I bought a CO2 monitor, and although the effects of CO2 in cognition and energy levels are debatable[1], it shocked me and raised awareness to how poor my indoor ventilation is.
We live in a small apartment, and just being 30 min with 2 people in the room raises the CO2 ppm from 400 to >1000. Opening a window quickly lowers it. Never-mind doing some light activity like yoga or similar.
So if we want to do something, I think the first step is really to get visibility to the problem, especially to the costs of the problem (productivity, public health, sick leaves, etc).
I don't understand why you are being downvoted, you raise a good point.
Based on some HN comment from a while ago I invested in a CO2 meter (they are still quite expensive for some reason). And I share the same experience, CO2 levels can raise rapidly indoors, but simply turning on ventilation or opening a window very quickly lowers CO2 contents.
Using the meter I found CO2 levels in my bedroom can become quite high at night. So I improved the ventilation in my bedroom, and in my case it helped me to achieve better sleep.
> "although the effects of CO2 in cognition and energy levels are debatable"
it's really not debatable. the feeling of stuffiness is a function of many things, but environmentally, it's mostly temperature and humidity (we humans are hot and breathe out lots of humidity). there are no cognitive/energy effects until you get into the 10's of thousand of ppm, as the mechanism of action is competing out oxygen, not some intrinsic maladaption to CO₂, which is actually vital to life on earth. it's fashionable to hate on carbon right now (it's mediopolitical), and that's really all there is to it.
particulates, VOCs and chemical off-gassing, on the other hand, do have known mechanisms of harm, and that's something you should be more concerned about, but not yet alarmed. most of that pollution comes from cars and coal/gas power generation, so long-term, we should move toward more efficient habitation (e.g., denser cities, public transit) and cleaner power generation (including nuclear) if we really care about our collective health.
practically no one should be worried about CO₂ in their daily lives. it's thoroughly a red herring.
It's a tradeoff, because good ventilation - ideally just open a window - also means heat is leaking out of the house, which costs money (and co2 emissions) to restore.
There's cyclic systems, but I live in a neighbourhood where some houses were equipped with it; on the proper setting, it was too loud so people turned it down, then people got sick from high CO2 levels in their house.
Not to hijack your thread, but I wonder if anyone here’s built their own Raspberry/Arduino CO2 monitor? Which (reliable) sensors did you use? Did you find it more affordable than purchasing a monitor, especially if you already had unused microcontrollers lying around the house?
I think the first step would be to buy a second monitor, ideally from a different manufacturer, and verify that your readings are actually correct. My experience is that cheap monitors are basically random.
This is of course also the reason why I don't like most office buildings. They don't have operable windows and rely on centrally managed HVAC. They sometimes have CO2 sensors but the system is too opaque for occupants to figure out at which level the mechanical ventilation starts.
All that's needed for good indoor air quality (IAQ) is an ERV/HRV which exhausts stale indoor air and brings in fresh outdoor air (through a filter).
For comfort you want a furnace+AC/heatpupmp and a dehumidifier.
And try to make the enclosure as air-tight as possible so the air comes in and out on your terms and not 'randomly' through cracks (where it can carry dust and pollen, and bugs can perhaps get through as well).
I share their sentiment, especially because they are trying to explain the topic for the novice buyer - but I think it oversimplifies the issue and the discussion/benefit of UVGI.
UVGI does not create Ozone, some companies even sell certified lamps that will definitively not go into the UV spectrum that can cause Ozone.
This is true for UV-C and in the postings mention of new far-UVC LEDs.
For personal homes UVGI is most likely not needed, unless immunocompromised I'd guess. For hospitals, pharmacies, schools, airplanes and other high risk institutions I would guess that this could prevent plenty of deaths.
Edit: Their criticism is about the high-voltage needed for Mercury-vapor UV-C lamps. This can leak ozone, also if the glass is not filtering the 185nm wavelength properly that will contribute even further. The article talks about LEDs which will definitively not leak into this range. Also as far as I know the specific wavelength of pressure-lamps is not input-frequency defined as implied by the interviewed guy - not exactly sure what he's referring to. My takeout would be only buy mercury-pressure lamps from trusted sources with proper certifications in place.
