Breaking Down Dark Sky Compliance, Project Requirements, and B.U.G. Ratings

What Is a BUG Rating?

Adam: Cool, so today we're going to
talk about Dark Sky and BUG ratings. Jake, what is a BUG rating?

Jake: A BUG rating — the letters stand
for Backlight, Uplight, and Glare. It's essentially a rating that's related to
a light fixture. It pulls data from the IES file. It tells you how much light
is going backwards, which would be the B, up which would be the U, and then G
is separate from those two — that's essentially the glare, or the candela, of
that light.

Adam: Gotcha.

BUG Ratings & Dark Sky Compliance

Adam: Trent, how do BUG ratings and
Dark Sky compliance relate to each other, and how are they different?

Trent: The uplighting is probably one
of the main concerns as far as having dark skies. You don't want to have the
sky glow happening, so usually you need a recessed light that's pointed down to
prevent any light from going up. You also want to consider light trespass —
that's where backlight comes in. You don't want light going on other people's
properties, and you just want to make sure that light is where it's intended to
be.

Adam: Cool.

Dark Sky Requests

Adam: So BUG ratings have nothing to
do with bugs.

Jake: They do not.

Adam: Not today. Gotcha. So when
people talk about Dark Sky, I would say that's often a misunderstood term.
There is an official Dark Sky rating — I believe it's IDA Dark Sky — and then
local cities, local areas have taken that and created their own version of Dark
Sky. I know it can mean everything from a 3000-Kelvin color temperature fixture
or warmer, with all the necessary accessories and recessed light engines to
create limited uplighting. It can also just mean a fixture at zero degrees —
any fixture at zero degrees. So Jake, you run our applications team, so you
guys see a variety of Dark Sky requests. How would you categorize the different
types of requests? I know there's probably infinite variations, but if you had
to chunk them together in a few different buckets, how would you categorize
Dark Sky requests?

Jake: It kind of goes by application —
that's probably the easiest bucket to put things into. So you have sports
lighting, which is a world entirely on its own when it comes to Dark Sky stuff.
Then you have general parking lot/facility-type lighting. Parking lot lighting
is by far the most common. Roadway is also relatively common, but we don't do a
lot of DOT-type roadway work, so it doesn't come up as much for us. So
specifically parking lot lighting. And then the next level of that is going to
be just diving into exactly what was requested on the front end from our sales
team, from the end user, whoever we're working with, whoever the salesperson is
working with, and just trying to dig through exactly what they need. It's a
little bit easier because we can take it a step further — we can figure out
exactly where the job site's located. Certain areas around the country have
much stricter requirements for dark skies. So when someone says, “I need a Dark
Sky fixture” in California, for example, that means something entirely
different than Dark Sky in Wisconsin.

Adam: That's a great point. Same term.

Jake: Way different requirements. So
those are like the general places that we would start with a design. From
there, we just go through different fixture options. Obviously, if it needs to
be Dark Sky, we're always talking about something zero-degree mounted, so
side-mounted, all the lights going straight down. But in a place like
California, they might have a hard requirement for 3000K, whereas here in
Wisconsin they might not necessarily care about the color temperature as long
as it's zero-degree mounted, like we kind of just discussed.

Dark Sky Requirements & Florida Wildlife Parallel

Adam: So it's similar to the Florida
wildlife — like Florida Wildlife Commission for amber and turtle-friendly —
where in some ordinances, some codes, as long as you have the right amber LED
chip with the right wavelength and maybe a glare shield, that's good enough to
comply with their standards. In other areas, you need official FWC compliance.
But all requests come in as turtle-friendly, and like you said, part of our
applications process is to identify how strict is the requirement, and a lot of
that is based on geo. I think I've also seen factories that will make up their
own certification, and there's nothing wrong with doing that, but it can maybe
create some confusion. So would you say the four categories are: official IDA,
and then you have local city codes, and then there are third-party compliance —
now other than IDA, like ETL has a certification — and then the last would be
factory certifications? Are those kind of the four categories?

Jake: Yeah.

Adam: Okay. So Trent, as far as the
official certs — IDA versus ETL or UL — how do those differ, and what are they
trying to accomplish?

Trent: The certs would be IDA and DLC.
DLC just put out technical requirements at the end of 2021 for what would meet
their standards, and they created this along with IDA. It's just something to
give customers a point of reference and maybe a single source for Dark Sky
compliance-type stuff. It is similar to a manufacturer creating their own cert,
but it's more standardized, and it's also going to have to do with the quality
of the light fixture and how reliable it is — lumen maintenance and things like
that. So it kind of goes beyond IDA. It kind of mixes DLC and IDA in some
regards, but it's just another thing for people to use.

Adam: Okay.

Dark Sky Challenges: Bollards & High-Output

Adam: Trent, you spend the majority of
your time on product engineering and running that team at Wisconsin Lighting
Lab. What are some of the challenges from a factory or product engineering
standpoint that these requirements create? Let's pick bollards for one example.
Bollards — we do a lot of bollard work. We also do a lot of high-output
products. What are challenges in each category when it comes to Dark Sky
compliance?

