Coronavirus COVID-19

[BDKJMU]

Chinese Virus related, and

Arkansas restaurant customers brawl over social distancing dispute
A fight broke out at Saltgrass Steak House in Little Rock
https://www.foxnews.com/food-drink/arka ... ng-dispute

[kalm]

I hope we’re past peak too but much of that is due to voluntary and mandated lockdowns, as well as improved tracing and therapeutic measures. The other thing to keep an eye on is long term health issues.

Get the hospitalizations and deaths down to a more manageable number and the rollercoaster will be less of a thrill ride.

Hospitalizations and deaths ARE down, and ARE manageable. EVERY metric tells us that. The only ones who don’t are the fear porn peddlers in the MSM and government.

So open back up and? There are still things that go bump in the night like new outbreaks, additional waves, and long term health effects which can potentially destroy the economy further.

It’s a risk tolerance/death tolerance/economic crises due to voluntary social distancing question.

[Gil Dobie]

Anyone think the AC could be spreading the virus in the warm southern states?

[kalm]

Anyone think the AC could be spreading the virus in the warm southern states?

Yes. Let’s send those droplets into an air circulation system that takes them throughout the room and building!

Mask, stay outside, 6 feet, no longer than 5 minutes with anyone outside side your household and we’d be approaching somewhat normal by September. But we won’t.

[kalm]

Awesome! why not?

Fauci: New virus in China has traits of 2009 swine flu and 1918 pandemic flu

White House coronavirus advisor Dr. Anthony Fauci said Tuesday that U.S. health officials are keeping an eye on a new strain of flu carried by pigs in China that has characteristics of the 2009 H1N1 virus and 1918 pandemic flu. The virus, which scientists are calling “G4 EA H1N1,” has not yet been shown to infect humans but it is exhibiting “reassortment capabilities,” Fauci told the Senate Health, Education, Labor and Pensions Committee during a hearing.

[UNI88]

Awesome! why not?

Fauci: New virus in China has traits of 2009 swine flu and 1918 pandemic flu

White House coronavirus advisor Dr. Anthony Fauci said Tuesday that U.S. health officials are keeping an eye on a new strain of flu carried by pigs in China that has characteristics of the 2009 H1N1 virus and 1918 pandemic flu. The virus, which scientists are calling “G4 EA H1N1,” has not yet been shown to infect humans but it is exhibiting “reassortment capabilities,” Fauci told the Senate Health, Education, Labor and Pensions Committee during a hearing.

When are we going to hold China accountable for enabling environments where all of these viruses are allowed to develop?

What is worse? A bunch of individuals who refuse to wear a mask or a nation's government that allows some combination of shoddy laboratory procedures and markets where various wild and domesticated animals are kept in close proximity to one another?

Maybe we need to establish a permanent 2+ week quarantine on travelers who have been to China.

[∞∞∞]

Anyone think the AC could be spreading the virus in the warm southern states?

It really depends on the system type, airflow design, humidity, room type, usage, etc.

We've been modeling a ton of different items and in reality, it's been all over the place.

That said, the worst offenders are single or multi-split systems and basically anything with a ceiling fan.

Basically anything that's residential, businesses which use small split systems, and (most) gyms are higher risk. Public restrooms are particularly awful but there's also less of an exposure time, which is where the JHU folk we're working with come in.

Large commercial buildings aren't as bad because of the required ventilation rates as well as the wider capabilities to control the HVAC system. They can also be more easily retrofitted and the buildings are typically more voluminous (more viral diffusion).

But again, there's so many variables that go into it you'd really have to examine each space individually. For example, all other things being equal, the location of the supply/return grilles could be the difference between spreading the virus and everyone being ok.

Here are some ASHRAE links if you want to go into what engineers are thinking about heading forward:

https://www.ashrae.org/file%20library/t ... schoen.pdf
https://www.ashrae.org/technical-resour ... tation-faq
https://www.ashrae.org/technical-resources/resources

But the most important thing...wear a mask and practice social distancing! There is no substitute to those.

[AZGrizFan]

Anyone think the AC could be spreading the virus in the warm southern states?

It really depends on the system type, airflow design, humidity, room type, usage, etc.

We've been modeling a ton of different items and in reality, it's been all over the place.

That said, the worst offenders are single or multi-split systems and basically anything with a ceiling fan.

Basically anything that's residential, businesses which use small split systems, and (most) gyms are higher risk. Public restrooms are particularly awful but there's also less of an exposure time, which is where the JHU folk we're working with come in.

Large commercial buildings aren't as bad because of the required ventilation rates as well as the wider capabilities to control the HVAC system. They can also be more easily retrofitted and the buildings are typically more voluminous (more viral diffusion).

