Cleanroom lighting design should provide the right amount of illumination
Senior Value Stream
Specifying lighting systems for cleanroom facilities requires considerations beyond energy and maintenance savings. While lighting for cleanrooms should be energy efficient and provide proper illumination for the task at
hand, it is crucial that lighting coordinates with air-supply systems and minimizes any chances for contamination.
The first step to identifying what lighting solution can be
utilized in the cleanroom facility is determining the ISO classification. The higher the ISO classification, the greater the
number of particles allowed into the controlled environment.
This means there will be fewer air filters taking up space
in the ceiling. In the most stringent cases, the entire ceiling
must be covered with filters to allow the absolute minimum
amount of particles into the environment.
Airflow systems create lighting challenges
Everything in the cleanroom, including the lighting fixtures,
is designed to ensure successful air filtration and maintain
the laminar airflow in a contamination-free environment.
Depending on the function of the controlled environment,
a cleanroom will use either HEPA or ULPA filtration. These
air-filtering systems are typically an expensive component
and one of the first to be considered in construction. They
take up a majority of the ceiling space, which leaves a real
challenge for lighting the environment.
Hours of thorough research and design are required to
create cleanroom lighting fixtures that maintain the integrity
of the space and work effectively with the HVAC system.
Regardless of the industry, every cleanroom lighting design
should be virtually maintenance-free and provide the right
amount of illumination.
Common fixture styles
The need for multiple air filters in cleanroom facilities leaves
minimal space for light fixtures. There are three common
fixture styles for cleanrooms that maximize the use of the
space: recessed troffers, surface-mount fixtures, and surface-mount teardrop fixtures. These are best-suited for use in
cleanroom facilities, depending on ISO classification.
Recessed troffers: These fixtures are ideal for cleanrooms
designated with an ISO 8 to ISO 5 classification because
they have enough space in the ceiling and plenum. While
rooms with an ISO 8 and ISO 7 classification have more
space in the plenum than rooms with a classification of ISO
6 or ISO 5, both environments can use recessed fixtures.
Environments with these classifications are typically electronic assembly, pharmaceutical processing, semiconductor
manufacturing, and chemical lab facilities.
Surface mounts: For more demanding environments—those
with ISO 3 and ISO 4 classifications—surface-mount fixtures
can be installed below the ceiling plane. Because of the high
air-filtration level required, there typically is not enough plenum space for recessed troffers so surface-mount fixtures are
The need for more energy efficient and
reduced maintenance options means
advancements in LED luminaires for
cleanrooms are on the horizon.
Surface-mount teardrops: Surface-mount teardrop fixtures
are suitable for controlled environments with an open-area
design and moderately demanding classifications of ISO 5
and ISO 4. These fixtures are mounted to a 2-in.-wide ceiling grid and are suitable for individual or continuous row
mounting. The aerodynamic shape of the teardrop fixture
minimizes any disturbance of the laminar airflow.
Achieving effective light quality
In addition to becoming familiar with the fixture styles for
each ISO classification, it is important to know what to consider when selecting the exact fixture. Understanding what
lighting features are most important for cleanroom environments will help determine the most efficient solution that
requires the least amount of maintenance possible.
In most cases, cleanroom facilities produce and/or test small
objects. Pharmaceutical and semiconductor industries, for
example, typically use cleanrooms to manufacture small pills
and computer chips, respectively.
Lighting fixtures must provide a high level of illumination
so employees have enough light to carefully handle small
components. Illumination levels may vary depending on the
different process areas within the cleanroom, so it is important for the specifier to review each process area to determine
the illumination level required for each task.