Regular ventilation is one of the simplest and most effective methods of preventing the transmission of the corona virus in closed rooms. But the implementation seems difficult: pictures of freezing students in winter jackets next to open windows make the measure appear inefficient and dangerous. How can air quality and CO2 be easily measured and then analyzed to determine which courses of action are best to implement the ventilation concept? The Internet of Things and a Digital Twin provide answers to these questions.
The DIGIMONDO team has been working on CO2 measurements in rooms for several years. Good indoor air ensures better concentration and a better learning environment - this was already important for Schulbau Hamburg in its pilot project "Digitalized School". This year CO2 measurement is more up-to-date than ever. The CoVid19 pandemic is creating new challenges in schools and at the workplace. High CO2 levels are increasing the distribution of aerosols. Hygiene concepts for schools prescribe ventilation within certain time frames. But the CO2 content depends on many factors: How many people are in the room, is there a lot of talking and how large is the room? Setting up a general rule seems counterproductive and it often seems to be a matter of impulse ventilation by feeling. Especially when the outside temperature is cold, there is a high risk that the students will catch a cold.
Solutions such as CO2 traffic lights and smart air space measurement are now springing up like mushrooms. Combined with a CO2 sensor, these aids indicate when a room needs to be ventilated and when the window can be closed again. The DIGIMONDO team has thought one step further in its full-service solution.
The DIGIMONDO team uses CO2 sensors in classrooms and other closed rooms with high through traffic. The LoRaWAN room sensor from Elsys has already been certified as a particularly suitable sensor by the IoT experts. The Elsys ERS CO2 sensor can centrally record the indoor climate via LoRaWAN. The integrated sensors send data on temperature, humidity, brightness, movement (PIR) and CO2 content to the Digital Twin, DIGIMONDO's latest software solution. In the Digital Twin, IoT data is received, aggregated with other data, processes are automated and analyzed. For indoor CO2 measurement, this means that the CO2 sensor continuously measures and transmits the values. As soon as the values exceed a pre-defined limit, such as 1000 ppm, this appears visualized in the Twin itself and at the same time triggers an alarm - on the tablet, by e-mail or via SMS. As soon as the airing is done and the CO2 value is back in the green range, the Twin gives the all-clear. However, the functions of a CO2 traffic light often end here. With the Twin, even more is possible: Using the analysis functions and the combination of different sensors such as CO2 sensors or window sensors, and data such as room size and number of people, it is determined which ventilation time is necessary for which room occupancy and which situations cause higher CO2 levels.
Thus the efficiency of ventilation as an anti-corona measure can be backed up with facts and figures. With room air sensor and window sensor a room can be equipped within a few hours. Setting up the sensors in the Twin and creating the corresponding rules for automating warnings also takes little time. With appropriate preparation, it takes only 5 minutes from sensor in hand to the fully visualized CO2 value in the Digital Twin. The result is a quickly set up and cost-effective solution for not only measuring the CO2 content in rooms, but also using the data to draw conclusions about which measures are appropriate and when, and to back these up with facts.
