Optimize Smart Home Lighting Using Color Temperature
November 5, 2024
With Debbie and I on the verge of starting our new home build, we’ve been finalizing a lot of the design around lifestyle. One of those interesting areas is lighting, its functionality in homes and how it impacts physical and mental health. As our goal is to maximize our well-being, especially as we age, however we can, this was worth taking a deeper dive on.
So what’s the big deal with light? Well, it’s a bigger deal than you’d think.
The light that comes from the overhead fluorescents at your office is probably nothing like the light that from your entry way chandelier at home or the bedside lamp that lets you read your favorite book in bed.
That’s because different light sources produce light with different color temperatures. In the early days of energy conservation, everyone recommended replacing incandescent bulbs with fluorescent bulbs because the latter consumed less electricity. But the tradeoff only saved on your electric bill because of the poor quality of light the typical fluorescent bulb produced. This prompted the lighting industry to come up with better alternatives. As you think about which type of lighting to use in your home, you should consider how you can use color temperature to optimize your environment.
To understand why color temperature is important, you must first understand what it is. Imagine the filament of an incandescent light bulb. Now begin heating this filament with fire. As the filament heats up, it begins to glow, first red, then yellow, then white, and then various shades of blue as the flame gets hotter and hotter.
Certain temperatures of this flame, measured on the Kelvin temperature scale, correspond to various wavelengths of light from the filament. The bottom end (around 1800 Kelvin, or 1800K) corresponds to the intensely red-orange light from a match or a candle. At the high end (15,000K and up), the readings correspond to the light observed looking up at a clear, blue sky.
You’re probably familiar with terms like “cool white” and “warm white” lighting, like those you’ve seen on a standard incandescent or fluorescent light bulb. If you read the fine print on the back of a light-bulb package, you might even find an estimated color temperature denoted in degrees Kelvin.
Most commercial lighting falls between about 2000K and 6000K, but two color temperature levels dominate. Around 2700K is typically denoted as “warm white” or “soft white.” These bulbs are designed to approximate the typical incandescent bulb, offering an orange-tinted, cozy, “warm” light just like in the house you grew up in (especially if you’re ‘older’ like me. Warm light is considered a comfortable, homey light most suitable for use in the home.
At about 3500K we enter the range know as “cool white” or “bright white.” Lamps at this color temperature take on a more neutral color and may appear to have a slight blue cast. Standard fluorescent lighting is typically produced at this color temperature, and it’s what you’ll find in most business environments, as light at this wavelength is considered ideal for reading and other detail-oriented task work.
The use of the terms “warm” and “cool” is a bit paradoxical because, when examining the Kelvin scale, you’ll see the “cool” light is actually hotter than “warm” light. The terms warm and cool aren’t intended to describe the actual temperature of the flame used to produce the light but rather the aesthetic these lights generate. Also, color temperature ratings aren’t always entirely meaningful on their own. The color temperature of the sun is measured at about 5600K, but the actual sun itself varies in temperature widely. It is only the visible portion of the energy emitted by the sun that we detect as light that approximates its color temperature rating.
If you’ve ever replaced an incandescent light bulb with a fluorescent bulb and discovered how cold or downright ugly the room looked after your “upgrade,” you’ve experienced just how dramatic an impact color temperature can have.
Everything in a room is impacted by the light source in that room. A wall that is white under a 3200K light source can look green under a 4000K light source. That same wall under a 2500K light source may look yellow. This is why designers advise you to place lighting elements and choose bulbs before you paint and furnish a room. As Debbie and I won’t have this luxury with our build we’re going to have to get creative with testing different combinations of lighting and color. It’s not uncommon for DIYers to return paint because the color they picked under the fluorescent bulbs at a hardware store looked very different when they saw it under the light bulbs in their home.
The appearance of your room aside, the color temperature of your light can have some subtle and not-so-subtle effects on the way you live and work. Bulbs that mimic daylight (in the 5000K to 6500K range) are becoming increasingly popular in a variety of rooms. Some homeowners appreciate having daylight lamps in their bedrooms because the color of the light, mimicking daylight, helps them get moving much quicker in the morning than the warm, cozy soft-white lamps. Does that sound familiar to anyone?
