Below is one part of a series of white papers based on our Conversation Series: New Perspectives on Health and Well-Being where we discussed a range of mitigation strategies with our community of engineers, architects, specialists, and industry professionals. We break down all the latest and greatest (and not so great) methods of disease control through engineering, design, and building maintenance strategies by their effectiveness and considerations for sustainability.
Why we should care
Continuous Air Quality monitoring is used to protect people in the indoor and outdoor environments. In an indoor office space, occupants are exposed to air pollutants while they are in the building but effects can continue with the occupant throughout life. Air pollution can cause a variety of health complications including lung cancer & disease, heart disease, and asthma. Many common chemicals are known to be endocrine disruptors, immune suppressors, neurotoxins, or hold other harmful properties. Protecting people while inside a building can help to eliminate risks and create a safe space from outdoor pollutants. As pollutants thrive in specific environmental conditions, monitoring the conditions can lead to the elimination of risks. While air monitors are more of an indirect mitigation strategy, data can improve long-term health and help pinpoint and eliminate sources of exposure.
How do we measure air quality
Green building standards, beginning with LEED, have set guidelines for healthy air. More recently, RESET and WELL have expanded upon guidelines to focus on indoor air quality. RESET Air focuses on long-term occupant health and on-going results with continuous monitoring of the space. While RESET Air sets out guidelines, it is not a design standard nor does it specify solutions. The goal is to collect information in order to make solutions in the future. The WELL standard promotes clean air and the reduction of indoor pollution. Included the standard is VOC reduction, ventilation effectiveness, air flush, and air quality monitoring and feedback. Sensors can be placed in specific areas or whole buildings, making the monitoring customizable and specific for each building.
Examples of Monitored Conditions
Particulate matter included organic and inorganic solid or liquid particles that are suspended in air. Particles can include dust, pollen, or smoke. Different sizes of particles, for example PM2.5, refers to the particle size in micrometers. Filters are able to trap some particles depending on the size. Health impacts can include respiratory systems and cardiovascular challenges.
Acceptable PM Level
Annual standard for PM2.5 set to 12 μg/m3 and daily standards set to 35 μg/m3. Daily PM10 standard set to and 150 μg/m3.
Total Volatile Organic Compounds
VOCs are found in products such as paints, cleaning supplies, varnish, and cosmetics. In the short-term, side effects include headaches, sinus inflammation, skin irritation, coughing, and pneumonia. Long-term side effects include nervous system damages, cardiovascular and respiratory disease, and impacts on major organs, blood, and reproductive systems.
Acceptable VOC Level
Less than 500 µg/m3
Indoor CO2 is a result of outdoor combustion, breathing, and ventilation rates. Effects of CO2 can include increased heart rate and blood pressure, drowsiness, headache, sweating, and restlessness. Increasing fresh air can lower CO2 rates and reduce side effects.
Acceptable CO2 Level
Less than 800 ppm
Air temperature measures how hot or cold the air is. Temperatures either too high or too low can result in uncomfortable occupants.
Average temperatures range from 68-76 degree Fahrenheit
The relative humidity of a space measures the amount of present water vapor at a certain temperature. Humidity control can be used as a factor to mitigate virus spread, as the viral particles survive longer and travel farther in dry air. Keeping humidity between 40%-60% can be effective towards mitigation. However, not all buildings can withstand higher humidity levels and can lead to moldy and damaged surfaces.
Levels range from 30-60% relative humidity with 40-60% being used in COVID-19 mitigation efforts.
Systems have the ability to collect data and share it in reports. Sharing data can keep track of long-term progress and provide insight to the health of the building and occupants. Enabling notifications for conditions allows maintenance to quickly fix a factor that has changed. Data trends will also provide insight to the effectiveness of air handling systems. Data sharing also allows for building occupants to be aware of their surroundings. Overall, recordings without insight can be meaningless. The ability to observe trends, control spikes, and share information is vital for healthy environments.
Sustainability Impacts of mitigation efforts
While monitors themselves are not a mitigation strategy, sensors can provide building operators with the quantifiable data necessary to make effective improvements to the indoor environment and indoor air quality. Installing air monitoring sensors can help make the space more efficient and safe. Monitors are also a great way of ensuring occupant health and productivity. If air conditions are causing health problems or discomfort, the employee will not be able to perform to the best of their ability.
Continuous Air Quality monitoring systems are offered by many different manufacturers and can be integrated into the building system or stand alone as a separate system. The best option would be up to the builders and/or operators, but timing can play a large role. Stand-alone systems make sense for existing buildings while integrated systems would make sense in new construction.
Air monitoring provides building maintenance and occupants a clear way of understanding what is in the air. Sensors installed around the building collect readings of different air and environmental conditions. As workers return to buildings after COVID-19, it is important to understand air quality to ensure mitigation strategies are effective. However, specific COVID-19 detectors are not yet available. Scientists and engineers are working on possible sensors and establishing reliable proxies for the virus.
Continuous Air Quality Monitoring uses sensors to measure air quality and environmental conditions of a space. Common monitored factors are particulate matter, volatile organic compounds, carbon dioxide, temperature, and relative humidity.
Pollutants (indoor & outdoor) are air particles that can be dangerous to humans.
Figure 1: Example of monitor dashboard from Awair monitoring system (Source: https://www.getawair.com/business/dashboard)
Figure 2: This chart identifies strategies, calls out sustainability factors and ranks the efficacy of COVID-19 / SARS-CoV2 mitigation and keys in a color and abbreviation linking to the larger, compiled strategy chart.
Figure 3: This image is a key, specifying the location of each solution on the compiled strategies chart.
Air Things: CO2
Increasing fresh air can lower CO2 rates and reduce side effects.
EPA Air Quality
Daily PM10 standard set to and 150 μg/m3.
Green Facts: Particulate Matter
Health impacts can include respiratory systems and cardiovascular challenges.
Prism Analytical Technologies
Acceptable VOC level: Less than 500 µg/m3
The goal is to collect information in order to make solutions in the future.
Long-term side effects include nervous system damages, cardiovascular and respiratory disease, and impacts on major organs, blood, and reproductive systems.
Included the standard is VOC reduction, ventilation effectiveness, air flush, and air quality monitoring and feedback.