“This device monitors CO2 level in the living or bedroom and controls a ventilation fan to improve airflow.
Carbon dioxide (CO2) is the fourth most abundant gas in the earth’s atmosphere. CO2 is a byproduct of normal cell function when it is breathed out of the body. It is also produced when fossil fuels are burned or decaying vegetation. Surface soils can sometimes contain high concentrations of this gas, from decaying vegetation or chemical changes in the bedrock.
We measure the CO2 level in ppm units. This number tells us how many parts of CO2 there are in one million parts of air. For example, if CO2 is at 800 ppm, that means in one million particles of air there are 800 particles of CO2.
Exposure to CO2 can produce a variety of health effects. These may include headaches, dizziness, restlessness, a tingling or pins or needles feeling, difficulty breathing, sweating, tiredness, increased heart rate, elevated blood pressure, coma, asphyxia, and convulsions.
The levels of CO2 in the air and potential health problems are:
400 ppm: average outdoor air level.
400–1, 000 ppm: typical level found in occupied spaces with good air exchange.
1, 000–2, 000 ppm: level associated with complaints of drowsiness and poor air.
2, 000–5, 000 ppm: level associated with headaches, sleepiness, and stagnant, stale, stuffy air. Poor concentration, loss of attention, increased heart rate and slight nausea may also be present.
5, 000 ppm: this indicates unusual air conditions where high levels of other gases could also be present. Toxicity or oxygen deprivation could occur. This is the permissible exposure limit for daily workplace exposures.
40, 000 ppm: this level is immediately harmful due to oxygen deprivation.
In this project I built a simple and portable device using Seeed Wio Terminal which displays indoor CO2 level, temperature and percentage relative humidity on its LCD screen. When the CO2 level is exceeded by a set threshold value the inbuilt buzzer starts beeping and a 5V USB powered ventilation fan turns on to keep the circulation going and reduce CO2 levels. This device is useful especially during sleep when CO2 level can increase due to bad air circulation and can affect health.
This project was conceived by my own requirement in the bedroom where airflow was severely affected but I had no idea about it and after working on another data collection project it was revealed that the air circulation of the bedroom was not good and the CO2 level was increasing during night.”