The Foundation of COVID Mitigation Strategy Should be Mask Effectiveness 

Cummins is Making Masks with Uniquely Charged Meltblowns

BelEmsa  Producing 200 Million Masks per Month

H+V will Expand to 100 Million Mask Equivalents per Year

Lincoln, RI Buys Air Purifiers for Schools

Outdoor Air Reliance in NY is not a Great Winter Solution

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The Foundation of COVID Mitigation Strategy Should be Mask Effectiveness 

The strategy to defeat COVID should be based on use of highly efficient masks. All other options are more costly and less effective with the exception of total lockdowns. The virus spread with near normal activity but correct use of CATER 95 masks will be less than if there is a partial lockdown and use of ASTM 20 masks. 

The strategy which treats all masks as equal makes little sense. It is the equivalent of saying that whether a room has one occupant or 100 the risks are the same. In fact if all occupants are wearing CATER 95 masks the risk is equivalent to the room with one unmasked occupant. If every one of the 100 people is wearing  an ASTM 20 mask you have the equivalent of 71 unmasked people. This 70 to 1 ratio means that mask efficiency should be the cornerstone of COVID policy.

The following examples were calculated based on available information for various types of masks. The net efficiency equals the media efficiency less leaks.

The leaks are derived from fit testing and cannot be precisely quantified in a given case. One comprehensive set of tests with a CATER 95 masks showed leakage between 2 and 8 %. The actual leakage depends on the face, the mask dimensions and construction. Where suppliers can show a range of mask sizes and extensive testing under various motion conditions a low leakage level can be assessed. In the case of the upcoming ASTM standards the leakage declaration is left to the manufacturer with little assurance that low leakage will be achieved in any specific situation.

Masks are worn by the both the transmitter and the recipient. So the total virus inhaled becomes a function of the removal in the two sets of masks.

 

The CATER 95 mask is therefore 71 times more effective at preventing virus inhalation than is an ASTM 20 mask. Granted that fitness and other variables are not precisely quantified but this is a reasonable comparison.

Another approach is to compare combined efficiency.

 

If the decision is made on a basis of comparative efficiency it is easy to argue that a less efficient mask is better than nothing. At least an ASTM 20 will remove 29% of the virus if worn by all.  But when you consider that it allows 71 times as much virus to penetrate as does a CATER 95 mask this is a powerful metric and one that can be used in a total plan which includes social distancing, HVAC, and lockdowns.

The selection of more efficient masks can be viewed from the perspective of resumption of more normal behavior.

Rigorous Social distancing including prevention of large gatherings could have an effect of reducing virus inhalation by 40%.  If partial lockdown is combined with ASTM 20 masks a total reduction of 79% might be achieved. It could be argued that if everyone wore CATER 95 mask you could eliminate most social distancing. In the case of bars fan filter units and directional air flow would be needed because of the need to remove masks while drinking or eating.

The value of CATER 95 masks is even greater compared to alternatives when you consider that air pollution, wildfires and other air contaminants are equally important. Hypothetically let’s assume a total load which is 200% of the COVID. So the COVID load could equal 50% of the contamination (100), colds and other virus related infections are 10% (20) and air pollutants and other air contaminants are 40% (80).  The graph then reflects a total contaminant load of 200

It is clear that the benefit of CATER 95 masks is far superior to the alternatives when all pollutants are considered. Social distancing does not reduce the amount of air pollutants inhaled.

Mask efficiency should be the basis of all the social distancing, lockdowns, school, bar and restaurant openings. If everyone wears a highly efficient mask there will be the ability to return to near normal activities while reducing the COVID spread.

Ignoring mask efficiency is as illogical as saying social distancing of one foot or one mile should be treated equally. The mask protection has been proven in every pandemic. Doctors were kept safe from EBOLA by wearing masks and taking other protections. The  highly efficient masks provided the 99 % protection but other PPE assured that the protection was 99.9999%.

It is recommended that we immediately change our strategy and consider mask effectiveness as the foundation of any program.


Cummins is Making Masks with Uniquely Charged Meltblowns

Cummins is making material for millions of face masks out of its Cookeville, TN, filtration plant — thanks to a partnership with the U.S. Department of Energy’s Oak Ridge National Laboratory nearby.

“Because of our expertise in the automotive filtration industry, we believed we could adapt to supply the filter media used in the face masks worn by healthcare providers, which are also in high demand across the nation,” Christopher Holm, director of filter media technology and IP at Cummins, said in a news release posted yesterday.

