The Color of Light

A lot of attention is currently being drawn to the debate of the switch from incandescent bulbs to more energy efficient lighting types. The type (or color) of light plays second fiddle. Here's our take on both plus what we selected and why. First a bit of background...

Lighting type

The newer type of lights most used and known to people are the CFLs (Compact Fluorescent Lights) better known as the 'swirly' lights. The next big thing is the switch to LED (Light Emitting Diodes) that are even more efficient, have even longer lifespans but are currently a bit too expensive to be the bulb of choice, especially in bulk quantities. There are additional lighting types such as halogen and fluorescent tubes, but for simplicity-sake we'll focus on the now 'run-of-the-mill' CFLs.

There is still a bit of a debate as to how green the CFLs are (versus ye ol Edison bulb) due to some amount of mercury in them making them technically chemical waste. However you have to offset that by the amount of energy saved and the cost of producing that amount. We like the lower utiliy costs and simply include the busted CFLs in the run for disposing empty batteries which your local DIY store will take. Most people reading this blog will frequent those stores often enough that it wouldn't even mean an extra trip...

We are having all CFL bulbs installed except for two locations where we are using LED, the under-cabinet lights in the kitchen and the ceiling fan in the great room. The latter is simply to avoid having to replace bulbs 14 feet in the air... They now come incased in 'regular' shapes as well so you don't have to look at the swirly part if you don't like too. They also come in almost all light colors now. Again, a little bit of background...

Color Temperature

Most people have heard of cool and warm colors. By convention, yellow-red colors (like the flames of a fire) are considered warm, and blue-green colors (like light from an overcast sky) are considered cool. Color temperature is measured in Kelvin (K) temperature.

Confusingly, higher Kelvin temperatures (3600–5500 K) are what we consider cool and lower color temperatures (2700–3000 K) are considered warm. Cool light is preferred for visual tasks because it produces higher contrast than warm light. Warm light is usually preferred for living spaces because it is more flattering to skin tones and clothing.

Temperature	Source
1,700 K	Match flame
1,850 K	Candle flame, sunset/sunrise
2,700–3,300 K	Incandescent light bulb
3,200 K	Studio lamps, photofloods, etc.
3,350 K	Studio "CP" light
4,100–4,150 K	Moonlight
5,000 K	Horizon daylight
5,500–6,000 K	Vertical daylight, electronic flash
6,500 K	Daylight, overcast
6,500–9,300 K	LCD or CRT screen

For our build we've actually selected CFL bulbs that generate a 5000K / Daylight color. It keeps the paint colors chosen for our house relatively similar between the day and night and is preceived as more 'bright' with the same amount of lumes (light intensity, similar to a wattage equivalent). Also, contrary to what you might think, the bright light acutally helps Jen's headache as it provides more contrast. Plus, we like the color... ;-)

Our bulb of choice - simply because of accessibility from a nearby Lowes - is the Utilitech  60-Watt Equivalent Daylight Compact Fluorescent Light Bulb. We buy 'm in a 4-pack so we always have a couple spares. We did the same brand/color with the kitchen flood lights.