> All that's needed for good indoor air quality (IAQ) is an ERV/HRV which exhausts stale indoor air and brings in fresh outdoor air (through a filter)
The recommendations you mention are together features of the Passive House[1] building standard that seeks low energy use as well. If you build a building to a high standard, it will have a tighter envelope to retain heat/cool and protect against water intrusion. If the envelope is tight, you must actively manage airflow through an ERV/HRV. The consequence is that these buildings are supplied with continuous fresh air, and their ERV can be set up to dynamically react to air quality and other issue to ramp up the transfer.[2]
There's a subculture of builders pursuing these qualities in their building, represented for example by groups like "Building Science and Beer" in Austin[3], and Matt Risinger's Build Show[4].
That is an interesting explanation. I won’t summarize other than to say that as someone who might have added UV next hardware cycle, there were several A-Ha moments. Well worth watching.
Clean air and water issues are not limited to biological contamination with pathogenic microbes and viruses, and some of the suggestions (ensuring good ventilation) run into problems when external air quality is dangerously bad (when health agencies tell people to keep their windows closed).
It's not entirely unlike water issues, for example the Thames was used to dispose of wastes from animal slaughtering, leather tanning, production of dyes from coal tar, alcohol distillery wastes as well as for human excrement. Cleaning up air quality requires addressing these issues as well (coal power plants, diesel truck emissions, agricultural dust, etc.).
It doesn't take away from the general thrust of the post but it's interesting that lack of quality sewage treatment leading to it being dumped into rivers is thought to be a key issue in the current British council voting:
Local elections 2023: How sewage topped the political agenda
The Victorian-era sewage systems described in this article are actually one of the key reasons that sewage is ending up in rivers and the sea in the first place. Notice how they worked: sewage was collected, pumped, and dumped downstream of London. It was not treated. Most of the UK's sewage treatment is retrofitted to sewage systems that were never designed to have it. This causes various problems, the main one being that rainwater drainage and sewage are mixed in many areas and this overwhelms the sewage system during heavy rain.
(As for why it became a key election issue, well, basically the British press lied to make it one - the BBC included. They made an increase in monitoring of sewage discharges look like a massive increase in sewage discharged whilst tricking people into thinking monitoring had got worse by deceptively-worded articles about the few overflows that weren't monitored yet, they told people the Environmental Agency was lying about only recently being able to measure the full extent of sewage discharges based on a hnadful of previously-recorded incidents, they claimed other European countries which still had Victorian-esque sewage systems with no treatment plants that just pumped directly into their rivers and seas in some urban areas were doing a better job, and so on.)
I don't think the clear water and clear air analogy works very well. They seem to be very different cases. Keeping clean and dirty water separate is trivial and requires no more advanced technology than plumbing. Keeping clean and "dirty" air separate is impossible. We will always breathe air that includes pathogens. That isn't to say there should be efforts to improve air quality, but I think a lot of times analogies like this oversimplify things. It's easy to eradicate cholera through cleanliness and modern plumbing, but we will never eradicate airborne viruses through air filters and masks.
It's a good analogy. Invest in infrastructure to extract dirty air and deliver clean air into living spaces. Provide suitable standards and technologies to do so.
It would be cheaper than the infrastructure to extract dirty water and deliver clean (treated) water because we don't need to transport the air anywhere near as far and air treatment is simpler.
I wish more of the funds that were allocated to combat Covid were used to install better air handling systems in public areas here in the US. The education side received billions of dollars, which if used for better air would help keep kids more kids from getting sick and then bringing it home to families.
Other than the obvious benefits like avoiding a pandemic this hits close to home. My dad passed away 2 weeks ago from Pulmanory Fibrosis. A respiratory disease without a cure and one where we know very little about the causes. Better air quality would drop cases, relive strain on the health system and just let people live longer. Its something I want to help with where I can. I hadn't even thought about the obvious step of raising awareness about air quality.
If, hypothetically, we dramatically reduced the prevalence of airborne disease, what would the effect on our immune systems be? Some hypothesize that living in too sterile an environment leads to autoimmune diseases, since the immune system is calibrated to a certain baseline level of activity, and will turn on the body if this level is not met by external pathogens.
If it turns out that actual pathogens are necessary, and we can't use the kinds of harmless bacteria that get sold as "probiotics", it would still be better to identify pathogens with optimal risk:benefit ratio and determine the optimal dose. Exposure to wild pathogens varies widely, so very few people will be lucky enough to have the best exposure.
Our hunter gatherer ancestors living in bands suffered from drastically fewer respiratory diseases than we do, you need a large connected population for something like the flu to survive in a human population in the long term. The issue with sterile environments is about the lack of random bacteria, not human adapted pathogens.