Trent: By nature, the design of the
bollard — there's a light source above, and the bollard tube is below it, and
there's going to be a certain amount of light that hits internal parts of the
bollard tube, and they're going to get reflected back up into the sky. So
immediately, you're going to start seeing the BUG rating, the U value, go to
one no matter what you do. Then you have to side-mount a fixture to a bollard
tube in order to get to a U0, which from a customer's perspective is a bit of a
compromise, because you don't want people walking by and catching their leg on
it.

Adam: It's not as nice to look at
either.

Trent: So there's just give and take
with bollards, for sure. And then as far as high-output stuff goes — they just
put out so much light that any light going in the up direction is going to
increase your U-value. Even though it's like 1% maybe of the total light
output, it's still going to be up to like a thousand lumens of uplight, and you
have a hundred-thousand-lumen fixture. So you can certainly have challenges
with getting Dark Sky compliance out of a very high-output product.

BUG Ratings Don't Scale

Adam: Jake, that's one thing you've
mentioned in the past — the BUG rating and the requirements do not scale along
with the fixture itself. So if you have a 1,000-lumen fixture and the BUG
rating calls for a thousand lumens or less of uplighting — I'm not sure if
that's exactly what it is — but then you have a hundred-thousand-lumen fixture
and it still calls for that. You're kind of handcuffing some of your
higher-output products.

Jake: Obviously the BUG rating is —
this is where we run into issues, because the markets that we're primarily
dealing with are going to be the high-output markets. The bollard one is a
little bit of a weird one too, because there are a lot of times when they have
hard requirements for a zero uplight in that area, and there has to be some
type of light somewhere, and bollards are usually kind of the go-to to fill in
the blank of not having poles in an area. So the bollard — just to wrap up that
— is like having an uplight of one on a bollard, you're talking 10 lumens. So
something like that's not necessarily going to create issues with sky glow.
You're talking, when you have uplights of a rating of five — like on a really
crazy bright floodlight in the markets that we deal with — that's where you're
getting a majority of your sky glow from. So those are the — that market, the
high-output market, is really where the BUG rating is coming into play the
most. And again, like you mentioned, it doesn't scale at all. So basically
it's: zero to ten is your BUG rating of one, zero being a zero for the U
rating. And then anything beyond that, I think it's ten to a hundred, then a
hundred to a thousand. Up to — before B5, I believe, is up to ten thousand. I
could be wrong on that, it might be 5,000. But either way, it doesn't scale
linearly with the output of the fixture. So that puts us in kind of a tough
place when we're talking about high-mast type applications, because there's
just so much light coming out of those fixtures — you can't control everything.
Like you said, it's difficult to control 100%.

Fixture-Specific Ratings & Application Thinking

Adam: I would think for a high-mast
fixture too — if you have a 120-foot lighting assembly, the downlight is
creating as much sky glow as the uplight as well, because the downlight in that
case is way brighter than an uplight for a 20-foot lighting assembly.

Jake: That's why, when you think of
the BUG rating stuff, especially the up — it's all fixture-specific, it's not
application-specific. And they do that obviously because you can't control
every application, you can only control what you can control, and the easiest
point to control is the fixture. But that's one of the biggest takeaways with
this BUG rating stuff — the uplighting — there probably needs to be a little
bit — in some areas they're very strict — and there probably needs to be a
little bit more variation. People need to realize that just because we're
supplying a fixture that has an uplight of two doesn't necessarily mean that
that's going to be better than an uplight of one or zero. If you have a bunch
of fixtures — like you have 12 fixtures all with an uplight of zero, as opposed
to two fixtures with an uplight of one — the application itself is going to
create less sky glow, just based on the reflections of the ground. Maybe
there's less overall lumens. So that's something to keep in mind for people —
you've got to think about the entire application, not just dial down to the
exact fixture specs.

Application Engineering Support

Adam: Maybe a good thing to close on
too — our application engineering and product engineering teams get pretty
involved on pretty much any high-output job. We do a lot of our own lighting
designs, and we can work through the technical details on a project-to-project
basis. Help educate our customers, our sales partners, their engineers. Rather
than simply just publishing, here's the data, here's the requirements — we're
here to help get through those nuances. Because there are nuances on every
single application. Mounting height affects it, the location of the job affects
it. There are certain things you can't work around, so we can help identify
some of those. We're certainly here to help, not just publish information, but
on a job-to-job basis, help work through some of these things. Do you guys have
anything else you want to make note of on the topic?

Lighting Zones & Western States

Jake: One thing too, just for people
to keep in mind — especially in areas like California, I mentioned this
already, where they're relatively strict with the uplighting and just the BUG
rating overall. Depending on the actual location and what's all going on in the
environment — California and other states like Colorado, Arizona, New Mexico —
these states generally have specified lighting zones, and those lighting zones
are basically what you need to follow if you're trying to follow a specific BUG
rating. So knowing those lighting zones — we can help determine what those
lighting zones are, they're all found on the government websites — but just
knowing those lighting zones helps us when we're selecting products and
creating the lighting designs. So just something additional to keep in mind —
that's another layer to just the BUG rating.

Adam: Okay. Well, great to know.
Anything else?

Trent: Sounds good. I'm good.

Adam: Well, thanks a lot guys.

Jake: Yeah, thank you.

Trent: Thanks.