[HN Gopher] Ventilation Made Easy
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       Ventilation Made Easy
        
       Author : Tomte
       Score  : 28 points
       Date   : 2024-07-21 07:01 UTC (16 hours ago)
        
 (HTM) web link (www.mpg.de)
 (TXT) w3m dump (www.mpg.de)
        
       | constantcrying wrote:
       | What a time that was...
       | 
       | Really glad it is over and that it never got the point of me ever
       | seeing such a thing.
        
         | redrove wrote:
         | Are you actually insinuating there still isn't a pandemic going
         | on or am I misreading your comment?
         | 
         | I don't see how this couldn't possible be anything but
         | beneficial in public places.
        
           | baggy_trough wrote:
           | I mean, there isn't? Just endemic viruses, as we always have
           | had, and always will have.
        
             | redrove wrote:
             | Putting that aside, don't you then agree ventilation in
             | public spaces is useful for obvious health reasons?
        
               | constantcrying wrote:
               | Hilariously Air conditioning is very common in the US but
               | very uncommon in Europe.
               | 
               | Is there actually any evidence of a positive effect?
        
               | eep_social wrote:
               | The Minergie (Swiss) folks probably have a 90 page
               | application guide that goes into those kinds of details: 
               | https://www.minergie.com/media/guia_de_aplicacion_latam_v
               | 202...
        
               | constantcrying wrote:
               | Why are you just sending me a 90 page PDF about housing
               | regulation. Obviously that does not contain a shred of
               | scientific evidence that filtering certain particles
               | reduces transmission of infectious diseases.
               | 
               | Genuinely no idea what you are thinking with this or what
               | the point of that PDF is.
        
               | eep_social wrote:
               | > housing regulation
               | 
               | is it? I think you may want to do some research of your
               | own.
        
               | constantcrying wrote:
               | Your document contains zero relevant information and you
               | refused to point to any specific part of its 90 pages.
               | Obviously you have no evidence for your claims and you
               | made stuff up by linking to an irrelevant document and
               | then being extremely obtuse and annoying when being asked
               | to substantiate what you are saying or even to specify
               | why the document contains relevant information.
               | 
               | If you have zero evidence of a claim being true, stop
               | making it.
        
           | _def wrote:
           | Maybe they are referencing that the article is from Dec 2020.
           | I agree, it still seems highly useful.
        
           | constantcrying wrote:
           | Not a pandemic that has any relevance to me, above the
           | prevalence of the common cold.
        
         | nequo wrote:
         | This is about more than pandemics, it is about indoor air
         | quality in crowded spaces:                 "Our system also
         | solves the long-standing problem of CO2 in classrooms, because
         | it not only transports aerosols outside. It also cuts CO2
         | accumulation, helping students to concentrate better on their
         | lessons."
        
           | constantcrying wrote:
           | Oh, so Europeans have finally invented air conditioning?
           | 
           | Of course when I was in school we opened the windows to solve
           | this massive issue, but times change I guess. Hopefully they
           | also have an app, for the kids.
        
             | jimkleiber wrote:
             | I'm not sure if you've ever lived in a place where you're
             | not supposed to drink the tap water because it can bring a
             | lot of disease. I think we as humans realized that water
             | carried a lot of disease and in many places started
             | treating water much better to protect our health. To me it
             | seems very logical that we should also treat the air to
             | protect our health from diseases carried in the air.
        
               | constantcrying wrote:
               | >I'm not sure if you've ever lived in a place where
               | you're not supposed to drink the tap water because it can
               | bring a lot of disease.
               | 
               | Can't say I have ever done that.
               | 
               | >To me it seems very logical that we should also treat
               | the air to protect our health from diseases carried in
               | the air.
               | 
               | There is an absolutely great feature of air, which makes
               | it totally distinct from water. If you open the window
               | inside and outside air will mix. I know this is kind of
               | miraculous and might just be a very big deal, but I think
               | it could allow us to replace the stale air in the inside
               | with fresh air from the outside.
        
               | jimkleiber wrote:
               | Fair point on that its vastness allows quick recycling.
               | They do this in Germany a lot, where even in deep winter
               | they'll open windows to recycle the air.
               | 
               | I think there are a few challenges to this:
               | 
               | 1) It's mostly manual, compared to an automatic
               | ventilation system. Perhaps if it were more automated,
               | I'd agree with you.
               | 
               | 2) If it's very hot or cold or humid outside, I think
               | doing this can impact indoor conditions and I'm not sure
               | how much that energy cost compares to other forms of
               | ventilation.
               | 
               | 3) Not every part of an indoor space is very close to a
               | window. Large indoor spaces, underground indoor spaces,
               | small ebclosed areas such as bathrooms in the middle of
               | homes, etc., may make it hard to just open a window and
               | flush out the "bad" air.
        
