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

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

#261

Post by vwcx » Mon, Nov 29, 2021, 3:04 PM UTC

bit_logic wrote: post #220

mlyle wrote: post #48

Earlier quoted context omitted.

I'm a teacher at a school. - We eat outside. - We have filters upgraded to MERV-13 and the fans run the entire school day. - We have windows and doors open on all classrooms, except for A) a few that don't open outside, or B) when it's rainy/windy to the point it's not possible. We have small, secondary HEPA filters that we run in those circumstances. (Often, we're blaring AC or heat into a room with all doors and wi…

I’m very concerned that the mask debate for elementary school (and especially pre-school) is not considering the potential long term negative effects. The anti-mask side uses false arguments about breathing too much CO2. And the pro-mask side uses irrelevant arguments about how plenty of adults wear masks all day with no harmful effects (nurses/doctors). But we’re talking about young kids here. Pre-school (age 2 - 4)…

Great. We acknowledge the importance of this developmental period. So what are the options, and which option contains a downside that is more palatable than the others?

I.e. we fear the effects of total isolation of a four year old more than the risk of their stunted facial recognition practice etc etc

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

#262

Post by anthonypasq » Mon, Nov 29, 2021, 3:34 PM UTC

mlyle wrote: post #140

jkhdigital wrote: post #117

Earlier quoted context omitted.

So let me ask you: with such well-ventilated facilities, what is the marginal benefit of masking? And is this benefit worth the difficult-to-quantify but very real cost of students being unable to see the faces of their classmates?

> So let me ask you: with such well-ventilated facilities, what is the marginal benefit of masking? It's difficult to estimate. Of course, even with all this care, not everywhere is equally well ventilated. My room is wide open to the outside, but there are other rooms depending on central air and the room filter which may not be as well off. Trying to form policy on a room by room basis would be nutty. > And is this…

yikes, you think "feeling" safer is an adequate reason to mask?

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

#263

Post by antoniuschan99 » Mon, Nov 29, 2021, 4:04 PM UTC

tsimionescu wrote: post #234

antoniuschan99 wrote: post #204

Earlier quoted context omitted.

I live in Toronto. You can still open the windows just wear a sweater, sweatpants, and socks. When the polar vortex happened a few years ago we had no power for a week but the -40C is usually just in Jan-Feb.

Toronto is the same latitude as Cannes in southern France. Sure, it's colder because of wind and ocean patterns, but it's not exactly the ultimate argument in "I know what it's like to live in a cold climate".

Cannes weather is more like Vancouver. Toronto might not be as Cold as Winnipeg, Edmonton, or Montreal but it's in Canada. Other than if they lived in Vancouver, to say someone who lives in Canada doesn't know what it's like to live in a cold climate is strange.

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

#264

Post by fulafel » Mon, Nov 29, 2021, 4:12 PM UTC

viraptor wrote: post #154

Eelongate wrote: post #96

Earlier quoted context omitted.

In much of the world for much of the year, it doesn't get below freezing for at least part of the day. The solution to the heating problem is simple then: simply don't. Open windows when it's above 50F / 10C (to give a healthy safety margin to the water pipes) and tell people to wear sweaters. Do this where it's possible and you'll offset the energy expenditure of heating in places were it actually earnestly gets col…

> Open windows when it's above 50F / 10C (to give a healthy safety margin to the water pipes) and tell people to wear sweaters. Yeah, please don't. There's a comfortable level somewhere above that, but at 10C I wouldn't be able to function in context of work / school. With worse circulation you just end up with your hands / feet feeling like they're constantly freezing. Some teachers thought that's a good idea, but I…

If you open windows when weather starts to warm up past 10c, you won't get a cooling to 10c indoors.

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

#265

Post by belorn » Mon, Nov 29, 2021, 4:26 PM UTC

ceejayoz wrote: post #118

belorn wrote: post #109

Earlier quoted context omitted.

The bangladesh study showed that groups of people that are spending large portion of their days inside small huts will benefit from mask. One particular area was also mosques which has a large number of people coming and going, with people being near each other indoors. Mask makes great sense in specific contexts. Near vulnerable groups. In tight spaces and areas of low ventilation. In areas where a large number of p…

Sure, skip the mask at the beach. We've known outdoors is likely quite safe due to ventilation for a long time now. The Bangladesh study is likely informative in busy grocery stores, retail, offices, schools, etc.; certainly more than just "inside small huts".

> The Bangladesh study is likely informative in busy grocery stores, retail, offices, schools, etc.; certainly more than just "inside small huts".

The study did not show that. It was a study conducted in rural areas of Bangladesh, areas with small villages of huts and some mosque. Those are quite different from a large city mall and office complex. Schools are a even more complex since while children has a significant higher rate of getting sick in general, the transmission rate between children and adults is significant lower. The ruling on school lock downs and mask in schools has yet to be established.

