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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

#241

Post by willyt »

neilwilson wrote: post #177
willyt wrote: post #72

> Pumping in adequate amounts of fresh outside air, however engineered, will challenge running costs as well as carbon status. This is wrong. Mechanical Heat Recovery Ventilation (MVHR) is a well established technology which can recycle 96% of the heat from the waste air in a house. It costs about the same to fit as a central heating system. Passive houses have very high Air Changes per Hour (ACH) compared to convent…

"There is no reason not to put MVHR in normal houses" There's no reason in new normal houses, but it is very often impossible to do it sensibly in the existing housing stock. But then there is no reason houses shouldn't be built in factories, shipped to site and assembled. After all we already do that for hotels and the like. Yet that hasn't happened yet either.

You can get self contained through wall units and do it room by room, less efficient but cheaper to retrofit.

Hotels prefab the bathrooms typically, but not the rest of the room.

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

#242

Post by BoxOfRain »

chmod600 wrote: post #168
nr2x wrote: post #151

Earlier quoted context omitted.

To add to that - younger children are really good with mask wearing in my experience - which is a big factor compared to the teenagers who ditch the mask as soon as no authority figure is in sight...or the adults with the maturity level of teenagers.

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…

I think the environmental damage is going to be a big issue in the near future, those hundreds of millions of plastic masks getting thrown away every day don't just dissolve into the aether; they stay around where they will pollute the environment especially the oceans. As far as I'm aware this topic hasn't been discussed at all by my government let alone a plan put in place to mitigate this environmental harm.

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

#243

Post by mattzito »

willyt wrote: post #238
3np wrote: post #226

Earlier quoted context omitted.

I think it’s not wrong when considered in the context of already existing large buildings (office complexes, public transit stations, department stores, restaurants, hotels, etc) as opposed to newly built individual houses (where, arguably, increased ventilation may not have that much effect on infection spread) Or are you saying it’s still cost-efficient to retrofit in a high-rise from the day 1980s?

Most of those places are already very well ventilated. You’re not catching covid in the train station, you’re catching it while sharing 1m² with 4 other people on the train. Or because you’re in a crowded restaurant and you’re between the air extract point and the person on the table next to you who has covid. I can’t see how it would be different if the air circulation is because of open windows or mechanical ventil…

FWIW, my office building was quite transparent about the fact that pre-pandemic, there were 1.5-2 ACH, well below the recommended 3-6 for reduction of Covid spread. They have since upgraded/reconfigured the HVAC for 4 ACH. Two of my previous offices didn’t have building-wide HVAC at all, relying on local units without configurable access to fresh air. This doesn’t invalidate your point, just highlighting that perhaps many office buildings are not up to the levels of air turnover needed without real investment.

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

#244

Post by andi999 »

Eelongate wrote: post #202
andi999 wrote: post #195

Earlier quoted context omitted.

Do you live in a non tropical region?

I live in Seattle. It's 12C in my apartment right now, I have the windows open and I'm certainly not wearing any gloves. Hell, I'm not even wearing any socks. I'm wearing long pants and a thickish shirt with long sleeves, and I feel totally toasty.

Next holiday try Shanghai in winter.

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

#245

Post by willyt »

_benedict wrote: post #236
willyt wrote: post #72

> Pumping in adequate amounts of fresh outside air, however engineered, will challenge running costs as well as carbon status. This is wrong. Mechanical Heat Recovery Ventilation (MVHR) is a well established technology which can recycle 96% of the heat from the waste air in a house. It costs about the same to fit as a central heating system. Passive houses have very high Air Changes per Hour (ACH) compared to convent…

Many non-passive house buildings have 0.4ACH or more without mechanical ventilation. The purpose of an MVHR is to provide similar trickle rates of ventilation without the high energy cost, but the goal of "opening a window" is to provide much higher airflow rates, in which case the cost would be much higher with mechanical ventilation. It looks like 3-6ACH[1] or more is desirable to control the spread of infection. T…

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 do it.

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

#246

Post by neilwilson »

mdekkers wrote: post #205
neilwilson wrote: post #177

Earlier quoted context omitted.

"There is no reason not to put MVHR in normal houses" There's no reason in new normal houses, but it is very often impossible to do it sensibly in the existing housing stock. But then there is no reason houses shouldn't be built in factories, shipped to site and assembled. After all we already do that for hotels and the like. Yet that hasn't happened yet either.

The fine folks at Hufhaus would like a word. As well as quite a few others….

Yes, but they are more like a Rolls Royce than a Model T Ford.

There's no mass production, and we really need to ask why.

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

#247

Post by newaccount74 »

jhugo wrote: post #126
newaccount74 wrote: post #41

Earlier quoted context omitted.

Heat exchangers can recover a large fraction of the energy lost through ventilation. Modern systems can even recover humidity from the air leaving the building. Air purifiers are very loud and mostly effective at removing particulates. If you want to remove VOCs, formaldehyde and CO2 then ventilation is a lot more effective. A well designed ventilation system can be completely inaudible.

> Air purifiers are very loud and mostly effective at removing particulates. If you want to remove VOCs, formaldehyde and CO2 then ventilation is a lot more effective. Modern air purifiers are basically silent in normal operation, and there are models that remove VOCs and formaldehyde. CO2 is still best removed with ventilation.

> Modern air purifiers are basically silent in normal operation

Maybe on the lowest setting, but I doubt you'll actually have clean air on the lowest setting. Especially if you want to filter VOCs.

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

#248

Post by beagle3 »

irjustin wrote: post #165
sharperguy wrote: post #50

A metaphor I was thinking of earlier. If a guy is going to piss on you, you're going to be happy if he has to keep a pair of speedos on as he attempts it. You could also just move further away from him. But if you're both swimming in the same pool while he pisses in it, those speedos will make little difference anymore. Neither will your distance from him help very much. What will help much more is the amount of wate…

Sometimes metaphors are less than helpful. This is one. > Neither will your distance from him help very much. The amount of piss distributed is still determined by volume, so more distance => weaker concentration, which... helps a lot?

only in the transient stage. in the "steady state", it distributes evenly to the entire pool, and the only thing that matters is total volume (+ intake, - outlet), distance irrelevant.

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

#249

Post by zulln »

ajmurmann wrote: post #76
orblivion wrote: post #11

It baffles me that Fauci etc didn't mention this in the next breath after hand washing and masking. It's easy during nice weather.

Is hand washing even that relevant given the virus gets mostly inhaled? I've never seen any studies on this.

Limiting other diseases is relevant as well though, as the goal is to not overload hospitals during a pandemic.

(+ just getting a cold is really annoying since I would need to quarantine more than I would with a cold before covid)

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

#250

Post by IgorPartola »

sn41 wrote: post #232
IgorPartola wrote: post #191

Earlier quoted context omitted.

The only issue I have seen so far is that constantly exhaling onto your eyes dries them out and can make them more prone to minor infections. Happened to me, doctor told me to not use contacts for a bit and take mask breaks once in a while. Outside of that, medical professionals wear masks all the time. Nurses are often subjects of medical studies because they are an accessible caprice audience. I know of no known ca…

hmmm... thanks for that anecdote. i have been having dry eyes since last year... i thought it was age. But maybe I should try taking breaks when wearing masks.

Artificial tears are of great help as well.
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