> An aside: ventilation plus filtration is the major reason that the risk of Covid infections on flights was and is so relatively low: air in the cabin is replaced every couple minutes, fresh air is drawn from outside the plane, and mixed with recycled air passed through HEPA filters.
IME, the most effective thing to do in a house is filtration inline with the intake of a ventilation system.
In my case, I have an activated carbon and a MERV13 filter that cleans incoming outdoor air just before it's fed to the heat recovery and distribution system.
You still need a separate recirculating filtration system to deal with particulates generated within a house.
I wish the author had spent more time to unfold the public vs private debate here:
>if a country installed all the measures I mentioned
As opposed to the wastewater infrastructure in the first section that can be mandated and put in motion by a government, it's up to individuals and institutions to install the measures.
This makes implementation significantly more challenging, as it relies on the collective efforts and cooperation of numerous parties, each with their own priorities and resources. Government-led initiatives, on the other hand, can be more easily streamlined and enforced, ensuring a higher degree of compliance and effectiveness.
Governments are perfectly capable of setting building codes. This isn't an instance fix, but would be effective over the long term.
Governments also have a well established mechanism to incentives faster compliance: tax refunds to offset the cost of improvement. We already offer such incentives for energy efficiency improvements (some of which actively harm ventilation).
From an engineering perspective, the clean air proposals are much easier than wastewater management. There is no centralized infastructure needed. Every building can be upgraded independently, and the people in that building will see an immediate benefit.
Further, the upgrades needed are typically not that major. Most building already have a forced air HVAC solution. These solutions already have inline air filters, and often already have the ability to actively pull in fresh air.
We can get significant improvement my simply leaving the fan on these units running regardless of if they are actively heating/cooling; and using already available high quality filters.
In that subject, a quick PSA to home owners: if you have not changed your HVACs filter recently, you probably should.
It's just silt churned up by high tides. When you're on the river, you can easily see that bits shielded from the turbulent flow, where the silt has a chance to settle down, are crystal clear. You can also see eels, seals, cormorants, kingfishers, seagulls of all kinds, and lots of life generally. It's great.
“The expectation of clean water in wealthy countries is enabled by technology and infrastructure; like effective sewage systems and water treatment facilities. But to a large extent it is also enabled, and was initially bootstrapped, by sound policymaking and regulation.
Regulation requires verification.”
Regulation of water does not require verification. We live on a planet where clean water is abundant and cannot escape the planet’s atmosphere. Why you think we need to measure how this is verified is beyond the beyond’s.
Here’s a wiki page reference if you need help measuring how much water exists on Earth:
While the majority of Earth's surface is covered by oceans, those oceans make up just a small fraction of the mass of the planet. The mass of Earth's oceans is estimated to be 1.37 × 1021 kg, which is 0.023% of the total mass of Earth, 6.0 × 1024 kg. An additional 5.0 × 1020 kg of water is estimated to exist in ice, lakes, rivers, groundwater, and atmospheric water vapor.[20]
There are only so many ways and places to extract clean water for large populations in an efficient way. Once water is used, it has to go somewhere, which is back into the water system. Every person/population downstream then no longer has 'clean water' without verification. We could have 10x the clean water we have now and we would still have to consider this aspect.
sergioisidoro|2 years ago
We live in a small apartment, and just being 30 min with 2 people in the room raises the CO2 ppm from 400 to >1000. Opening a window quickly lowers it. Never-mind doing some light activity like yoga or similar.
So if we want to do something, I think the first step is really to get visibility to the problem, especially to the costs of the problem (productivity, public health, sick leaves, etc).
[1] at the levels found in my apartment
isp|2 years ago
A sensible first step would be to very visibly display CO₂ monitors in buildings (e.g., throughout office buildings, schools, etc)
Once the CO₂ levels become visible, this in itself creates an incentive to improve.
Related from UK (2021): "All schools to receive carbon dioxide monitors" - https://www.gov.uk/government/news/all-schools-to-receive-ca...
LeonM|2 years ago
Based on some HN comment from a while ago I invested in a CO2 meter (they are still quite expensive for some reason). And I share the same experience, CO2 levels can raise rapidly indoors, but simply turning on ventilation or opening a window very quickly lowers CO2 contents.
