News & Stories

IoT in practice: Covid19-prevention with the "CO2 Traffic Light"

IoT in practice: Covid19-prevention with the "CO2 Traffic Light"

The pandemic has taken over public life this autumn/winter. We have become accustomed to social distancing, hygiene regulations and daily mask-wearing. Now the German government has extended its recommendations to include the Corona-Warn-App and ventilation. Wherever groups of people meet, ventilation should be intensive, regular and correct.

Leaving windows open constantly was quite easy to do in the warm temperatures of summer, but will now become increasingly difficult in the cold half of the year. The balancing act between cooled rooms and excessive airborne droplet exposure is a difficult one, especially in offices and classrooms. But there are good IoT-based solutions that schools in particular can use to monitor the air quality in their rooms.

A reduced aerosol load in the air is considered a good indication of a reduced risk of infection. ZENNER relies on a combination of hardware and software as well as LoRaWAN transmission to enable fast and reliable alerts in the event of increased CO2 concentration indoors.

In summer 2020 we developed the CO2 Traffic Light together with Stadtwerke Strausberg and Stadtwerke Steinburg. Both utility companies have already successfully implemented several application scenarios in the Smart City and Smart Building sectors in collaboration with ZENNER.

The system is as simple to implement as it is effective to use. The data is collected via the sensor, aggregated in the IoT platform, interpreted by a dashboard and then correlated. All you need is an intelligent platform and a reliable sensor.

The sensor from Elsys (learn more in the ZENNER Shop) measures the CO2 content of the room’s air at flexibly configurable intervals and sends it via LoRaWAN to the IoT platform ELEMENT IoT, where the information is evaluated and visualised in real time – in this case as a traffic light display. The school caretaker, for example, as well as every teacher can immediately see on a smartphone or tablet which class needs its windows opening – or even where they can be closed.

Elsys Raumsensor

As soon as a predefined limit value is exceeded, the platform warns the user. This can be done via a graphical data dashboard, but also via separate hardware such as displays, lights or on digital signage screens. But alerts can also be sent by SMS, e-mail or push notification.

In the classroom example, ELEMENT IoT can even display several rooms, so that an overview of the entire school is possible, for example in the secretary's office. Since the displays are directly connected to the sensor via the platform, status changes are transmitted immediately. It is also possible to monitor and analyse the data to develop a ventilation concept beyond responding ad-hoc to warnings as they’re generated.


Dashboard Co2 Ampel in der ELEMENT-Plattform


Since the battery-powered sensors are small, light and easy to install, essentially any room can be equipped with them. Such fast and efficient solutions are of course very important, particularly in view of the current background of coronavirus prevention, and are therefore in great demand. ZENNER has therefore included the CO2 Traffic Light in its regular portfolio after a successful test phase in Steinburg and Strausberg.

It is then only a small step from the CO2 Traffic Light to a smart building. As soon as the LoRaWAN infrastructure is in place, ELEMENT IoT can be used to implement numerous applications that increase comfort and security for room users and at the same time relieve facility management. This starts with the fact that the Elsys sensors can measure not only CO2 but also temperature and humidity as well as movement and brightness. Together with smoke detectors, door and window sensors that can report unauthorised openings or leakage sensors, a digital picture of the classroom or even the whole school can be created.

Implementing such applications no longer poses a problem today and is worthwhile in every situation – especially now that the barriers to digitisation are being lowered by federal and state subsidies. So today's CO2 Traffic Light may soon become tomorrow's smart building.


Melanie Richter

Author: Melanie Richter, Project Manager IoT at ZENNER International



Team IOT:

At the IoT specialist ZENNER International, a whole team of developers and project managers is working on a large number of new innovations. The two teams - project management and product management - together form the Team IoT. They develop new IoT applications in cooperation with each other and with customers and partners - from the idea through the development and test phase to market readiness. The Hamburg-based ZENNER IoT-Solutions GmbH ensures technical implementation on the software- and platform-level with a lot of know-how and creativity. With ELEMENT IOT, ZENNER IoT-Solutions operates a platform on which digital data become smart solutions.