In this LIFE KIT episode, we're going to talk about what you need to know about LEDs to avoid bad experiences - you know, light that hurts your eyes or just makes you feel tired. And we're going to learn how to get just the right light, which can be different depending on what room you're talking about.

There are really good reasons to switch to LEDs. Later, we'll learn how using them can help you sleep better. While they are a bit more expensive, they last a lot longer, so you'll change bulbs less often. And they use a fraction of the energy old bulbs do. That's important for addressing climate change. The Energy Department estimates switching to LED bulbs across the country saves the amount of electricity produced by 44 large power plants. Interior designer Erin Shakoor says that's good for your budget, too.

ERIN SHAKOOR: Here's the deal - you're going to save so much money on your electric bill by transitioning from regular incandescent to LED bulbs. So that's the first, like, no-brainer.

BRADY: Erin owns Shakoor Interiors in Chicago, and she knows how to use light to enhance your space. She often talks about the role of light fixtures like this...

SHAKOOR: Like, that badass hat that you put on right before you walk out the door or that beautiful piece of statement jewelry that you're like, oh, this just made my outfit. Yes, I'm ready to go. And I'm just - I'm rocking this look (laughter).

BRADY: Erin says LEDs allow her to be more creative because they're small. You no longer need a big, ugly lightbulb poking up from a metal base. She says manufacturers are coming up with all kinds of interesting new fixtures. And if you really want to go crazy with this - and assuming you have the cash - firms like hers can even design a custom fixture with LEDs.

SHAKOOR: And then you've got this amazing statement piece that is, you know, calling, you know - what's that "Milkshake" song?


SHAKOOR: ...Calling all the boys to the yard, so to speak (laughter).

BRADY: (Laughter).


KELIS: (Singing) ...Better than yours. Damn right, it's better than yours. I can teach you, but I have to charge.

BRADY: So here's our first takeaway - the LED revolution has made the lightbulb aisle more complicated. But there are big benefits to switching to LED lighting in your house. You can save energy and money, and you can be more creative.


BRADY: So now, assuming you're sold on LEDs, Erin says it's really important to think about how you want a lighted space to feel. What happens in that room? That can affect what lightbulbs or even what light fixtures you buy.

SHAKOOR: When you're sitting on a sofa sectional watching the game, you're not interested in, you know, high, glaring lights right on your face, your head and coming into your sort of view while you're watching the TV. So we would like this footprint within the room one way, usually with dimmable, recessed fixtures.

BRADY: But in the kitchen, Erin says you want to flood the space with light. It's a workspace where it's important to see things clearly. That's our second takeaway - think about the space you're lighting and choose bulbs and fixtures that complement what happens in that space. Erin says if you're renting, you can use floor and table lamps - those can be pretty inexpensive.

SHAKOOR: Once you make those fixture choices or those lamp choices, now you can easily make a bulb choice.

BRADY: And to do this, we need to learn a few terms - watts, lumens and Kelvin. Watts refer to energy consumed. Lumens refer to brightness. And Kelvin is the color of the light. First, watts.


BRADY: The old way of picking a lightbulb focused on watts. I always thought that was an indication of how bright the bulb is. One hundred watts is brighter than 60. But actually, watts refer to the energy the bulb consumes. And since LEDs need less energy to produce the same amount of light, those bulbs have really low wattage numbers.

SHAKOOR: The simple formula and kind of rule of thumb is to multiply that number times five to understand what kind of light output you're going to be getting in a lamp or fixture in the room. If it says 12, you're going to be getting 60 watts of light.

BRADY: But the real measure of light output is lumens - that's the second term you need to know. Many manufacturers still use both watts and lumens. They'll say something like, this is equivalent to a 60-watt incandescent bulb, and that's 800 lumens. You don't need to obsess over any formula for this. Just know that more lumens is brighter and less is dimmer. Another term you may really want to pay attention to is Kelvin. That's a measure for something called color temperature. Now, if you're confused already, don't worry - Erin was there, too.

SHAKOOR: In the beginning, it confused all of us.


SHAKOOR: So designers and architects alike were like, wait - what?

BRADY: (Laughter).

Erin says color temperature is a scale. And the most important thing you need to know is, on that scale 2,700 Kelvin is about the same color as a typical incandescent bulb.

SHAKOOR: It's got a slightly warm glow to it. And I think from my perspective when I see it next to a 3,000 - oh, the 3,000 makes me so happy because the 3,000 reads as daylight, and everything is crystal clear and perfect color in daylight.

BRADY: So is there sort of, like, a general guide to, like, the lower the Kelvin number, it's closer to this color and the higher the Kelvin number, it's closer to that color?

SHAKOOR: Yes. And so when you start going lower, it gets very gold, very yellow and you can - in almost that Edison bulb, that retro Edison bulb kind of look.

BRADY: So lower number's going to be golder. If it's a higher number - the 3,000 is the one you like. That's, like, daylight so you can see best.


BRADY: And if you go higher than that, what are you getting to?

SHAKOOR: You're getting blue. It just gets bluer and bluer and bluer.

BRADY: For our third takeaway, we need to learn a few new terms. Lumens measure light output - the higher the number, the brighter the light. Color temperature is measured in Kelvins. Lower numbers look more gold, and higher Kelvin numbers look blue. If you're still a little confused, we have all this written out. Search NPR LIFE KIT and lightbulbs.


BRADY: We need to talk about dimming.

What do I need to know?

SHAKOOR: I love to dim.

BRADY: (Laughter).

SHAKOOR: Dimming is my fave.