But again, there's so many variables that go into it you'd really have to examine each space individually. For example, all other things being equal, the location of the supply/return grilles could be the difference between spreading the virus and everyone being ok.

Here are some ASHRAE links if you want to go into what engineers are thinking about heading forward:

https://www.ashrae.org/file%20library/t ... schoen.pdf
https://www.ashrae.org/technical-resour ... tation-faq
https://www.ashrae.org/technical-resources/resources

But the most important thing...wear a mask and practice social distancing! There is no substitute to those.

Why would that be? The HEPA filters in my AC system at home are about 1000x more efficient at trapping particulate than the mask I wear. do commercial systems not use actual filters?

[∞∞∞]

They use filters, typically MERV 11 or MERV 13.

The higher you go, the more static pressure the blower fan has to overcome (and HEPA filters increase it by significant margins).

Commercial (and sometimes residential units) are designed with two things in mind: energy efficiency and longevity. The higher the static pressure, the more energy it takes to overcome it. The more energy it uses (aka. the harder the fan works), the shorter the lifespan.

Fans also operate with a curve (called the fan curve) where the y-axis is the static pressure and the x-axis is the cubic feet per minute. There are zones in the curve (stall regions) which which fans can't safely operate in, or don't operate at all (stall).

It's not as simple as retrofitting HEPA filters into existing systems because more likely than not, they system can't safely handle them. Most engineers won't design for HEPA filters unless they're necessary and even now, the recommendation is not to do because of the major energy-use and lifespan implications. However, we will be designing to MERV 13 (and not 11) from now on.

In fact, you might want to check the specs of your residential unit and make sure you won't prematurely blow up the motor.

[SeattleGriz]

Anyone think the AC could be spreading the virus in the warm southern states?

Yes. Let’s send those droplets into an air circulation system that takes them throughout the room and building!

Mask, stay outside, 6 feet, no longer than 5 minutes with anyone outside side your household and we’d be approaching somewhat normal by September. But we won’t.

Sounds like Legionnaires disease!

[Winterborn]

They use filters, typically MERV 11 or MERV 13.

The higher you go, the more static pressure the blower fan has to overcome (and HEPA filters increase it by significant margins).

Commercial (and sometimes residential units) are designed with two things in mind: energy efficiency and longevity. The higher the static pressure, the more energy it takes to overcome it. The more energy it uses (aka. the harder the fan works), the shorter the lifespan.

Fans also operate with a curve (called the fan curve) where the y-axis is the static pressure and the x-axis is the cubic feet per minute. There are zones in the curve (stall regions) which which fans can't safely operate in, or don't operate at all (stall).

It's not as simple as retrofitting HEPA filters into existing systems because more likely than not, they system can't safely handle them. Most engineers won't design for HEPA filters unless they're necessary and even now, the recommendation is not to do because of the major energy-use and lifespan implications. However, we will be designing to MERV 13 (and not 11) from now on.

In fact, you might want to check the specs of your residential unit and make sure you won't prematurely blow up the motor.

AG and Construction equipment is the same way. Though with the OSHA silica rules in place, most new equipment one can replace the MERV filters with HEPA without any issues.

[AZGrizFan]

They use filters, typically MERV 11 or MERV 13.

The higher you go, the more static pressure the blower fan has to overcome (and HEPA filters increase it by significant margins).

Commercial (and sometimes residential units) are designed with two things in mind: energy efficiency and longevity. The higher the static pressure, the more energy it takes to overcome it. The more energy it uses (aka. the harder the fan works), the shorter the lifespan.

Fans also operate with a curve (called the fan curve) where the y-axis is the static pressure and the x-axis is the cubic feet per minute. There are zones in the curve (stall regions) which which fans can't safely operate in, or don't operate at all (stall).

It's not as simple as retrofitting HEPA filters into existing systems because more likely than not, they system can't safely handle them. Most engineers won't design for HEPA filters unless they're necessary and even now, the recommendation is not to do because of the major energy-use and lifespan implications. However, we will be designing to MERV 13 (and not 11) from now on.

In fact, you might want to check the specs of your residential unit and make sure you won't prematurely blow up the motor.

That doesn’t answer my question. Are the filters in my home system (and commercial systems) better at filtering than a mask or not?

[kalm]

Yeah...let’s all just get it and be done with it...

Hundreds of thousands of seriously ill coronavirus patients who survive and leave the hospital are facing a new and difficult challenge: recovery. Many are struggling to overcome a range of troubling residual symptoms, and some problems may persist for months, years or even the rest of their lives.

Patients who are returning home after being hospitalized for severe respiratory failure from the virus are confronting physical, neurological, cognitive and emotional issues.

And they must navigate their recovery process as the pandemic continues, with all of the stresses and stretched resources that it has brought.