Oak Ridge’s Carbon Fiber Technology Facility meanwhile worked with Peter Tsai, the inventor of N95 filter media, to develop a novel in-line charging device that could be placed on the precursor production line to electrostatically charge melt-blown material made of polypropylene or PP. Electrostatically charging the material with millions of microfibers layered on top of each other creates a filter material able to remove more than 95% of submicron particles and viruses such as the one that causes COVID-19.

“We reached our target goal in only a few weeks on pilot scale melt blowing capability at the CFTF and had the capability to produce filter media for 9,000 masks per hour when we connected with Cummins for potential technology transfer and scale up,” said Merlin Theodore, director of the CFTF at Oak Ridge. “Cummins was an ideal partner to scale what we had accomplished and helped us produce material that passed all required testing for filter media.”

ORNL’s research team designed and manufactured a custom electrostatic charging device for Cummins, assisting in the installation of the device on the company’s Cookeville facility production line.

“Their research has made it possible to be where we are today,” Holm said. “We can manufacture material that has passed all the required testing for N95 filter media.”

Two months ago, Cummins had never produced filter media for face masks. Today, it’s already shipped material to multiple customers across the country for the production of millions of masks.

BelEmsa Producing 200 Million Masks per Month

BelEmsa, one of the leading manufacturers of disposable hygienic products, has increased mask production to 200 million pieces per month in Europe, according to Aleksandr Kolesnov, the first deputy director of BelEmsa in an article in Nonwovens Industry.

In the fight against the novel coronavirus, medical masks are a vital item for healthcare workers on the frontline. Kolesnov states, “We are fully aware that access to PPE is challenging and we must secure the production of such an important item to encourage business organizations and public health through the recovery period.”

Detailed research on face masks have been conducted by the BelEmsa R&D project team since the beginning of the Covid-19 outbreak, Kolesnov adds. “We were aware that performance and comfort requirements must be offered under hygienic conditions due to public needs. We applied extensive know-how accumulated through our experience and created soft ear loop masks for perfect fit and comfortable use. Meanwhile, BelEmsa worked closely with EC accredited laboratories and German Federal Institute for Drugs and Medical Devices (BfArM) for manufacturing facilities at European standards.

"We risk significant amount of funds and invested millions in machinery, raw materials, hundreds of new employees and factory space to manufacture an item projected to have a short-lived demand. However, contributing to society has become one of our key priorities under the current circumstances,” he continues.

According to Kolesnov, BelEmsa has never experienced challenges in nonwoven materials, logistics and other key equipment thanks to its long standing experience and reputation in the hygiene industry. He adds, “We have always been a reliable partner to the governments and healthcare institutions to ensure high-quality medical products."

Kolesnov ends, “I’m proud of the fantastic efforts of our operational team who took our business out of China and brought to home. BelEmsa become the first company producing what it says is a unique comfortable ear loop mask in Europe and offering this innovative item with the Senso Med brand since June.”

 

H+V will Expand to 100 Million Mask Equivalents per Year

The Department of Defense (DOD), in coordination with the Department of Health and Human Services (HHS), has awarded a $2.5 million contract to nonwovens manufacturer Hollingsworth & Vose, to increase domestic production capability of filter media.

This industrial base expansion effort will allow Hollingsworth & Vose to increase production capacity to 100 million mask equivalents per year in Floyd, VA by October 2021, to support the production of filter media.

The DOD’s Defense Assisted Acquisition Cell led this effort in coordination with the Department of the Air Force’s Acquisition COVID-19 Task Force. This effort, funded through the HHS Coronavirus Aid, Relief and Economic Security (CARES) Act, supports domestic industrial base expansion for critical medical resources.

 

Lincoln, RI Buys Air Purifiers for Schools

All told, Lincoln Public Schools have spent roughly $1.2 million in unbudgeted funds responding to the COVID-19 pandemic.

Lincoln schools received four separate grants to assist with safely reopening in the COVID environment.

The first source was the Coronavirus Aid, Relief and Economic Security (CARES) Act – money specifically allocated to elementary and secondary schools for a wide range of activities, including the prevention, preparation for and response to the coronavirus.

Gov. Gina Raimondo awarded Lincoln with $472,779 to help fill a gap in state aid to education. Essentially, McNamee said the state shorted Lincoln in education aid this year but replaced the shortfall with CARES Act Elementary and Secondary School Emergency Relief funds.

