Maintaining HVAC to Address COVID-19

You might find yourself asking, “What should we be doing with our heating and cooling systems regarding COVID-19?”

The American Society for Heating, Refrigerating and Air-Conditioning Engineers came out with guidance related to COVID-19 last month. Its recommendations revolved around the following:

• Supplying clean air to susceptible occupants
• Containing contaminated air and/or exhausting it outdoors
• Diluting the air in the space with clean and filtered outdoor air
• Cleaning the air within a room

With these topics from ASHRAE in mind, here are some steps you can take to be proactive about COVID-19.

Outside Air

Due to the newness of this virus, there are no filter or building system features that have been proven to remove COVID-19 from the air so it is our recommendation to use outdoor air to dilute indoor contaminants.

Some HVAC systems control the amount of outdoor air flow based on the demand. For example, your gymnasium HVAC system may bring in less outdoor air when it is at a lower occupancy. This energy-savings measure makes sense in a typical situation. However, the spread of coronavirus is not a typical situation. Consider asking your HVAC technician to stop the demand control ventilation for while COVID-19 continues to be a concern. Setting your system to increase outside airflow will maximize the amount of clean air in the building.

Another option would be to “purge” the building by bringing in more outside airflow than required. The best time for this to occur would be during unoccupied hours, as your HVAC system is likely not designed to maintain temperature and humidity set points with this amount of outside air. Make sure you talk to a building system or mechanical engineering professional before doing so.

Ultraviolet Lights

If your air handling units have ultraviolet lamps, make sure they are turned on and operational. If your system doesn’t have these, now might be a good time to think about upgrading your system with this feature, as UV lights have added benefit all year round, not just in times of a pandemic. According to the EPA, HVAC systems with ultraviolet germicidal irradiation cleaners may help destroy pollutants such as viruses and bacteria.

Maintenance Procedures

While new filters won’t stop the spread of infectious disease, dirty or ineffective filters can exacerbate underlying respiratory issues that make occupants more vulnerable to COVID-19. We recommend focusing your near-term maintenance procedures in three key areas:

Replace air handling unit filters on a regular and consistent basis. If you haven’t changed your filters recently, now is the time to do it.

Look at increasing the Minimum Efficiency Rating Value (MERV) rating of your filters. The higher the rating, the more airborne particles you will capture.

Wipe down the inside of your air handling unit cabinets. When doing this, be careful with cleaning the coils. Using the wrong cleaning products or procedures can damage the coils and/or void your warranty. Consult the unit manufacturer for proper cleaning products and procedures.

Follow the Latest Guidance

There is no way to completely prevent the spread of COVID-19 in your homes and buildings but proper maintenance and building operation strategies will help. It is also important to reference the World Health Organization, the Center for Disease Control and other government agencies for the latest guidance on washing your hands, cleaning surfaces and staying home when sick.

You might find yourself asking, “What should we be doing with our heating and cooling systems regarding COVID-19?”

The American Society for Heating, Refrigerating and Air-Conditioning Engineers came out with guidance related to COVID-19 last month. Its recommendations revolved around the following:

Supplying clean air to susceptible occupants

Containing contaminated air and/or exhausting it outdoors

Diluting the air in the space with clean and filtered outdoor air

Cleaning the air within a room

With these topics from ASHRAE in mind, here are some steps you can take to be proactive about COVID-19.

Outside Air

Due to the newness of this virus, there are no filter or building system features that have been proven to remove COVID-19 from the air so it is our recommendation to use outdoor air to dilute indoor contaminants.

Some HVAC systems control the amount of outdoor air flow based on the demand. For example, your gymnasium HVAC system may bring in less outdoor air when it is at a lower occupancy. This energy-savings measure makes sense in a typical situation. However, the spread of the coronavirus is not a typical situation. Consider asking your HVAC technician to stop the demand control ventilation for while COVID-19 continues to be a concern. Setting your system to increase outside airflow will maximize the amount of clean air in the building.

Another option would be to “purge” the building by bringing in more outside airflow than required. The best time for this to occur would be during unoccupied hours, as your HVAC system is likely not designed to maintain temperature and humidity setpoints with this amount of outside air. Make sure you talk to a building system or mechanical engineering professional before doing so.

Ultraviolet Lights

If your air handling units have ultraviolet lamps, make sure they are turned on and operational. If your system doesn’t have these, now might be a good time to think about upgrading your system with this feature, as UV lights have added benefit all year round, not just in times of a pandemic. According to the EPA, HVAC systems with ultraviolet germicidal irradiation cleaners may help destroy pollutants such as viruses and bacteria.

Maintenance Procedures

While new filters won’t stop the spread of infectious disease, dirty or ineffective filters can exacerbate underlying respiratory issues that make occupants more vulnerable to COVID-19. We recommend focusing your near-term maintenance procedures in three key areas:

Replace air handling unit filters on a regular and consistent basis. If you haven’t changed your filters recently, now is the time to do it.

Look at increasing the Minimum Efficiency Rating Value (MERV) rating of your filters. The higher the rating, the more airborne particles you will capture.

Wipe down the inside of your air handling unit cabinets. When doing this, be careful with cleaning the coils. Using the wrong cleaning products or procedures can damage the coils and/or void your warranty. Consult the unit manufacturer for proper cleaning products and procedures.

Follow the Latest Guidance

There is no way to completely prevent the spread of COVD-19 in your homes and buildings but proper maintenance and building operation strategies will help. It is also important to reference the World Health Organization, the Center for Disease Control and other government agencies for the latest guidance on washing your hands, cleaning surfaces and staying home when sick.