“It’s not just, ‘Oh, I had a terrible time in hospital, but thank goodness I’m home and everything’s back to normal,’” said Dr. David Putrino, director of rehabilitation innovation at Mount Sinai Health System in New York City. “It’s, ‘I just had a terrible time in hospital and guess what? The world is still burning. I need to address that while also trying to sort of catch up to what my old life used to be.’”

https://www.nytimes.com/2020/07/01/heal ... ivors.html

[AZGrizFan]

Yeah...let’s all just get it and be done with it...

Hundreds of thousands of seriously ill coronavirus patients who survive and leave the hospital are facing a new and difficult challenge: recovery. Many are struggling to overcome a range of troubling residual symptoms, and some problems may persist for months, years or even the rest of their lives.

Patients who are returning home after being hospitalized for severe respiratory failure from the virus are confronting physical, neurological, cognitive and emotional issues.

And they must navigate their recovery process as the pandemic continues, with all of the stresses and stretched resources that it has brought.

“It’s not just, ‘Oh, I had a terrible time in hospital, but thank goodness I’m home and everything’s back to normal,’” said Dr. David Putrino, director of rehabilitation innovation at Mount Sinai Health System in New York City. “It’s, ‘I just had a terrible time in hospital and guess what? The world is still burning. I need to address that while also trying to sort of catch up to what my old life used to be.’”

https://www.nytimes.com/2020/07/01/heal ... ivors.html

There haven’t even been hundreds of thousands of hospitalizations, let alone believing that every single one has gone home to continue suffering.

[AZGrizFan]

https://www.cdc.gov/coronavirus/2019-nc ... index.html

A great link. Almost zero in here that should alarm anyone, yet here we are shutting down the country again.

[Gil Dobie]

In restaurants it's more about blowing the virus around the room before it gets back to the return and the filters.

[Winterborn]

They use filters, typically MERV 11 or MERV 13.

The higher you go, the more static pressure the blower fan has to overcome (and HEPA filters increase it by significant margins).

Commercial (and sometimes residential units) are designed with two things in mind: energy efficiency and longevity. The higher the static pressure, the more energy it takes to overcome it. The more energy it uses (aka. the harder the fan works), the shorter the lifespan.

Fans also operate with a curve (called the fan curve) where the y-axis is the static pressure and the x-axis is the cubic feet per minute. There are zones in the curve (stall regions) which which fans can't safely operate in, or don't operate at all (stall).

It's not as simple as retrofitting HEPA filters into existing systems because more likely than not, they system can't safely handle them. Most engineers won't design for HEPA filters unless they're necessary and even now, the recommendation is not to do because of the major energy-use and lifespan implications. However, we will be designing to MERV 13 (and not 11) from now on.

In fact, you might want to check the specs of your residential unit and make sure you won't prematurely blow up the motor.

That doesn’t answer my question. Are the filters in my home system (and commercial systems) better at filtering than a mask or not?

For comparison a N95 mask is 95% efficient at blocking particulates of 0.3 micron or larger.

A HEPA filter is rated at between a MERV 17-20 (depends on the HEPA filter) and is 99.7% efficient at blocking particulates of 0.3 micron or larger.

MERV stands for Minimum Efficiency Reporting Values which is a filters ability to hold larger particles between 0.3 and 10 microns.

[JohnStOnge]

Yeah...let’s all just get it and be done with it...






https://www.nytimes.com/2020/07/01/heal ... ivors.html

There haven’t even been hundreds of thousands of hospitalizations, let alone believing that every single one has gone home to continue suffering.

I think there have been hundreds of thousands of hospitalizations. For one thing, there have now been 127,299 deaths. That pretty much assures that hospitalizations have been in the six figures.

Another thing is what you can see in the graph on the page at https://www.cdc.gov/coronavirus/2019-nc ... alizations. You can see that the line for "Overall" is right at 100 per 100,000 population. So 1 in 1000. The population of the United States is, as I type, 329,877,505. 100 in 100,000 translates to 329,878.

So, yes, it appears that there have been hundreds of thousands of hospitalizations.

Another thing: Just in terms of the proportion, having 1 in every 1,000 people in the United States having been hospitalized due to this thing is a lot.

[Skjellyfetti]

That doesn’t answer my question. Are the filters in my home system (and commercial systems) better at filtering than a mask or not?

The AC thing is also about blowing air (and particulates) before they reach the filter.

There was a pretty well circulated study from March or April on a restaurant and diners who caught Covid and who didn't based on air flow from the AC, for example. Look it up if you're curious

[Gil Dobie]

BTW the IHME model run of March 25 projected the US peak deaths number at 2,341 on April 14. I don't immediately see info on which day the CDC says had the highest death rate. However, according to the Worldometers site, the highest US death count was 2,804 and that was yesterday, April 21. The April 14 number was 2,553; which is the 3rd highest 1 day death total so far.

