Indoor climate through algae

The aim of the project was to develop a device system for indoor air treatment for a healthy indoor climate by lowering the carbon dioxide concentration or increasing the oxygen content and reducing the germ load in the room air with the simultaneous realization of relaxation elements.
In addition to pollutants, the CO2 concentration plays a decisive role in indoor air quality. Although carbon dioxide is only toxic to humans from a concentration of 2.5% by volume, performance, concentration and well-being are already impaired from a concentration of 0.08% by volume (800 ppm) of carbon dioxide. Especially in closed rooms, such as conference rooms or waiting rooms, where there are often many people and where ventilation is limited, levels of 5,000 to 6,000 ppm carbon dioxide occur after just a few minutes.
Where there is a lot of CO2, a particularly high number of germs are also found. The risk of infection is particularly high in waiting rooms in doctors’ surgeries and hospitals.
The BioAir system provides for the use of microalgae in photobioreactor systems (PBR) for climate management in buildings. One advantage of such systems is, for example, the reduced space requirement compared to plant systems. Encapsulated microalgae are used in the PBR to increase the service life of the photobioreactor. By using the innovative encapsulation concept, it is possible to introduce and remove the phototrophic microorganisms with minimal effort. The use of semi-permeable membranes as capsule material enables the organisms to be optimally supplied with dissolved and gaseous nutrients, so that the biology only needs to be changed every few weeks. Each capsule represents an independent reaction space (membrane capsule system). Gases such as carbon dioxide and oxygen as well as low-molecular compounds such as nutrient salts can diffusively pass through the capsule membrane, whereas the microorganism cells are immobilized inside the capsule.
The PBR system thus represents an active CO2 sink with simultaneous O2 production. The integration of a UV clarifier reduces the bacterial load in the room air.
As a visual highlight with a moving water component, the system has a calming effect similar to an aquarium and therefore contributes to people’s general well-being. The BioAir lighting can also be used to partially illuminate the room, whereby the installation of different colored LED elements allows a wide range of light colors to be realized.

Project partner: BAT Automatisierungstechnik-Planungs GmbH
Duration: 01.10.2015 – 30.09.2017
Funding body: VDI/VDE-IT on behalf of the BMWT