Modern Building Services

MODERN BUILDING SERVICES NOVEMBER 2021 25 FEATURE INDOOR AIR QUALITY cornerstone of any buildings HVAC system, Advanced Air Cleaning Technologies are available which can complement both by helping to enhance the quality of air provided to the occupied space. Ensuring traditional system- installed methodologies are effective at actually “reaching-into” the occupied environment would be a major accomplishment for all building air cleaning systems, therefore something different than what we are now doing may warrant consideration Easily understood is a simple concept that if the pollutants in the space are removed, they are no longer a concern to its inhabitants. Comprehending this, along with all the dynamics discussed above is key in helping us to properly design buildings that can better contribute to the well-being and productivity of occupants breathing the indoor air. Needlepoint Bipolar Ionization (NPBI) is a patented air cleaning technology that can bemounted in the HVAC systemyet works on the contaminants and pollutants in the space, where we are being told the issues of concern originate andmay remain. While not a filter itself, NPBI can supplement traditional ventilation and filtration by influencing the removal of small airborne particulate (viruses, pathogens, and other contaminants) from the environment based on the principle of electrostatic attraction and agglomeration. Ions, like those already abundant in cleaner outdoor air, are generated fromwithin the HVAC system so that when released and distributed throughout the building canmix with roomair and attach (electrostatically) to airborne particles. As these charged particles are increasingly attracted and joined to one another, their size and weight is increased to the point where they (now being larger) can bemore easily influenced by HVAC systemair movement. Particles may now be effectively removed from the space and exhausted, filtered, or treated. Air filters becomemore effective at removing these larger particles from the air, while any other internallymounted HVAC systemair purification device (including filters) can encounter the pollutants they have been tasked with cleaning, those which beforemay have remained in the space untouched. Applied upstream of wet cooling coils, NPBI can help eliminate issues with biofilm and microbial growth (mold) in HVAC systems which in the past could be transferred through HVAC ductwork and into the occupied space, becoming another issue of concern Recent air ionization testing and analysis by the Built Environment Research Group, Department of Civil, Architectural, and Environmental Engineering at the Illinois Institute of Technology has presented some compelling results. The Clean Air Delivery Rate (CADR) of a tested air cleaner was improved by 44% for 0.9-1.0 µm size particles (smoke), 19% for 0.5-3.0 µm size particles (dust), and 53% for 5.0 to 10.0 µm size particled (pollen). Based on these results, scientists estimated that between 20-50% of the measured CADR during normal operation may be attributable to the ionization process. With the basic understanding that everything in the air we breathe is a particle, and that their removal is fundamental in improving IAQ, this important research provides additional insight into how the air may be more effectively cleaned. Conclusion Ventilation and filtration are two key components in creating truly productive environments for individuals occupying buildings of all types. Themore efficient each is the better the results will be, individually or in combination. The field of indoor air quality is ripe for advancements that canmake improved indoor air qualitymore effective and affordable. Add to this an assurance that the HVAC system is being properly serviced andmaintained over its operational lifetime and you will have takenmajor steps toward making sure we are truly cleaning the air we breathe. AUTHOR BIO: David Schurk DES., CEM. LEED-AP., CDSM., CWEP., SFP., CIAQM., HCCC., serves as Director of Healthcare and Applied Engineering Markets for Global Plasma Solutions, headquartered in Charlotte NC (USA). David is a Licensed Designer of Engineering Systems with over 38-years of experience in the design and analysis of heating, ventilating, and air-conditioning systems for a variety of market sectors, with a special focus on hospital and healthcare environmental control and indoor air quality. He is also an ASHRAE Distinguished Lecturer. Email: david.schurk@ globalplasmasolutions.com