When the novel coronavirus burst onto the scene, it quickly realized that the mighty HEPA filter was one of its greatest foes.
It began an aggressive anti-HEPA filter lobbying campaign with politicians, public health officials and school boards.
1/9
The goal was to spread lies about HEPA filters to ensure it could infect as many kids as possible. These gullible individuals have been doing PR for the virus and the lies need to be put to rest.
2/9
Myth: HEPA filters blow the virus around
Fact: They remove the virus from the air
Myth: HEPA filters aren't needed if minimum ventilation standards are met
Fact: HEPA filters reduce risk for airborne pathogens, even if there is already ventilation.
Myth: Electrical safety issues
Fact: >100000 classrooms. No issues
Myth: Child safety issues
Fact: >100000 classrooms. No issues
Myth: They are inequitable
Fact: So put one everywhere
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CONCLUSION
Using HEPA filters is a simple way to clean the virus out of the air. It can be deployed everywhere really quickly. Air filtration is one of the main tools we have against this virus and we need to start using it. Making up lies puts everyone at risk.
9/9
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This is one of the most prevalent lies against HEPA filters. It’s been used by school boards and politicians as an excuse to not put HEPA filters into schools. This myth needs a thorough debunking.
1/9
AEROSOL SPREAD IN A CLASSROOM
The air in a classroom is well mixed. Anyone who is concerned about blowing the virus around needs to know that it's already been blown around. Here's a diagram of what classroom airflow looks like:
I've been asked about sizing a HEPA filter for your home. This is different than sizing one for public spaces with other people.
This does not provide fresh air. Ventilation is required for that. Here are some things to consider:
1/10
WHAT IS YOUR GOAL?
Do you just want to improve the air quality in your house in general or do you want to have a gathering and use the HEPA filter to mitigate risk of COVID transmission? The clean air delivery rate (CADR) for these two goals is very different.
The hierarchy of controls is a system to reduce or eliminate exposure to hazards. It has been misused by people pushing an anti-mask agenda. They misunderstand how this works.
1/6
Here's Martha Fulford misunderstanding it to push an anti-mask agenda.
Respirators (N95, KN95...) right now are the most effective tools to prevent infection. It's preferable to use the other methods, but the other methods don't work as well.
Here's how the different controls can be used to combat COVID (some is up for debate):
3/6
If you have 3 ACH (air changes/hour) from air being supplied through mechanical ventilation/filtration and 2 ACH being supplied by stand-alone HEPA filters, you have a total of 5 ACH. (3+2=5)
5 ACH > 3 ACH
It's pretty easy to understand.
2/7
Those who have been pushing this misinformation didn't bother checking with engineers. They are stating blatantly incorrect facts about ventilation/filtration when they do not know what they are talking about.
3/7
CR Boxes are a cheap, quick and effective way to increase filtration. They are one of the best tools we have right now to protect kids from COVID. How to get them into classrooms?
1/13
First, call up the teacher, principal, superintendent, trustee and tell them about these. Recommending that the kids build them themselves in science class might help. You'll definitely get resistance though, here are some counter arguments:
2/13
ALREADY HAVE A HEPA FILTER
What HEPA filters they are using? Are they run on high (probably not)? What's the CADR? They aren't going to do anything meaningful. At least ask that they be run on high speed and if not, they need more filtration.