This is the text-alternative version of Specifying LED Color-Tunable Products.
If you can specify color-tunable products, you can decide the day the client moves in whether you want a warm color light or a cool color light or something in between.
When you have controls that are dimming to warm, it may be more complex to specify. It means that if you want to reduce the light level, you're also changing the color temperature. You're warming it up as you dim down.
White-tunable products sometimes means you're putting in more expensive fixtures. Usually these fixtures will have at least two kinds of LEDs in them. We call them LED primaries.
In some fixtures, you have a cool color primary and a warm color primary. And these different LEDs are raised and lowered in output in order to get a specific color temperature and a specific light output. Other white-tunable luminaires may have red LED primaries included in the mix. Some may have red, green, blue, and white included.
Every different manufacturer has a slightly different formula for creating white-tunable luminaires. So it's hard to make broad statements on exactly how they work. But adding additional LED primaries to the mix means you have more complexity to the controls, more complexity, and probably more cost to the luminaire.
We've had a lot of problems here installing these color-tunable luminaires because the instructions that come in the box weren't very good. So if manufacturers can provide better information on how to install them, better information on their cut sheets on how they perform, provide specifiers more information on how much light they emit at the warmest point in their dimming range, at the coolest point in their dimming range, and something in between, giving us some idea of what the spectral power distribution at different ranges is, that would be very, very helpful.