What is a negative air environment and why is it important?

MRS containment area

Performing disaster restoration work, as in other construction activities, can create a good bit of debris including dust and odor.

A containment area that creates a slight vacuum pressure within the containment may need to be constructed in order to prevent dust and other airborne particulates from escaping into other areas of the structure. The industry calls this creating a “negative air environment”. The goal of a negative air environment is to have air rush into the containment (as opposed to air rushing out of the containment) whenever a door is opened or other containment breach occurs (leaks, etc.). The action of air rushing into the containment effectively prevents dust and other particulates from escaping the containment area. Note that the need for an effective negative air environment is especially acute in medical (immunosuppressed patient & sterilization concerns) and other “clean” facilities.

A negative air containment system is first built by creating an enclosed “near air tight” space using existing walls, ceilings, and plastic sheeting where needed. Specialized air scrubbers equipped with HEPA filtration systems are then installed to exhaust the containment air to the outdoors or into an exhaust system within the building.
To ensure that a vacuum is present within the containment area, a device called a manometer is typically used. Its function is to indicate the presence of a vacuum in the containment. For many medical and other clean environments the amount of vacuum pressure (typically expressed in inches of water column) must be continuously measured, maintained (above a defined minimum value), recorded over time, and monitored with visual and audible alarms if the vacuum drops below the minimum value defined by the facility.

Massaro Restoration, an Infection Control Risk Assessment (ICRA) certified response team, utilizes digital differential pressure monitoring manometers that continuously display the vacuum pressure readings, record them over time, and will activate visual & auditory alarms if the vacuum pressure drops below the established minimum value.


Article by Franco Tavella, Business Development Executive