Indoor Air Quality (IAQ)

Introduction:

• People spend more than 90% of their time indoors, therefore IAQ management is crucial.
• Good IAQ affects the health, well-being, and productivity of occupants.
• The COVID-19 pandemic has brought increased attention to ventilation and air cleaning systems in buildings.

Standards:

• Measuring and setting IAQ standards at a non-occupational level is a relatively young field.
• This guide is based on practical experience and takes an ambitious approach to setting IAQ standards.
• Aim: to support the interpretation of IAQ data and to actively promote health and well-being in buildings.

Measurement technology:

• Advances in technology allow for the measurement of many indoor air pollutants using low-cost devices.
• Examples: CO2, TVOC, PM2.5 sensors.
• It is important to choose the right technology for the intended purpose and to ensure the reliability of the data.

Selection of pollutants to monitor:

• Particulate matter (2.5 & 10 μm), CO2, CO, TVOC are common pollutants that can be easily measured.
• Other pollutants such as formaldehyde, nitrogen dioxide/oxide, ozone, radon require more complex measurement techniques.
• It is recommended to rely on easily measurable parameters to characterize the environment.

Description and limits of pollutants:

• The guide provides pollutant levels and characteristics based on practical experience and official guidelines.
• For example:
• CO2: optimal level <1,000 ppm, a reasonable ventilation level to dilute airborne viruses is 800 ppm.
• TVOC: values above 300 μg/m3 may indicate contamination from specific sources.
• Formaldehyde: should not exceed 100 μg/m3.
• PM2.5: annual average should not exceed 25 μg/m3.
• CO: should not exceed 9 ppm as an 8-hour time-weighted average.
• NO2: annual average should not exceed 40 μg/m3.
• Ozone: 100 μg/m3 8-hour average limit for ozone.
• Radon: 300 Becquerels/m3 annual average action level.

Conclusion:

• Good IAQ is essential for human health, well-being, and productivity.
• There are many technologies and methods for measuring and controlling IAQ.
• It is important to choose the right measures for the specific needs and conditions of each building.