Community, Work, and School (2024)

By definition, a High Efficiency Particulate Air (HEPA) filter is at least 99.97% efficient at capturing particles 0.3 µm in size. This 0.3 µm particle approximates the most penetrating particle size (MPPS) through the filter. HEPA filters are even more efficient at capturing particles larger and smaller than the MPPS. Thus, HEPA filters are no less than 99.97% efficient at capturing human-generated viral particles associated with COVID-19.

Research shows that the particle size of SARS-CoV-2 is around 0.1 micrometer (µm). However, the virus generally does not travel through the air by itself. These viral particles are human-generated, so the virus is trapped in respiratory droplets and droplet nuclei (dried respiratory droplets) that are larger. Most of the respiratory droplets and particles exhaled during talking, singing, breathing, and coughing are less than 5 µm in size.

The excellent capture efficiency of HEPA filters comes at a cost, namely the significant pressure drop (and energy) required to move air through the HEPA filter. For this reason, most traditional HVAC systems are not able to use HEPA filters and are limited to the use of less-efficient filters. To account for the increased pressure requirements, HEPA filtration units often combine a HEPA filter with a dedicated fan system.

In-room HEPA air cleaners that combine a HEPA filter with a powered fan system are a preferred option for auxiliary air cleaning, especially in higher risk settings such as health clinics, vaccination, and medical testing locations, workout rooms, or public waiting areas. Other settings that could benefit from in-room HEPA filtration can be identified using typical risk assessment parameters, such as community incidence rates, facemask compliance expectations, and room occupant density. While these systems do not bring in outdoor dilution air, they are effective at cleaning air within spaces to reduce the concentration of airborne particulates, including SARS-CoV-2 viral particles. Thus, they give equivalent air exchanges without the need for conditioning outdoor air.

In choosing an in-room HEPA air cleaner, select a system that is appropriately sized for the area in which it will be installed. This determination is made based on the air flow through the unit, which is typically reported in cubic feet per minute (cfm). Many portable HEPA filtration units are assigned a Clean Air Delivery Rate (CADR) (SeeEPA’s Guide To Air Cleaners In The Home), which is noted on a label in the operator’s manual, on the shipping box, and/or on the filtration unit itself. The CADR is an established standard defined by the Association of Home Appliance Manufacturers (AHAM). Participating portable air cleaner manufacturers have their products certified by an independent laboratory, so the end user can be assured it performs according to the manufacturer’s claims. The CADR is generally reported in cfm for products sold in the United States. The paragraphs below describe how to select an appropriate air cleaner based on the size of the room in which it will be used. The procedure below should be followed whenever possible. If an air cleaner with the appropriate CADR number or higher is not available, select a unit with a lower CADR rating. The unit will still provide incrementally more air cleaning than having no air cleaner at all.

In a given room, the larger the CADR, the faster it will clean the room air. Three CADR numbers are given on the AHAM label, one each for smoke, dust, and pollen. The smoke particles are the smallest, so that CADR number applies best to viral particles related to COVID-19 and other viral respiratory diseases. The label also shows the largest room size (in square feet [ft2]) that the unit is appropriate for, assuming a standard ceiling height of up to 8 feet. If the ceiling height is taller, multiply the room size (ft2) by the ratio of the actual ceiling height (ft) divided by 8. For example, a 300 ft2room with an 11-foot ceiling will require a portable air cleaner labeled for a room size of at least 415 ft2(300 × [11/8] = 415).

The CADR program is designed to rate the performance of smaller room air cleaners typical for use in homes and offices. For larger air cleaners, and for smaller air cleaners whose manufacturers choose not to participate in the AHAM CADR program, select a HEPA unit based on the suggested room size (ft2) or the reported air flow rate (cfm) provided by the manufacturer. Consumers might take into consideration that these values often reflect ideal conditions which overestimate actual performance.

For air cleaners that provide a suggested room size, the adjustment for rooms taller than 8 feet is the same as presented above. For units that only provide an air flow rate, follow the “2/3 rule” to approximate a suggested room size. To apply this rule for a room up to 8 feet tall, choose an air cleaner with an air flow rate value (cfm) that is at least 2/3 of the floor area (ft2). For example, a standard 300 ft2room requires an air cleaner that provides at least 200 cfm of air flow (300 × [2/3] = 200). If the ceiling height is taller, do the same calculation and then multiply the result by the ratio of the actual ceiling height (ft) divided by 8. For example, the 300 ft2room described above, but with an 11-foot ceiling, requires an air cleaner that can provide at least 275 cfm of air flow (200 × [11/8] = 275).

While smaller HEPA fan systems tend to be stand-alone units, many larger units allow flexible ductwork to be attached to the air inlet and/or outlet (note that larger ducted units don’t fall under the “room air cleaner” description and may not have a CADR rating). Using ductwork and placing the HEPA system strategically in the space can help provide desired clean-to-less-clean airflow patterns where needed. Ducted HEPA systems can also be used to establish direct source capture interventions for patient treatment and /or testing scenarios (See CDC/NIOSH discussion on Ventilated Headboard). Depending on the size of the HEPA fan/filter units and how the facility in which they are being used is configured, multiple small in-room HEPA units deployed to high-risk areas may be more useful than one large HEPA unit serving a combined space.

Example 2.Given: The room described in Example 1 at the bottom of FAQ #2is now augmented with a portable HEPA air cleaning device with a smoke CADR of 120 cfm (Qhepa= 120 cfm). The added air movement within the room improves overall mixing, so assign k = 3.

