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Comment by Someone1234 | Hacker News Reader

Informative article with fair, fact based, conclusions.

I'd like to add that:

- The VINDRIKTNING is extremely consumer accessible ($11.99, good build, simple traffic light system).

- It may be put into spaces that previously had no particulate air quality monitoring.

- The spouse-acceptance-factor is extremely high (unlike e.g. a couple of circuit boards wired together off of Aliexpress).

There are other consumer friendly offerings, but they aren't affordable (e.g. Amazon Smart Air Quality Monitor 4x cost, Airthings 10x cost). That being said, IKEA could fix their traffic-light system's cut off points for free and should consider it.

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It is actually pretty easy to build a much more accurate air quality sensor with the Plantower PM2.5 module as a base and a Wemos D1 mini as WiFi connected MCU. We have build instructions on our website on how to do it [1] + a nice 3D printable enclosure to pass the spouse-acceptance ;).

[1] https://www.airgradient.com/diy/

I don't think our usages of "accessible" are the same.

For example expecting to consumers to have a 3D printer and know how to use one would preclude it from my definition by a lot. Let alone needing a breadboard and to manually solder on components onto it.

Accessible is walking into a store, putting a reasonable amount of money down, and plugging the thing in. Then providing output anyone can understand without training or expertise (e.g. traffic lights, smiley faces, etc).

I once bought an air filter that had the pm 2.5 rating surrounded by a blue/yellow/red halo. The only things it was missing were logging, and the ability to run the sensor without the fan. It could change fan speeds based on PM 2.5, but it was calibrated for a small room, and always ran way too slow.

I wish there were standards around thermostats these days. If there were, then people could sell gizmos that measure PM 2.5, then (if the windows are closed), use it to set the speed of the variable speed blower in central air furnaces accordingly. This would cut our electricity usage by at least 20-30% during fire season.

(I’d love to see a legal mandate for interoperability in this space.)

My furnace blower isn't in use any longer, but it has connections for varying speeds, 6, I think. It only uses 1, though. I'm unsure of how it would even be used in practice, as it appears it's just various voltages. Ideally furnace blowers would be inverter ran so you could just tell the inverter how fast to run the fan, rather than changing the supply voltage.

Mine was a 3.5 ton HVAC, I replaced it with a five head, five and a half ton "mini split"; while the split air has had it's share of issues (like, I got a full refund of the purchase price a few months ago due to manufacturing defects of the copper lines), I prefer having air handling done bear the ceiling and using 20x20x1 inch filters on box fans (or fancy filters if those are your style) on the floor. The mini split has the inverter driven motors everywhere, and is completely silent during normal use.

I have two AQM, and occasionally one or the other will register high CO2 or whatever and I will open a couple of windows and run exhaust fans (built in to the home) to cycle the air, it takes about 20 minutes. The main furnace style system did no filtering or air quality management.

> I wish there were standards around thermostats these days.

https://en.wikipedia.org/wiki/OpenTherm

to be fair, ahaucnx didn't use the word 'accessible', he just said 'easy to build' -- and this is hacker news, not consumer reports.

but if you do want 'accessible' in your sense of the word (pay some money, get a working assembled unit), AirGradient does sell assembled units. And can provide a back-end system for remote monitoring if you would like.

The comment was edited to remove the word. “Easy to build” wasn’t originally there.

Fortunately this is even easier: https://sensor.community/en/sensors/

I see that there's a tiny 20x20 fan in these modules. Do these make audible noise or are the fans in these running rather slowly just to have air movement "better than convection" through the sensor?

The person who did the original hack on these says they are audible and the controller is constantly switching the fan on and off so they reconnected it to 3.3v all the time. So it runs at a lower speed and constantly.

See this link under the low noise mod heading

https://github.com/Hypfer/esp8266-vindriktning-particle-sens...

Spouse acceptance factor is an underrated engineering constraint.

I think being low-cost is very important, otherwise I wouldn't consider it. I don't live near a major road, but in a small city. I don't think the air-quality is bad, but I also don't know for sure. I would not invest a significant amount of money (more than 10-15€).

I've found a lot of indoor sources of contaminants for example cheese that fell off a Pizza onto the oven floor will put you into "yellow" the next time you run the oven.

You may find the Breezometer app helpful - I’ve found it quite accurate for local outdoor air quality in several different areas.

> - The spouse-acceptance-factor is extremely high (unlike e.g. a couple of circuit boards wired together off of Aliexpress).

Which circuit boards do you recommend that have high accuracy that can be ordered?

I can recommed the Plantower 5003 PM sensor. Plantower also has smaller ones, e.g. 7003 or A003 but we get the best (most accurate and stable) readings from the 5003 model.

We also experienced with more expensive ones e.g. from Sensirion but did not really measure a significant advantage compared to the Plantower.

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