AirBits Smart Home Detection
2021-09-25 | By M5Stack
License: General Public License Arduino
* Thanks to the project info and source code provided by @Andrew Van Tassel
Story
The goal of AirBits is to keep you informed about the levels of CO2 and TVOCs in real-time for indoor spaces before you enter or even while you are there. These bits in the air can be dangerous to you when exposed at high levels for a period of time.
As we have found out with the recent pandemic and COVID-19 (SARS-CoV-2), air flow and good ventilation in indoor spaces is critical for keeping you healthy. High CO2 levels could mean there is poor air flow or simply that there are too many people in that space, and you are best to get out of it ASAP.
AirBits measures CO2, TVOCs and decibel levels. One or many devices could be installed in a space. The real-time data will be displayed on the M5 Core2 device screen along with colored LED lights based on current levels. This data is also sent in real-time to AWS, which would allow anyone in a geo-fenced area to be notified after installing an app. This data could also be made available on any map app for indoor air quality (Google Maps, Apple Maps).
Bourbon Street Hypothetical
Imagine you are walking down Bourbon Street in New Orleans where each bar or restaurant had an AirBits device sending real-time data to AWS. You would have a smart phone app subscribed to the data stream that would notify you before entering a space.
Or an employee working the door could regulate foot traffic into their establishment if levels started to rise. Of course, this could also be automated and built into digital signs in windows or automating door access.
OSHA
According to OSHA, restaurant facility workers cannot be exposed to CO2 levels higher than 5, 000 parts per million (ppm) over an 8-hour work day, which is about 0.5% of CO2 in the air. If exposure is short term, the limit is set to no more than 30, 000 ppm for the duration of 10 minutes.
Source: http://air-source.com/blog/osha-safety-standards-for-monitoring-restaurant-gases
CO2
*Health effects of high levels of carbon dioxide*
CO2 is considered to be minimally toxic by inhalation. The primary health effects caused by CO2 are the result of its behavior as a simple asphyxiant. A simple asphyxiant is a gas which reduces or displaces the normal oxygen in breathing air.
Symptoms of mild CO2 exposure may include headache and drowsiness. At higher levels, rapid breathing, confusion, increased cardiac output, elevated blood pressure and increased arrhythmias may occur.
Breathing oxygen depleted air caused by extreme CO2 concentrations can lead to death by
suffocation.
Source: https://www.fsis.usda.gov/sites/default/files/media_file/2020-08/Carbon-Dioxide.pdf
TVOC
*Health effects of high levels of volatile organic compounds*
Symptoms include eye, nose and throat irritation. Headaches, loss of coordination and nausea. Long exposure to high levels can cause damage to liver, kidney and the central nervous system. Some organics can cause cancer in animals, some are suspected or known to cause cancer in humans.
Source: https://www.epa.gov/indoor-air-quality-iaq/volatile-organic-compounds-impact-indoor-air-quality
Decibels
*Health effects of high sound levels*
| dB | Damage |
|---|---|
| 80 - 85 | Damage to hearing possible after 2 hours of exposure |
| 95 | Damage to hearing possible after about 50 minutes of exposure |
| 100 | Hearing loss possible after 15 minutes |
| 105 - 110 | Hearing loss possible in less than 5 minutes |
| 110 | Hearing loss possible in less than 2 minutes |
| 120 | Pain and ear injury
| 140 - 150 | Pain and ear injury
Source: https://www.cdc.gov/nceh/hearing_loss/what_noises_cause_hearing_loss.html
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