Indoor Air Quality (IAQ) in office buildings has gained prominence as it directly affects well being and comfort level of its occupants, particularly, employees. According to US Environmental Protection Agency (EPA), people tend to spend around 90 per cent of their time indoors i.e. offices. The office buildings are susceptible to poor IAQ due to lack of proper ventilation system and faults associated with heating, ventilating and air conditioning (HVAC) systems.
In most office buildings, HVAC systems work with limited or complete lack of fresh air. As a result, HVAC systems circulate stale air or return air leading to high levels of carbon dioxide in the indoor environment. Moreover, these systems work at different efficiency levels and if there is extra load on them, the quantity of stale air increases in the environment (fresh air reduces) leading to multiple problems and even system failure, informs Kalidas Bhangare, Managing Director, Testo India. Further, this has an impact health of employees, leading them to suffer from sick building syndrome with symptoms like headaches, dizziness, eye irritation and excessive yawning due to lack of fresh air during long meetings in conference rooms. For these and many other reasons one needs to monitor the IAQ in the office buildings.
“Fresh air itself will not help in the absence of an efficient filtration system that keeps out particulate matter (PM10 and PM2.5) present in high concentration in ambient air, especially, in large Indian cities,” informs Srinivasa Desikan, Sales Director – South Asia, UL. Elaborating he further says, filters must be rated minimum efficiency reporting value (MERV) 13 and higher and be changed periodically.
Multiple studies prove a direct correlation between indoor air quality in an office and employee health, brain function, sleep, productivity and job satisfaction.
As a result, Bhangare from Testo India points out that the facility manager or the supervisors often try to ensure that the indoor work environment, be it air conditioning, temperature regulation or light etc., is controlled and comfortable for the people as it directly impacts their health and efficiency.
Giving importance to IAQ in office buildings, Gaurav Burman, VP & APAC Head, 75F specifically states, “Poor air quality makes the workforce sluggish, unproductive and sick directly, diminishing the business’ bottom line.” He further exemplifies through research by Lawrence Berkeley National Laboratory and Harvard and Syracuse Universities informing that good indoor air quality can improve work performance by as much as 10 per cent and employees’ cognitive abilities by 61 per cent.
“Investing in good indoor air quality for a workplace not only impacts employees’ well-being but also makes business sense. A surge in revenues, greater productivity per worker and increased employee morale and retention are just some of the many pay offs,” opines Burman.
What contaminates air
ISHRAE considers the indoor air as healthy when it does not contain contaminants in harmful concentrations and is acceptable when the majority of people feel comfortable. Lack of proper ventilation and filtration and improper distribution also leads poor indoor air quality.
Particulate Matter PM2.5 and PM10, CO2, nitrogen dioxide (NO2), ozone (O3) and other volatile organic compounds (VOCs) also contribute to deterioration the quality of indoor air.
Indoor air pollution can originate from within the building or can be drawn in from outdoors. Contaminated outdoor air, pollen, radon, pesticides, etc. that enter the building from outside and pollution from within caused by occupants, smoking, cleaning supplies, motors, unclean ducts, improper ventilation or emissions from office equipment like printers, photocopiers, informs Gaurav Burman of 75F.
Modern commercial buildings are air-conditioned and insulated to regulate the temperatures. Burman of 75F says, through insulation, they also manage to keep pollutants and allergens locked in with cool air inside the building. Without fresh air circulation, the air becomes stale and gradually accumulates unhealthy levels of the above-mentioned pollutants.
VOCs constitute one of the major contaminants that pollute indoor air. Paints, furniture, doors, carpets, flooring, laminates, computers and laptops (due to printed circuit boards) release VOCs that can trigger asthma, allergies, headaches, respiratory diseases, reproductive and developmental defects, and eye, nose and throat irritations. Desikan from UL recognises some VOCs and formaldehyde as being carcinogenic and known to cause a few forms of cancer. He mentions Health of the Nation’s States report by the Union Ministry of Health, which pegs the blame of 10 per cent of the nation’s disease burden in 2016 to both indoor and outdoor pollution.
UL’s Environment and Sustainability division has conducted pioneering studies in nearly 3,000 environments wherein it has analysed emissions from over 65,000 different materials and furnishings. It identified over 13,000 unique VOCs in product emission studies and found that many of these VOCs are present in buildings.