Also, many of the reading lights on the market are daylight temperature, as the color provides great contrast between black type on white or off-white paper, making it easier on the eyes to read. Daylight bulbs are also popular in bathrooms, because they make it easier for women to see what their makeup will look like outdoors.
Some studies suggest that light in the blue portions of the spectrum can help you wake up in the morning, making cool white and daylight bulbs especially suitable for bedrooms. This ‘upper high-Kelvin’ light can trigger a photoreceptor called melanopsin that helps set your body’s daily cycles and can keep you more attentive and alert. For example, you can read and study longer, comprehend better, and make fewer errors.
That said, there’s no real need to replace your warm bulbs with daylight bulbs, as they can make it tough for you to get to sleep in the evening. One option would be to install color-tunable smart bulbs supported by apps that automatically adjust the brightness and color temperature according to the position of the sun.
Cree Lighting has a line of WiFi-connected smart bulbs with an app that has a “follow-the-sun” setting. This will automatically change the brightness and color temperature of the light they produce to help wake you gently in the morning, keep you energized during the day, relax you in the evening, and help you fall asleep at night. No matter what you do to change the light around you, remember that it will impact your mood and your overall health. Light can even make your immune system work more effectively.
There are a few popular basic strategies when it comes to choosing bulbs for the home. Perhaps the most popular is to select a color temperature you like — typically in the warm light rangean — and install these bulbs everywhere. This has the advantage of making your home’s lighting uniform, which makes transitions from one room to the next less impactful.
Alternately, warm bulbs can be used for the primary lighting in areas like the living room, dining room, bedrooms, and hallways and cool or daylight bulbs can be used where more attention to fine detail is required. Bathrooms, the garage, offices, the kitchen, and focused task lights like reading lamps — particularly fixtures directly over work areas — are good places for cool white or daylight lighting. There are no standard rules about where to use which type of bulb. Ultimately, you’ll have to experiment to see which looks best to you in each fixture in the house.
If any of this seems complicated or confusing, hold on. Thanks to the rise of LEDs, which are available in a much wider range of colors than have been available through other technologies, “color tuning” has become an increasingly popular option for homeowners looking to really define their homes through lighting design.
Modern LED bulbs let you switch between cool and warm light on the fly — setting bulbs to any color you choose. Products in this rapidly growing space include Philips Hue, LIFX, Cree Lighting, GE Lighting, and Nanoleaf. Each is designed to replace your existing bulbs, and many can be controlled using a mobile app via common wireless home networks — Bluetooth, WiFi, or Zigbee, most commonly. Some allow you to use the app to tweak the color temperature or choose wild alternative color to set a fun or festive mood in addition to turning the bulb on and off and establishing schedules for their use.
The big advantage of color and color-temperature adjustable bulbs is that they free you from having to pick a single bulb for each room in the house. For example. the Hue system has four preset “recipes” for color temperature built into its app: relax, reading, concentrate, and energize. So, if your kids are always doing homework in a particular room during a set time of the day, you can program Hue to ‘concentrate,’ about 4300K, during that time. Then later switch to ‘relax,’ about 2100K, to help your body wind down at the end of the day.
If your head is spinning, don’t feel bad. When I first started looking into our lighting planning and discovered all this I was amazed. But also intrigued as I never realized how light can impact your health and well-being. Understanding what color temperature is and why it matters, will help you choose the right types of light bulbs to improve the quality of your life at home.
I’d love to hear your thoughts on smart home lighting. Have you used any of the lighting types to enhance the quality of life in your home? Have they made the expected difference? Have you thought of any applications for special lighting I’ve not addressed here? Let Debbie and I know what you think in the comments, DMs and emails as we really enjoy hearing from you. Thanks again to all those following Debbie and I through our home building journey. It’s great to hear your success stories and suggestions as we move through the process. And if you like the content I’m posting each week, don’t forget to ‘Like’ and ‘Follow.’
In full disclosure, I’m not an affiliate marketer with links to any online retailer on my website. When people read what I’ve written about a particular product and then click on those links and buy something from the retailer, I earn nothing from the retailer. The links are strictly a convenience for my readers.
