If you’re looking for a weekend project and are even slightly handy… a fan and a decent furnace filter is a good cheap solution.
I’ve got two 3M filtrete filters, some activated charcoal sitting in front of them, and a small duct fan to pull air through it all. (Build information is in this comment and the one reply: https://news.ycombinator.com/item?id=37223106). For what a filter rated for 600sqft would have cost me, I instead got one that can do 3,000sqft. Or more usefully less space with more air changes per hour (like ten per hour instead of two).
I’ve got a $600-ish German air quality monitor that says it does what it should, which makes sense because as long as you’re pulling air through the filters… they’re gonna filter.
If you’re looking smaller scale, you can buy sheets of activated charcoal and sheets of MERV13 filter material. A little 120mm fan and a tiny filter box could run pretty quietly in an office and do the trick.
However I think the most important advice I’d give (and also the cheapest!) is to, unless you’re in a _heavily_ polluted area, open your windows. No air filter you’re going to get will remove CO2 and once you start measuring it you’d be amazed/horrified how quickly it builds up indoors to “brain fog” levels.
I've gotten the Winix ones from Costco and they work great. I really notice a difference now that it's getting cold and my windows are shut most of the time.
1100-1200.
I believe in the mining industry anything over 800 inside a truck cab is considered unsafe.
Fresh air is 470ish.
I try to keep my room around 600 but not always possible.
If that's in ppm you're nowhere close to any limits I'm aware of. OSHA limits start at 5000ppm, which is approximately where the ISS and most submarines are kept. It's possible that 3000ppm would be a safer upper limit, but you're still at less than half of that.
It’s interesting because I’ve seen this CO2 anxiety on HN and Twitter before but I’ve never found any solid rationale for people to worry about CO2 concentrations at those magnitudes. Part of me wonders where this idea came from. Hopefully it isn’t just a ploy to sell CO2 monitors.
I can certainly personally feel the difference health-wise between 600ppm and 1200 ppm.
This is what ChatGPT has to say on the subject:-
The difference in acceptable CO2 levels between submarines and office buildings is due to different environmental and operational constraints.
Enclosed Environment: Submarines operate in a highly enclosed environment where air cannot be easily exchanged with the outside. This leads to a natural accumulation of CO2, making higher levels unavoidable.
Air Filtration and Recycling: Submarines are equipped with advanced air filtration and CO2 scrubbing systems to manage air quality. These systems can handle higher CO2 levels effectively, unlike typical office HVAC systems.
Occupational Health Standards: Office buildings adhere to civilian occupational health standards that prioritize comfort and long-term health, aiming to minimize any impact on cognitive functions and overall well-being of the occupants.
Operational Necessity: Submarines often have to remain submerged for extended periods without venting or taking in fresh air. The operational demands and limitations necessitate tolerating higher CO2 levels.
Adaptation and Training: Submarine crews are trained and gradually adapted to higher CO2 levels, something that is not feasible or necessary for office environments.
The higher tolerance for CO2 in submarines is a trade-off between operational needs and environmental constraints, whereas office buildings prioritize occupant comfort and health under normal environmental conditions.
If you're into smart home stuff, I can recommend the IKEA STARKVIND. It integrates nicely into the room, filters are decently easy to swap and Zigbee works well with Home Assistant
I’ve got two 3M filtrete filters, some activated charcoal sitting in front of them, and a small duct fan to pull air through it all. (Build information is in this comment and the one reply: https://news.ycombinator.com/item?id=37223106). For what a filter rated for 600sqft would have cost me, I instead got one that can do 3,000sqft. Or more usefully less space with more air changes per hour (like ten per hour instead of two).
I’ve got a $600-ish German air quality monitor that says it does what it should, which makes sense because as long as you’re pulling air through the filters… they’re gonna filter.
If you’re looking smaller scale, you can buy sheets of activated charcoal and sheets of MERV13 filter material. A little 120mm fan and a tiny filter box could run pretty quietly in an office and do the trick.
However I think the most important advice I’d give (and also the cheapest!) is to, unless you’re in a _heavily_ polluted area, open your windows. No air filter you’re going to get will remove CO2 and once you start measuring it you’d be amazed/horrified how quickly it builds up indoors to “brain fog” levels.