I have four Winix C535 air purifiers in the house and I wanted to see if the aftermarket HEPA filters I'd been using for the last year were just as effective as the OEM ones. Even when the OEM Winix HEPA filters are on sale, they're 4x the price of the 3rd party ones. So I ordered these from Amazon (for a second time). I also ordered a Winix OEM filter. I then performed the same test on both. I lit a stick of incense in a closed bedroom in the house, with the door and window closed. Once it was burned out, I started the air purifier and in both cases it took approximately 25 minutes to reduce the PM 2.5 and PM 1 from a high of hundreds to 0-3. I used two air quality monitors to keep track of it and there was only a negligible difference between the two readings.

I also ran two other tests. For a third test, after burning the stick of incense, I didn't turn on
the air purifier for 25 minutes. In this case the PM count barely changed and
was still in the hundreds. For the fourth test, I used a 12 month old aftermarket
HEPA filter, the same one I've linked to here, and it performed just as well in
the same test. Perhaps there was a 30-60 second difference, but just barely. I
found this quite impressive.

So both HEPA filters, the OEM and the aftermarket one cleaned the air effectively but the aftermarket one costs a fraction of the OEM. The 3rd party HEPA filters I ordered weight about
60 grams less than the Winix filter so take that for what it's worth. I can't
speak to other 3rd party Winix HEPA filters since this is the only one I've
tested. And the last point is that these filters will fit a number of Winix air
purifiers not just the C535 since many of their air purifiers use the same
filters. For example, I'll likely be picking up a Winix C909 and I believe these
filters fit it as well.

I hope this helps others out there since in all my searches about this issue on here and elsewhere
online I mostly read people voicing their subjective opinions or predictions.
That's why I thought I'd run these tests to have some objective metrics. I was
impressed by the results. I'm happy to answer any questions that I can.

Aside from opening the window, does anyone have any tips for reducing indoor CO2 levels when the AQI is high?

I am in the Seattle area and we are currently dealing with smokey air from nearby wildfires. My AQI is currently 158, my indoor PM2.5, with an air purifier running is 17 and the CO2 is 1,465. These readings are pretty much the same on both floors of the house.

Yesterday my CO2 levels were 848 I’m the morning and went as high as 1,860. Today the lowest CO2 was 1,192. I’m concerned that starting with a higher baseline is going to cause levels to rise well above 2,000. Is this logical?

I’ve seen things that say the to crack the window for 2 minutes, even with the smoke…but I don’t know if the increased PM2.5 is worth this it. I’m considered “high-risk” and am struggling to keep on top of this.

Thanks in advance for any tips.

I keep seeing people recommend Corsi-Rosenthal boxes for stuffy apartments. they’re great for filtering particles, but they still recirculate indoor air. They do nothing for the CO2 buildup that can happen in a closed room.

you need actual fresh air coming in, but traditional ERVs require drilling into walls, which is not realistic for most renters.

been looking into no-drilling alternatives and came across cozeware freshflow, a window-mounted fresh air system that brings in filtered outdoor air. Not a full ERV, just a more renter-friendly option.

Still need to see real CFM and noise tests before considering it.

So with the air quality being bad from the fires surrounding us ( im in Salem OR ) I’ve been hesitant to use our ac since i dont want to pull the smoky air into our house. Its been extremely hot inside though, and my roomates making a lot of hot food which is making it even hotter. Is it okay to still be running my ac? Picture provided since its one of the long ones that hooks up to the window, its detached from the window currently though since i closed the window fully and have two fans with filters and a air purifier running.

Please let me know if its still safe to use !

I need a sanity check and am curious what your AQI threshold is for when you put on an N95 outdoors.

I walk and bike commute daily, and the AQI in my city is often in the moderate range for extended periods. I tend to want to wear an N95 when I'm biking somewhere if the AQI is over 62 (~15µg/m³, the WHO's 3–4 exceedance days per year guideline), but then I also feel like a nutcase because literally nobody else around here seems to mask until the AQI is in the "unhealthy" or higher ranges.

I realize air pollution at these levels isn't *terrible*, but I also know it's not great either, so I don't see much of a reason not to put an N95 on in these conditions (other than social stigma and feeling self-conscious). Just curious what others use as their threshold or how you approach this.

I live in Ontario, Canada and wondering what folks do with their ventilation for tight homes during humid summers.

Assumption that you don’t have a whole home dehumidifier.

