So you'll see where some lights are on, and that's because we have emergency lighting, or egress lighting. So we leave a certain number of lights on, even though, technically because of occupancy sensing, you don't necessarily need it.
Now are these the LEDs?
These are all LEDs. These are all dual LEDs. And you can see that when we trigger that light, this whole group that we have together came on as an individual group.
Are they individually controlled or is it a circuit that's being controlled?
They're individually controlled. And what we did when we commissioned these lights – so for private offices, because it becomes cumbersome when people go in and out, in and out, or simply just walk by and enable the occupancy sensor, we have a wireless wall unit that we set up for it to be manual on and it will automatically turn off. Or you can manually turn it off. So, I mean, you do have that kind of functionality too.
Is it wireless via ZigBee?
Yeah, that's wireless basically using ZigBee technology. So we actually have – we make the office a group of lights, and then we figure out what the radio frequency is to have the switch connect to the group. Now, if we took that switch off and took it to the other end of the building, it would still control these lights within radio frequency range.
As long as you didn't change the group?
Are these changing their output at all once they come on?
When they come on, what they do is they sense daylight, and they go through and adjust to the light level. So when they first come on, it's programmed to go through and say, let me calibrate. As you know, LED lights are bright. And so what we wound up doing is putting these at the lowest setting that we could coming out of the factory. The factory is normally set as like a medium level. We try to set them at low, so we're not wasting energy. And we're getting roughly the 30 foot-candles that you need to do work in an office space.
So is it actually doing daylighting now, or is it just going to a set point?
It's going to a set point.
OK, does it do any daylighting?
It does. It does daylight harvesting. So we do more daylight harvesting on the north side of the building because we have these electrochromic windows on the south side. So you have two technologies in essence kind of fighting with each other because the windows will tint as you get more sunlight, but on the north side, they actually sense how much daylight is out. And they will adjust – each individual light. Even in a group, if one light in the group senses that it doesn't need as much daylight and has a right level output, it'll daylight harvest what it can.
About each three or four windows has a manual override. So, if a person is sitting here at the window says tinted, and I don't want it tinted, they can manually override it. It takes about 20 minutes for it to take effect. Yeah, so that's why whether we want it to or not, that's why you still see shades because some people say, I don't want to wait 20 minutes to get sun out of my eyes or let sun in.
You have any problems with light sharing? And so one light will start getting dimmer because this light gets brighter?
We don't. We haven't had it yet. So we –
Seems like you've got a fairly low ceiling.
They're far enough apart so that --
It is a very low ceiling and, we put – because we were putting in lights, we put in new ceiling tiles with very high reflective level of – I think we're at like 90 for the reflective level on the ceiling tile to kind of get the most out of the light so that the lights aren't overworking, and they're working in concert with their surroundings.