Using the meter I found CO2 levels in my bedroom can become quite high at night. So I improved the ventilation in my bedroom, and in my case it helped me to achieve better sleep.
clairity|2 years ago
it's really not debatable. the feeling of stuffiness is a function of many things, but environmentally, it's mostly temperature and humidity (we humans are hot and breathe out lots of humidity). there are no cognitive/energy effects until you get into the 10's of thousand of ppm, as the mechanism of action is competing out oxygen, not some intrinsic maladaption to CO₂, which is actually vital to life on earth. it's fashionable to hate on carbon right now (it's mediopolitical), and that's really all there is to it.
particulates, VOCs and chemical off-gassing, on the other hand, do have known mechanisms of harm, and that's something you should be more concerned about, but not yet alarmed. most of that pollution comes from cars and coal/gas power generation, so long-term, we should move toward more efficient habitation (e.g., denser cities, public transit) and cleaner power generation (including nuclear) if we really care about our collective health.
practically no one should be worried about CO₂ in their daily lives. it's thoroughly a red herring.
Cthulhu_|2 years ago
There's cyclic systems, but I live in a neighbourhood where some houses were equipped with it; on the proper setting, it was too loud so people turned it down, then people got sick from high CO2 levels in their house.
mypastself|2 years ago
rcme|2 years ago
beebeepka|2 years ago
I do this every day regardless of the season. Works best during windy weather
sbaiddn|2 years ago
Once I install an HRV system then I'll do the windows!
kccqzy|2 years ago
c3534l|2 years ago
Do you want indoor circulation? Wouldn't that just mean your apartment loses heat/AC?
aidenn0|2 years ago
za3faran|2 years ago
throw0101b|2 years ago
Please do not do/use this.
Generally anything that is 'active', like UV lamps or ozone emitters, is not a good idea:
* https://www.youtube.com/watch?v=hSFQQpgvgeo&t=6m1s
* Interviewee: https://civmin.utoronto.ca/home/about-us/directory/professor...
All that's needed for good indoor air quality (IAQ) is an ERV/HRV which exhausts stale indoor air and brings in fresh outdoor air (through a filter).
For comfort you want a furnace+AC/heatpupmp and a dehumidifier.
And try to make the enclosure as air-tight as possible so the air comes in and out on your terms and not 'randomly' through cracks (where it can carry dust and pollen, and bugs can perhaps get through as well).
miduil|2 years ago
UVGI does not create Ozone, some companies even sell certified lamps that will definitively not go into the UV spectrum that can cause Ozone.
This is true for UV-C and in the postings mention of new far-UVC LEDs.
https://www.uvresources.com/the-ultraviolet-germicidal-irrad...
For personal homes UVGI is most likely not needed, unless immunocompromised I'd guess. For hospitals, pharmacies, schools, airplanes and other high risk institutions I would guess that this could prevent plenty of deaths.
Edit: Their criticism is about the high-voltage needed for Mercury-vapor UV-C lamps. This can leak ozone, also if the glass is not filtering the 185nm wavelength properly that will contribute even further. The article talks about LEDs which will definitively not leak into this range. Also as far as I know the specific wavelength of pressure-lamps is not input-frequency defined as implied by the interviewed guy - not exactly sure what he's referring to. My takeout would be only buy mercury-pressure lamps from trusted sources with proper certifications in place.
Empact|2 years ago
The recommendations you mention are together features of the Passive House[1] building standard that seeks low energy use as well. If you build a building to a high standard, it will have a tighter envelope to retain heat/cool and protect against water intrusion. If the envelope is tight, you must actively manage airflow through an ERV/HRV. The consequence is that these buildings are supplied with continuous fresh air, and their ERV can be set up to dynamically react to air quality and other issue to ramp up the transfer.[2]
There's a subculture of builders pursuing these qualities in their building, represented for example by groups like "Building Science and Beer" in Austin[3], and Matt Risinger's Build Show[4].
[1] https://www.treehugger.com/what-is-a-passive-house-principle...
[2] https://www.broan-nutone.com/en-us/ai-series
[3] https://www.instagram.com/bs_and_beer_atx/
[4] https://www.youtube.com/@buildshow/videos
anecdotal1|2 years ago
Reme uses UV against titanium dioxide which releases airborne peroxides which takes out bacteria/viruses/yeast/mold
This is the same tech used in self-cleaning concrete -- just add titanium dioxide and let the sun do the work
adolph|2 years ago
photochemsyn|2 years ago
It's not entirely unlike water issues, for example the Thames was used to dispose of wastes from animal slaughtering, leather tanning, production of dyes from coal tar, alcohol distillery wastes as well as for human excrement. Cleaning up air quality requires addressing these issues as well (coal power plants, diesel truck emissions, agricultural dust, etc.).
