Comment by bloopernova | Hacker News Reader

Comment by bloopernova | Hacker News Reader

AirThings air quality monitors! If you're worried about indoor air quality, I enthusiastically recommend them. They provide a no-subscription app that displays various sensor readings, charts over time, etc. Plus a web dashboard with the same kind of information, and an API with pretty good instructions on grabbing info: https://developer.airthings.com/docs/api-postman-insomnia

I was worried about air quality and wasn't having much luck making my own sensors, so I bought a couple of AirThings air sensors.

Lucky I did. Our furnace air intake pipe had been blocked by multiple birds nests, and the secondary pipe for the water heater was incorrectly connected. Our indoor CO2 levels were higher than 4,000ppm! The levels would also jump when the furnace kicked on, even with windows open.

Thankfully apartment complex maintenance was able to fix it immediately and levels are much lower now, especially when the furnace is running. (About 500ppm with windows open, 700 with them closed and furnace running, 1,100ppm if the windows haven't been open and the furnace hasn't run for a while.) It's possible our health has improved because of the sensors.

I got 2 AirThings View Plus. I'm not affiliated with the company other than having bought their products.

Shameless plug.

If you prefer an open source / open hardware air quality monitor check out our popular DIY air quality monitor [1]. The built uses high quality sensors for PM, CO2, Temperature and Humidity. You can either build it yourself or get a kit from us with a nice plastic enclosure.

You can also get the SGP41 as an optional module which not only measures TVOCs but also NOx and we can see it reacts to gas ovens/boilers.

Since it is open source, you can either send data to our dashboard or to your own server / home assistant etc. So it does not force you into a subscription or a specific dashboard.

[1] https://www.airgradient.com/open-airgradient/kits/

Oh wow, that's really nice. I wish I'd known about that before I tried to make my own sensors with an ESP32, MicroPython, and a bunch of stuff from Adafruit.

Very cool stuff, I'll share this with my coworkers and social group :)

Is this extensible for things like CO and Radon?

It's open source and additional pins are broken out on the PCB so you can easily add additional sensors yourself.

I have 3 questions about SGP41:

1. Is SGP41 (the one in your website) something that I can just insert into the PCB like how we could connect a computer case fan into the motherboard header or will it need soldering? Also, I saw in your build instructions that 2 tiny resistors have to be removed for SGP30 sensor. Is that the case with SGP41 as well?

2. Do you sell the "PRO Pre-soldered" kit or any other products/devices that come with SGP41 prebuilt? If not, is there an option to buy the "PRO Pre-soldered" one with SGP41?

3. Will the software automatically start reading SGP41 values or are any changes needed on software side?

1. Yes. No soldering required. Just put it on the socket on the presoldered board.

2. Just buy the presoldered kit and SGP41 module together (put both items into the shopping cart).

3. Yes. The software will already show the TVOC and NOx values.

Seconding this. I picked up an Airthings wave plus sensor a few months back and have been quite happy with it. I was shocked by how quickly the co2 value would rise in my home office during a typical work day. Now I can tell when I need to open a window to let in fresh air to avoid feeling drowsy.

I was able to connect it to my Home Assistant server using a USB Bluetooth dongle which was a nice bonus.

I was also surprised. I bought another brand of data logging monitor and could easily see which days were weekends and which days I’d worked from the office or been on a trip.

From the readings, I came up with alternative hypothesis about why I felt tired in the afternoon and could use ventilation to reduce that.

Thanks for the information. I'm interested, but can't figure out:

Where is the data stored? "In the cloud" (on their servers)? Is there an option to store the data locally and never connect to their servers?

As far as I can tell, data is stored in the cloud. The Android app does talk directly to the sensor devices.

I don't think there's a non-cloud option. They have a chat on their homepage though, if you wanted to find out more than I know :)

They don't appear to have an android app?? Although they do appear to integrate with home assistant so that almost solves the lack of android app.

I'm using the AirThings Android app, they definitely have one.

I'm skeptical of products when they have copy such as this on their homepage:

  > Virus
  > Tracking your humidity and keeping CO2 levels low will greatly reduce spread of virus.

I know nothing about the product other than seeing some enthusiasm for it on HN, but writing like this would typically be enough for me to discount purchasing anything from the company.

I think they’re using CO2 as a proxy for air changes with the outside. (It’s tortured language, but there is underlying positive correlation between high observed CO2 from human occupancy and low air changes per hour and between low air changes and higher concentrations of other airborne contaminants.)

So I should keep the window open while I cough on my family? Not to shoot the messenger, but that's just PR to include things like virus during / after a pandemic.

That’s probably less unhealthful than to do that with the window closed.

I would expect that keeping windows open will decrease the risk of passing on an airborne disease to your family, yes.

My point was, if I am sick, and not isolating properly at home, it's not gonna make a difference, especially for something like covid.

Keeping CO2 levels low but I come and cough at the sofa and go will not make any difference.

Infections are a stochastic phenomenon, so while keeping your windows open won't protect your loved ones from you coughing on their faces, it may make a difference if you're attempting to isolate properly, or in other shared spaces.

Not doubting you, but why do you think this is so unbelievable? It seems intuitive to me that tracking CO2 levels in a shared space would act as a proxy for tracking how much of other people's breath you are breathing in. Some quick googling suggests this is a real effect.

https://www.sciencedaily.com/releases/2021/04/210407143809.h...

>> Tracking your humidity […]

> I know nothing about the product other than seeing some enthusiasm for it on HN, but writing like this would typically be enough for me to discount purchasing anything from the company.

There is a bunch of research on which things grow (or do not grow) at various humidity levels, and having your structure be in the 40-60% range tends to help in reducing various things you don't want to grow. See Figure 1:

* https://www.ashrae.org/file%20library/technical%20resources/...

Also:

* https://www.energyvanguard.com/blog/humidity-health-and-ster...

* https://www.energyvanguard.com/blog/bad-advice-about-indoor-...

Same; after clicking through tons of copy to get at how their "Mold Detection" works, hoping it was a novel sensor but finding it just uses the existing humidity and temperature values to 'guess', I think I'll go with the open source version.

Just the facts, please :)

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