Secondly, the state of Rhode Island was provided with roughly $1.25 billion in federal coronavirus relief funds under the CARES Act. Of that number, Raimondo allocated $50 million for the schools, with Lincoln receiving $570,908.

Lincoln spent an additional $64,234, provided by the Council on Elementary and Secondary Education, to purchase portable air filtration units and make improvements to all of the schools’ existing air filtration and ventilation systems.

In total, Lincoln schools received $1,159,916 in COVID relief.

 

Outdoor Air Reliance in NY is not a Great Winter Solution

My feet are starting to freeze,” a Brooklyn public-school teacher tweeted on December 9, when she had two classroom windows open despite the temperature outdoors dropping to 31 degrees. Despite the weather getting colder, she said teachers in her building have been told to keep the windows open indefinitely. It’s the same in schools across the city, where scores of NYC elementary teachers and students are bundled up in frigid classrooms to prevent the spread of the coronavirus.

Is this the best that New York City schools can offer? Until the city upgrades hundreds of New York City school buildings, the short answer is yes. Ventilation systems in the buildings built in the early 1900s “basically rely entirely on open windows, like the whole one wall of a classroom is just all windows,” said Edward Olmsted, an industrial hygienist, whose job it is to make sure that an indoor space has good air quality with no mold or other contaminants. Olmsted serves as a consultant for the United Federation of Teachers (UFT) and has been working on fixing school ventilation issues since the summer. A lot of these prewar school buildings built during the Spanish flu pandemic were designed to keep airborne illnesses at bay with steam radiators overheating rooms and the windows always open — but a century later, that doesn’t always work in practice. The city’s Department of Education also issued new guidance that when the room temperatures are uncomfortably cold, custodians should raise boiler settings and preheat the building — but this still leaves teachers and students shivering in class.

Newer school buildings have better ventilations systems, but the problem is that schools — old or new — now need the kinds of systems found in hospitals. “Nobody builds a regular building that way, so suddenly everybody is being asked to upgrade their ventilation systems, to really perform like it would in a hospital,” Olmsted said. “[But] you can’t just easily make a few changes, turn a few screws, or change a couple pieces or parts, and suddenly it’s a hospital system; it can’t be done.” A typical fan system’s filter is rated MERV 8, while hospitals usually have MERV 15 or 16 filters (the higher the MERV numbers, the smaller the dust particles it can filter out). Experts are now recommending MERV 13 filters, which remove about 90 percent of the aerosol that could carry infectious virus particles.

The DOE is now installing thousands of MERV 13 filters, prioritizing buildings with a central HVAC system or no windows. The agency is also installing 30,000 High Efficiency Particulate Air or HEPA purifier units in classrooms, which capture over 99 percent of particles in the air. Once these purifiers are installed, classroom windows don’t need to remain open, said a DOE spokesperson. The agency expects to deliver an additional 30,000 purifiers by January, according to an internal memo sent to DOE custodians. Once the 60,000 units are installed, this should cover most of the classrooms that need it, said the department.

But some parents are skeptical. “I am not confident that those air purifiers will be enough to circulate the air. I am not confident that if they do show up, they will be working,” Naomi Peña, director of the Community Education Council for District 1 and public-school mom, told me. She may have a point. According to the EPA, both filters and air purifiers are effective at filtering out coronavirus particles, but by themselves are not enough — they should be used in conjunction with mask-wearing, social distancing, and other common safety practices — like opening windows.

Though Peña’s children are studying remotely, they see their classmates at the school via Zoom. Her 11-year old son was puzzled to see one of his friends wearing a coat inside the classroom and asked her, “Why can’t he just come over to our house so he can be warm?” And he has a point, Peña says. “When it’s cold and you’re wearing gloves and a coat … How can you possibly learn?”

 

Doug Engel analyzed the changes in thinking relative to HVAC strategy to fight Covid in the December issue of Facility Executive.  As he points out ASHRAE’s Epidemic Task Force (ETF) has been at the forefront of providing actionable recommendations for mitigating the airborne transmission of COVID-19 in buildings. Initially ASHRAE recommended maximizing the outside air intake of mechanical systems and minimizing recirculation. It encouraged opening windows and increasing ventilation with fans. High-efficiency filtration was an additional key consideration, with guidance urging an upgrade to a minimum of MERV 13 filters for central HVAC systems. In the absence of central systems, or if they could not accommodate high-efficiency filtration, then it was recommended that “demonstrated safe and effective” in-room air cleaners be employed.