Question: How much time is saved to achieve the same 99% reduction in airborne contaminants by adding the portable HEPA device to the room?

Solution: The addition of the HEPA filter device provides additional clean air to the room. Here, the clean volumetric air flow rate (Q) is: Q = Qe+ Qhepa= 80 cfm + 120 cfm = 200 cfm.

ACH = [Q x 60] / (room volume) = (200 cfm x 60) / (12’ x 10’ x 10’) = 12,000/1,200 = 10 ACH.

UsingTable B.1, the perfect mixing wait time based on 10 ACH and a 99% reduction of airborne particles is 28 minutes.

Using the mixing factor of 3, the estimated wait time for 99% reduction of airborne contaminants in the room is 3 x 28 = 84 minutes. Thus, the increased ACH and lower k value associated with the portable HEPA filtration unit reduced the wait time from the original 5 hours and 45 minutes to only 1 hour and 24 minutes,saving a total of 4 hours and 21 minutesbefore the room could be safely reoccupied.

Adding the portable HEPA unit increased the equivalent ventilation rate and improved room air mixing. This resulted in over a 75% reduction in time for the room to be cleared of potentially-infectious airborne particles.

Community, Work, and School (2024)

FAQs

What does cis mean in education? ›

The Council of International Schools (CIS) is a global membership community shaping the future of international education.

What is the purpose of community in schools? ›

Community schools emphasize positive relationships and interactions. Restorative discipline practices such as peer mediation, community service and post-conflict resolution help students learn from their mistakes and foster positive, healthy school climates where respect and compassion are core principles.

How can students make a difference at school and in the community? ›

100 Ways to Make a Difference in Your Community
  1. Help teach a younger child to read.
  2. Help cook and/or serve a meal at a homeless shelter.
  3. Gather clothing from your neighbors and donate it to a local shelter.
  4. Make "I Care" kits with combs, toothbrushes, shampoo, etc. ...
  5. Pack and hand out food at a local food bank.

What is the relationship between the teacher and the community? ›

Teacher-community relationship is the process by which the teacher and community interact or enter into mutual co-operation and team up to carry out some reciprocal services in other to give learners a sound and lifelong education (United Nations Education Social and Cultural Organization, 2012).

What is the cis program? ›

The Central Independent Study (CIS) program is an optional alternative instructional program for students whose needs may be best met through study outside of the regular classroom setting.

What is the meaning of cis children? ›

The prefix 'cis' means on the same side. So, someone who is cisgender has a gender that is on the same side as the sex they were assigned at birth. The prefix 'trans' means on the other side. So, someone who is transgender has a gender that is on a different side from the sex they were assigned at birth.

How does community affect education? ›

When schools, families, and community groups work together to support learning, children tend to do better in school, stay in school longer, and like school more. earn higher grades and test scores, and enroll in higher-level programs. be promoted, pass their classes, and earn credits. attend school regularly.

How do schools play the role as a community? ›

Schools do so much for a community. They provide a safe place for children to learn and grow each day, filled with educators who truly care. However, as a parent or educator, it's important to understand that many schools aren't being used to their full potential.

Why do students need community? ›

We find that students who engage in their communities as volunteers early on in their education are far ahead of their peers with respect to skills in problem solving, collaboration, time management, communication and leadership.

How can I make my school community better? ›

  1. Create parent and family advocacy groups.
  2. Expand volunteer opportunities.
  3. Offer home visits.
  4. Get information out in the community.
  5. Schedule regular student meetings.
  6. Host family workshops.

How can I positively impact my school community? ›

  1. Build strong relationships and a culture of trust. This starts with the adults. ...
  2. Implement rigorous and relevant classroom instruction. ...
  3. Support the whole child with heart. ...
  4. Create future-focused schools. ...
  5. Cultivate equitable classrooms. ...
  6. Personalize learning using data. ...
  7. Encourage empathy. ...
  8. Foster a growth mindset.
Feb 27, 2019

What are three ways you can be involved in your school or community? ›

Here are 10 ways to get involved today.
  • Mentor a student. ...
  • Volunteer at school events. ...
  • Join a parent organization. ...
  • Donate Supplies. ...
  • Attend school board meetings. ...
  • Follow local education reporters. ...
  • Volunteer for career day. ...
  • Share your story.

Why community involvement in schools is important? ›

Family and community engagement greatly increases the likelihood that students will learn and thrive. Students are more prepared for school, more likely to achieve, and more likely to graduate when they are supported by schools, families, and communities working together in a coordinated manner.

How do teachers make a difference in the community? ›

Teachers inspire students and parents.

A teacher passionate about literature may inspire students to become advocates for literacy. In society, inspired students become motivated individuals who, in turn, inspire positive change within their neighborhood.

How do teachers connect with the community? ›

Engage a broad base of community leaders and organizations. Include community partners in your decision making and respect their opinions. Parents or family members should be a part of the school action team or include them in your community connections or partnerships.

What is the full meaning of cis? ›

Cis, short for cisgender (pronounced sis-gender, or just sis), is a term that means whatever gender you are now is the same as what was presumed for you at birth. This simply means that when a parent or doctor called you a boy or a girl when you were born, they got it right.

What is cis in academic? ›

Computer Information Systems (CIS) > Academic Calendar.

What is cis standing for? ›

Commonwealth of Independent States / CIS.

What does cis mean in Masters? ›

Online Computer Information Systems (CIS) Master's Degree | CSU Online.

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