Carbon dioxide monitoring and other practical tools to investigate infection prevention issues associated with heating, ventilation, and air conditioning systems: You can't improve what you don't measure.

BACKGROUND: Heating, ventilation, and air conditioning (HVAC) systems play an essential role in minimizing the risk for transmission of airborne pathogens. A basic understanding of how HVAC systems work and of tools that are available to assess their performance is essential for infection prevention.

METHODS: The published English literature was searched for articles on use of practical tools to assess ventilation and airflow and their application to address infection prevention issues related to health care HVAC systems.

RESULTS: Carbon dioxide monitoring is an inexpensive, easy-to-use tool that provides rapid information on the quality of ventilation and the efficacy of interventions. Clearance of aerosol particles provides supplemental information on ventilation and devices that emit smoke or condensed moisture show patterns of airflow. Multiple publications have demonstrated the use of these tools to evaluate ventilation and airflow patterns and assess the impact of interventions.

CONCLUSIONS: Several practical tools are available to assess ventilation and patterns of airflow. These tools can be used to develop effective interventions to reduce the risk for airborne transmission of pathogens.