Coronavirus Technology Solutions
August 10, 2020
MERV 13 Can Become MERV 8 After Charge is Dissipated Higher Efficiency Filters Needed in Schools and Commercial Buildings Oklahoma Schools are Not Going to be Safe Penn State Upgrading to MERV 13 Boston University Upgrading to MERV 13 but there are Concerns about Mask Efficiency Filters and HVAC Webinar Slated for September 10 Ways to Improve Air Filtration Efficiency McIlvaine is Forecasting Large Market for Fan Filter Units Largest Growth will be in More Efficient Filters ______________________________________________________________________________ MERV 13 Can Become MERV 8 After Charge is Dissipated Camfil has released a new video explaining MERV-13 air filters, the importance of a MERV-A rating, and advice for publicly accessible facilities. Some manufacturers rely on an electrostatic charge to increase the efficiency of filters. As this charge dissipates over time, so does the filter’s efficiency. The ASHRAE 52.2 test standard includes an Appendix J to the standard which details a procedure to test the filters without the benefit of an electrostatic charge. The efficiency without this charge is referred to as a filter’s MERV-A value. A good way to select the proper filter is to remember that ‘A’ stands for ‘actual’ and a food plant should always select filters based on their MERV-A value, not simply their MERV. It may seem like a small difference, but it’s not,’” says , Patrick Lally, Food and Beverage Segment Manager for Camfil USA. “If your system has the capacity, Camfil air filtration experts recommend an air filter labeled as a MERV-15A or MERV-16A. A basic guideline would be the highest MERV-A that your infrastructure can handle,” says Greg Herman, Camfil’s National Accounts Segment Manager. What is the Difference Between MERV-13 and MERV-13A? Recommendations and mandates have recently been citing MERV-13 air filters as a starting point for reducing infection risks in publicly accessible buildings. In the filtration industry, efficiency refers to ASHRAE’s (The American Society of Heating, Refrigerating and Air-Conditioning Engineers) national testing standards, known as MERV, or Minimum Efficiency Reporting Value. Some manufacturers rely on an electrostatic charge that temporarily increases the MERV value of their air filters. As this charge dissipates over time, so does the air filter’s MERV value. Though it may seem like a small difference, it’s essential to know the air filter’s MERV-A value. “Many states and organizations are pushing MERV-13,” says Mark Davidson, Manager of Marketing and Technical Materials at Camfil USA, “and because they are not specifying MERV-13A, effectively speaking, many are actually getting only MERV-8 filtration.” When it comes to stopping the spread of infection, the higher the air filter efficiency, the better. COVID-19 & Respiratory Droplets and Droplet Nuclei in Commercial & Public Buildings Respiratory droplets and droplet nuclei are two categories of droplets based on size and are expelled when people cough, sneeze, talk or even breathe. Respiratory droplets are those greater than 5 microns in size. Masks and social distancing measures are designed to prevent us from inhaling these larger droplets from infected individuals, and sanitizing measures prevent us from picking them up off of surfaces once they settle nearby. Higher Efficiency Filters Needed in Schools and Commercial Buildings If one assumes that the capture of COVID on a percentage basis is equivalent to the MERV efficiency at 0.3 microns, the MERV 8 filters installed in most schools are removing only 10%. They may be capturing 75% of the 10 micron cough droplets but if these droplets evaporate then 90% of the virus in these droplets will pass through the filter. Children wearing masks will be generating small aerosols. So even a MERV 16 filter will remove only 70% of the virus. A vaccine vial in a pharmaceutical cleanroom is protected by a 99.999 % removal of any potential virus in the air. It would therefore be a priority to do better than 70% to protect children and teachers. As evident by Kowalski and Bahnfleth's data, the MERV rating has a significant effect across the full spectrum of particle mean diameter. Of particular interest here is for airborne microorganisms smaller than 0.3 micrometers, which includes the majority of viruses and smaller bacteria. Generally speaking, MERV 13-16 will filter over 80 percent of airborne microorganisms smaller than 0.3 micrometers. There are many qualifiers to this data, however; as noted by Kowalski and Bahnfleth:
