The COVID-19 pandemic has created huge demand for measuring air quality and viral loads in indoor spaces. Increasing numbers of studies indicate that CO₂ (carbon dioxide) can be a good indicator for monitoring air quality in enclosed spaces. Proper ventilation is becoming more and more important. This is because when there are many people in a room, a huge amount of air is exhaled – an adult exhales an estimated eight liters per minute. This exhaled air contains CO₂ and aerosols. The aerosols convey viruses, and are therefore a medium for transmission. The aerosol concentration in a room rises in parallel with the CO₂ concentration. In classrooms, the CO₂ concentration should not exceed 1,000 ppm (ppm stands for “parts per million” – a measure of concentration). By way of comparison, fresh air outdoors has a CO₂ concentration of 400 ppm. Too much CO₂ in a room and it becomes stifling, impairing concentration and increasing the risk of catching a virus.
According to various media, there is currently a shortage of CO₂ monitoring systems. As a world leading manufacturer in environmental sensing, Sensirion is now supporting Swiss schools. Schools are at a particularly high risk in the ongoing coronavirus pandemic. Pupils sit in classrooms for hours, leaving them exposed to potentially infectious aerosols. In winter, this is particularly problematic as classrooms cannot be continually ventilated; the pupils would have to keep on their winter coats all day or catch cold. A CO₂ monitor can make the school day easier by indicating the right time for opening windows to ventilate the room. This time can vary according to the size of the room, the number of people in it and its natural ventilation rate. A CO₂ sensor allows ventilation to be carried out as needed. This is where Sensirion’s monitor comes in, based on the new SCD4x sensor.
"In closed rooms, like classrooms without much air circulation, you are at risk of catching a virus. This can happen even several minutes after a pupil has left the room. This is where we want bring in our sensors to help teachers ventilate effectively and regularly, thereby reducing the risk of infection and increasing classroom well-being and safety," says Pascal Gerner, Director Product Management at Sensirion. The sensor manufacturer is therefore donating reliable, precise CO₂ monitoring sensors or CO₂ monitors to 2,500 classrooms in the canton of Zurich.
Sensirion’s CO₂ monitor for monitoring air quality has a highly accurate and reliable CO₂ sensor built in, as well as LED lights that indicate the air quality using a traffic light system. The colors red, yellow and green indicate when it is time to ventilate the room. The handy gadget also has a USB port, allowing it to be connected to any hardware that has a USB connector, whether it is a USB charger, a computer or a car. The sensor manufacturer also offers an iOS and Android app to record and display measurement data in real time.
"Concepts for smart ventilation in classrooms are vital, especially now that the weather is getting steadily colder. The Swiss media have also stated that there is a shortage of CO₂ monitoring systems at the moment. That is why Sensirion, the innovative Swiss sensor expert, has done everything in its power to rapidly develop a CO₂ monitor that measures air quality, to help reduce COVID-19 infections in this unprecedented situation," says Marc von Waldkirch, CEO of Sensirion. "Promoting up-and-coming talent is an essential part of our company culture, so Swiss education holds a special place for us."