[Eric_WVGG]

I felt similarly, but I have a family member who is bed-bound, there’s some asbestos removal going on, so I decided to take the plunge.

I can vouch for their ability to detect impure air. If I start cooking anything, it switches on within seconds. It’ll turn on within about three minutes of sweeping the floor. And if the detectors can turn on when the air is dirty, it stands to reason that they can tell when the air is clean and they turn off as well.

Shortly after getting this, some intriguing news surfaced regarding the installation of air filters in a California school (due to a gas scare) which resulted in a jump in test scores vs other schools in the same district.

I am not a scientist, but I’m feeling pretty convinced about the efficacy of these things.

https://www.vox.com/2020/1/8/21051869/indoor-air-pollution-s... https://news.ycombinator.com/item?id=18219391

[Eric_WVGG]

(A few minutes after posting this, morning rooftop construction started. Sounds of saws and drills buzzing, large objects and beams being dropped directly overhead. Air purifier just kicked into high gear. Yes, I’m definitely into this thing.)

https://thewirecutter.com/reviews/best-air-purifier/

[bradknowles]

I’m a big fan of thewirecutter, and I reference them frequently on most things I’m buying. But for HEPA air filters, I don’t feel like they test the models that I feel are best for someone with asthma, or other similar breathing problems.

We have several IQAir units, of at least a couple different models. None of them have sensors to automatically ramp up the filtering when they detect pollution, that would be nice. But according to the air quality sensors I have in the house, they do an amazingly good job of filtering the air, at least if you turn them up to high enough levels.

I have yet to see demonstrated clear benefit of the units with activated charcoal filters for removing VOCs from the air, but my gut feeling is they do help in those areas where VOCs are a concern. Not all parts of our house needs that, however.

Having four furballs does greatly increase the dander and other allergens we have to deal with, but we wouldn’t give them up for anything, so the IQAir units at least make our lives a bit more livable. Especially during “Cedar Fever” season.

[driverdan]

Being able to detect particulates in the air isn't what's important. You need to know if it's actually improving the air quality.

[Eric_WVGG]

If you're referring to "air quality" in the form of particulates… it does turn off after a while. 15-30 minutes after cooking, one or two after sweeping, etc. Presumably it's triggered by no longer detecting particulates in the air, one would have to be fairly conspiracy-minded to suggest that it's working on some kind of timer (and can tell the difference between dust-timeouts and gas range waste timeouts)… I figured this was too obvious to point out, even given the sort of pedantry we get around here.

If you're referring to some quality of the air beyond particulates… well that's not what a HEPA is even for, is it? I could be mistaken.

[driverdan]

How does it compare to a control? If the pollution stops (eg you stop cooking) the particulates will settle on their own. You'd expect the count to go back down to normal over time. How much faster does the air purifier cause the particulate count to decrease?