Special Considerations – Lighting Indoor Industrial Applications feat. Trent

Setting the Stage

Adam: So yeah, we're going to talk
about indoor industrial lighting applications and some of the different
application considerations when working on a high-bay or low-bay project. High
bay isn't necessarily our main focus at Wisconsin Lighting Lab, but we do quite
a few indoor industrial applications. Oftentimes people pull us in when it's a
challenging environment — it could be high temp, high dust. We've done some
remote power applications. So I just want to talk through some of the things
the sales team and our sales partners should consider when selecting products.

Temperature

Adam: The obvious one when selecting a
light fixture for an indoor environment would be temperature. Walk me through
some of the temperature considerations when selecting the right product.

Trent: In industrial applications you
typically have a much higher ambient temperature at the ceiling than you do at
the ground. It's especially the case in foundries or places that have equipment
that generates a lot of heat — and the locations directly above that equipment
are even more susceptible than the rest of the facility to a much higher
ambient. You just have to make sure to keep that in mind when you're specifying
products.

Adam: A few years ago we did an
application for one of our part vendors at their facility up in Oshkosh —
pretty big facility, hundreds of thousands of square feet, multiple-shift
operation. They originally installed some lighting products as a linear
high-bay product, and whoever had provided that solution didn't properly
consider temperature. We replaced some of the fixtures with our Eco Bay
fixture, and for several years we haven't had any issues. The same with our
facility here — same type of product. But high bay — a lot of people think
about a warehouse the same way as they think about an indoor facility. Like you
said, on the temperature side, it's a lot warmer at the ceiling than it is down
by the workspace.

Trent: Another thing with that
customer you're talking about — they had a bunch of those fixtures put up, and
they kept getting dust and dirt on the inside of the lens. Instead of going up
and cleaning it regularly, they decided to tape off the whole top of the
fixture, which also added to a lot of the thermal issues that you saw. Having
products that don't have openings on the top that are going to compromise your
light output — those are important.

Adam: To address those issues on the
temperature topic, we have a couple of different design considerations. Number
one: we often use a lot of heat sinking for high-temperature environments. The
same heat sinking we use for a high-output sports application — we use that
same proprietary design for an indoor environment. We also turn the drive
current way down. So that gives it a higher elevated ambient temperature
rating. But to your point you just made, why don't you talk about the LED
optics compartment for the products that we use silicone optics on?

Trent: Products like the Helios and
the Eco Bay — and the new HDX as well — have silicone optics and they have the
heat sink on the back. Everything is sealed the same as if it were an outdoor
fixture, so nothing — water, dirt, dust — is going to get into the LED
compartment. All the products are rain-tested and dust-tested. We have
pass-through heat sinks so that any dust that falls on top of these products is
going to fall through the heat sink to not compromise any of the thermal
properties that we have.

Adam: We've been using that design for
interior applications for five or six years now, so we've had very few issues
when it comes to temperature in LEDs.

Power Quality

Adam: Drivers are sometimes another
story depending on the environment. I think a lot of driver issues — people
think it's temperature-related, but it's probably more due to power issues,
which is a big concern in an indoor industrial environment. Our plant here in
town is primarily a final assembly facility, so we don't have a lot of heavy
machinery. Oftentimes in environments where you have heavy machinery, there's a
lot of startup and shutdown of the equipment, which can cause problems for
solid-state lighting. So I think what's sometimes a temperature-related driver
issue is really a power issue. If the first consideration is temperature, I
would say the second consideration would be power quality within the facility.

Trent: When you think of industrial
facilities, they have motors on most equipment, they have large ovens or heat
sources that are firing up. A lot of these foundries have big electrical
foundry equipment that is going to suck a lot of electricity instantaneously
out of the system, and then you're going to have these dips and peaks every
time that they run the equipment. We had a customer that had installed a bunch
of our Helios lights on a crane, and every time they run the crane, the lights
would flash. It was because the motors on the crane were drawing power, and
stuff wasn't properly grounded. So you can have a lot of electrical issues in
indoor applications.

Adam: There are things that owners and
customers and end-users can do to help with some of that, but they have to be
aware that it's an issue. I think the industry is starting to become more
educated around some of that. Especially industrial manufacturers that have had
solid-state equipment for a long time — they've been forced to have power
conditioning and other things at the panel to help clean up the voltage. But
some of the other places, like some of the foundries where there's maybe not as
much — there's probably some computerized equipment, but a lot of that stuff is
still just older equipment with larger motors and things like that.

Trent: It's hard to educate those
types of people on how more sensitive the solid-state stuff is than their old
HID.

