2700 - 3000 Kelvin or Bust: An Appeal to Human Decency
Have you ever walked into a house and instantly wanted to leave? Look up, because it could be the light bulbs. In the mid-1800s, William Kelvin observed the color changes in a carbon block as it heated. The colors transitioned from red to orange, then white, and, finally, to a bluish hue. This observation laid the foundation for the color temperature scale, measured in Kelvins (K).
The Worst Offender: Mixed Kelvin Bulbs
Nothing says "I just don't care" like multiple bulb temperatures in the same room. The effect is messy, visually confusing, and creates uneasiness in the space. I’ve often had buyers say things like “this house doesn’t seem well cared for” or “something is off” or “it feels uncomfortable” when walking into spaces with multiple Kelvin temperatures. The paint looks muddy in the spaces where the two temperatures meet, and there’s a “can't put my finger on it” off-ness.
The Cold Fish: 4000-6700K (high color temperature)
It’s giving ER waiting room. Bulbs ranging from 4000 to 6500K make homes feel cold, clinical, and even sterile. They accentuate imperfections in wall texture and generally make you feel more on edge. Basking in the glow of a 6000K bulb, your skin will look green and even a little jaundiced. This is why no one feels their best in an office building with fluorescent lighting.
Light with a high color temperature (4000-6700K) emits significant amounts of artificial blue light, which activates melanopsin, a photosensitive pigment in the retina that inhibits melatonin production. This is effectively signaling to the brain that it's constantly daytime! A study revealed that light with a high color temperature of 6700K adversely affects the ability to enter stage four slow-wave deep sleep, a crucial reparative phase of sleep.
Additional studies indicate that light with a high color temperature (4000-6700K) stimulates the brain's arousal center through non-visual photoreceptors in the eye. This influence extends to the nervous system and stress responses, impacting stress hormones, muscle tension, heart rate variability, blood pressure, body temperature regulation, and sleep.
So, when a buyer wants to leave a house with a high color temperature, they are responding in a completely rational - and even biological - way!
The Model Home: 2700-3000K (low color temperature)
The hospitality industry has long understood the power of the warm light bulb, championing the 2700-3000 Kelvin bulb as the go-to for the ideal atmosphere. If you've ever wondered why your skin looks better in a nice hotel room or at your favorite restaurant, this might be it!
In 2013, a study discovered that individuals exhibited greater relaxation in environments illuminated by warm, low color temperature lighting. Another intriguing study revealed that adults exposed to warm, low light were more inclined to express praise, engage in collaborative conflict resolution, and dedicate time to unpaid volunteering compared to those under high color temperature lighting.
The Bulbs to Buy:
3000K bulbs are often sold as "warm white," and 2700K bulbs are often sold as "soft white." Sometimes the names are reversed.
Click here for my favorite, plain E26 bulbs from Amazon by Philips. They’re flicker-free and fast warming (4 for $20). Another great option is this very affordable Feit bulb from Home Depot at $12.98 for 4.
Real Estate Tip: If you're planning to list your home, make sure the bulbs you choose "warm" quickly, meaning they get bright as soon as possible. Some energy-efficient bulbs take up to 10 minutes to reach their brightest, meaning buyers will see your home at half capacity.
In conclusion, warm light bulbs may not be the answer to all of life's problems, but they're certainly better than living in a space that makes you feel like you're waiting for the DMV to call your number. Homeowners and realtors, I beg you, banish the blue. For more tips on making your home feel warm and inviting or for my full list of favorite bulbs from chandelier to recessed, reach out!
