Stadt Hennef

Customer reference: City of Hennef – Integration of air quality data in the smart city map


City of Hennef


Public sector / city administration

Project duration:

2019 – today

Project type:

Municipal air quality monitoring


Monitor air quality in the city center to analyze the effect of traffic and mobility measures


Provision of historic and real-time air quality data based on Breeze Technologies’ sensor platform, support with integrating the real time data feed into the municipal IT systems (smart city map)

“The environmental sensors help us investigate changes: For example, how air quality values have changed since the corona pandemic. The data enables us to understand connections better and to investigate irregularities more thoroughly. Obtaining this climate data would not have been possible in any other way. We are satisfied with the project.”Heike Behrendt, Climate Protection Manager for the City of Hennef


The city of Hennef is pursuing a comprehensive and integrated digital, environmental and climate strategy. Its aim is to promote and bring about sustainable urban development with added value for citizens, city administration and companies. This strategy also fits with the goals of the state of North Rhine-Westphalia, which has decided to further advance digitalization.

As part of this strategy, Hennef has been operating an online information system with real-time data from the areas of environmental and mobility for some time. For example, you can see information about available parking spaces or e-charging stations. The projects aim was to also included environmental data in this platform.

Through various initiatives by citizens in Hennef, air quality data has already been collected using inexpensive, uncalibrated sensors and published on portals such as The city administration therefore wanted to record calibrated measurement data for comparison and verification.


Hennef’s strategy includes various fields of action such as smart city. The aim here is, among other things, to use new possibilities for data collection for planning and control processes. Since state air quality measuring stations are usually difficult to afford for smaller cities, the city of Hennef turned to Breeze Technologies to add environmental sensors to Hennef’s smart city infrastructure in the area of air quality.

The aim was to record the quality of the air through the city’s own LoRaWAN network. Measures to improve air quality could then be drawn up based on collected data. Hennef wanted to counteract the climate emergency declared in June 2019 and set an example for sustainable urban development.


The environmental sensors from Breeze Technologies were installed and ready for use on the main road near Hennef’s historic town hall within two months. The sensors collect real-time data on ozone, particulate matter, ammonia, carbon monoxide and nitrogen dioxide. In addition to air quality data, the city is collecting data on traffic and mobility measures.

The project is supervised in Hennef by the climate protection manager, the IT department and volunteer-run associations. Breeze Technologies’ environmental sensors are integrated into the local LoRaWAN network. This technology was already available in Hennef’s smart city infrastructure and is particularly suitable for use in such projects due to its high transmission range and low energy requirements.

The collected data is particularly useful to support municipal decision making with the focus on improving urban air quality. In addition, citizens have also been very interested in their city’s air quality; they regularly access it via the air quality citizen portal from Breeze Technologies and via the smart city map of the city of Hennef. There are even plans to broadcast the results live on a screen in the city. A further expansion of activities is planned. Hennef clearly shows how quickly a city administration can initiate innovative projects and try out new technologies.


Hennef – Smart-City-Karte erweitert (Kommune21, 18.12.2019)

Dicke Luft? Von wegen! Wie die Stadt Hennef ihre Luftdaten erhebt (VKU, 21.10.2019)

Neuer Umweltsensor auf der Smart-City-Karte (Stadt Hennef, 03.09.2019)