Bhangare from Testo India points out that humidity and moisture levels along with the presence of dust particles in the surrounding can also degrade the air quality in the office premises.
To maintain the balance of oxygen vs carbon dioxide, it is important that minimum air circulation or air changes need to be maintained as per CPCB National Ambient Air Quality Standard (NAAQS) for AC buildings. With increased pollution in the outside air is becomes more important to provide indoor treatment, suggests Akash Deep, Senior Programme Manager, GRIHA Council.
How to maintain indoor air quality in office building
In ISHRAE’s opinion, controlling contaminants at source is the most important activity to improve air quality. Purification of outdoor air before being suppled into the building is important along with the equipment and material selection. Further, good construction and installation practices, low emission operation and maintenance practises are the need of the hour to improve IAQ in office buildings. When the outdoor air quality does meet the national AQI, ISHARE gives emphasis on ventilation and filtration design.
According to Bhangare of Testo India, encouraging fresh air ingress in the areas will lead to lesser air contamination issues. Also, people need to take care of the building material as well so that the climatic conditions can be met much more efficiently. But the most ideal way to maintain IAQ is to measure and monitor the necessary parameters regularly and properly and based on that, update or maintain the HVAC systems. Testo provides a range of multiple instruments that assist building managers in maintaining the desired IAQ level.
The Testo 160 wireless LAN data logger that measures, monitors and documents temperature, humidity, light intensity, UV radiation and CO2 concentration in offices– automatically and without interruption – hence, all indoor climate monitoring parameters in one.
An individually designable cover is also available for each data logger which allows the logger to blend into almost any environment. Testo in its recent upgrade, combines everything which makes the air velocity and IAQ measurement technology so successful – intuitive operation, precise measurement values and an extensive probe range which can even work wirelessly via Bluetooth.
The new Testo 440 and Testo 400 constitute of a compact handheld measuring instrument with user-friendly measurement menus and wireless probes – for the versatile and convenient measurement of all air conditioning and ventilation parameters. The probes are available for air velocity, temperature, humidity, degree of turbulence, CO2, CO and light intensity.
As per Burman from 75F, by scanning the indoor environment throughout the day, HVAC systems that are enhanced by IoT controls and predictive analytics are better equipped to react to building needs on a real time basis. They factor in data such as occupancy rate, weather forecasts, angle of the sun, etc. ensuring that the outside air supply at any given point in time is adequate and optimal. 75F offers Indoor Air Quality Management solution, for example, that detects the level of CO2 and NO2 in each zone in the building and proactively adjusts the outside air dampers to maintain air quality at appropriate levels while ensuring optimal temperatures, humidity and moisture levels. At the same time, it also ensures to save energy.
Low VOC paints, adhesives and sealants are readily available in the market. Acceptable VOC levels, composite woods free from urea formaldehyde products can be as per Green Rating for integrated Habitat Assessment (GRIHA) standards India’s national green building rating tool developed by The Energy and Resource Institute (TERI) and the Ministry of New and Renewable Energy (MNRE). CO2 levels can only be brought down by planting more and more trees/greenery both externally and internally.
In any AC space, CO2 levels shoot up drastically ranging from 1200 ppm to 1700 ppm, which is the way above acceptable limits. Also, we tend to close all-natural air infiltrations when using AC spaces, interestingly air leakages or air changes is important to maintain CO2 levels, suggests Akash Deep from GRIHA Council.
In order to boost morale and comfort level of employees, it is necessary to invest in good indoor air quality for a workplace. It helps to generate better revenues by enhancing greater productivity per worker. Srinivasa Desikan of UL, says, the threshold values to maintain IAQ parameters for CO2 are ambient air (+) 700 ppm, less than 15 µg/m3 for PM2.5, less than 9 ppm for CO, less than 50 µg/m3 for PM10, and less than 40 µg/m3 for SO2 and NO2.
He adds, “To prevent outdoor contaminants from entering, filters compliant with necessary standards should be used. On the other hand, indoor air quality can be improved by using products that do not emit harmful contaminants and proper ventilation of buildings.”
By Supriya A Oundhakar, Associate Editor