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
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...
My wife purchased an Aronet CO₂ monitor, and I took it with me on a business trip last week. The CO₂ while on the flight was in the 3000's range. The CO₂ at my client's office was in the mid 2000's range, as well as the hotel. Opening the hotel window the allowed 2 inches reduces CO₂ to the 600 range in 10 minutes, but the client's office windows do not open, and of course neither do the airplane windows.
I've also noticed when working indoors or when driving, if the CO₂ is above 1500 I get drowsy, so the degree it is no longer responsible driving a car.
Air safety: are we going to fight a moronic battle over this too?
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.
also, are there really people that can (or even prefer!) to sleep with closed windows?! Only with AC blasting, right?
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.
If these measurable declines have a sufficient impact on our lives and productivity is the debatable part.
Edit: here's one reference: "We also found effects of CO2 (a proxy for ventilation) on cognitive function. For every 500ppm increase, we saw response times 1.4-1.8% slower, and 2.1-2.4% lower throughput"
https://www.hsph.harvard.edu/healthybuildings/2021/09/09/imp...
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.
It's a neat technology but the jury is still out on it.
Some people praise them, other people revile them, and they seem to be either too bulky or too cumbersome or too expensive or too inefficient for a DIY retrofit project.
It uses the "Senseair S8" CO2 sensor, which costs a bit (25-30$), but (according to AirGradient) has a very high quality.
[1]: https://www.airgradient.com/open-airgradient/instructions/di...
My goal is to get a cheap (~$50) sensor in a small package that I can put in every room in my house. It will be modular so I skip the display and the PM2.5 sensor and it can be cheap as ~$25
[1]: https://www.airgradient.com/open-airgradient/blog/co2-sensor...
I haven't seen anybody take any of the cheap CO2 sensors and demonstrate that they are anywhere in the range of the readings of a lab grade CO2 sensor.
I do this every day regardless of the season. Works best during windy weather
Once I install an HRV system then I'll do the windows!
Household HRVs & ERVs have suspiciously low heat efficiencies for their costs.
Do you want indoor circulation? Wouldn't that just mean your apartment loses heat/AC?
There are ways around it though. The simplest is to not make sure ventilation goes where it needs to go. Modern buildings use mechanical ventilation to make sure every living space gets properly ventilated so one room doesn't get too much and another too little. Even better, some building use heat exchangers to heat/cool the incoming air with outgoing air, minimizing losses. Other techniques involve passing the fresh air underground, which, in a temperate climate gets you some free heating in the winter and free cooling in the summer.
Obviously, to limit heat losses, you want to reduce conduction and radiation too, which can be done without sacrificing ventilation.
In general there is likely some level of ventillation that will be worth taking on slightly increased heating/cooling costs.
Growing up we used to put on sweaters, wear shorts, use fans, have the windows open in a car.
Changing our heating/cooling preferences to get rid of all that costs money. People don't mind.
But somehow, spending a small bit to breathe well and avoid indoor pollution/viruses is beyond the pale.
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).
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.
Most people probably don't change their air filters often enough at home: I have zero confidence of them maintaining an UVGI (themselves, or wanting to shell out the cash for someone to come in).
The best thing to do is circulate air per ASHRAE-recommendations and get high-MERV filters (and hope they are swapped regularly).
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
ERV/HRV are actually part of regular building codes in many areas. The province of Ontario:
* https://www.greenbuildingadvisor.com/article/ontario-imposes...
* https://airfixture.com/blog/ontario-building-code-ventilatio...
* http://www.mah.gov.on.ca/AssetFactory.aspx?did=15947
* https://web.archive.org/web/20180626073728/http://www.mah.go...
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
Please view the video. The interviewee:
> Jeffrey Siegel, Ph.D., is Professor of Civil Engineering at the University of Toronto and a member of the university’s Building Engineering Research Group. He holds joint appointments at the Dalla Lana School of Public Health and the Department of Physical & Environmental Sciences. He holds an M.S. and Ph.D. in Mechanical Engineering from the University of California, Berkeley as well as a B.Sc. from Swarthmore College. He is fellow of ASHRAE and a member of the Academy of Fellows of ISIAQ. His research interests including healthy and sustainable buildings, ventilation and indoor air quality in residential and commercial buildings, control of indoor particulate matter, the indoor microbiome, and moisture interactions with indoor chemistry and biology. Dr. Siegel is an active member of ISIAQ and ASHRAE and was an associate editor for the journal Building and Environment from 2014-2018. He teaches courses in indoor air quality, sustainable buildings, and sustainable energy systems. Prior to his position at the University of Toronto, Dr. Siegel was an Associate Professor at the University of Texas.
* https://civmin.utoronto.ca/home/about-us/directory/professor...
Peroxide has at best generally been found to useless, and at worst you're introducing active chemistry to your ventilation system (including ozone). If you want to get rid of garbage in your air then (a) exchange it at ASHRAE-recommended volumes, and (b) use high-MERV/HEPA filters.
In wildfire zones and in wildfire season you can perhaps add charcoal filters—if your system is designed to handle the pressure/head loss—to get rid of the smoke-y smells.
There is no need to conduct chemistry experiments on yourself.
Some UVC generates Ozone, some do not. Wavelength and spectral Q factor matter.
It’s possible to have a UV system that does what you want without the downside, but it does cost.
Local elections 2023: How sewage topped the political agenda
(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.)
https://www.thelondoneconomic.com/news/brexit-to-blame-for-u...
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.
>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 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.
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...
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.).
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.
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.
Tried to get NYC officials to get interested — went through some channels that my friends had. Nothing.
Anyone here interested in doing it?
