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Comment by parkingrift | Hacker News Reader

Air purifiers and air monitors. It is shocking and disgusting how much dust and particles these air purifiers suck out of the air. The air monitors detect when to open windows for CO2, among other things.

My allergies no longer exist.

Edit: A few people have asked for recommendations. I recommend the Coway Airmega AP-1512HH for larger spaces and Blueair Blue Pure 411 for smaller spaces. For the air monitor I have the Qingping.

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While air purifiers are a great idea I just want to put a warning out there about the current state of air monitors.

The current summary is that most of them are wildly inaccurate with false positives and you might just be better off checking your outdoor air quality from the EPA using their app.

Would love for someone to provide a better recommendation.

"The Best Home Air Quality Monitor for 2022 | Reviews by Wirecutter" https://www.nytimes.com/wirecutter/reviews/best-home-air-qua...

>The current summary is that most of them are wildly inaccurate with false positives and you might just be better off checking your outdoor air quality from the EPA using their app.

That's partially missing the point of air monitors. In most western countries the risk is less outside smog etc and more what you get up to. Fry some bacon and suddenly you're at 20x the recommended values.

A warning: the cheap air monitors don't monitor particle count, just CO2. If you're allergic to pollen you expose yourself to it by opening windows. I've had to help a couple friends who used this and ended up sneezing and sniffling like crazy.

I have the Dylos monitor which does monitor particle count so you can see it drop when your air filter is working https://www.amazon.com/dp/B08F2YM8SM/ref=cm_sw_r_apan_glt_i_...

You really don't need a 270 usd device for particle count.

A PM2.5 particle count sensor is like 25 bucks and temp/humidity/pressure another 10, so you can DIY this quite cheaply with a raspberry if so inclined.

https://www.amazon.com/WINGONEER%C2%AE-Precision-Quality-Det...

https://www.amazon.com/bobotron-Compatible-Temperature-Atmos...

I have both the Dylos and other sensors. The Dylos is a very sensitive instrument that reports raw counts every second. There is no smoothing, no translation to PM2.5 scale. For the paranoid type it works REALLY WELL for providing direct feedback on the impact of an air filter- or on the impact even of minor contractor work. PM 2.5 sensors- quality ones- have their place. But the difference is kind of like the difference between reading labels and following FDA guidelines on nutrient intake vs getting a blood screen. Sometimes you want the blood screen. Dylos is a good device for that.

I'd imagine the Dylos will have better components and better calibration, so should provide superior accuracy.

Not convinced they're all that different though - both laser based particle counters, and results correlate pretty well in studies [0].

Certainly wouldn't trust a cheap SDS011 sensor for anything that really matters, but wouldn't characterize it as nutritional label vs blood screen either.

[0] https://www.researchgate.net/publication/337399372_Dynamical...

> raw counts every second. There is no smoothing, no translation to PM2.5 scale.

Slightly confused as to what you mean by this. Particle measurements via laser are by necessity over time and thus smoothed. I guess you could look at raw counts in a given time, but people use per millions because its more meaningful...else you'd need to consider fan speed to make it comparable and manually adjust air pressure/temp yourself.

Good point. I think you can get them embedded in consumer devices for pretty cheap lately; I bought the Dylos about a decade ago.

Yeah please some specific recs. I bought one and it was useless, yes I did take the plastic off.

I added a couple recommendations.

That's the one I have LOL.

Why did you think it was useless? Even if I didn’t have air monitors I can see with my eyes the dust on the hepa filter.

Hm, I'm looking to eradicate smells from my house. Do air purifiers help getting rid of that old-house smell?

As a quick solution, rent a commercial grade ozone generator.

Run it while you’re not in the house as in the concentrations they can put out it is damaging to lung tissue.

This is how hotels clear out smoke smells in rooms for instance.

Once you run it for a few hours, you can open things up and air it all out and the smells should mostly be gone unless there’s an active source of smell.

I did it while restoring an old house previously occupied by a smoker and hoarder. Would just run it at night when nobody was there and open the house in the morning when ready to get back to work on renovations.

It worked wonders.

I bought dirt cheap portable ozone generator that also produces toxic amount of ozone for human. It worked for removing smells.

Yes, if they have a charcoal filter. The Coway AP-1512 is a favorite to handle both odor and lower particulates.

I have three.

There are a number of past threads where people discuss their enthusiasm for this model. Have a search.

Can second that - I have four of them, they run 24/7 on medium and pull ~8 watts at the wall each, assuming my meter is accurate. Picked them up after the last big discussion on air quality here a few months back. They are the Wirecutter pick, I believe.

I keep an agent that monitors amazon pricing on the filters, and just buy a bunch when they dip abnormally low. Have you found any other ways to minimize cost on them? I have only used the ones sold by coway, as my pal tried some 3rd party and they were jenky.

Depending on where you live, filters are a once/twice a year expense, I believe (I’m only a few months in). Honestly my advice would be: just be diligent about maintaining them. I vacuum out the filter and charcoal screen once every couple of weeks. Takes a few minutes, pretty painless. Amazing how much dust they pick up in normal operation.

Incidentally, which agent are you using for Amazon?

Missed this reply--I use camelcamelcamel for Amazon. I'm not sure if they are able to handle the click-to-get-discount check boxes, though. I also don't know how timely they are.

I've considered setting up Huginn to do this, but haven't explored it enough: https://github.com/huginn/huginn

I can’t speak to that specifically, but they do help remove cooking smells.

Ditto. Coway Airmega 400 for me is slick and has an integrated sensor

Did you like the Qingping regular or Lite?

Yes. I prefer the Lite. I don’t have any testing data about the accuracy, but it seems to react identically to my air purifiers. For example, if I light a match or blow out a candle my air purifier will turn on and the air monitor will go ballistic. Likewise with CO2 if I sleep with the door closed it will slowly ramp up overnight.

can you recommend a specific product(s)?

I've been happy with the Wirecutter recommendation: https://www.nytimes.com/wirecutter/reviews/best-air-purifier...

Would like to hear some as well. Saw some at Home Depot but would like to hear some opinions.

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