CLEANROOM Design: It’s all about the Draft
Although a CLEANROOM is a tightly controlled space, any engineer will tell you, for a successful design, it is all about the “draft”.
What is a Cleanroom?
Cleanrooms are enclosed spaces that are engineered to restrict air particles. Because in certain environments, like critical manufacturing or pharmaceutical and university research labs, it is important to control contamination. And that contamination can come from from things like dust, clothes fibers, skin particles, etc.
So, to maintain clean air, you have to design systems that control airflow, pressure, filtration, temperature, humidity, vibration and noise. But it is not just the equipment that matters. You have to look at everything that affects the space. Materials that make up the walls, floors, ceiling and furniture also make a difference. So, hard surfaces such as stainless steel, epoxy and laminates are often chosen.
Now, all cleanrooms are not created equal. They are categorized depending on the level of particle restriction you need in a space. So, the ratings range from ISO 1 to 9. What does that mean?
Let’s say that you are working on nanotechnology to power a super tiny robot. You would want an ISO 1 level cleanroom because it is the “cleanest” of the cleanrooms. So, without getting into too much detail on the various micron sizes of the particles; the max number of particles allowed in an ISO 1 cleanroom is 10 per cubic meter (just under a cubic yard). And just to give you an idea of what THAT means; the average number of particles in a city street environment is about 35,000,000 per cubic meter. (ISO and particulate statistical data via WIKIPEDIA)
Key to a Cleanroom
But the ultimate key to the success of a cleanroom is the HVAC. To draft or “wash” away any particulates, you have to have constant airflow to the return vents. That way, the air goes back in to the system and is laundered through a complex system of HEPA filters. Once the air is washed, its mixed with fresh makeup air and the purified air is pumped back into the environment.
Cleanrooms date back to the 1960s. But with the boom in packaged food and electronics manufacturing; and the rise of the pharmaceutical industry and laboratory testing of all kinds, the business of cleanroom engineering has risen to an art form.