SHAKOOR: It's just because I'm a control freak. So if I walk into a space, it's like, oh, it's so bright, let me turn to the dimmer, and I don't see one, then I scream. What you need to know is to read the box, to read the label. And it just needs to say that it's dimmable. And they're all marked. And if it says dimmable, it's dimmable. If it doesn't say that, it is not.

BRADY: So here's our fourth takeaway - if you like controlling the light in your space, make sure your LED lights are dimmable. There are cheap LED bulbs out there that aren't dimmable. That's really what LED lighting gives us - more control, not just so we can create a nice feel; you can also use lighting to improve your health. At Rensselaer Polytechnic Institute in Troy, N.Y., there's a Lighting Research Center.


MARIANA FIGUEIRO: Hi, how are you?


FIGUEIRO: Nice to meet you. Thanks for coming up.

BRADY: Nice to meet you.



Mariana Figueiro is the director, and she's very interested in how lighting affects health, especially what it does to our circadian rhythm or sleep-wake cycles.

FIGUEIRO: So you have a clock in the brain that ticks, however, it ticks with a period slightly longer than 24 hours. So if you didn't have light, you would be, every day, out of sync with your watch. So what light does, especially morning light, it resets your clock daily so that you are in tune with your watch.

BRADY: Mariana says once you know that, you can use light almost like medicine to help you be awake or asleep when you want. Recently, her research focused on people with Alzheimer's disease. She talked about this in her lab, where we sat down at a table that has lights shining up from the surface.

FIGUEIRO: This is a light table that we built to deliver light to Alzheimer's patients in nursing homes. What happens is they tend to stay in a common area, they tend to sit around tables and they look down. So it was an ideal way to deliver that light at the eye because for the light to be effective, they have to reach the back of the eye.

BRADY: The light tables are turned on in the day and off in the evening. Mariana says that helps reduce depression and agitation because patients sleep better when their biological clock is synchronized to the local time.

FIGUEIRO: So therefore, they are not awake, wandering in the middle of the night. They're actually knowing that daytime is when they should be awake and nighttime is when they should be asleep.

BRADY: If I have trouble sleeping at night myself, could I have a table like this and expose myself to this kind of light during the day?

FIGUEIRO: Yes, you can if you have trouble.

BRADY: And it would help.

FIGUEIRO: It would help. I can tell you, it won't help if you're staying awake because you can't pay your bills. But it will help if you are desynchronized, so your biological clock is not synchronized with your local time on Earth.

BRADY: This is where the Kelvin color scale and lumens come back into play.


BRADY: Mariana says if you want to have light that will help you sleep better, the key is brighter and bluer lights in the morning and then dimmer and golder lights closer to bedtime. There's software and settings to make your computer and smartphone follow this pattern through the day, too.

That's our final takeaway - exposing yourself to certain light at different times of the day can help you sleep better and synchronize your biological clock to your watch. And you don't need a fancy light table. Mariana says there are simple ways to get light into your eyes at the right times. You can just go outside in the morning or the afternoon without sunglasses on. And because LEDs are semiconductors, like the things you find in your computer, that opens a whole new world of lighting technology developments that already are starting to be available.

SHAKOOR: You can buy the bulbs that you can, with your phone, change the color of it over the course of the day. So that's a feature that we have right now that we didn't have, say, with the incandescent lamp.

BRADY: It's a cool feature but still pretty expensive - about $100 for a starter kit with three bulbs. So we've covered a lot here, but you may still have questions. Erin Shakoor suggests skipping the big box, do-it-yourself stores for answers. She says go to a lighting store instead.

SHAKOOR: So that's the place to go where you can have someone who just is specializing in lighting, not in screwdrivers and lumber and lighting and power tools.

BRADY: And I might spend a few more pennies on the bulb or the fixture, but that's all right. That's worth it.

SHAKOOR: It's totally worth it because you're not changing it out in three weeks or in three months.

BRADY: And a specialist can help you pick that perfect fixture or bulb that will be the best fit for the space you're trying to light.


BRADY: So let's recap what we've learned. Takeaway number one - LED lighting is more complicated, but there are big benefits. The bulbs last longer. They save energy and money. And because LEDs are small, they make it easier to be creative. Takeaway two - think about the space you're lighting, and choose bulbs and fixtures that complement what happens in that space.

Takeaway number three, terms we need to know - lumens measure light output; the higher the number, the brighter the light. And Kelvin measures color - a lower number looks gold, a higher looks blue. Takeaway four - make sure your LED lights are dimmable if you want to control the light in your space. And our final takeaway, expose yourself to bluer, brighter lights in the morning and golder, dimmer lights in the evening. That can help you sleep better.


BRADY: For more NPR LIFE KIT, check out our other episodes, How to Teach Your Kids to Love Math and How to Run for Office. You can find those at And while you're there, subscribe to our newsletter so you don't miss an episode.

And here, as always, is a completely random tip. This time from listener Lindsey Dobruck (ph).

LINDSEY DOBRUCK: So you're making a soup or stew and the recipe calls for, like, two tablespoons of tomato paste. So instead of throwing it out or leaving it in the fridge for two weeks to get all moldy - like I do - scoop out one tablespoon dollops onto a sheet of wax paper, freeze and store them in the freezer for the next time you're making soup. And that way they'll be measured and ready to pop into the pot or slow cooker. You'll save money, you'll reduce waste, and you have one less spoon to wash.

BRADY: If you've got a good tip, leave us a voicemail at 202-216-9823 or email us at


BRADY: This episode was produced by Audrey Nguyen. Meghan Keane is the managing producer. I'm Jeff Brady. Thanks for listening.

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