Fresh air rate increase within occupied spaces improves air quality

Raji Panicker, Head of Engineering MEP, Adani Group, suggests several measures can improve indoor air quality within homes or workplaces. Eliminating VOCs from paints and varnishes is essential, and implementing air curtains and sticky mats can help remove dust from shoes before entering a building.

How do primary sources of indoor air pollutants differ from outdoor pollution sources?

Indoor air pollutants originate from various primary sources. Combustion sources such as tobacco smoke and kitchen activities can produce carbon dioxide (CO2), nitrogen dioxide (NO2), dust, liquids, pollens and particulate matter, ranging from coarse particles (PM10) to fine particles (PM2.5).

Building materials, including pressed wood products, often emit formaldehyde, while paints, varnishes, and cleaning products release volatile organic compounds (VOCs). Household products, such as cleaning agents, air fresheners, and personal care items, also release VOCs and other chemicals.

Vehicle emissions release CO, NO2, sulfur dioxide, VOCs, and particulate matter. Industrial emissions from factories and power plants release NO2, sulfur dioxide, VOCs, and particulate matter.

Biological contaminants, including pollen, mould, dust, and pet dander, are common indoor allergens. Outdoor pollutants further contribute to indoor air quality issues. Moreover, natural sources such as wildfires and dust contribute to CO2 levels, while agricultural activities release VOCs and particulate matter through pesticides and herbicides.

How can advancements in IoT technology impact IAQ monitoring in large commercial spaces?

The advancement of IoT impacts indoor air quality monitoring by increasing the fresh air rate or building flush. In Demand control Ventilation, fresh air rates are controlled by CO2 sensors inside and outside. However, with IoT, multi-level pollutants can be monitored. Hence, remedial measures can manage indoor air quality. These can be related to COVID mitigation measures for switching on the UV or other air purification measures.

Please talk about the filtration systems that optimise indoor air quality while minimising energy consumption.

Various filtration systems can optimise indoor air quality while minimising energy consumption. Mechanical filters with MERV ratings ranging from MERV 8 to MERV 13 are used in commercial and residential settings. These filters balance filtration efficiency and energy consumption, tailored to indoor air quality requirements. Carbon filters effectively remove gases and odours, such as VOCs. They are often used with mechanical filters to enhance air quality without significantly increasing energy use. Electronic air cleaner devices charge particles in the air, causing them to adhere to collection plates. They can be effective but may produce ozone as a byproduct, which must be managed. UV germicidal irradiation (UVGI) systems utilise ultraviolet light to kill or inactivate microorganisms, thus contributing to improved indoor air quality.

What are the latest innovations in integrating UV technology for disinfection into HVAC systems and improving ventilation?

UV-C LED technology is more energy-efficient when used at 254 nanometers. It has longer lifespans and is environmentally friendly, eliminating the use of hazardous materials. UV-C LEDs can be used in HVAC systems, such as coils and air ducts. They are effective if installed downstream of AHUs or FCUs. However, they can degrade materials. UV-C works efficiently at higher temperatures depending on the UV efficacy curve.

Photocatalytic Oxidation (PCO) systems use UV light to activate a photocatalyst, producing reactive oxygen species that break down pollutants and microorganisms, providing an additional layer of air purification. Technologies like chemical media filters or photocatalytic oxidation, along with Mechanical filtration, can be used. Fresh air can be increased by 30 percent as per ASHRAE 90.1. However, this will increase the cooling load.

How can IAQ solutions be tailored to address specific pollutants in different indoor environments?

IAQ solutions can be tailored to address pollutants in different indoor environments, depending on the contaminants that need to be controlled, such as dust, pollutants, VOCs, SOx, NOx, or odours. However, due to COVID-19, UV technology has become a new normal for future readiness. Additionally, provisions can be incorporated to ensure preparedness for future pandemics, further future-proofing indoor air quality solutions.

Please elaborate on filtration technologies to mitigate the spread of infectious diseases.

I have explored several technologies, such as electrostatic precipitators, ozonisers, and photocatalytic oxidation. However, only one technology could eliminate or minimise the spread of infectious diseases inside indoor spaces: UV-C in the range of 254.3 nanometers. The reason was evident when insufficient data was insufficient to support other technologies. However, UVC was able to eliminate the virus that required higher intensity data, which was proven, tested, and published in the UV Handbook and ASHRAE.

What measures can be adopted to improve IAQ within homes or workplaces?

Several measures can be adopted to improve indoor air quality within homes or workplaces. Eliminating VOCs from paints and varnishes is essential, and implementing air curtains and sticky mats can help remove dust from shoes before entering a building. Using mechanical filters is another strategy for enhancing air quality. Additionally, incorporating fresh air into indoor units or occupied spaces can improve the overall air quality.