The world has faced unprecedented challenges with the outbreak of COVID-19, and the reality is, irrespective of varied opinions and beliefs, it’s likely here to stay, popping up year after year. Amidst this landscape, the Heating, Ventilation, and Air Conditioning (HVAC) industry emerges as a crucial player in our annual combat against the virus. The key lies in understanding the complex interplay between ventilation, disease transmission, and proactive mitigation.

HVAC’s Frontline Defense Against Disease Transmission

It’s not merely about temperature control. HVAC systems, especially in healthcare facilities, directly influence the air we breathe. They regulate the indoor air quality, ensuring a substantial reduction in the potential for disease transmission. This is primarily achieved through three critical pillars: ventilation, filtration, and airflow control.

Airborne transmission is a significant concern when it comes to diseases like measles, tuberculosis, and most prominently in recent times, COVID-19. The airborne nature of these pathogens allows them to traverse long distances on air currents, meaning that effectively managing and controlling these currents can significantly reduce transmission.

Studies Linking HVAC to Reduced COVID-19 Transmission

Research conducted during the COVID-19 pandemic underscores the potential of HVAC systems in disease mitigation. A 2022 systematic review found a direct correlation between enhanced ventilation and reduced infection risk. It’s evident: direct airflow away from susceptible individuals, and you lessen the potential for disease spread.

A compelling example is the tuberculosis outbreak in a Taiwanese university. Poor ventilation exacerbated the spread, but once they revamped the HVAC system, ensuring improved air circulation and using CO2 levels as a benchmark for air quality, the transmission ceased.

The Science Behind HVAC Functionality

The performance of HVAC systems in healthcare facilities is governed by guidelines from prominent organizations, including the Facility Guidelines Institute, American Institute of Architects, and the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. The principles revolve around three core areas:

  1. Quantity: Refers to air changes per hour (ACH). A higher ACH signifies more efficient particle removal, thus reducing the risk of airborne diseases.
  2. Quality: It encompasses factors like filtration efficiency, temperature, and humidity. Both indoor and outdoor air quality factors can influence HVAC system performance. While external factors like pollution or wildfires might compromise outdoor air quality, an emphasis on fresh outdoor air intake, as opposed to recirculated air, can bolster indoor air purity.
  3. Flow: Pressure differentials, determined by air supply and removal, play a pivotal role in influencing disease transmission. For instance, negative pressure rooms, often used for patients with airborne diseases, ensure that contaminated air doesn’t escape, thus protecting other areas of the facility.

Innovative Strides in HVAC

Beyond conventional HVAC functionalities, innovations have further expanded the potential for disease mitigation. UV radiation, particularly UV-C, is a promising tool, proven to inactivate pathogens. Two primary applications exist: open-air and in-duct systems. While open-air systems come with human exposure risks, in-duct systems offer a safer alternative, especially in facilities where air recirculation is unavoidable.

Another exciting development is biofiltration technology, leveraging plant life and microalgae to purify air. While its practical application in healthcare is still under exploration, it showcases a promising avenue for future research.

The Way Forward

It’s imperative that professionals in infection prevention (IP) harness the power of HVAC systems. Collaborative efforts between IPs and engineering teams can lead to efficient and tailored HVAC solutions. Furthermore, as we adapt to the ‘new normal’ of living with COVID-19, it’s essential to view HVAC systems not just as comfort providers but as vital tools in our defense against disease transmission. Integrating advanced technologies like UV disinfection and prioritizing upgrades during construction or remodeling can substantially augment our fight against airborne pathogens.


As we navigate the persisting challenges of COVID-19 and potential future pandemics, the HVAC industry stands as a beacon of hope, offering tangible solutions to reduce disease spread and ensure safer indoor environments.

tl;dr: Despite varying views on COVID-19, it’s likely a recurring challenge. HVAC systems, crucial in regulating indoor air quality, play a pivotal role in reducing its transmission. Studies show improved ventilation directly reduces infection risk. Guided by expert guidelines, HVAC systems operate on principles of air quantity, quality, and flow. Innovations like UV radiation further enhance their potential. Collaborative efforts between infection prevention professionals and engineering teams are vital, emphasizing HVAC not just for comfort but as a key tool against disease spread.


Infection Control Today