Since the Spring, however, several developments have contributed to a shift in thinking regarding early guidance. Dr. Bill Bahnfleth, Professor of Architectural Engineering at Penn State and Chair of the ASHRAE ETF, recently shared in a widely attended October webinar that early guidance from the ETF in April was driven by perceived risk and possible effectiveness. He referred to the initial recommendations as “conservative” and that they “did not factor in cost and operational impacts.” Also, he outlined key factors that have prompted a re-evaluation of the guidance and previewed new core recommendations that will be forthcoming from ASHRAE.

KEY FACTORS

Risk estimations. Increased use of tools that estimate airborne transmission offers a quantitative prediction of risk. There are a number of estimators, but the most widely used is The COVID Airborne Transmission Estimator,² created by Professor Jimenez of the CIRES (Cooperative Institute for Research in Environmental Sciences) at CU Boulder. This estimator, and others, rely on the Wells-Riley model, an accepted industry standard approach for assessing the risk of airborne infection in buildings. The Wells-Riley model takes into account factors such as the size of the building, number of occupants, number of infected people, and the amount of time infected individuals spend in the building.

Equivalent filtration effectiveness. In numerous presentations, Prof. Bahnfleth has emphasized high efficiency filtration, and reiterated that guidance in the recent webinar, “We have evidence that better filtration is as effective as ventilation and lower cost.” He referenced this analysis conducted by Prof. Brent Stephens and Parham Azimi for the Built Environment Research Group at Illinois Tech that shows the relative cost of outside air ventilation in different U.S. locations versus filtration.

The graph below shows that the most cost-effective and efficient approach to reducing infection rates is using a MERV 13 filter, and that outdoor air increases cost at least four times as much to achieve the same benefit.

Energy, economic, and operational considerations. Prof. Bahnfleth also spoke to the fact that ASHRAE has taken a closer look at the energy, economic, and operational impacts of HVAC strategies for COVID mitigation, particularly its guidance on ventilation. As many in the industry have pointed out, maximizing outside air ventilation is expensive and energy intensive—the often-cited “energy penalty” associated with conditioning increased amounts of outdoor air. It is even more of a concern during the energy-intensive winter months. Additionally, there are other environmental considerations that need to be factored in: PM 2.5 from pollution and the smoke from wildfires plaguing the western U.S. are two significant concerns. Relative humidity also plays a role, as research emphasizes³ the need to keep relative humidity between 40-60% to both reduce the transmission risk of the virus and to support the respiratory health of building occupants.

Equivalent outdoor air changes. The Air Change Rate, e.g., the rate at which the air in a specific space is replaced with clean air is typically expressed in Air Changes per Hour (ACH). ACH has been assumed to refer to outdoor air exchanges. However, with limitations of HVAC systems, the superiority of highly filtered air given environmental issues such as pollution/smoke, and new consideration of energy impacts, experts are now promoting “equivalent outdoor air” changes. These equivalencies can be achieved by deploying high-efficiency filtration, in-room HEPA filters, as well as innovative approaches such as sorbent-based filtration.

A helpful tool for school facility managers is the Harvard-CU Boulder Portable Air Cleaner Calculator for Schools. It simplifies decision making around deploying in-room air cleaners and can also be adapted for office and retail settings.  Experts from the Harvard T.H. Chan School for Public Health recommend 5 ACH per hour, but provide ranges, with 4-5 ACH as Good, 5-6 as Excellent and 6 ACH as Ideal.

SIMPLIFYING GUIDANCE

The ASHRAE ETF will likely share new core recommendations before the end of 2020, with the goal of updating guidance to reflect the above factors, and to simplify recommendations across its various subcommittees. From the preview Prof. Bahnfleth offered,  the update will likely emphasize:

·         Use of minimum outdoor air as required by Standard 62.1

·         Employ high-efficiency MERV 13 filtration and/or stand-alone HEPA air cleaners for recirculated air

·         Achieve equivalent air changes using a combination of outdoor air, filtration, and air cleaners

·         HVAC controls that achieve exposure reduction goals while minimizing associated energy penalties

ENERGY, ECONOMIC, AND CARBON

With the renewed focus on cost from increased energy consumption, there is a need for a tool to help calculate costs of various ventilation and filtration approaches. While risk is the paramount consideration, models providing a more complete picture allows for more informed decision-making

Doug says  his company, enVerid, has released the enVerid COVID-19 Energy Estimator, an open-source, vetted tool building upon Prof. Jimenez’s COVID Airborne Transmission Estimator. This tool performs predictive calculations for energy expenditures. In addition to enabling a comparison of energy use among HVAC strategies, it offers insight into anticipated carbon emissions associated with each approach. For example, building engineers evaluating a 50,000 square foot office in Boston with 250 occupants and design supply air of 50,000 CFM can compare two approaches—switching to 100% outside air (OA) or upgrading to MERV 13 high-efficiency filters and bringing in minimum OA as per ASHRAE’s Indoor Air Quality Procedure (IAQP).

