Green City Solutions: Moss-Based Biofilters for Cooler, Cleaner Urban Air

Green City Solutions: Moss-Based Biofilters for Cooler, Cleaner Urban Air

Cities concentrate people, traffic, and economic activity—yet they also concentrate pollution and heat. Dense urban environments often lack the space for large-scale green infrastructure, while sealed surfaces intensify the urban heat island effect. As a result, improving air quality and thermal comfort in cities remains a complex challenge. Green City Solutions, founded in 2014 and headquartered in Bestensee near Berlin, develops compact biofilter systems designed to improve local air quality and microclimates in urban environments. The company combines the natural filtering capabilities of moss with IoT-enabled environmental control systems. By integrating biological processes with digital monitoring and ventilation technology, Green City Solutions aims to create deployable infrastructure that helps cities respond to air pollution and rising urban temperatures. The approach positions living ecosystems as an engineered component of the built environment.

Technology and Product

Instead of mechanical filters or chemical processes, the technology relies on a biological mechanism that has evolved over millions of years. Green City Solutions integrates cultivated moss surfaces into biofilter installations equipped with active ventilation, irrigation, and IoT monitoring technology. Polluted urban air is actively drawn through the moss modules, where particles such as fine dust and soot are captured and partially degraded by biological processes. At the same time, the high water retention capacity of moss enables evaporative cooling, releasing cooler air into the surrounding environment. Sensors measure parameters such as temperature, humidity, and air quality, while a control algorithm regulates airflow and irrigation to maintain stable operating conditions.

CityTree installation integrating moss-based air filtration into urban public infrastructure. (© Green City Solutions)

Industrial Fit and Applications

Urban pollution hotspots often leave little room for conventional greening measures such as trees or parks. This is where the company positions its modular biofilter systems. Typical deployment locations include public squares, transport corridors, and industrial areas with high pollution exposure. The installations are designed to integrate into existing urban infrastructure while requiring limited physical space. By combining environmental technology with urban design elements such as seating or digital displays, the systems can function as multifunctional installations while addressing localized air quality and microclimate challenges.

The WallBreeze module enables the biofilters to be integrated into building facades and indoor spaces. (© Green City Solutions)

Founding Team

Green City Solutions was founded by a team including Peter Sänger and Zhengliang Wu. Officially launched in 2014, the company brought together a young, interdisciplinary team with expertise in horticulture and biology, computer science, architecture, and mechanical engineering to develop nature-based solutions for urban air quality.