Winters may feel cosy and comfortable in your perfectly airtight modern house. But remember a cosier house might not always be a healthier house. Because air inside a house could also be polluted just like outdoors, and majority of researchers believe that indoor air pollution could be even more menacing than outdoor air pollution since we spend around 93% of our time indoors (87% in buildings + 6% in cars)[1].
According to a study presented at American Association for the Advancement of Science conference held in Washington D.C, pollutants can be released into your building by almost everything; furniture, carpets, construction materials, paints, adhesives, cleaning and combustion products making us continuously exposed to pollutants indoors[2]. And most of the things that cause indoor air pollution are invisible and odourless, so there is no way to find out how bad is the problem unless it affects health and well-being of occupants. Conventionally, CO2 has been predominantly perceived to be the sole factor for determining indoor air quality (IAQ), however, pollutants like Volatile Organic Compounds (VOC) and particulate matter smaller than 2.5 micrometers (PM2.5) are more harmful than CO2[3].
Heating, ventilation, and air conditioning (HVAC) systems in our buildings are used for maintaining indoor air quality (IAQ), but these systems are extremely energy-consuming, accounting for more than half of total building energy consumption. If they are not properly designed, operated, or maintained, however, HVAC systems can contribute to indoor air problems in several ways. For instance, problems arise when, in an effort to save energy, ventilation systems are not used to bring in adequate amounts of outdoor air. While high quality indoor air quality (IAQ) and thermal stability are key to occupants’ comfort and productivity, it is often in contradiction with energy saving objectives. Therefore, it is crucial to design some energy-efficient building HVAC control system. One of the ways to optimize the energy use of a building HVAC system could be by making ventilation system more responsive to occupants in the building: airflow is increased in response to high number of occupants, and then gradually decreased. By optimizing, and making small adjustments when necessary and possible in the ventilation system can lead to serious energy savings without sacrificing quality.
Certifications like ASHRAE 62.1 and WELL are available for improving indoor air quality (IAQ). However, more rigorous, vivid, and specific indoor air quality (IAQ)-related standards and regulations are required to develop a technically feasible, and comprehensive action plan. An action plan which should focus on improving the health of building occupants and also optimizing energy consumption.
References
https://www.nature.com/articles/7500165
https://www.forbes.com/sites/jessicabaron/2019/02/19/bringing-attention-to-indoor-air-pollution/#4e5cce5f8b3c
Work performance, productivity and indoor air. Available from: https://www.researchgate.net/publication/41464093_Work_performance_productivity_and_indoor_air [accessed May 05 2019].
https://www.csemag.com/articles/ashrae-62-1-using-the-ventilation-rate-procedure/
Donghyun Rim, Energy and Cost Associated with Ventilating Office Buildings in a Tropical Climate