We can look at specific examples. If you are on a packed plane then a mask is pretty good idea. Traveling on a bike then it is unlikely to do anything good. Mask in crowded open floor plan with bad ventilation, yes. Mask in personalized offices with good ventilation, no. A conferences, yes. A school, maybe. A bench, no. A large grocery store in off-hours, less likely. A crowded grocery store in rush hours, more likely. In a public bath house, the data seems to indicate no.

Things that seems to correlate with transmission rates seems to primarily be about: distance between people, ventilation and humidity, practicality of staying isolated at symptoms, age and risk groups. Raise any attribute of those to an extreme and one can get data that either prove or disprove masks as effective.

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

#266

Post by rtsil » Mon, Nov 29, 2021, 5:13 PM UTC

taeric wrote: post #147

rtsil wrote: post #132

Earlier quoted context omitted.

> 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 can assume that if you are taking those measures, you also avoid crowds of any sort. Which probably does a lot of the heavy lifting for you. For me, I also saw that we had fewer sicknesses when the kids were all home schooled. Not shocking, we got a ton of bugs when they started school back. Not sure how sustainable it is to have such isolated lives, though. :(

> I can assume that if you are taking those measures, you also avoid crowds of any sort.

Correct. Being a software developer helps immensely.

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

#267

Post by mlyle » Mon, Nov 29, 2021, 5:44 PM UTC

dredmorbius wrote: post #206

Sargos wrote: post #158

Earlier quoted context omitted.

If it's still being built then it likely won't start being used until sometime next year and at that point we're back to optimizing for energy usage. It's best to pick a long term metric over a short term win when dealing with a building that will last for decades.

This presumes no further epidemics / pandemics, and discounts benefits to "normal" cold and flu season.

Do you think in normal years we'll still keep classroom windows open in the middle of flu season? Even in temperate California, the costs to classroom comfort and running HVAC to try and overcome outdoor temperatures is ridiculous.

Good modern buildings are being built with more ventilation and heat recovery built in. Taking this over windows that open can be a reasonable trade. Yes, on the pandemic axis, many of these buildings may be a little worse than a classroom with a whole long wall of opening windows.

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

#268

Post by mlyle » Mon, Nov 29, 2021, 5:47 PM UTC

anthonypasq wrote: post #262

mlyle wrote: post #140

Earlier quoted context omitted.

> So let me ask you: with such well-ventilated facilities, what is the marginal benefit of masking? It's difficult to estimate. Of course, even with all this care, not everywhere is equally well ventilated. My room is wide open to the outside, but there are other rooms depending on central air and the room filter which may not be as well off. Trying to form policy on a room by room basis would be nutty. > And is this…

yikes, you think "feeling" safer is an adequate reason to mask?

Yes, I do. My dad has SLL, with a ridiculous risk of mortality should he be exposed. Yes, he's fully vaccinated, but the amount of protection he can expect from the vaccine is dubious.

Further bounding the risk of me getting exposed by a student (ventilation + masking) lets me both see my elderly father and continue to teach. I don't financially need to teach, and as much as I find it rewarding, I'm not willing to take a large risk of killing family members to do it.

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

#269

Post by mlyle » Mon, Nov 29, 2021, 5:56 PM UTC

chrismorgan wrote: post #214

mlyle wrote: post #200

Earlier quoted context omitted.

> More humid air with higher specific heat capacity OK, so I should add a little more nuance: * With more water vapor in the air, the air has a little more heat capacity * With more water vapor in the air, the temperature band for comfort is a little narrower * With more water vapor in the air, air conditioners need to work extra hard to provide the same cooling. That is, the more water there is in the air to begin w…

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.

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

#270

Post by mlyle » Mon, Nov 29, 2021, 6:01 PM UTC

chmod600 wrote: post #260

dboreham wrote: post #181

Earlier quoted context omitted.

Like the surgeons who have been dropping like flies for the past 100 years because they wear masks all day at work?

You could at least make an attempt to consider differences amd whether those differences might matter. * Adult vs child * Material (e.g. cotton) * Quality * Wash / replacement schedule * Activities performed And while you're at it, consider that kids aren't dropping like flies from covid, either. So if you're performing a cost / benefit analysis, the cost to kids wearing masks doesn't need to be very high before it g…

> So if you're performing a cost / benefit analysis, the cost to kids wearing masks doesn't need to be very high before it gets higher than whatever benefit the masks offer.

Outright death is rare, but there's quite a few pediatric hospitalizations. They likely come with long term consequences, too.

For that matter, influenza has been greatly reduced, and there's a lot of chronic sequelae to influenza infection in youth.

And don't forget to add secondary consequences. I'm still willing to teach them in part because of reduced risk to me and my father thanks to masking. And a slightly reduced chance of killing a parent or grandparent by bringing home COVID is notable, too.