Facility Construction Products Catalog
Download the Facility Construction Products Catalog


To speak with a Product Specialist, call:

U.S. 800-634-9091
Canada 800-827-6443
International 678-889-4200

Mon-Fri 8 AM - 5:30 PM Eastern

Product Information e-mail:


Contact Technical Support


Principles and Importance of Negative Pressure Containment

Effective Negative Pressure Particle Containment Using Abatement Technologies® Portable Air Scrubbers

Particles released into the air during facility construction, renovation, demolition and maintenance activities must be properly isolated and contained. Tiny particles and fungal spores are lightweight enough to remain aerosolized (suspended in the air) for hours, days or even weeks. The aerosolized particles can migrate into other areas of a facility on air currents and pose a potential threat to the health of sensitive patients. Larger particles can create housekeeping problems when they drop out of the air and settle on floors and other surfaces.

How Negative Pressure Particle Containment Works

Abatement Technologies HEPA-AIRE® and PREDATOR® series Portable Air Scrubbers (PAS) are designed to contain and capture indoor air particles and other contaminants and odors using a time-proven technique known as negative pressure particle containment. Effective negative pressure containment requires four main elements:

  1. Construction of a physical barrier around the work area to separate it from the rest of the facility.
  2. Sealing off any HVAC return air grills within the space to protect against particles being pulled into the HVAC system.
  3. Continuously pulling air within the area through a HEPA filtration device to reduce the number of airborne particles. Most job specifications require at least 6 air changes per hour (ACH), which means that the device must filter a volume of air equal to the air volume contained within the enclosed space 6 times per hour, or every 10 minutes.
  4. Exhausting at least 10% more cubic feet per minute of clean, HEPA-filtered air out of the space than is supplied into it to create and maintain negative pressure within that space. This helps ensure that any air leakage between the contained area and adjacent spaces will be “clean” air flowing in and not “dirty” air flowing out.

Modes of Operation

State-of-the-art Portable Air Scrubbers from Abatement Technologies can be used in any of three modes of operation, depending on the air cleansing objectives and space limitations:

View the animation.

1. Negative Pressure Mode with the Abatement Technologies Portable Air Scrubber Located Inside the Containment Zone:

The most common configuration is locating the Portable Air Scrubber within the contained work space and using it to propel clean, HEPA-filtered air out through flexible exhaust ducting.

View the animation of negative pressure mode with the Air Scrubber located inside of the containment zone.


View the animation.

2. Negative Pressure Mode with the Abatement Technologies Portable Air Scrubber Located Outside of the Containment Zone:

Space limitations within the containment zone sometimes require locating the Abatement Technologies Portable Air Scrubber in a nearby area. In these instances dirty air is pulled out of the contained area and fed directly into the scrubber inlet manifold through flexible ducting. The negative pressure inside the ducting by the air scrubber ensures that dirty air cannot leak from the ducting into the clean space. Filtered air can be exhausted into the area in which the PAS is located or ducted outdoors.

View the animation of negative pressure mode with the PAS located outside of the containment zone.

View the animation.

3. Continuous Air Cleaning and Recirculation:

Abatement Technologies Portable Air Scrubbers can be used as continuous air cleaners, with no affect on room pressurization, to facilitate the removal rate of airborne contaminants. The PAS is located within the containment zone with no inlet or exhaust ducting attached.

View the animation of continuous air cleansing and recirculation.

Click here for a spec sheet on the entire line of HEPA-AIRE Portable Air Scrubbers.

Click here for the Air Change Calculator.

Contact Us for pricing information or to ask questions about your application.