How to achieve a greener, healthier indoor environment
Many people spend long periods of time inside commercial and public buildings where only 10-15 % of the air may be fresh, with the remaining portion being recirculated, often for efficiency reasons. Unfortunately, exposure to low-quality air can lead to the increased presence of allergies and even respiratory diseases. The NANO-HVAC (Novel nano-enabled energy efficient and safe HVAC ducts and systems contributing to a healthier indoor environment) project used a dual approach to improve conditions in buildings. The first approach involved development of safe, highly insulating HVAC ducts that minimise loss of heat and cooling. Cost-effective, safe and extremely thin insulating duct layers were obtained using aeroclay-based insulation foams that can be automatically applied during manufacturing. Such technologies can achieve a 50 % saving in energy losses and reduction of 45 % of the duct cost, as compared with conventional insulated ducts. The second approach involved the removal of pathogens and allergens during operation and maintenance to reduce microbial growth. Project partners developed an antimicrobial, antifungal and antiallergenic sprayable and self-adhesive coating based on titanium oxide nanoparticles. This can be applied to HVAC filters during manufacture or while they are in situ. Furthermore, the use of a low-energy ultraviolet light-emitting dioxide system will not increase HVAC energy consumption by more than 1 %. Researchers also developed an injectable liquid polymer matrix comprising epoxy resins with polyamine-derived crosslinking catalysts, which contained antimicrobial nanoparticles of silver oxide. This was used for air ducts' in situ maintenance where the liquid polymer creates a coating that covers the surface, trapping dirt, debris and microorganisms and thereby generating the duct inner layer. The procedure can be repeated many times without compromising HVAC energy performance. NANO-HVAC successfully employed antimicrobial and antiallergenic solutions to improve the indoor environment. The system can dramatically improve air quality in buildings, thus improving people's health and well-being, and produce significant energy savings. It will also help make Europe a leader in state-of-the-art HVAC systems.
Keywords
Indoor environment, heating, ventilation, air conditioning, air quality, duct, NANO-HVAC