Adam: Exactly. They don't care so much
about those dips and peaks, but yeah. They've been used to — part of their
maintenance program has been servicing HID lighting. The expectation is that
the new fixture will last forever. We've had some applications where we're very
upfront with people — if this thing is running 24/7/365 in this type of
environment, if you start to see certain types of power supply issues, that
might be a sign of other issues. If you can have good dialogue with the
customer and explain solid-state lighting versus conventional lighting, it's
nice to get on the same page. So definitely the second consideration would be
power quality at the facility.

Adam: So the first one's temperature,
the second one would be power quality. That's not always something you know
about right away, so what we've done with some of our recent designs is ensure
that the driver replacement process is easy. If there are issues with their
power quality, sometimes it's easier just to have a program to easily replace
the driver than it is to completely change their electrical infrastructure.

Chemical Compatibility

Adam: Temperature, power quality — I
would say another one that we run into is chemical compatibility in the air.
We've done some indoor natatorium and pool applications. Walk me through some
of the considerations within the chemical umbrella.

Trent: Having our sealed optics, we
are pretty fortunate in not having a lot of chemicals be able to penetrate the
LED compartment. Sometimes, if there's a chemical compatibility issue, it can
discolor the LED — it's still going to output light, but it can be green, it
could be purple. We've seen that in Milwaukee, for sure, with all the roadway
failures right now. As long as we're not introducing the chemical into the
system during assembly, we're typically in good shape. As far as chlorine, it
doesn't penetrate through the silicone optics that maybe it would in some other
assembly. So we're able to have installs in these different locations that may
have some chemical in the air. We try to do our due diligence when a job like
that comes up — we check and see what chemical might be in the air, like
chlorine, if there are other chemicals.

Adam: If we're aware of it on the
front end, it's always good for us to know so we can do a chemical
compatibility check on all our components that could possibly be exposed to it,
whether it's our wires, the optics, gaskets on certain parts. We just want to make
sure that kind of stuff isn't going to have any issues long term.

Milwaukee's Purple Streetlights

Adam: We talk about chemical
compatibility. A lot of this is speculation, but I think it's pretty much known
what the problem is. Right now with a particular fixture — and it's not our
fixture, fortunately — there are several thousand lights in the city of Milwaukee
that are turning purple. About once a week I'll have somebody shoot me a text,
or somebody will ask me, hey, what's with these lights that are turning purple?
Are they supposed to be that color? I kind of explain to them that what could
be happening is there's outgassing that's happening once the fixture fires up.
What's the outgassing term? Like VOC?

Trent: VOCs.

Adam: It's like when you paint the
wall in your house — for the first few weeks you're going to smell the
chemicals. So if that happens upon initial fire-up and the gases get trapped
underneath the optic, and maybe they clean the optical surface with some type
of cleaner that was not compatible, that can actually ruin the phosphor coating
on the outside of the LEDs.

Trent: It is the purple, you know —
the LED's natural state. A white LED is actually blue or purple to begin with,
and then they add a phosphor coating that filters out all of the blue light and
you're left with the white.

Adam: So that's likely what's
happening with those fixtures. Usually not a consideration that's needed for
roadway, right — chemical compatibility — but when you think about the
environment the LED is in inside of the trapped optic, it doesn't like it.

Debris & Construction

Adam: Another one would be debris.
We've run into this with a recent application. Our fixtures are pretty solid —
pretty stout chassis and heat sinks and everything else. We really haven't had
too many issues when it comes to flying debris, but it can come up in foundry
environments and other types of environments. There are certain compliance and
certifications that some manufacturers are starting to go through to relay the
quality of the fixture. From a construction standpoint, what have we done to
ensure it's as durable as it can be?

Trent: The main thing is having
silicone optics. If they get hit by something, they have give to them — they
naturally absorb most of the impact. There aren't filaments or any glass that's
going to break on impact, so you don't have to worry about things like that
happening. Just having that silicone optic is a big help.

Adam: In a lot of high-bay designs for
warehouse environments, it's a piece of thin sheet metal with an acrylic or
polycarbonate lens over the top that is more or less just using gravity to hold
itself in place. We have a new design like that for less intense environments,
but it really comes down to: if you're going to be in a heavy industrial
environment and there's going to be debris, every component on that fixture
better be fastened pretty well with hardware, as opposed to just using gravity
to hold the lens in.

Trent: And we use a lot of
automotive-grade connectors that are designed for bouncing down the road for
thousands and thousands of miles. The drivers are potted — everything's fully
potted — so they absorb all the vibration and impacts as well from objects.

Glare & Human-Focused Lighting

Adam: Another consideration — you hear
this term thrown around a lot, not necessarily for high-bay applications but
more indoor office spaces and museums and other applications like that —
human-focused or human-centric lighting. When it comes to high bay, I think
glare management is definitely a consideration. Just a lumen bomb at the
ceiling is nice, but at the same time, it's also nice to maybe diffuse some of
that light so it's easier to look at. So what are some of the things we've done
over the years — design changes — and also when an applications team or a sales
team is looking at a particular job, when it comes to making things
human-focused, easy on the eyes, what are some of the things they should look
at?

