If you’re considering a cleanroom, you’re probably trying to gather as much information as possible. What type of cleanroom is right for you? What industry standards do you have to meet? Where will your cleanroom go? You get the picture. Well, it might be helpful for you to understand the difference between a positive and negative air pressure cleanroom. As you probably already know, airflow plays a leading role in keeping your cleanroom to standard, but you may not have known that air pressure can also have a big effect on that. So here’s a broken-down explanation of each positive and negative air pressure.
POSITIVE AIR PRESSURE CLEANROOM
Positive pressure means the air pressure inside your cleanroom is greater than outside. You achieve positive pressure by pumping clean, filtered air into the cleanroom — generally through the ceiling. In the event of a leak, or a door opening, clean air would flow out of the cleanroom, preventing unfiltered air from flowing into the cleanroom.
A balloon popping is a perfect illustration of positive pressure. When you pop a balloon, air rushes out because the air pressure in the balloon is higher than the ambient air pressure.
Positive pressure cleanrooms are used primarily for industries where the primary goal of the cleanroom is to keep the product clean and safe from particulates, like in the semiconductor industry, where even the tiniest particle can damage the integrity of the microchips or wafers.
NEGATIVE AIR PRESSURE CLEANROOM
In a negative air pressure cleanroom, the air pressure in the room is lower than outside pressure. If the goal for your environment is to keep contamination from escaping the cleanroom, you likely need a negative-pressure cleanroom.
Negative pressure is created by filtering air out of the room at a higher rate than the supply air. In most situations, air enters through filters near the floor, then removed through filters in the room ceiling.
Windows and doors need an airtight seal to prevent air outside the cleanroom from flowing into it rather than out of it.
Negative air pressure cleanrooms are needed for industries that manufacture pharmaceutical products, do biochemical and chemical testing, and also in hospitals to quarantine seriously contagious patients. Any air that is removed from the room must first flow out of a filter, ensuring no contaminants can escape.
CONTACT THE CLEANROOM EXPERTS AT ANGSTROM TECHNOLOGY
If you have any more questions regarding negative and positive air pressure cleanrooms, call the experts at Angstrom today! We custom design all of our cleanrooms to meet your exact specifications and standards. Call us at 888-768-6900, or contact us online.