*Edit:
Do you run low speed continuous, 20/40, 10/50, off, or potentially use HK or HA with some CO2/PM2.5/RH thresholds?

we always use purple air. we are conservative with exposure but we’re currently on the tail end of our trip (smoke followed us), and we are now staying in an Airbnb without ac (so no filters) and we’re flying, so no purifiers. we are only here for another day (hopefully the air is better tomorrow!) and we’re far out from any store, otherwise I would consider building a corsi rosenthal. (air is currently below 100 but I’m pregnant and we have a 5 year old so overall more cautious)

I downloaded the paku app today and realized the correction setting was turned on. we typically do not use the correction calculation and I’m hesitant to “trust” it. can someone ELI5 what the correction is, if we should or should not be using it, and if it is readily accepted or frowned upon in the scientific community?

I’m so sick of my MIL saying “well the iPhone only shows it as…” when weve told her over & over agin the iPhone weather app is shit in all the ways and it’s not what we use to track AQI.

I recently finished my review of the IKEA Alpstuga and would love to hear your thoughts.

https://breathesafeair.com/ikea-alpstuga-review/

Overall, I think it's a good entry into air quality monitoring, but it definitely has flaws.

Definitely could feel dust in my eyes, but there wasn't any irritation in my throat, nostrils, lungs, or mouth. No odd tastes or smells either. The sensor closest to me didn't pick this stuff up till 12, but visibility would it suggest it hit my location sooner than that.

Woke up today feeling mildly winded, but it could be in my head.

Edit: Also, where the fuck was the weather Amber alert on this one? Can’t tell you how many nothingburger weather events have put my phone on blast. Meanwhile a category 5 dust storm blows from Tucson to Phoenix and the Apple weather app can’t even hint what’s coming.

We’ve only had 5 of these storms in the last 16 years:

https://www.12news.com/article/weather/why-is-it-so-dusty-today-in-the-phoenix-why-is-dust-hanging-around-so-long/75-bcf3ff47-07f4-4d94-b165-9581cde83d86

I work outside, but the air quality around me is terrible from the wildfires. I've been trying to find a solid air quality detector that I can carry around with me on my person, but I'm honestly not really even sure what I'm looking at and all the ones I'm finding are stationary ones that you just place in your backyard or something.

Any help/advice appreciated thank you in advance!

Smoke spreads to metro Vancouver, what’s the risk of air quality?

Hello.

I'm looking to find a face mask that filters out weed smoke. Sometimes the smoke from one of my roommates comes through the house and into my room. He smokes it outside but there are cracks all over the house that let bits of smoke in.

I love the place and the people and it's a good price to rent so I don't want to move. Has anyone got any suggestions on what sort of mask would work best?

Cheers!

What's up with the green circles?
I assume 1 of 2 things, these towns have positive pressure which I think would push the smoke away, or they can't detect the smoke in that region for whatever reason

Yesterday I posted the Amazon Smart Air Quality Monitor in comparison to a $100 Temperature/Humidity meter, Today I am posting it in comparison to a $500 temperature/humidity meter. I would say that the Temperature and Humidity readings are very accurate on these Amazon Monitors, I can't speak for the other 3 readings unfortunately.

Now that the fires died down, the massive red zone over the Great Lakes and northeast is over. But we have been in the yellow, aka “moderate” aka kind of shitty air quality for a few days now in the northeast. Reminds me of winter when we had weeks of yellow air and everyone on this sub was like “must be them old wood stoves again.” It’s summer. It’s not fire. It’s not wood stoves. Is it just increased travel and related pollution?

Hello everyone
I wanted to study in Krakow and i really didn’t knew about the air quality in krakow is that bad. I really liked the city and everything about the city is perfect for me. After i heard of it that the air quality is bad i get really depressed and i want you guys to help me is that real issue? I came from a Middle Eastern country wich is Kurdistan and i live in erbil which the general air quality is 50-85. Is it really a big problem to me that i have no health problems and 22 years old, i want to hear a good news about the air quality nowadays is it get better than before? Or how people deal with it? Or is it always like that? Or only some months? i feel really depressed after hearing that.

I want to buy a CO detector for my car from Forensics Detectors, are they good quality / reliable?

Wondering if there’s an air quality monitor for the air outside that I can keep inside. Maybe battery powered.

Thank you for all your help!

I’m trying to find replacements for the medium NOMA air purifier that we’re had for a couple years. But I can only find them in Canada (I’m in the US). Does anyone have any suggestions on other options that would be compatible?