Painting the walls a dark color, or not painting the walls at all. A key factor in the brightness of any space is the reflectances of the surfaces. The more reflective your walls, ceiling, floor, and furnishings, the less it will cost to make the room feel bright. A can of white paint is one of the most inexpensive lighting accessories you can buy.

Closing shades or draperies to keep out daylight. (Or letting the daylight in but leaving the lights on anyway.) Daylight is free, has all of the characteristics people crave in lighting - good color rendering, changing throughout the day to improve circadian rhythms, and did I mention free? Adjust the blinds to direct glare toward the ceiling, but keep the light switch off when the sun is shining.

Not using dimmers. At certain times of day or on certain days of the year people need or want more light. At other times, less is better. Dimmers save energy and increase lighting satisfaction by giving occupants control of their spaces. They're easy to install. Do it. You'll be glad you did.

Forgetting to take advantage of warranties. Sure, we've all had bad experiences with either an LED or CFL lamp. But do your research to find a high quality product from a reputable manufacturer that meets your lighting specifications. Then hold them to their warranty. If something goes wrong, don't go elsewhere. Go back to the manufacturer and get them to fulfill their warranty. That will help them improve the products in the long run, too.

Avoiding new technology. New technology does require you to understand more about lighting and the visible spectrum. You have to watch for the right color temperature and good color rendering. Lighting quality issues aren't simple. But if you choose carefully, the energy savings will be worth the extra front-end effort.

Which lighting mistakes are you making? Which is most surprising to you?

I have just returned from another Fabulous Las Vegas Lightfair - the biggest annual lighting trade show in the US. Three years ago I returned from Lightfair on a rampage. It seemed that everyone was showing off their "new" LED product, and every one of those products was failing at everything that matters to lighting designers: glare, color, flicker... Then last year I saw improvement. The story wasn't just, "hey we have LED" but rather, "our LED is better because of its color" and "we have improved the optics by..." Thank goodness the manufacturers have continued this trend. There were some LED products that actually made me hopeful. BUT...

This year my favorite question to ask became, "What do you mean by that?" 

I was repeatedly told, "Our LED fixture is fully dimmable." If someone says something is fully dimmable, I think that should mean FULLY dimmable, as in it can dim from zero to 100% without flickering and can be switched on or off at any point along that dimming curve without flickering. We are NOT there yet, folks. None of the products I saw had that capability. None of them. But I was told at least 20 times that various products were fully dimmable.

What does that mean?

Sometimes they meant the product would dim down to only 10% before turning itself off or beginning to flicker. In the best case scenario they meant it would dim to 1% and then off. I know that is close to full dimming and most of the time that is good enough. But that is fluorescent dimming at its best. That is not equivalent to incandescent dimming. The language with fluorescent dimming has always been 10%, 5%, 1%. I don't recall it being described as fully dimmable. I don't think LED should be described as fully dimmable yet, either. But I am still hopeful it will get there. Don't settle for less. And don't forget to ask, "What do you mean by that?" until fully dimmable truly means fully dimmable!

Maybe we could turn these off during the daytime?