             | adolph wrote:
             | It would be an interesting experiment to inject additional
             | oxygen into school air supplies.
             | 
             | On the other hand, following the principle of "train high,
             | play low" it might be better to educate in lower oxygen and
             | then add oxygen to workplaces.
        
               | constantcrying wrote:
               | Maybe, of course putting people permanently on oxygen to
               | improve performance is not a viable alternative.
        
             | nequo wrote:
             | Your dismissive response is uncalled for. Air conditioning
             | does not dispose of CO2 in the air, and opening the windows
             | is not always feasible. For example, if the outside air is
             | hot or humid. Ventilation has actual use cases.
        
               | constantcrying wrote:
               | >Air conditioning does not dispose of CO2 in the air
               | 
               | Anything which circulates the air will remove it.
               | 
               | >and opening the windows is not always feasible. For
               | example, if the outside air is hot or humid.
               | 
               | I can tell you with 100% certainty that hot or humid air
               | does not prevent you from opening a window. I myself have
               | done this multiple times.
        
               | nequo wrote:
               | Beyond a certain point, humid air causes mold and hot air
               | makes it hard to get any work done. This is not some
               | esoteric idea. The northern hemisphere has just gone
               | through a two week heat wave.
               | 
               | If your bio is up to date, I wish you the best in
               | whatever your life situation.
        
               | constantcrying wrote:
               | >If your bio is up to date, I wish you the best in
               | whatever your life situation.
               | 
               | Thankfully it isn't. And I escaped from writing software.
        
               | adolph wrote:
               | >>Air conditioning does not dispose of CO2 in the air
               | 
               | > Anything which circulates the air will remove [CO2]
               | 
               | Circulation does not remove CO2, only displace it from
               | one place to another. To remove it, you need a scrubber
               | [0].
               | 
               | 0. https://en.wikipedia.org/wiki/Carbon_dioxide_scrubber
        
       | hedgehog wrote:
       | This is a pretty cool project, it's basically a retrofit approach
       | to what in industry is known as "displacement ventilation" or
       | "stratification ventilation". In the US our typical approach is
       | "mixing ventilation" where you try to mix and equalize the air
       | everywhere within a space, then cycle a portion of the air
       | through an air conditioner to get the temperature and humidity to
       | the desired level. This is mechanically intensive, needs big
       | ducts, and has the downside that contaminants in the air tend to
       | get spread everywhere. Displacement ventilation uses the fact
       | that hot and humid air rise, instead of mixing everything
       | together it removes the most stale air at the top of the room and
       | replaces it. Trickier to get right, but quieter and more
       | effective in many cases.
       | 
       | Here's a blog post with illustrations:
       | 
       | https://blog.hoffman-hoffman.com/blog/the-basics-of-displace...
        
         | kurthr wrote:
         | For efficiency you need to minimize leakage of outside
         | conditions, but you also really need a heat/energy exchanger
         | (HRV/ERV) at the fresh air input so that you're not
         | recirculating stale air.
        
           | toast0 wrote:
           | School buildings with operable windows often don't condition
           | the air. This design collects / guides air from around the
           | pupils towards an exhaust window and suggests leaving a door
           | or opposite site window to get fresh air in. It's not a
           | solution for highly conditioned spaces.
        
       | adolph wrote:
       | _Due to its low material and operating costs, it could turn out
       | to be a clever alternative to expensive filter systems and
       | ventilation by shortly wide opening the windows._
       | 
       | This is a neat idea that seems penny smart and pound foolish. For
       | one, the article does not address overall system reliability and
       | maintenance tempo. Given a low material to install cost ratio
       | this is an important factor since repeated re-installation or
       | rework will moot any cost savings from materials.
       | 
       | For two, ejecting the gases that have been expensively
       | conditioned for thermal and humidity properties will drive up
       | operating costs since replacement gasses will be required.
       | 
       | For three, hopefully they carefully plan for where the system
       | exhausts since they have made something that concentrates
       | contaminants as well as it evacuates them. To the extent that it
       | uses tragedy of the commons to get better odds for people indoors
       | by worsening odds for people outside that building, the primary
       | innovation of the system is statistical arbitrage based on a
       | larger outdoor volume.
        
         | toast0 wrote:
         | > For two, ejecting the gases that have been expensively
         | conditioned for thermal and humidity properties will drive up
         | operating costs since replacement gasses will be required.
         | 
         | This application optimizes exhaust in rooms with operable, high
         | mounted windows for exhaust. Most rooms with expensive
         | conditioning don't have operable windows, so it's not really an
         | option to use this design for those anyway. In a heavily
         | conditioned space, the expectation would be external air
         | ventilation would be managed near the centralized air handlers.
         | Plenty of options there, like HRV/ERV depending on climate
         | specifics.
         | 
         | It might be possible to use a similar design to augment air
         | returns from a conditioning system, but it's going to depends
         | on the system if it would be useful or reasonable.
        
       | danjc wrote:
       | (2020)
        
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       (page generated 2024-07-21 23:14 UTC)