HVAC Testing and Balancing for Healthcare Facilities

HVAC Challenges in Healthcare Facilities

Healthcare HVAC systems are among the most complex in commercial construction. A single hospital floor may contain operating rooms requiring 20 or more air changes per hour, isolation rooms maintained at negative pressure relative to adjacent corridors, positive-pressure protective environment rooms, sterile processing areas, and general patient rooms. Each space has its own ventilation requirements and pressurization relationship to adjacent spaces.

Maintaining correct directional airflow between spaces of different pressure class is critical. If a negative-pressure isolation room loses its pressure differential due to an unbalanced HVAC system, contaminated air can migrate to adjacent corridors and patient areas. If a surgical suite is not at positive pressure, unfiltered air from less-controlled areas may enter during procedures. These are patient safety issues, not comfort issues.

• Meeting minimum air changes per hour requirements for each room type per ASHRAE 170 and FGI Guidelines
• Maintaining correct positive or negative pressurization between adjacent spaces
• Verifying exhaust airflow rates in restrooms, soiled utility rooms, janitor closets, and other exhaust-only spaces
• Confirming outside air quantities meet minimum ventilation requirements for occupied clinical spaces
• Documenting all measured parameters in a format accepted by state health department reviewers
• Coordinating testing around active clinical operations and infection control requirements

Testing and Balancing Services for Healthcare Facilities

Healthcare TAB begins with a thorough review of the mechanical design documents and the applicable ventilation requirements for each space. Every room in the facility is assigned a ventilation classification per ASHRAE Standard 170 or FGI Guidelines, which specifies minimum supply air change rates, exhaust requirements, pressurization class, and maximum recirculated air fraction. Our TAB report documents design values and measured values for each parameter in every room.

Air balancing in healthcare settings involves measuring supply and exhaust airflows at every terminal device, calculating air change rates per hour from measured supply airflow and room volume, and verifying that directional airflow is maintained from cleaner to less-clean areas. Space pressurization testing confirms that the differential pressure between adjacent spaces of different classifications is within the specified range under normal operating conditions.

For facilities with chilled water or heating hot water systems, hydronic balancing ensures that air-handling units and terminal units receive the correct water flow to deliver their design heating and cooling capacity.

Industry Standards and Compliance

Healthcare HVAC systems in the United States are governed by several overlapping standards and regulatory requirements. ASHRAE Standard 170, Ventilation of Health Care Facilities, specifies minimum ventilation rates, air change requirements, pressurization classes, and filtration requirements for each space type. The Facility Guidelines Institute (FGI) Guidelines for Design and Construction of Hospitals and Outpatient Facilities incorporate ASHRAE 170 requirements and add additional requirements for specific facility types.

State health departments typically require that TAB documentation be submitted as part of the construction documents package before issuing a Certificate of Occupancy for licensed healthcare facilities. This documentation must demonstrate that each space meets the ventilation requirements of the applicable standard. In many states, the authority having jurisdiction requires that TAB be performed by a NEBB- or AABC-certified firm, and that the TAB report be signed by a certified professional.

The Joint Commission and other accreditation bodies also include HVAC system performance in their standards for hospital accreditation. Facilities that cannot produce documented TAB reports demonstrating compliance with ASHRAE 170 may face findings during accreditation surveys. Maintaining accurate TAB documentation is an ongoing facility management responsibility, not just a construction closeout requirement.

Our Testing and Balancing Process

1. System Evaluation. We review the mechanical design documents, ASHRAE 170 room schedules, and project specifications to identify the ventilation requirements for every space. We confirm system readiness and coordinate with the infection control team before beginning field work.
2. Airflow Measurement. Supply, return, and exhaust airflows are measured at every terminal device using calibrated flow hoods and digital instrumentation. Air change rates per hour are calculated for each room and compared to ASHRAE 170 minimums.
3. Pressurization Testing. Differential pressure between adjacent spaces is measured using calibrated digital manometers. Door undercut airflow is measured in spaces where pressure differentials are required to be maintained with doors open.
4. Hydronic System Testing. Water flow rates through AHU coils and terminal units are measured and adjusted to deliver design heating and cooling capacity.
5. System Adjustment. Dampers, balancing valves, VAV controllers, and terminal unit setpoints are adjusted to bring all spaces within the required tolerances. Coordination with the controls contractor ensures correct sequences of operation.
6. Final Verification and Reporting. Final measurements are recorded for all spaces. A certified TAB report is prepared in a format suitable for submission to the state health department, the commissioning authority, and the facility owner.

Serving Healthcare Facilities Across the Tennessee Valley

MGM Associates provides healthcare airflow testing and hospital HVAC balancing for new construction, renovation, and expansion projects throughout North Alabama and the Tennessee Valley. We work with mechanical engineers, general contractors, infection control teams, and commissioning agents on projects ranging from single-floor clinic renovations to multi-story hospital additions.

• Huntsville and Madison County, Alabama
• Guntersville and Marshall County, Alabama
• Decatur and the Tennessee Valley corridor
• Birmingham and North-Central Alabama
• Chattanooga, Tennessee
• Nashville and Middle Tennessee

Related HVAC Testing and Balancing Services

Healthcare TAB is one specialized application of our complete HVAC testing and balancing services. Additional services relevant to healthcare facility construction include:

• Air balancing: airflow measurement and adjustment at every terminal device
• Hydronic balancing: chilled water and heating hot water system flow verification