Designing temporary containment for construction and renovation projects requires careful planning. However, safety always comes first—especially in healthcare settings, where protecting patients, caregivers, and staff from construction dust and potentially dangerous pathogens is critical.
As a result, dust containment raises important questions about the role of negative air pressure in infection control and prevention. To help clarify this topic—and explain how we integrate negative air functionality into our wall designs—we spoke with Norris Gearhart, CR, CCHM, and President/CEO of Gearhart and Associates. He shared insights on what negative air pressure is, how it works in healthcare spaces, and why it matters for reducing infection risk.
What is Negative Air Pressure?
Negative room pressure, often referred to as “negative air,” helps prevent cross-contamination. It stops air from a dirty or hazardous space from moving into clean or non-contaminated areas.
How Is Negative Air Achieved?
Negative air occurs when the air pressure inside a space is lower than in the surrounding areas. As air naturally flows from areas of higher pressure to lower pressure, this setup ensures that contaminants remain contained.
Where Is Negative Air Pressure Used in Healthcare?
Many areas in healthcare facilities rely on negative air pressure to protect patients and staff. Common examples include isolation rooms for patients with airborne contagious diseases, such as:
- Tuberculosis
- Measles
- Chickenpox
- Severe Acute Respiratory Syndrome (SARS-CoV)
- Middle East Respiratory Syndrome (MERS-CoV)
- Influenza (flu)
- Coronavirus Disease 2019 (COVID-19)
Beyond patient rooms, negative air pressure also helps safeguard spaces like:
- Bathrooms
- Emergency Departments
- Radiology
- Morgues
- Soiled Utility Storage
- Dirty Side Sterile Processing
- Environmental Services Closets and Storage Areas
What Are the Requirements for a Negative Pressure Room?
To function properly, hospital Airborne Infectious Isolation Rooms (AIIRs) with negative-pressure differentials must be well sealed. Tight construction helps prevent unwanted air leakage, allowing the room to maintain pressure efficiently. In healthcare settings, negative pressure rooms should support at least 12 air changes of exhaust per hour and maintain a minimum of 0.03 inches of water column.
Why Is Negative Air Critical for ICRA Class IV/V Requirements?
Infection Control Risk Assessment (ICRA) Class IV/V focuses on using construction barriers to keep dust and potentially harmful pathogens out of patient care areas. Negative air pressure plays a key role by ensuring airflow moves from “clean” patient spaces into the “dirty” work area. This airflow pattern keeps contaminants from escaping into occupied areas.
While negative air is essential during construction and renovation projects, it’s also important when expanding patient care areas. For example, many hospitals turned to negative air solutions during the pandemic to manage the surge of COVID-19 patients.
When Is Positive Air Pressure Necessary?
While negative air helps protect clean areas from contamination, positive pressure does the opposite. It keeps contagious diseases away from vulnerable patients, such as those undergoing cancer treatments or transplants. Hospitals also use positive pressure in areas that require extra cleanliness, including:
- Operating rooms
- Delivery rooms
- Procedure rooms
- Catheterization labs
- Sterile storage
- Serology
- Biochemistry
- Pharmacies
- Medication rooms
- Clean linen storage rooms
Can You Convert HVAC Systems to 100% Outside Air?
In some cases, hospitals have converted specific areas to negative air wards using 100% outside air. Although possible, these conversions are often costly and time-consuming—especially in older facilities.
Is Filtration a Substitute for Negative Air?
Filtration does reduce the risk of spreading airborne infectious agents. Particles vary in size, and they can enter the upper or lower respiratory tract or settle in open wounds during procedures. When used correctly, portable HEPA filters create an effective airborne isolation environment. However, they do not fully replace the need for negative air pressure in high-risk areas.
What Are Common Challenges to Maintaining Negative Air Pressure?
Several obstacles can interfere with establishing and maintaining negative air pressure, including:
- Identifying make-up air sources and exhaust locations
- Managing existing walls and soffits
- Meeting egress requirements
- Complying with NFPA 241 fire sprinkler standards
- Preventing supply air leaks
- Managing expansion joints
- Installing sensors for variable speed fans
- Navigating fire damper placement
How STARC Supports Negative Air Solutions
At STARC, we designed our RealWall™, LiteBarrier™, and FireblockWall™ systems to help contain construction dust and dangerous pathogens. These temporary containment solutions are ICRA IV/V compliant, easy to clean with standard antimicrobial disinfectants, and simple to reconfigure. They also offer unmatched durability and reusability, delivering long-term cost savings for our customers.
Learn more about temporary wall systems that prioritize infection control.