The high transmission rate of coronavirus (COVID-19) has prompted the Center for Disease Control and Prevention (CDC) to recommend that everyone in the U.S. wear nonsurgical face masks when going out in public because people infected with the virus may emit aerosols (particulates or microorganisms) when they talk or breathe. These infectious viral particles can float or drift around in the air. This has raised concerns about indoor air quality and the potential for airborne transmission through an HVAC system. Therefore, in many industries from healthcare to manufacturing, facilities managers are exploring whether their buildings are equipped to reduce the threat of infection.
To help our customers gain a better understanding of HVAC filtration as it relates to COVID-19 and other airborne transmissions, our filtration experts have compiled a list of frequently asked questions.
The spread of the novel coronavirus (COVID-19) mainly occurs through respiratory droplet transfer from person-to-person within a close range of about six feet according to the CDC. The virus can also be transmitted on objects and surfaces that a contagious person may cough on, sneeze on, or touch. Pathogens can also travel on dust and dirt particles as those particles move through the air. Therefore, the potential for airborne transmission through an HVAC system exists.
HVAC filters can reduce but not eliminate the threat of infection. The coronavirus and the particulate it travels on is very small in size, and can range from submicron (less than 1.0 micron in size) and larger. High-efficiency filters on the market today can trap particulate sizes that are likely to remain in the air. Selecting the right filter can reduce risk while improving the quality of indoor air.
When selecting a filter to combat the threat of airborne transmission, you have to consider the level of filtration wanted versus effective system operation. HEPA and ULPA filters provide the highest rate of effectiveness, but many HVAC systems would not be able to use them without extensive retrofit. We suggest a minimum efficiency reporting value (MERV) rating of 14 to 16 for most HVAC systems. Sub-HEPA, HEPA and ULPA filters can be used where needed and for systems which can use them effectively. Where systems cannot accommodate higher efficiency filters, MERV 13 filters can provide significant improvement in efficiency and can be easily installed in the majority of HVAC and residential units. There are several filters in Parker’s line that can be used as part of an overall comprehensive strategy. We can assist you to determine which filter or filters would be the best choice for your application.
Our best recommendation is to visit the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) website. ASHRAE has developed proactive guidance for building industry professionals to help address the ongoing concerns of the coronavirus (COVID-19) outbreak. There you can access the latest response resources from ASHRAE and other leading organizations with respect to the operation and maintenance of HVAC systems.
MERV stands for “minimum efficiency reporting value.” It’s a rating system that was developed by the American Society of Heating, Refrigeration and Air Conditioning Engineers (or ASHRAE). MERV values range from 1 to 16. The higher the MERV value, the more efficient the filter will be at trapping airborne particles. When selecting a filter to combat the threat of airborne transmission, we suggest a MERV rating of 13 to 16.
Yes, we recommend Puro-Green or DP-Green MERV 13 filters for use in residential applications. Our MERV 13 high-efficiency rigid filters can be used in residential HVAC systems to achieve better indoor air quality without the need to retrofit systems.
Today's historic global pandemic has raised awareness of the importance of maintaining healthy breathable air inside buildings. Parker is dedicated to providing honest and transparent information about our filtration products to help customers decide which technologies offer the highest chances of trapping virulent pathogens before they enter a building or circulate to different rooms. Parker’s products can reduce airborne particulate in a controlled environment. They would not eliminate the risk of exposure to airborne viruses but can be part of a comprehensive plan to help reduce that risk.
After more than a century of experience serving our customers, Parker is often called to the table for the collaborations that help to solve the most complex engineering challenges. We help them bring their ideas to light. We are a trusted partner, working alongside our customers to enable technology breakthroughs that change the world for the better.
This post was contributed by the HVAC Filtration Team.