while also being appropriately gauged to the cleanroom classification.
When specifying fixtures, the goal is to select the least
number of fixtures that can provide the necessary illumination for a cleanroom. Limiting the number of fixtures helps
reduce the amount of maintenance needed. Often,
lighting manufacturers can help determine
the number of fixtures needed for a
given space by reviewing the layout of
the cleanroom facility.
Furthermore, surfaces in most
cleanrooms tend to be highly reflective.
Fixtures need to produce a high intensity of light but should not produce any
glare. There are high-efficiency fluorescent luminaires on the market today—
ones that produce the amount of light
intensity needed with minimal glare.
Recessed troffers are suited for
ISO 8 to ISO 5 cleanrooms
because there is sufficient
space in the ceiling
Fixture housings must be constructed of
materials such as aluminum, carbon steel, or
stainless steel. These help eliminate the chance of contamination
and stand up to rigorous cleaning procedures. The fixture should
be welded or sealed shut to prevent the passage of particles into or
out of the housing. This minimizes the chance for dust or particle
collection on the fixture.
In some cases, fixtures should be wet-listed to accommodate cleanrooms that need to be periodically hosed down.
Lenses should have a smooth outer surface, meaning those
with prisms should be inverted so the prisms are on the
inside of the fixture. This makes the fixture easy to clean and
creates less opportunity for contaminants or dirt to collect.
Many lenses and diffusers are available for each ISO classification. Acrylic lenses currently are the most common type
because they are the most durable.
For cleanroom environments in the semiconductor industry, lenses can be constructed with radio filters so they do
not compromise any electronics in the facility.
Advancements in cleanroom lighting
Continuous technological innovations have made the cleanroom industry dynamic and ever-changing. Manufacturing
has become more demanding and regulations are becoming
more stringent. Given those factors, plus the current focus on
energy savings and the environment, a growing number of
cleanroom lighting projects today are retrofits or renovations.
Currently, fluorescent lighting is the most common
source for lighting cleanrooms. However, because of the need
for more energy-efficient and reduced-maintenance options
for cleanroom facilities, research and advancements in LED
luminaires for cleanrooms are on the horizon.
Even with international standards for cleanroom facilities, it
is important for the lighting specifier to consider the function
of the specific controlled environment. Ultimately, the primary
goal for all cleanroom facilities is to ensure there is no contamination and the space is properly illuminated for the task at
hand. Selecting the most reliable and efficient lighting fixtures
can help ensure both of these objectives are achieved.
Jamie Pearson is the Senior Value Stream Manager of
Special Applications at Acuity Brands Lighting. With 15
years of experience in the lighting industry, Pearson manages
special-application products, which include those for the