The complex interaction between pollutants, ventilation, and other environmental factors within enclosed spaces has serious implications on respiratory health, cognitive function, and overall occupant comfort. Clean India Journal sought inputs from Tushar Kalra, Founder, Air Exchange Solutions on the ins and outs of ensuring effective maintenance of IAQ.
Critical parameters affecting indoor occupant health include the concentration of CO2, volatile organic compounds (VOCs), radon, formaldehyde, and biological contaminants such as mould & bacteria. Building design, ventilation systems, and regional climate also contribute to the impact of air pollutants on occupant health.
Spot measurements and real-time monitoring are employed to collect air quality data from enclosed spaces. Both provide an accurate understanding of IAQ and help in taking proactive steps to maintain a healthy indoor environment. The choice between the two methods depends on specific requirements and the available resources.
Health concerns associated with indoor air quality include respiratory issues, respiratory infections, irritation of the eyes, nose & throat, cognitive effects, and aggravation of pre-existing health conditions.
Various factors contribute to adverse health effects:
• Ventilation Rate: Poor ventilation can lead to a buildup of pollutants like CO2 and VOCs, thereby increasing the risk of respiratory and other health problems
• Mould and Microbial Contaminants: Exposure to mold spores and microbial contaminants leads to cross-infection and other respiratory issues
• Allergens (dust mites, pet dander, pollen): Allergens such as dust mites, pet dander, and pollen can lead to allergic rhinitis, asthma symptoms, and other allergic reactions
• Carbon Monoxide (CO): CO interferes with the body’s ability to transport oxygen, and leads to symptoms like headaches, dizziness, nausea, and, in severe cases, unconsciousness or death
• Occupant Behaviour: Activities like smoking, cooking, and the use of products like perfumes, etc. can significantly impact IAQ
Ventilation strategies to improve IAQ in commercial buildings:
• Increase Ventilation Rates, based on occupancy or as prescribed in ASHRAE Standard 62.1-2022
• Conduct regular inspections, cleaning, and maintenance of HVAC systems to ensure they function efficiently and deliver clean air. This includes routine checking and replacing air filters when required
• Use mechanical filters such as ePM2.5 / ePM1 as per ISO 16890:2016 standards to capture smaller particles, including allergens and fine particulate matter
• Use occupancy sensors to adjust ventilation rates based on the actual occupancy of different areas within the building
• Identify and control sources of indoor pollutants
• Use commercial-grade air purifiers with high-efficiency filters and carbon filters to remove airborne particles and gaseous pollutants
• Maintain optimal indoor humidity levels (30-50%) to prevent the growth of mold and dust mites
• Educate building occupants about the importance of IAQ and encourage practices that contribute to a healthier indoor environment, such as proper waste disposal and not blocking vents
• Conduct regular IAQ assessments, including real-time monitoring of pollutant levels and gathering feedback from occupants
This helps identify areas for improvement and ensures ongoing IAQ maintenance
• Implement strict no-smoking policies within the building to prevent exposure to second hand smoke, a significant indoor air pollutant Tailor the above strategies to suit the specific characteristics of each commercial building, including its size, occupancy, and existing HVAC systems. Consulting with HVAC professionals and conducting regular assessments will help validate the chosen ventilation strategies in the maintenance of high IAQ.
