Unlocking economic and health benefits of IAQ

Optimising indoor air quality (IAQ) is essential for improving health, increasing productivity and cost savings. HVAC expert Harsh Bardhan explains that by implementing IAQ strategies, organisations can reduce absenteeism and lower healthcare costs, leading to ample returns on investment.

Indoor Air Quality (IAQ) is essential for occupant health, comfort, and productivity within any residential or commercial building. Numerous studies underline that optimising IAQ yields significant economic and productivity benefits for organisations while reducing health risks for occupants.

Cost benefits of improved IAQ

Improved indoor air quality (IAQ) offers a range of cost-saving benefits for businesses and organisations. First, reducing poor IAQ can significantly reduce absenteeism rates, a major contributor to missed workdays due to health issues. Poor IAQ leads to numerous health-related problems, accounting for approximately 1.24 million missed workdays annually in the U.S. alone, according to the EPA. Enhancing IAQ has been shown to reduce absenteeism by 20–50 percent (Harvard University), leading to higher productivity.

Moreover, better IAQ relates to increased productivity. Studies from the Lawrence Berkeley National Laboratory suggest that individuals experience an 8-11 percent increase in productivity when air quality improves. This is due to fewer distractions from discomfort or illness.

Improved IAQ also leads to lower healthcare costs. According to the World Health Organisation, enhanced air quality reduces health-related expenses by 10–30 percent as fewer respiratory issues and other health problems arise.

Another benefit of improved IAQ is its impact on extended equipment life and energy efficiency. Proper IAQ management also prolongs HVAC equipment life by 20–50 percent, as noted by ASHRAE. Furthermore, improved ventilation systems and air quality reduce energy consumption by up to 20 percent, offering environmental and financial savings.

Strategies for enhancing IAQ

Organisations can implement various strategies to maintain optimal indoor air quality (IAQ) and secure related benefits. First, optimising ventilation is crucial. ASHRAE recommends increasing outdoor air ventilation rates by 20-50 percent, as outlined in Standard 62.1, which helps dilute indoor pollutants. Advanced air filtration systems also play a key role; Installing high-efficiency filters, like HEPA or MERV 13+ filters, effectively removes airborne contaminants.

Controlling humidity and sources of pollution is equally essential. Maintaining relative humidity levels between 30-60 percent, as advised in ASHRAE 55, prevents mould growth and ensures occupant comfort. Source control eliminates indoor pollution sources such as tobacco smoke or volatile chemicals, which is equally crucial for a healthy indoor environment.

Finally, regular maintenance of HVAC systems is indispensable. Scheduling biannual HVAC maintenance ensures the efficiency and longevity of equipment while keeping IAQ high.

Cost and ROI

The initial investment for IAQ improvements ranges from $0.50 to $2.50 per square foot, depending on the specific measures chosen. Most organisations achieve a return on investment (ROI) within 1.5 to 3 years, thanks to lower energy and healthcare costs and reduced absenteeism.

Case Studies

Companies like Google and Microsoft have reaped the benefits of optimised IAQ. At Google’s headquarters, improved IAQ resulted in a 20 percent increase in productivity and a 15 percent reduction in energy consumption. Similarly, Microsoft’s Building 92 achieved a 25 percent reduction in energy use and a 10 percent productivity boost through IAQ enhancements.

Maintaining IAQ: Standards, calculations, and practical approaches

Optimal IAQ relies on a comprehensive understanding of air quality parameters and adherence to regulatory standards. Critical factors include temperature, relative humidity, carbon dioxide levels, particulate matter, and volatile organic compounds (VOCs).

Key IAQ parameters and standards

Key Indoor Air Quality (IAQ) parameters and standards emphasise maintaining optimal conditions for temperature, humidity, carbon dioxide (CO2) levels, particulate matter (PM), and volatile organic compounds (VOCs).

ASHRAE Standard 55 suggests keeping indoor temperatures between 22–25°C (72–77°F) and relative humidity between 30–60 percent. For CO2 levels, ASHRAE Standard 62.1 recommends keeping CO2 levels below 1,000 ppm to prevent fatigue and discomfort. The EPA recommends PM levels below 50 μg/m³ and VOC levels under 500 μg/m³ to minimise health risks.

Calculations for IAQ optimisation

Proper ventilation rate (VR) and air changes per hour (ACH) calculations are essential for effective IAQ management. For example:

Ventilation Rate (VR) is calculated as VR = (Occupant Density x Activity Level x Ventilation Efficiency). This formula helps determine how much fresh air a space needs based on usage and density.

Air Changes per Hour (ACH): ACH, calculated as (Total Supply Airflow / Room Volume), indicates how often the air in a space is replaced, ensuring pollutants are regularly removed.

Maintenance strategies

Organisations can implement several practices to sustain optimal IAQ. Regular HVAC maintenance, including filter replacement and biannual coil cleaning, is essential for efficient operation and high air quality. Air quality monitoring with CO2, particulate matter (PM) sensors and volatile organic compounds (VOCs) allows for proactive monitoring and quick responses to air quality concerns.

Additionally, Minimising indoor pollutants and educating occupants on best practices for indoor air quality can significantly improve the overall air quality, promoting a healthier indoor space.

Conclusion

Investing in and maintaining high indoor air quality standards provides organisations substantial benefits, from productivity gains to financial savings. By following established standards and maintenance practices, organisations can achieve healthier, more comfortable, and more productive indoor environments.