Hi All,
With the air quality degrading in my area due to wildfire smoke it prompted a question for me. What is worse having high pm2.5 or high CO2? If we keep out house all closed up the pm2.5 stay low due to HEPA filters, but the CO2 goes up. If we open things up the pm2.5 goes up, but the CO2 stays down. Ideally, we would have some sort of ventilation system that also filtered, but we do not have anything like that currently. I’d love to know thoughts around this.
Thanks,
Mud0556
How high on either are you seeing? If CO2 is getting over 2500, that is pretty high, but about the max that I get when sleeping in a closed room. If lower than that, I would think the PM2.5 is probably worse for you, but I’m not on the data science team.
If PM2.5 is in the 100’s, that is likely far worse, than high CO2
But I’m just some random person on the internet, so if someone with more credentials replies, go with what they say.
I would say the same as MallocArray.
WHO states:
Ambient (outdoor) air pollution in both cities and rural areas was estimated to cause 4.2 million premature deaths worldwide per year in 2019; this mortality is due to exposure to fine particulate matter, which causes cardiovascular and respiratory disease, and cancers.
The mortality associated with airborne particulate matter is roughly as high as the estimated mortality for dementia, road traffic injuries, suicides and malaria combined (according to WHO and UNICEF).
Thanks that is in line with my thinking as well. Some numbers:
PM2.5 ~120 US AQI
CO2 ~1200 ppm
That’s an acceptable CO² level. Different sources set the limit at different numbers, but they’re far higher than 1200 ppm.
For example, OSHA says over 5000ppm is unacceptable for an 8 hour workday, but the short term exposure limit is 30000 ppm. Their “immediate danger to life or health” limit is 40000 ppm.
Source: hxxps://www.osha.gov/chemicaldata/183
And in case they block you, here’s an archived version of that page: hxxps://archive.is/pfAXb
If you want to get lower CO² levels with the windows closed, plants can help. I don’t have it handy, but NASA published some studies of how many plants would be required to offset the CO² for each human.
What’s the conversion between the ppm’s you’re mentioning and the units shown on the app?
For reference, I have a whole house Zehnder ventilation system, and due to the fires I have a Hepa filter installed inline right now (usually it is a MERV 13). My CO2 is 470 and my PM 2.5 is 2. (Our outdoor AQI is decent the past 24 hours at under 100, but has been up to 170.)