Trent: Fixture height is probably a
big deal as far as how much glare there is. Having more fixtures is another
thing they want to consider — instead of having one really bright light in a
20-by-20 area, maybe you need three or four spread out just to get the light
spread out. The other thing: thermally, we turn down the fixtures so that they
work better in indoor environments, and that lends itself to having less glare
because we've turned the drive current down. We can also do a PMMA or acrylic
lens that's diffused in front of some of our products so that it diffuses all
the LED light. And we can also do like a glare grid. But all this should
probably be talked about on the front end, as we've discussed.

Adam: Absolutely. With the diffuse
lens, there's a trade-off when it comes to — there are actually probably two
major trade-offs. One would be the efficiency of the fixture goes down, and it
changes the lighting distribution of the optic.

Trent: We likely are going to have to
turn that down as well, so you're losing efficiency, you're losing lumen output
because we have to turn it down further so we don't compromise the thermal
properties. And then, like you mentioned, the distribution.

Adam: Okay.

Indirect Lighting Options

Trent: We also have indirect options.
We've done quite a few indirect lighting applications. It seems like tennis and
pickleball and a lot of those sports are increasing in popularity, so we're
doing a lot of indoor applications and designs. If they have reflective
ceilings, it's a nice option.

Adam: Yeah, for sure. If you're using
something like the KB4 as an indirect uplight, putting it upside down creates
pockets, so you'll want to be sure to have — not glare grids, sorry — wire
guards, so that no balls or anything can get stuck on top of the fixture,
because they will start on fire. That's definitely a consideration. Many years
ago, I remember doing an indirect job, and we went to inspect the application,
and he looked inside the visor, and it's like, oh, there's a baseball, there's
a tennis ball. So definitely important to have those wire guards on there.

Compliance: Safety, Performance, Reliability

Adam: The last thing would just be
different types of compliance. We don't necessarily have to talk about specific
compliance — we know there's a lot of options out there — but when you think
about compliance, it's really a way for us as the manufacturer or the
specifying engineer to relay certain information in a fast way to whoever is in
charge of buying or selecting the products. What categories do you put
compliance in? Is it safety, performance, and reliability? How do you think
about compliance, both as an engineer selecting parts that go into finished
goods, and then if you're a specifying engineer selecting our fixtures for your
application — how do you approach that?

Trent: First and foremost, you want to
make sure that they comply with safety requirements. In our world, safety
typically is UL 1598.

Adam: Right, for that's indoor and
outdoor, correct? And there's dry, damp, and wet location ratings within 1598.
There's also a marine rating, which is 1598A.

Trent: From a specifying engineer
standpoint, you've got to check that box. If it doesn't check that box, it's
just not probably going to happen. I guess the performance side of things kind
of goes also with DLC and longevity, because DLC is testing the overall
performance of your fixture. But you can't get DLC if you don't have safety
testing. So I guess if a specifying engineer sees that it's on the DLC listing,
you can assume that it has the safety requirements.

Adam: Good point.

Trent: They check how long a fixture
is intended to last — like L70 or L90 hour. So 90% of light output, or 70 — how
long that takes — and they have minimum standards that you have to hit to be
able to be on DLC.

Adam: So DLC, in reality, is kind of a
shorthand for both safety and performance, if you think about it. So you have
safety, which in our world is typically UL 1598 — for dry, damp, or wet
location — that's within safety testing. You have performance testing, which is
light output, lighting distribution — what else is within —?

Trent: Color, CRI, CCT, like all that
stuff gets measured during performance testing.

Adam: And then you have DLC, which is,
in theory, a combination of both. Then we have reliability testing — that would
be things like vibration testing and some of the impact tests out there.

Trent: You have impact testing, you
have vibration testing, you've got lifetime testing — just having product in
use. We install a bunch of our product here locally and it gets run every day,
all day, all night. We have it in our facilities, we have it outside of our
facilities, local sports fields. That's part of lifetime testing — making sure
in application everything — because you can rain-test the fixture, it's great
here, but you go put it out in the wild for a few years, and you also know
these issues come up.

Wrap-Up

Adam: Cool. I think that's a pretty
good overview. I think indoor heavy industrial environments, aside from water —
although we do have some applications where we've done indoor with wash-down
ratings and things like that — but when you think about that environment where
you have high-temperature issues, you have debris, you have power quality
considerations, you have impact, you have chemical compatibility, those really
stress-test a platform about as much as any platform. And the cool thing about
the way that we approach our designs is the things that we learn in these
environments get applied to outdoor environments as well, in a similar way. The
things we learned for outdoor get applied to indoor — such as the optics and
the sealed electrical compartments for the LEDs and things like that. Anything
else to touch on?

Trent: I think that's good.

Adam: Alright man, thank you very
much.