As people begin to return to offices, building owners and managers confront the challenge of both creating healthy work environments and convincing tenants and occupants that proactive measures are being taken to protect their health. Evidence suggests the airborne spread of COVID-19, putting HVAC systems at the forefront of limiting the spread of disease.
What options are available to minimize the risk and to show your tenants that proactive measures are being taken to protect them? Managers face multiple options for upgrading their HVAC system, ranging from simple operational changes to major modifications requiring significant capital outlays.
A variety of approaches can be considered, based on guidance from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), including the following options.
Increase Outdoor Airflow
According to ASHRAE, increasing the amount of fresh outside air in your facility can lower the concentration of indoor air contaminants, including viruses, thereby lowering the risk of transmission. Many ventilation systems have traditionally used 20 percent outside air and 80 percent recirculated air. By contrast, many hospitals have used 100 percent fresh air.
Modifying your HVAC system to increase the percentage of fresh air can be done with minimal modifications and without additional purchases. In fact, many managers have already modified their systems.
However, the EPA warns that increased airflow is not sufficient to protect occupants from COVID-19. Furthermore, your HVAC system might be unable to handle 100 percent outside air. This option should not be viewed as a standalone solution; rather it should be combined with other options to enhance the health of your facility.
Upgrade Air Filters to MERV-13
Mechanical air filters remove particles from the air. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) uses the Minimum Efficiency Reporting Value, or MERV, standard to measure how effectively air filters remove particles, with higher numbers removing a larger number of smaller particles. Many, but not all, commercial HVAC systems can use them in place of existing air filters, with minimal additional energy or maintenance costs.
MERV-13 filters can combine with increased outdoor airflow to remove approximately 60 percent of 0.3-micron particles—the size of the COVID-19 virus. However, this comparatively low efficiency may be insufficient for your facility or fail to reassure tenants and occupants.
Upgrade Air Filters to MERV-16
MERV-16 air filters can remove even more viral particles (approximately 90 percent) at minimal incremental unit, energy and maintenance cost compared to MERV-13 filters. However, many HVAC systems may be unable to handle these filters. In addition, many systems already use MERV-13 filters, and replacing all filters may represent a significant investment of capital and labor for consumables that must be replaced regularly.
Check with your engineer to confirm if your system can handle this level of filtration and whether upgrading to a rigid cell filter can improve on overall indoor air quality.
Install UVC Systems in Air Handlers
Ultraviolet (UV or UVC) energy can inactivate disease-causing viruses, bacteria and fungi, and has been used to disinfect drinking water for decades. Many HVAC systems can be modified with UVC systems to kill up to 99 percent of viruses.
Tenants will not experience an impact on the airflow to their space, and they would be reassured by your proactive measures to protect their employees. However, these systems have significant capital, maintenance and energy costs, which might be prohibitive for many facilities.
Install a Bipolar Ionization System
Bipolar ionization creates positive and negative ions in the air. These ions create radicals on the surface of microbes, removing hydrogen and killing the microbe. The technology has been around for decades with proven high efficiency, but still lacks documentation of its efficiency when used in HVAC systems.
The ASHRAE, the Centers for Disease Control (CDC) and the U.S. Environmental Protection Agency (EPA) have acknowledged the potential of bipolar ionization, but they have not confirmed its effectiveness against COVID-19. Bipolar ionization systems still have additional capital and operating expenses, although significantly less than UVC systems, and they require proper installation to work effectively.
Which Option Is Right for You?
There is no one-size-fits-all solution. Selecting the right option for your facility depends upon its unique conditions, including its location, age and size. In addition, you must consider the HVAC system’s capabilities and limitations, because some systems might prevent the implementation of certain technological solutions. Furthermore, you might have capital or operational constraints restricting your options.
Building owners and managers should work with their engineering departments to identify the available options and evaluate them based upon objective criteria, understanding the costs and benefits of each as it applies to their building’s specific conditions. The options included above can serve as a starting point to evaluate the best solution for your facilities.
Able Services supports the recommendations shared in this blog, but notes that individual buildings require different solutions and the best option is to discuss upgrades with your building engineer.