Oklahoma Schools are Not Going to be Safe Plans to safely reopen Oklahoma schools are plentiful, but not much can be done to improve air quality in buildings. School officials must rely on existing equipment that is not designed to filter out coronavirus particles. Tulsa school district will spend $ 300,000 to bring in more outside air. Penn State Upgrading to MERV 13 Penn State has more than 2,000 buildings across all campuses, there are numerous other efforts underway to help prevent COVID-19 from spreading on campus. The University has purchased 6,000 hand sanitizer stations, with up to 3000 of them to be installed at University Park, 1200 being deployed to the campuses, and the remainders to be available for purchase by units. Hands-free faucets are being installed in some of the most high-traffic areas on campus, and Plexiglass sneeze guards, while limited in application, will also be installed where appropriate. The university is in the process of upgrading the air conditioning filters from ones with a Minimum Efficiency Reporting Value (MERV) 8 rating to ones with a MERV 13 rating. They also have changed the mechanical systems in many buildings on campuses to use more outside air, instead of recirculated inside air, to improve ventilation. Boston University Upgrading to MERV 13 but there are Concerns about Mask Efficiency BU Facilities Management and Operations Staff is working to improve mechanical heating, ventilation and air-conditioning systems in the 120 buildings on campus that have them. A report released July 28 states that improvements to these buildings include replacing current Minimum Efficiency Reporting Value 8 air filters, which capture larger particles such as dust and pollen, with MERV 13 filters that are able to capture smaller contaminants, including airborne viruses like SARS-CoV-2. For the other 198 buildings on campus without mechanical ventilation, BU spokesperson Colin Riley said that BU Facilities will be following U.S. Centers for Disease Control and Prevention guidelines by recommending windows and doors stay open when possible. BU Facilities is also recommending the installation of portable air purifiers in some spaces to increase air exchange rates. In a message that circulated within the College of Arts and Sciences and was forwarded to The Daily Free Press anonymously, one faculty member wrote the University’s attempt to manage the situation is unrealistic. “BU’s complex technical claims about sophisticated measures to fix HVAC classroom vulnerability do little to address concerns about the health and safety of the larger BU community,” the professor wrote. “Good luck opening the windows in our third floor seminar room or controlling circulation of air and of aerosols in CAS.” Nathan Phillips, a professor in BU’s Department of Earth and Environment, said that while BU’s planned ventilation improvements are a step in the right direction, he is still concerned about teaching indoors because of the University’s mask policy, which currently requires students and faculty to purchase their own masks that meet basic criteria. “The mask and ventilation issues are linked in a way that is not being fully understood right now,” Phillips said. “Where is the most important filter that no one’s talking about? I mean for airborne transmissions, it’s the masks that we have on our faces.” Phillips said he does not think BU’s mask criteria will cut it when it comes to safety from airborne transmission. “We’ve got to do better than just saying, ‘do-it-yourself face coverings,’” Phillips said, “because if students or faculty or instructors, whoever, show up in bandanas, that is not going to be sufficient based on what we know.” Filters and HVAC Webinar Slated for September 10 The next Filters and HVAC webinar is scheduled for 10:00 AM CDT September 10, 2020. To register Click here This webinar will continue the analysis created in previous webinars. This webinar will be a high level discussion and debate relative to the issues affecting filter or treatment type, efficiency, air quantity, and direction. It will expand on the previous webinars and interviews which you can see below. It will also reference the articles in the Alerts. Even if you are not a subscriber you can see the titles Search All Alerts by Keyword. We just added to the issues which will be discussed along with any others volunteered by participants. Here is the expanded list of air filter issues to be discussed on September 10.
Ways to Improve Air Filtration Efficiency There is a need for lower pressure drop media with higher efficiencies to battle COVID. Here are articles in the Alert from July 1 until August 7.
Mcilvaine is Forecasting Large Market for Fan Filter Units Room air purifiers, fan filter units, and laminar flow systems will be critical to preventing the spread of COVID. There is already a market for small air purifiers but growth in larger units will be the trend in the future. There will be high growth for fan-filter units which will be a better solution than partitions. The best solution is controlled laminar air flow systems with HEPA filtered air. They will find increasing use in nursing homes, meat processors and other applications in addition to their present use in cleanrooms and hospital operating suites. McIlvaine is forecasting each of these products for every application in each country. Largest Growth will be in More Efficient Filters Evidence is growing that highly efficient air filters will be needed to vanquish COVID. A proactive program by filter and media suppliers would greatly reduce COVID and generate very large revenues for suppliers of media and filters. MERV 8 filters will not remove more than 15% of the viruses. MERV 13 filters will remove about 40% of the viruses. The MERV 16 filter will remove close to 70%. The market for high efficiency MERV 17-20 filters with a proactive supplier program is forecast to grow 10 fold over the next 4 years. While the MERV 14-16 market will grow 7 fold according to the latest McIlvaine forecast. |