Controlling the amount of outside air entering a building is required to maintain pressurization, meet energy efficiency goals, confirm compliance with local building codes, and maintain the health of the building and its’ occupants.
Outdoor HVAC Airflow Measurement and Monitoring for Healthy Work Environments during COVID-19
COVID-19 has highlighted the role of HVAC systems in maintaining healthy environments in buildings. Viruses may be spread by infected individuals even when they do not exhibit symptoms. Improving indoor air quality protects employees and members of the public by helping to reduce the spread of disease. The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) offers guidance for building operations during COVID-19. The U.S. Centers for Disease Control and Prevention (CDC) also provides recommendations that rate strategies from most to least effective.
Precision measurement of outside airflow rates is required to implement many of these recommended strategies in a way that does not compromise the core functions of the air conditioning systems. the following strategies, curated from ASHRAE and the CDC:
- Increase ventilation rates above code.
- Disable demand-controlled ventilation (DCV).
- Implement flushing strategy outside of occupancy.
- Maintain space relative humidity between 40% and 60% to decrease the bio-burden of infectious particles in the space and decrease the infectivity of many viruses in the air.
- Improve central air filtration to the MERV-13 or the highest compatible with the filter rack, and seal edges of the filter to limit bypass.
- Make adjustments needed to maintain building pressurization.
- Keep systems running longer hours, 24/7 if possible, to enhance air exchanges in the building space.
Sources:
The Air Monitor Outdoor HVAC Airflow Measurement Solution
The accurate measurement of outside airflow is required for the proper operation of today’s high-performance buildings. Outside air can pose a challenge regarding the metering technology to choose due to low airflow velocities, high moisture content in certain climates, and the presence of airborne contaminants at the point of measure.
The products below are commonly used for this application:
