This is another way to do IoT wrong - collecting data but just displaying it.<p>The idea is to use CO₂ levels to control your HVAC system. The HVAC system should be able to draw fresh air from outside or recirculate air from inside, depending on CO₂ level. This is a standard option on modern HVAC systems, and there are standard sensors for it. Better systems sense temperature, CO₂, CO, humidity, and smoke. This is a huge win for rooms where the people load varies widely, such as hotel function rooms and classrooms. Such control systems save money, because, when nobody is using the room, they detect that CO₂ is low and cut down the ventilation rate. When the room fills up, the CO₂ level goes up, the fans speed up and the outside air intakes open until the CO₂ level comes down.[2] There are smart control units which manage heat, fans, vents, and air conditioning compressors. The hardware pays for itself in power consumption.<p>And yes, you can get this stuff Internet-enabled, although that's mostly for remote maintenance. The HVAC works just fine without connectivity.<p>Surprisingly, this technology is a tough sell. Except for convention hotels. They get this. They're in the competitive business of keeping large numbers of people comfortable and coming back. They have big rooms where the people load may go from zero to a thousand in minutes, and go back down an hour later. It's a huge win for them.<p>[1] <a href="http://www.airtesttechnologies.com/support/reference/CO2SeqOfOperation.pdf" rel="nofollow">http://www.airtesttechnologies.com/support/reference/CO2SeqO...</a>
[2] <a href="https://buildingcontrols.honeywell.com/literature/Advanced_RTU_Retrofit_Solution_Program_Sell_Sheet-01-00041.pdf" rel="nofollow">https://buildingcontrols.honeywell.com/literature/Advanced_R...</a>
If you're interested in a hardware solution, I've used the MH-Z19 CO2 sensor to great results. It's an NDIR (read:not electrochemical) sensor with a UART interface and temperature compensation. It will report up to 5000ppm and comes factory calibrated.<p>It's also $20 in singles from China. Coupled with whatever microcontroller you want, it's totally possible to have a distributed net of CO2 sensors for a low cost per node.<p>That being said, it's a ton of work and this is an excellent solution with much quicker results.
I was looking in to a indoor quality monitor, and seems like for $80, you could just buy this which connects to homekit <a href="https://www.amazon.com/Elgato-Eve-Room-technology-Bluetooth/dp/B01M2YTIBC/" rel="nofollow">https://www.amazon.com/Elgato-Eve-Room-technology-Bluetooth/...</a>
I'm sure it's just a coincidence, but Amazon just bumped the price of that sensor up by almost $40. Perhaps that is a proxy for how popular this article is and how quickly Amazon notices the trend.
Do the huge corresponding drops in CO2 and temperature at 11pm and 9am mean that the "solution" was to open a window or door for ~15 minutes a couple times a day?<p>Seems like a simple solution, other than there's a good half-hour of sub-17 degree temperatures right at the start of the workday, which isn't exactly a great motivator to start working. Unless you are skilled at typing with winter gloves on, I guess.
Well $80 dollar is affordable but certainly isn't low cost to me. Why are all Co2 Monitor cost so much?<p>And on the subject, do we have O2 level monitor as well?
What do you guys think about ozone? I know its banned in California from what I've heard. But I hear it kills a lot of bad compounds like mold. I could be wrong though, would love to hear you guys opinion on it.
In almost every office I was there was a poor ventilation. I have extremely high co2 ppm in my university labs. I try to always open windows where it possible.
i am looking for something similar but for particulate matter instead of co2 like PM2.5. I am also looking for a solution that would work mobile, eg. on a bike. Any help greatly appreciated!