Technology - Forschungscluster an der CBS

Research Cluster: Technology

Technology deals with new technologies that are developed to improve processes, solve problems or increase the quality of life. The following section presents projects aimed at improving air quality.

INDAIRPOLLNET (Indoor Air Pollution Network)

Project participant: Prof. Dr. Sascha Nehr

In industrialized countries, around 80-90% of our time is spent indoors, where exposure to air pollution is highest. However, air pollution regulation is mainly focused on the outdoor environment, while the indoor environment is much less well characterized. Concentrations of many air pollutants can be higher indoors than outdoors, especially after activities such as cleaning and cooking. With the increasing impact of climate change, energy efficiency measures are making buildings much more airtight. Such measures can further increase indoor pollutant concentrations. Therefore, to reduce human exposure to air pollution, both the indoor and outdoor environment and the role of ventilation must be considered in order to reduce exposure through appropriate building operation, building use and building design.

The overall aim of this network was to develop a plan for an optimal indoor air chemical characterization campaign relevant to the buildings in use and the way they are used.

INDAIRPOLLNET (INDoor AIR POLLution NETwork) has improved the understanding of the causes of high concentrations of indoor air pollutants. It has brought together experts in laboratory and chamber experiments, modeling studies and measurements relevant to indoor air quality, including outdoor air chemists. The aim of this action was to significantly advance the field of indoor air pollution science, identify future areas of research and bridge the gap between research and industry to identify appropriate mitigation strategies to optimize indoor air quality. The results were disseminated to relevant stakeholders such as architects, building engineers and equipment manufacturers.

This project had the following objectives:

Improved understanding of indoor air pollution
Improved and/or new techniques for measuring indoor air chemistry
Improved models for indoor air chemistry
Improved buildings for the future
Improved standardization protocols
Identification of potentially harmful substances in indoor air
Data collection, review and development of rigorous recommendations for future indoor air pollution science
Knowledge transfer to policy makers and other stakeholders with an interest in indoor air quality.

Objectives were also set with regard to capacity building:

Building a new scientific community at the interface of outdoor and indoor air chemistry
Maximizing research collaboration in Europe
Submission of future proposals
Scientific training - dissemination of information

DACBE - Direct Air Capturing in the Built Environment

Project participants: Lukas Baus, Prof. Dr. Sascha Nehr S

ocial loads influence indoor air quality. Airborne trace substances result from sources related to room furnishings (e.g. material emissions) and room use (e.g. CO2 from breathing). CO2 is the recognized key parameter for the hygienic assessment of indoor air quality, as the CO2 concentration correlates with other trace substance concentrations. Excessive CO2 concentrations also cause headaches, tiredness, dizziness and poor concentration. A CO2 concentration of less than 1,000 ppm is considered hygienically safe. With conventional ventilation methods, it is assumed that a reduction in the CO2 concentration also leads to a reduction in other trace substance concentrations. However, outside air can also contribute to the contamination of indoor air during ventilation. O3, NOx, organic compounds and particles in particular play a role here. According to the current state of the art, a normal level of expectation for indoor air quality is defined by a CO2 indoor air concentration that exceeds the outdoor air concentration of CO2 (approx. 400 ppm) by a maximum of 800 ppm. With conventional ventilation methods and if a normal level of expectations is met, the guide value of 1000 ppm CO2 in the indoor air can no longer be maintained and further indoor air hygiene measures are required.

The DACBE was made possible by a grant from the IMCD Cares Fund for a 6-month part-time position and an in-kind grant of €4,000. DACBE presented a solution approach in which the indoor air hygiene requirements could be met through CO2 capture using direct air capture (DAC) and air recirculation. Furthermore, this approach had the potential to resolve the conflict of objectives between energy-efficient building operation and high indoor air quality. It should be emphasized that ventilation and air conditioning systems (HVAC systems) with a total delivery volume of approx. 5 ∙ 109 m³ h-1 are installed in Germany. Assuming that these systems are operated continuously with atmospheric air, they transport around 40 % of

Germany's CO2 emissions over the course of the year. This results in an enormous potential for CO2 provision through capture from the building sector.

DACBE was dedicated to the research question: "How can the indoor air quality be improved by coupling existing HVAC systems with DAC in a new way, while at the same time reducing building energy consumption and recovering CO2?" To this end, the following had to be investigated in the period from January to February and September to December,

how an air handling unit with DAC can contribute to improving indoor air quality,
how an air handling unit with DAC can contribute to reducing building energy consumption and
how CO2 can be separated from building air in an energetically sensible way and how it can be used for further energy and/or material use in decentralized applications