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Why don’t we just open the windows? Covid-19 prevention lost in translation

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Re: Why don’t we just open the windows? Covid-19 prevention lost in translation

#281

Post by dude187 »

mlyle wrote: post #278
dude187 wrote: post #273

Earlier quoted context omitted.

The risk of them getting sick is not significant. People are using their trumped up unjustified fears the media and government have whipped into them into demanding _some_ form of child abuse. The only thing they're willing to question is "which form?"

Significant hyperbole. Elementary kids do not care one bit about wearing masks indoors. They picked up the habit quickly, don't complain, and now put the rest of us to shame. Indeed, they often don't bother (not out of fear, but just forgetting or not bothering) to remove when going outside. And, the risk is much more significant than you imply, and the risk to us who work with them is substantial. I'm looking forwar…

> Elementary kids do not care one bit about wearing masks indoors.

Well I believe the opposite, and from having a teacher in the family I can tell you masks are INCREDIBLY detrimental to the educational experience. We're harming our children's education immensity by clinging to them.

> , the risk is much more significant than you imply

No it is not. It's not even a large enough risks in adults for the removals of freedom to have been justified, and there's MUCH, MUCH less in kids. The risk is virtually non-existent, not a worry whatsoever.

If you're still sitting here in 2021 and pushing for the continual suspension of freedom "for the children" over a near nonexistent worry, you are part of the problem.

Re: Why don’t we just open the windows? Covid-19 prevention lost in translation

#282

Post by mlyle »

dude187 wrote: post #281
mlyle wrote: post #278

Earlier quoted context omitted.

Significant hyperbole. Elementary kids do not care one bit about wearing masks indoors. They picked up the habit quickly, don't complain, and now put the rest of us to shame. Indeed, they often don't bother (not out of fear, but just forgetting or not bothering) to remove when going outside. And, the risk is much more significant than you imply, and the risk to us who work with them is substantial. I'm looking forwar…

> Elementary kids do not care one bit about wearing masks indoors. Well I believe the opposite, and from having a teacher in the family I can tell you masks are INCREDIBLY detrimental to the educational experience. We're harming our children's education immensity by clinging to them. > , the risk is much more significant than you imply No it is not. It's not even a large enough risks in adults for the removals of fre…

> and from having a teacher in the family I can tell you masks are INCREDIBLY detrimental to the educational experience.

OK. I'm teaching and doing fine. So are my colleagues.

Re: Why don’t we just open the windows? Covid-19 prevention lost in translation

#283

Post by dude187 »

mlyle wrote: post #169
chmod600 wrote: post #168

Earlier quoted context omitted.

Does weaing a mask so often have downsides? I'm not "anti-mask". I'm just wondering whether we will see studies in 10-20 years about a bunch of children with lung problems from restricted airflow or weird fibers or chemicals, or other pathogens that grew on the masks, or something we haven't thought of yet. Or who knows? Maybe kids will all have super strong lungs. Or maybe lucky ones will have stronger lungs and oth…

Who knows. But we do have large parts of the world where wearing masks during cold season is normalized, without any massive evidence of adverse effect.

Having an entire population hiding their face on a routine basis when interacting with the public is an enormous downside. Completely unacceptable, and forcing it on the _entire_ population is downright evil.

Re: Why don’t we just open the windows? Covid-19 prevention lost in translation

#284

Post by dude187 »

mlyle wrote: post #282
dude187 wrote: post #281

Earlier quoted context omitted.

> Elementary kids do not care one bit about wearing masks indoors. Well I believe the opposite, and from having a teacher in the family I can tell you masks are INCREDIBLY detrimental to the educational experience. We're harming our children's education immensity by clinging to them. > , the risk is much more significant than you imply No it is not. It's not even a large enough risks in adults for the removals of fre…

> and from having a teacher in the family I can tell you masks are INCREDIBLY detrimental to the educational experience. OK. I'm teaching and doing fine. So are my colleagues.

Well they were hugely detrimental to all the teachers I know. So either you're downplaying the impact or ignoring it.

Re: Why don’t we just open the windows? Covid-19 prevention lost in translation

#285

Post by mike_hock »

geoduck14 wrote: post #160
mike_hock wrote: post #56

Earlier quoted context omitted.

