09 Jun HVAC Air Purification and COVID-19
Air purification has always been a major consideration for those who design, operate, and maintain HVAC systems. The pandemic has brought these considerations to the forefront of the public eye and HVAC management must rise to the occasion with more effective and even better solutions. Johnson Controls has recently published some general guidelines and suggestions to include as you work with a qualified professional like Albireo Energy to adjust your HVAC system settings and maintenance to be more effective against the virus and other pathogens.
Since COVID 19 is an extremely small virus that stays viable as it travels short distances in the air, the virus can be picked up by the HVAC system and transported to other spaces within the building. The building manager’s challenge today is to do everything possible to disrupt the virus, preventing its travel and destroying it as soon and as much as possible. There are a number of practices that can support this goal.
The HVAC system is a major component when managing indoor air quality. HVAC systems can be adjusted to operate differently to increase their effectiveness against the virus’s lifespan. Most are designed to deliver a small amount of ventilation, so a first step can be to increase the amount of fresh, outdoor air they deliver to spaces. While this sounds simple, the effect on the humidity levels and the capacity that the air handler was designed for requires the delicate balance of the system to be evaluated by an expert. This method is usually coupled with other technologies in the overall strategy to fight the virus.
The HVAC filter can capture the virus and other air contaminants. Filters are effective by trapping the particles that the virus is attached to. There a few things to consider before replacing or upgrading the filter. Filters generally operate better after being slightly loaded with particles than when brand new. Also, if an upgraded filter is being considered, the system should be assessed to ensure that the fan power can handle the increased resistance.
Once the ventilation and filter have been evaluated, another popular technology that can be added to the system is Ultraviolet Germicidal Irradiation (UVGI). UVGI inactivates the virus, killing it. It can be used in air handlers, ducts and in spaces when unoccupied. This lighting cannot be used in occupied spaces or near occupied spaces to prevent occupant exposure. The effectiveness depends on the UVGI dosage, exposure time and humidity levels that should be calculated by a qualified professional.
A promising method of air cleaning that is gaining recognition is air ionization because it affects contaminants in the air as well as on surfaces. It can be used anywhere inside the building without negative side effects. Bipolar ionization is the process of flooding the air with negatively and positively charged ions. The charged ions react with microbes, viruses and other contaminants inactivating them. It also causes smaller particles to coalesce into larger particles allowing them to be captured by static filters. The benefits of using ionization are that it doesn’t have a negative effect on occupants and can be used at any selected location that will be best for the application. Another advantage to ionization is that humidity levels have no bearing on its effectiveness.
Albireo Energy has the expertise and experience to analyze and evaluate the HVAC system to determine the best strategy for the building manager to deploy. With careful evaluation, Albireo will design a strategy that includes multiple technologies while supporting the budget and goals for each unique system and space usage. Since new information is coming out daily, Albireo is staying on top of the best settings and targets to maintain the highest effectiveness possible against the COVID-19 virus and other contaminants.
Going forward there will need to be changes to the maintenance practices of the HVAC equipment and components. Albireo is prepared to perform and advise on the best path forward. The first step should be an increase in HVAC equipment inspections, including the UV light systems for effectiveness, the filters, general cleanliness, and the entire air path.
Clean filters will be of the greatest importance and should be changed more often. Since the virus can remain viable on the surface of the filter, when changing filters, PPE will be required for personnel. Filters should be considered contaminated and treated as such. When removed, they should be immediately bagged and disposed of in the appropriate manner for contaminants.
It is common to use a pressure washer to clean a system, but the high pressure could spray the virus into the air. Alternate methods should be considered such as low-pressure washing or hand cleaning.
While we briefly touched on some general practices for improving the HVAC systems role in the battle against COVID-19, Albireo is ready to assist facility managers in developing customized strategies around enhancing existing air quality technologies, adjusting settings, and outputs with the latest recommendations and revising maintenance practices and schedules.