So the March 25 Model run was not exactly dead on. But I think it's absurd to expect that it would be. It was saying it would peak around this time. Now, if it turns out that it's distinctly higher in mid June then they will have been way off on the peak thing. But right now they are not.

The models are close enough for this wave of COVID-19. Just wondering when the second wave will hit. You mentioned the virus being airborne, and I just read yesterday where the CDC posted a study of a restaurant with AC running. Person A came into the restaurant not having any symptoms. Later that day he starts feeling the flu-like symptoms. After 2 weeks, 9 people at from that lunch at the restaurant were tested positive, from 3 different tables. That is something that needs to be looked at.

Bump

[Ivytalk]

The models are close enough for this wave of COVID-19. Just wondering when the second wave will hit. You mentioned the virus being airborne, and I just read yesterday where the CDC posted a study of a restaurant with AC running. Person A came into the restaurant not having any symptoms. Later that day he starts feeling the flu-like symptoms. After 2 weeks, 9 people at from that lunch at the restaurant were tested positive, from 3 different tables. That is something that needs to be looked at.

Bump

So I’m willing to bet that you haven’t been to a restaurant since social distancing measures were introduced. Some of you guys seem to be scared of your own shadows.

[Ibanez]

They use filters, typically MERV 11 or MERV 13.

The higher you go, the more static pressure the blower fan has to overcome (and HEPA filters increase it by significant margins).

Commercial (and sometimes residential units) are designed with two things in mind: energy efficiency and longevity. The higher the static pressure, the more energy it takes to overcome it. The more energy it uses (aka. the harder the fan works), the shorter the lifespan.

Fans also operate with a curve (called the fan curve) where the y-axis is the static pressure and the x-axis is the cubic feet per minute. There are zones in the curve (stall regions) which which fans can't safely operate in, or don't operate at all (stall).

It's not as simple as retrofitting HEPA filters into existing systems because more likely than not, they system can't safely handle them. Most engineers won't design for HEPA filters unless they're necessary and even now, the recommendation is not to do because of the major energy-use and lifespan implications. However, we will be designing to MERV 13 (and not 11) from now on.

In fact, you might want to check the specs of your residential unit and make sure you won't prematurely blow up the motor.

That doesn’t answer my question. Are the filters in my home system (and commercial systems) better at filtering than a mask or not?

What sort of mask are you talking about? N95 masks and the like do a great job. Seems like the answer is yes - with some caveats.

To test everyday materials, scientists are using methods similar to those used to test medical masks, which everybody agrees should be saved for medical workers who are exposed to high doses of virus from seeing infected patients. The best medical mask — called the N95 respirator — filters out at least 95 percent of particles as small as 0.3 microns. By comparison, a typical surgical mask — made using a rectangular piece of pleated fabric with elastic ear loops — has a filtration efficiency ranging from 60 to 80 percent.

Dr. Wang’s group tested two types of air filters. An allergy-reduction HVAC filter worked the best, capturing 89 percent of particles with one layer and 94 percent with two layers. A furnace filter captured 75 percent with two layers, but required six layers to achieve 95 percent. To find a filter similar to those tested, look for a minimum efficiency reporting value (MERV) rating of 12 or higher or a microparticle performance rating of 1900 or higher.

The problem with air filters is that they potentially could shed small fibers that would be risky to inhale.

https://www.nytimes.com/article/coronav ... k-ppe.html

[Ivytalk]

Interesting piece by Jacob Sullum in the June 30 Reason Online suggesting that (1) voluntary conduct may have been at least as effective as mandatory lockdowns in reducing the Massachusetts “R” rate below 1, and (2) focusing on “superspreading events,” like large public gatherings in poorly ventilated places, may be far more fruitful than indiscriminate economic lockdowns in controlling that rate.

[∞∞∞]

That doesn’t answer my question. Are the filters in my home system (and commercial systems) better at filtering than a mask or not?

HEPA? Yes. Other filters? It's not worse, but it's not better.

That said, a HEPA filter somewhere in the building won't protect two people near each other for an extended period of time.

That's where masks come into play. They keep viral particulates close to the source.

[Gil Dobie]

Bump

So I’m willing to bet that you haven’t been to a restaurant since social distancing measures were introduced. Some of you guys seem to be scared of your own shadows.

Just for take out. Mask are not required here, so we are not taking a chance with vulnerable family members. Some local restaurants have open and closed with covid cases.

Did go to a large funeral in a county with no active cases. Everyone acted normal, hugs, shaking hands etc. Open to kids, one is working at a casino, mask and temp checks required for employees and customers. Still do my biking, 30 to 40 miles on the weekend, public trails.

Trying to be part of the solution. Not a big burden for us.