As shown in the table below, the Energy Estimator shows both strategies will deliver over five effective air changes per hour (ACH), considered excellent by the Harvard School of Public Health, but the 100% OA strategy will cost $85,827 per year compared to $12,261 per year for the MERV13/IAQP approach. When reviewing the carbon impacts of the two approaches, the Energy Estimator shows the 100% OA strategy will generate 325 metric tons of CO2 per year versus 28 metric tons for the MERV 13/IAQP approach.

This graph shows findings that the most cost-effective and efficient approach to reducing infection rates is using a MERV 13 filter, and that outdoor air increases cost at least four times as much to achieve the same benefit. (Graph: Provided by enVerid)

AN UNDERUTILIZED APPROACH

Given the current focus on IAQ, it makes sense that building management and engineers take a close look at ASHRAE’s Indoor Air Quality Procedure. In its Standard 62.1, ASHRAE defines two procedures for mechanical ventilation: the Ventilation Rate Procedure (VRP) and the Indoor Air Quality Procedure (IAQP). VRP defines ventilation requirements based on space size and occupancy without factoring in the efficiency benefits afforded by air cleaning technologies. Alternatively, IAQP is a performance-based ventilation approach that achieves the same results with less outside air, and therefore a reduction in energy expenses, particularly when employing air scrubbing technology.

Designing HVAC systems using IAQP combined with sorbent-based air cleaning and high-efficiency filtration significantly reduces first and operating costs without increasing the risk of airborne transmission of viruses. When put to the test utilizing the Wells-Riley equation described above, it was found that same relative risk of airborne transmission can be achieved with improved filtration and reduced ventilation when ASHRAE’s 62.1 IAQP is used with sorbent-based air cleaning technology. Using this approach, savings from reduced ventilation can more than offset the cost of increasing filtration (see graph below).

Modeling the cost-benefit of filtration and ventilation to reduce the risk of infection by SARS-CoV-2 in a 100,000 square foot office building in New York City. Comparison of VRP (blue line) and IAQP + sorbent-based air cleaning (green). Life cycle cost includes first cost and20 years of operational cost. (Graph: Provided by enVerid)

There are other important IAQ considerations that arise from utilizing high-efficiency filtration and air scrubbing technology:

·         ASHRAE’s contaminants of concern, including formaldehyde, are scrubbed out of the air.

·         By using less outside air, it is easier to maintain relative humidity (RH) in the 40-60% range which experts posit inhibits the spread of viruses. In winter we are concerned with the dry air and introducing more outside air would likely cause the RH figure to drop below 40%.

·         Air scrubbing reduces fine particulates (PM 2.5) from pollution or smoke, while ventilation increases them. Particulates inflame the lungs, making catching the virus potentially more likely and its impacts more severe.

·         Certain air scrubbing technologies can also reduce CO2 levels. Research from Harvard points to the degradation of cognitive function when CO2 levels rise in indoor air, an issue of particular concern in schools and offices.

·         Ozone exists in outside air and is known to damage the lungs and exacerbate chronic respiratory conditions.

Building engineers evaluated a 50,000 square foot office in Boston with 250 occupants and design supply air of 50,000 CFM using the enVerid COVID-19 Energy Estimator. This open-source, vetted tool performs predictive calculations for energy expenditures. (Chart: Provided by enVerid)

COVID-19 has thrust IAQ issues into the spotlight. Controlling airborne transmission of the virus is the most pressing task, yet there are a host of IAQ considerations that need to be addressed. Facilities need to employ effective and energy efficient solutions to respond to the pandemic today, and to future proof for the next crisis. Additionally, for many, addressing IAQ must also be managed within the context of lowering a building’s carbon footprint. This is a tall order, but all within reach.

 
Doug Engel is SVP quality products including localized high-, sales and marketing for enVerid Systems, a Westwood-MA provider of commercial indoor air filtration devices and the award-winning HVAC Load Reduction® (HLR®) module.

The complete article is found at https://facilityexecutive.com/2020/12/indoor-air-quality-and-the-pandemic/