> it also may decrease the attack vector in our societies for airborne bio-terrorism/warfare Sounds extremely far-fetched. Any terrorist attack will be designed with the countermeasures in mind. Deploying enough biological agent to swamp the ventilation system would likely not be an issue.

I'm pretty certain I worked in an open-floor plan office that had windows designed to "impede" small airplanes being flown into it. I speculate this fact -after- a someone actually did fly their airplane into our building. The pilot received exceptionally bad customer service from us and was attempting to kill one of our leaders.

Lesson learned: Don't give bad customer service if you work in the World Trade Center.

Re: Why don’t we just open the windows? Covid-19 prevention lost in translation

#286

Post by dude187 »

rtsil wrote: post #132
taeric wrote: post #34

Earlier quoted context omitted.

Annoyingly, my intuitive impression is that we are still far more ignorant than we'd care to admit. Being in a place where we all willingly wear masks to grocery shop, I get the impression we are far more cautious than most places. Still, I expect it is just a matter of time before we are exposed. Why? I honestly don't know. It isn't lack of wanting to be safer. But it has gotten fatiguing to try to keep up with what…

> I remember the start when folks wiped down delivered groceries. Even isolated them for a few days. I still isolate groceries for at least 6 hours, delivered or not. Still clean my hands or wear a glove when I touch something outside. I haven't got sick since Covid appeared. I used to have pretty severe nasal allergies (or so doctors told me) at least once a month, I haven't had one episode since early 2020. This is…

I do absolutely nothing, including not wearing a mask in an area that demands I wear one. Nor have I gotten any sort of shot.

The only thing I do is that I wash my hands every time I return from public, as I always have been. I haven't gotten sick either.

Re: Why don’t we just open the windows? Covid-19 prevention lost in translation

#287

Post by willyt »

_benedict wrote: post #255
willyt wrote: post #245

Earlier quoted context omitted.

Depends on construction standards. I can’t find my source, but my understanding is that passive house is 3-4x better ACH than a typical recently built house in the UK when you take as built measurements of typical usuage patterns. Heat recovery ventilation is an available technology and it’s not practical in the winter to sit in a house with the windows wide open, even with the heating on full so no-one will actually…

> my understanding is that passive house is 3-4x better ACH than a typical recently built house in the UK Part L1A of UK building regulations stipulate an air permeability of no more than 10m3/hr/m2 of building envelope at 50pa of pressure. My home has approximately a 1:1 ratio of building envelope to volume, though this will vary a great deal. But for such a home this works out to 10ACH at 50pa. There are various st…

As built and as normally used measurements being the key here. Very small new build houses in the damper western parts of the uk often have problems with mould growth because of actual in everyday use ACH below building regulations design levels. It’s particularly an issue in new build social housing. People don’t open trickle vents, they turn down the extract fan timer because of fan noise and buildings are often more airtight than regulations expect and the minimum standard details are a compromise between the convenience of old conventions and prevention of cold bridging. In my experience it’s more common to fail the airtighness test by being too airtight to vent only with trickle vents than it is to come anywhere near 10@50pa. 2-3@50pa being common which drops you below the 0.4 guaranteed ACH of passive house. I’ve never seen a result over 4 @50pa. According to your calculation methodology 2-4@50pa could be anywhere between 0.07-0.4 ACH. Also, this air circulation is not designed so it just vents randomly, some rooms in the house could have very stale air while others might be quite good.

Re: Why don’t we just open the windows? Covid-19 prevention lost in translation

#288

Post by chrismorgan »

mlyle wrote: post #269
chrismorgan wrote: post #214

Earlier quoted context omitted.

Certainly the comfort band is the key to it. Everything else is rounding error under even the most pessimistic estimates. On phase change energies: I don’t know enough to quantify things definitely there, but https://en.wikipedia.org/wiki/Latent_heat#Specific_latent_he... looks like the right thing, and suggests around 2.4kJ/g, which with water being as much as 5% of the air (100% humidity at 40°C) would be as much a…

Each of the terms is a small single digit percentage, but they multiply together to become a small but noticeable effect on building efficiency.

