Modern Building Services

28 MODERN BUILDING SERVICES JULY 2022 M ost of us recognise that air pollution is a major threat to health in the modern world. We have all seen warnings of the impact emissions from diesel and petrol engines, plus the effect burning fossil fuels, can have on our daily lives. Public Health England figures show that pollution causes between 24,000 and 36,000 deaths in the UK every year, making it the fourth biggest killer after cancer, obesity and heart disease. But perhaps one of the biggest hidden dangers is an assumption that we can protect ourselves from the airborne perils of the outside world by heading inside and closing the door. In fact, indoor environments are between 5-10 times more polluted than outside, due to a combination of affected outdoor air and further impurities generated inside. Cocktail of risk Particulate matter is viewed by the World Health Organisation as one of the pollutants most damaging to health because it can penetrate deep into the bloodstream and organs, via the lungs. The smaller the particles, the more harmful they are because they are more easily moved through the airways to other parts of the body. The size of fine particulate matter is PM2.5 or below, with increasing attention now being focused on PM1. Further indoor impurities are caused by the air we breathe out, dust from people and processes, and from fixtures and fittings including carpets and furniture. Added to that is carbon monoxide (CO) from gas appliances, carbon dioxide (CO 2 ) build-up in poorly ventilated areas, volatile organic compounds, radon, mould and excessive humidity. Finally, the Covid-19 pandemic underlined the serious threat viruses pose, particularly when they can spread through the air in the formof droplet particles. Airborne viruses can infect the respiratory system and spread easily in crowded spaces without proper ventilation. That’s a pretty potent cocktail of risk and, with most people estimated to spend up to 90% of their time inside, it is clear to see why the way we address the issue of indoor air quality (IAQ) is so important for the health of this and future generations. The good news is that, while outdoor pollution is dependent on many factors which individuals and organisations may feel they are unable to influence, at least in the short term, the ability to manage our IAQ is well within reach. Creating a healthy space Correct operation and maintenance of HVAC systems to improve the indoor environment while reducing risks hold the key, with four main factors involved in managing airflow and creating a healthy space with minimal risk of infection: 1. Ventilation – With 100% fresh air, provides highly filtered outdoor air to occupants 2. Air purification and filtration - Single-space particle filtration units can help reduce or lower concentrations of infectious aerosols 3. Hygienic technology - Ultraviolet germicidal irradiation can inactivate microorganisms 4. Temperature and humidity - Microorganism are less likely to survive in relative humidity (RH) between 40-60%, with RH below 40% likely to increase infections Andrew Robinson the managing director of HVAC equipment supplier Exi-tite and Exi-tite Air Filtration explains why improving the air quality in our indoor spaces has never been more important. Staying safe indoors FEATURE INDOOR AIR QUALITY