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.