News & Insights

According to the Centers for Disease Control and Prevention (CDC), on any given day, approximately 1 in 31 hospital patients has at least one healthcare-associated infection (HAI). Infection control in hospitals has always been a complex balancing act, but recent years have pushed hospital administrators and healthcare engineers to reimagine their approaches.

The pandemic underscored an essential truth: no single system operates in isolation. Managing airborne pathogens, water safety, and touch-based transmission requires a holistic approach. The good news is that there are new tools and approaches available for mechanical, electrical, and plumbing systems to help in the fight.

New tools in the toolbox: innovations in mechanical and electrical systems

While technologies like UV-C lighting, HEPA filtration, and touchless controls are not new, their use and adoption in hospitals have radically increased since the pandemic. Here is what hospital administrators and designers need to know:

UV-C lighting. Upper-room UV-C effectively reduces airborne pathogens, while its use in air handling units helps prevent microbial growth by keeping cooling coils and drain pans clean. In critical care spaces like operating rooms and ICUs, UV-C can be activated during cleaning cycles to enhance disinfection when rooms are unoccupied.

Filtration. Filters are essential for maintaining air quality and infection control in healthcare facilities. By removing particulate matter, microorganisms, and other airborne contaminants, filters help create a safer environment for patients and staff. Higher risk areas require higher efficiency filters, with many inpatient areas requiring MERV 14 final filters. Critical spaces, such as operating rooms or protective environment rooms, often require HEPA filters. The application of the HEPA filters at the terminal diffusers provides the best protection by eliminating any possible contaminant source downstream of the filter before air enters the room. Regular maintenance and timely replacement of filters are essential to ensure optimal performance and compliance with healthcare standards.

Electromagnetic field manipulation is an emerging technology for improving air quality. While not yet widely adopted, it works by precisely applying positive and negative charges to individual particles and pathogens. The process neutralizes pathogens and causes particles to cluster, making them easier to filter out, and complements approaches like filtration and UV-C lighting. There are a number of companies that supply variations of this electromagnetic field manipulation technology which are designed to address some of the challenges associated with bipolar ionization.

Touchless controls. Touchless technology has been widely adopted in isolation rooms and high-traffic areas like ICUs and NICUs. The integration of sensor-activated sinks and fixtures is a simple but impactful measure to reduce the risk of cross-contamination.

Telemedicine. A pandemic-inspired move that significantly cuts cross-contamination risks is the expansion of telemedicine. However, it often requires upgrades to low voltage infrastructure to accommodate more telehealth devices, remote monitoring tools, and advanced communication systems for patient care. Increased bandwidth, added capacity for power distribution, and improved HVAC configurations to support telehealth equipment are playing a pivotal role in enabling this transformation.

New strategies in mechanical and electrical systems can address airborne and touch-based transmission but incorporating plumbing system design is essential for a comprehensive approach to infection control.

Plumbing system design: battling waterborne pathogens

While airborne transmission often takes center stage in infection control discussions, plumbing systems play a critical role in preventing the spread of waterborne pathogens. Among the most significant risks in hospital water systems is Legionella, a bacterium that thrives in stagnant water and can cause severe respiratory illness.

To mitigate this risk, hospital plumbing systems must be designed to minimize areas where water remains stagnant for extended periods. The domestic hot water distribution system plays a crucial role in this effort. Best practices include:

• Recirculating systems to keep water moving and prevent stagnation
• Minimizing tank-type storage whenever possible
• Strategic water heating and mixing to maintain safe distribution temperatures—hot enough for disinfection but cool enough for usability

Beyond system design, water disinfection methods further enhance protection. Copper-silver ionization (CSI) has long been a trusted solution, leveraging electrolysis to combat biofilms and pathogens. While Canada commonly implements CSI system-wide, many U.S. hospitals integrate it with other disinfection strategies such as UV treatment and secondary disinfectants like monochloramine. This combined approach helps balance microbial control with energy efficiency and operational costs.

As hospitals continue to refine infection prevention strategies, a holistic view—one that accounts for both airborne and waterborne risks—is essential to ensuring safer healthcare environments.

Leveraging negative pressure zones

Negative pressure zones (outbreak control zones) are areas where air pressure is intentionally kept lower than the surrounding areas. Mechanical engineers design these zones to direct airflow from “clean to contaminated” spaces, preventing air from moving in the opposite direction and carrying contaminants into clean areas.

Initial response during COVID-19 often involved retrofitting existing spaces into temporary negative pressure zones by installing HEPA filters or adding exhaust fans to create isolation areas, but today hospitals are taking a more proactive approach.

Many new facilities are incorporating pandemic-ready wings designed to quickly convert zones on patient floors to negative pressure at the flip of a switch. These spaces are outfitted with either pre-installed exhaust fans or by utilizing the base building return/exhaust fans with the system switched to 100% outside air mode of operation, differential pressure sensors, programmable controls, and digital monitoring systems, allowing for seamless transitions to “pandemic mode” without disrupting normal operations.

One challenge with negative pressure zones is that their effectiveness depends on well-built walls that are air tight and maintenance. Even minor gaps—such as poorly sealed doors or leaky walls—can compromise the entire system, allowing contaminated air to escape.

Exhaust discharge locations are another critical consideration. ASHRAE 170 requires certain exhaust fans including Airborne Infectious Isolation Rooms to discharge air at least 10 feet above the roof surface to prevent contaminants from re-entering the building’s breathing zones.   Where the exhaust cannot be discharged in a safe location bag in bag out HEPA filters can be provided to clean the exhaust air prior to discharging air to the exterior of the building.

To get alignment between design intent and operational reality requires expert oversight during construction and commissioning to identify and resolve potential issues.

How Salas O’Brien can help

MEP systems in hospitals aren’t standalone components; they’re interdependent pieces of a larger infection control puzzle. Success depends on collaboration across disciplines, from architects and engineers to healthcare providers and facility managers.

Salas O’Brien is deeply experienced working with healthcare systems across North America to leverage the full potential of MEP systems to help hospital administrators stay ahead of infectious disease control. Reach out to one of our contributors below or to an office near you to discuss your MEP needs.

For media inquiries on this article, reach out to [email protected].