ZeroGravitas|2 years ago
Local elections 2023: How sewage topped the political agenda
https://www.bbc.co.uk/news/uk-politics-65190097
makomk|2 years ago
(As for why it became a key election issue, well, basically the British press lied to make it one - the BBC included. They made an increase in monitoring of sewage discharges look like a massive increase in sewage discharged whilst tricking people into thinking monitoring had got worse by deceptively-worded articles about the few overflows that weren't monitored yet, they told people the Environmental Agency was lying about only recently being able to measure the full extent of sewage discharges based on a hnadful of previously-recorded incidents, they claimed other European countries which still had Victorian-esque sewage systems with no treatment plants that just pumped directly into their rivers and seas in some urban areas were doing a better job, and so on.)
steviedotboston|2 years ago
JBorrow|2 years ago
gridspy|2 years ago
It would be cheaper than the infrastructure to extract dirty water and deliver clean (treated) water because we don't need to transport the air anywhere near as far and air treatment is simpler.
vondur|2 years ago
xmdx|2 years ago
MontyCarloHall|2 years ago
mrob|2 years ago
Symmetry|2 years ago
GordonS|2 years ago
danans|2 years ago
IME, the most effective thing to do in a house is filtration inline with the intake of a ventilation system.
In my case, I have an activated carbon and a MERV13 filter that cleans incoming outdoor air just before it's fed to the heat recovery and distribution system.
You still need a separate recirculating filtration system to deal with particulates generated within a house.
leblancfg|2 years ago
>if a country installed all the measures I mentioned
As opposed to the wastewater infrastructure in the first section that can be mandated and put in motion by a government, it's up to individuals and institutions to install the measures.
This makes implementation significantly more challenging, as it relies on the collective efforts and cooperation of numerous parties, each with their own priorities and resources. Government-led initiatives, on the other hand, can be more easily streamlined and enforced, ensuring a higher degree of compliance and effectiveness.
gizmo686|2 years ago
Governments also have a well established mechanism to incentives faster compliance: tax refunds to offset the cost of improvement. We already offer such incentives for energy efficiency improvements (some of which actively harm ventilation).
From an engineering perspective, the clean air proposals are much easier than wastewater management. There is no centralized infastructure needed. Every building can be upgraded independently, and the people in that building will see an immediate benefit.
Further, the upgrades needed are typically not that major. Most building already have a forced air HVAC solution. These solutions already have inline air filters, and often already have the ability to actively pull in fresh air.
We can get significant improvement my simply leaving the fan on these units running regardless of if they are actively heating/cooling; and using already available high quality filters.
In that subject, a quick PSA to home owners: if you have not changed your HVACs filter recently, you probably should.
kazanz|2 years ago
It requires a slew of regulation, enforcement bodies, and - from a US perspective - profitability for litigation attorneys.
Again with a US slant, ADA is the obvious legislative model for similar clean air regulations.
So it's possible, just more challenging than public sewage.
EGreg|2 years ago
https://uvspinner.com
Tried to get NYC officials to get interested — went through some channels that my friends had. Nothing.
Anyone here interested in doing it?
sdfjkl|2 years ago
dgroshev|2 years ago
panchtatvam|2 years ago
[deleted]
markrankin|2 years ago
Regulation requires verification.”
Regulation of water does not require verification. We live on a planet where clean water is abundant and cannot escape the planet’s atmosphere. Why you think we need to measure how this is verified is beyond the beyond’s.
Here’s a wiki page reference if you need help measuring how much water exists on Earth:
While the majority of Earth's surface is covered by oceans, those oceans make up just a small fraction of the mass of the planet. The mass of Earth's oceans is estimated to be 1.37 × 1021 kg, which is 0.023% of the total mass of Earth, 6.0 × 1024 kg. An additional 5.0 × 1020 kg of water is estimated to exist in ice, lakes, rivers, groundwater, and atmospheric water vapor.[20]
https://en.m.wikipedia.org/wiki/Origin_of_water_on_Earth#Ear...
twojacobtwo|2 years ago