With 45 years of experience and thousands of active cleanroom installations across the world, Terra is committed to helping its customers understand what they'll need to own and operate a cleanroom. Let's skip the guesswork, and discuss some of the most common questions about buying and owning a cleanroom.
A standard lab may appear clean, but it’s not as clean as it looks. Cleanrooms are isolated areas equipped with ceiling-mounted filtration systems designed to remove pollutants from the air.
Dust is one pollutant, but the filtration system also removes airborne particles, microbes, and other contaminants.
Virtually every cleanroom operation requires cleaning procedures that remove contaminants from work surfaces, tooling, equipment, and fixtures. .
Contaminants in the air steam cannot be removed through strict cleaning protocols. If the environment in your work zone is contaminated, you are likely to experience inaccurate test results, QC failures, and potential product recalls. Your standard lab doesn’t include controls to alert you of contamination, so you may not find out until it’s too late.
HEPA filters capture virtually all particles larger than 0.5 microns in diameter. This includes dust, bacteria, VOCs, and the most common airborne contaminants. ULPA filters are designed to catch particles as small as 0.17 microns in diameter, including viruses and tobacco smoke. For most applications, HEPA filters are optimal.
When choosing a fan filter unit, there are many factors to consider. If power consumption is a concern, smart FFUs with EC motors reduce energy costs by up to 60%. For certified spaces demanding regular filter changes, roomside-replaceable models allow for easy filter replacement without sacrificing cleanroom integrity. For microscopy labs, low-vibration units are the gold standard. Other factors to consider include noise level, overhead make-up air space, and facility voltage.
Although the filtration system is the first line of defense against cleanroom contamination, a secondary defense mechanism is air circulation. Cleanrooms are designed to maintain uniform, unidirectional laminar airflow. Filtered air flows from the FFUs across the most critical work zones before diverting toward exit points. Laminar airflow protects the work zones from contamination caused by second-pass air, or the particle swirling effect. To achieve complete laminarity, facilities will install false, or raised, perforated flooring with an air plenum installed underneath.
Yes, cleanrooms maintain a higher internal pressure, or “positive” pressure, as compared to adjacent spaces. This positive pressure is maintained by the constant air influx provided by the motorized fan filter units. We know from inflating a tire or a balloon that passive air flows from an area of high pressure toward an area of low pressure. Cleanrooms are designed in the same manner. So, “dirty” air will not seep into the cleanroom through an open door or exhaust grate.
Yes, cleanrooms include a broad range of atmospheric controls. Depending on your application, you may specify controls for static discharge, temperature, pressure, and moisture.
Certain products, like microelectronics and medical devices, are sensitive to static discharge. Other products, like bulk chemicals and resins, degrade in the presence of moisture. Humid environments promote mold and mildew growth, which may contaminate cell cultures. Pharmaceutical cleanrooms commonly include particle-counting systems, which sound audible alarms if levels are too high.
Static control is accomplished through the use of ionizing bars and static-dissipating plastic surfaces, like PVC. The cleanroom temperature and humidity are controlled through integration with facility-wide HVAC systems or stand-alone AC modules appended to the room. Moisture is controlled through desiccant-based air dryers.
The International Standards Organization, or ISO, categorizes cleanrooms based on the quantity of detected particles per cubic foot of air. The cleanest classification, ISO 3, denotes an environment containing 1 particle per cubic foot. The least rigorous classification, ISO 8, specifies an atmosphere containing 10,000 particles per cubic foot. Check with your compliance officer to confirm which ISO class is appropriate for your application.
The ISO classification is validated by particle measurements performed with a benchtop or handheld particle counter. Traditionally, particle counts are performed 6” underneath the filter face, but certain standards require particle fall-out tests, which are performed at desk height.
We still need to discuss the different types of cleanrooms, the common features of a cleanroom, typical cleanroom applications, and safeguards to protect your cleanroom from cross-contamination.
Terra Universal is a leading manufacturer of critical environment solutions, with over 40 years of experience in the industry. Terra products include cleanroom construction, cleanroom equipment and furnishings, environmental monitoring systems, and high-performance air filtration products. We serve a variety of industries, including pharmaceuticals, medical device manufacturing, aerospace, and semiconductors.