Smart Schools Roundtable: HVAC Indoor Air Quality


For the April session of Fanning Howey’s Smart Schools Roundtable, we heard from ASHRAE Distinguished Lecturer David Schurk on how HVAC systems can improve and maintain indoor air quality to promote healthy learning environments. David is a licensed designer of engineering systems, and has over 35 years of experience in the design and analysis of heating, ventilating, and air conditioning systems for a variety of market sectors. His presentation covered current information on filtration, ultraviolet light, bipolar ionization and other strategies for creating healthy learning environments.

The Power of Ionization

According to the EPA, indoor air is often two to five times more polluted than outdoor air. Outdoors, naturally-occurring ions are constantly working to clean the air, while indoors these ions are almost nonexistent. Ions clear the air of particles such as dust, dander, pollen, smoke, and even pathogens such as mold, viruses and bacteria. An ion is simply a charged atom or molecule in the air. It is charged either positively or negatively with electrical energy, so there are no more neutrals left. When these atoms and molecules are charged with a positive or negative electrical potential, they can interact with certain pollutants and contaminants to help remediate them.

To lower the concentration of particles suspended in the air, ventilation systems can incorporate bipolar ionization technology which safely introduces ions into the air stream. What happens with ions that are allowed to go out into space and mix with the particles which also have a charge, the positive ions will adhere to the negatively charged particles, the negative ions will adhere to the positively charged particles, they will clump together and become bigger and bigger until they are large enough to be influenced more easily with air motion.

Balancing the HVAC System Approach

The cornerstones of a balanced HVAC system are filtration, ventilation, humidification and advanced IQ or indoor air quality solutions. Advanced IQ technologies can consist of an array of things that have been found to work such as UVC lights,  photocatalytic oxidation, dry hydrogen peroxide, bipolar ionization and more specifically, needlepoint, bipolar ionization. When all elements are well planned out and balanced the HVAC system can be an effective approach at helping to clean the indoor air and create healthier indoor air environments.

Filtration Effectiveness Concerns

Filters can only be effective at extracting those particles and pathogens that can reach the filter itself. It can do nothing for those that remain suspended in the space. This is of utmost concern for airborne pathogens such as those that carry SARS Coronavirus variants, because they fall into what’s called fine particle or ultrafine particle ranges. Highly efficient filters such as HIPAA filters, commonly used in hospitals, are only effective when particles reach them. The airflow of most ventilation systems will not pick up ultrafine particles, leaving them in the air to potentially be inhaled.

Currently, the two things that may be most effective at reducing transmission of COVID particles indoors are, number one, make sure that occupants are wearing a good, tight-fitting mask that may reduce infection risks by up to 50%, and then implementing bipolar ionization. More specifically, needlepoint bipolar ionization may reduce the transmission rates by an additional 20 to 30%.

Understanding effective strategies for ionization, balance HVAC systems and filtration are essential to creating smarter and healthier schools. Before you move forward with building improvements, including using ESSER III funds, contact a knowledgeable engineer to determine the right approach for your community.