Each of the terms are single digit percentages if you were completely replacing cool, implausibly bone-dry air with implausibly hot and saturated air. With more realistic ambient and goal saturation, temperature and leakage figures, I think you’re looking at more like single digit hundred thousandths or millionths for most of the terms.

Re: Why don’t we just open the windows? Covid-19 prevention lost in translation

#289

Post by mlyle »

chrismorgan wrote: post #288
mlyle wrote: post #269

Earlier quoted context omitted.

Each of the terms is a small single digit percentage, but they multiply together to become a small but noticeable effect on building efficiency.

Each of the terms are single digit percentages if you were completely replacing cool, implausibly bone-dry air with implausibly hot and saturated air. With more realistic ambient and goal saturation, temperature and leakage figures, I think you’re looking at more like single digit hundred thousandths or millionths for most of the terms.

I disagree, and you can take it up with the people codifying energy efficient building standards and working on compliance with them if you care. :P

Re: Why don’t we just open the windows? Covid-19 prevention lost in translation

#290

Post by dredmorbius »

mlyle wrote: post #277
dredmorbius wrote: post #276

Earlier quoted context omitted.

I don't know, though I'd suspect that plans for increased air exchange are being considered. For much of the state, through much of the year, open windows are a reasonably minor consideration. Heat-recovery air-exchange would be more efficient, and again, though I don't know what's being considered, I'd suspect that this is part of current discussions. The chief challenge is that of retrofits vs. new construction. Mu…

> I don't know, though I'd suspect that plans for increased air exchange are being considered. In general, newer buildings with sealed windows have pretty good air exchange ( with heat recovery ) and filtration. > For much of the state, through much of the year, open windows are a reasonably minor consideration. Yah, tell that to me languishing masked a 95 degree classroom between building heat gain and a temperature…

Much depends on just how open those windows are. "All windows wide open in every classroom" during very warm or very cold weather is excessive. A window cracked open for ventilation, and either at the top of the classroom (warm weather w/ cooling active) or bottom (with heating), and a fan within the room for vertical mixing ... might help.

(Keep in mind that mixing air also mixes infectious particles.)

A slight improvement is to have a single exit point (vented with a fan) and rely on structure permiability to introduce fresh air. That's effectively a negative-pressure system.

From there, exhaust and intake with heat recovery is the next obvious step.

I mention older construction as replacing building stock is a long-term and expensive process. New construction will account for an exceedingly small percentage of all utilised buildings. New construction currently planned or in process should if at all possible incorporate lessons from the COVID-19 pandemic, but that's a drop in the bucket. Retrofits are highly likely.

If you want to read further, I'm finding numerous results for a search on school ventilation in new construction and retrofits:

https://duckduckgo.com/?q=+school+retrofit+construction+vent...

Among the first of those, from the CDC:

Reoccupying a building during the COVID-19 pandemic should not, in most cases, require new building ventilation systems. However, ventilation system upgrades or improvements can increase the delivery of clean air and dilute potential contaminants. Consult experienced heating, ventilation, and air conditioning (HVAC) professionals when considering changes to HVAC systems and equipment. Buildings that provided healthy, code-compliant indoor air quality prior to the pandemic can be improved for pandemic occupancy using less costly interventions. Below is a list of ventilation interventions that can help reduce the concentration of virus particles in the air. They represent a list of “tools in the mitigation toolbox,” each of which can contribute towards a reduction in risk. Implementing multiple tools at the same time is consistent with CDC’s layered approach and will increase overall effectiveness of ventilation interventions. These ventilation interventions can reduce the risk of exposure to the virus and reduce the spread of disease, but they will not eliminate risk completely.

...

Open windows and doors, when weather conditions allow, to increase outdoor air flow. Do not open windows and doors if doing so poses a safety or health risk (e.g., risk of falling, triggering asthma symptoms) to occupants in the building. Even a slightly open window can introduce beneficial outdoor air.

https://www.cdc.gov/coronavirus/2019-ncov/community/ventilat...

That cites an industry study by ASHRAE (professional association):

https://www.ashrae.org/file%20library/technical%20resources/...

It also recommends on exhaust fans rather than interior circulation fans to minimise strong internal air currents, with intake provide as I've indicated above.

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