Material Analysis and Indoor Chemistry

Research project

Influence of wood and wood-based materials on indoor air quality

Wood releases volatile organic compounds: What is perceptible as a typical wood scent in indoor areas is reflected in measurable values. Building materials are currently only tested individually. In real-life installation situations, however, interactions or secondary reactions can occur. The aim of the project as a whole is the development of a proposal for the procedure for the evaluation of CE-labelled wood-based materials and technically dried cross-laminated timber with regard to the release of substances into the indoor air. The Fraunhofer WKI sub-project focuses on the development of new investigation procedures with regard to ensuring compliance with existing guideline values for the evaluation of the quality of indoor air as well as the secure classification of the wood-based materials with respect to their health compatibility.

The results should serve as a foundation for recommendations for action regarding the structural application of wood products.

© Fraunhofer WKI | Manuela Lingnau
Transport of a composite component (wall section) in the 30m³ emission test chamber at the Fraunhofer WKI
© Fraunhofer WKI | Manuela Lingnau
The emission measurement on the composite component is performed in the test chamber at the Fraunhofer WKI under standardized conditions over a time period of 4 weeks or 3 months (long-term test)

In this project, we are addressing the question as to how the emissions of wood and wood-based materials develop over a longer period of time and how they are relevant as regards indoor air in a real-life installation situation. The established evaluation schemes for building products stipulate an examination after 28 days for the evaluation of the long-term emission. This measurement alone may not be representative for the assessment of the long-term emission behavior of wood and wood-based materials as it may not adequately depict their contribution to the quality of the indoor air.

In the part of the project being supervised by the Fraunhofer WKI, we initially measure individual emissions from building materials in accordance with conventional methods. Subsequently, investigations into interactions of individual components within the composite are performed. The focus is hereby placed upon the inspection of the emissions of such a composite, for example a wall, over a longer period of time as well as their effect on the indoor air quality. In order to nevertheless be able to set standardizable boundary conditions, the tests are performed in large test chambers. For the verification of the results of the research, the scientists at the Thünen Institute perform parallel measurements on real buildings made from the same materials. For the realization of the structures, close cooperation takes place with associations from the wood industry and manufacturers of wooden houses as well as their suppliers.
 

Tasks of the Fraunhofer WKI:

  • Definition of a scenario in large test chambers in the standardization model room for the simulation of real room conditions
  • Individual testing of all utilized building materials, including an evaluation in compliance with AgBB (Health-related evaluation of building products)
  • Installation of exemplary, standardized wall elements in a large test chamber
  • Possibilities for evaluation of odors in component measurements (AgBB) and in the construction (large test chamber and real room)
  • Long-term behavior
  • Assistance in the Thünen Institute project section (recommendations for action with regard to odor and large test chambers)

Additional information can be found on the Project website of the Thünen Institute.

 

Assembly of test houses at the Thünen Institute

© Thünen-Institut | Saskia Poth
Construction phase of test houses at the Thünen Institute
© Thünen-Institut | Saskia Poth
Construction phase of test houses at the Thünen Institute
© Thünen-Institut | Saskia Poth
Construction phase of test houses at the Thünen Institute

Results

We were able to determine that the influence of the emission rates of individual materials on the concentrations actually found in the indoor air is very complex. In principle, however, system tests on entire components in large test chambers are suitable for approximating reality and describing the interactions between the emissions from the materials, thereby taking into account the structure of the construction. 

Project partners

  • Thünen Institute
  • Industry

Funding

Funding body:
Federal Ministry of Food and Agriculture (BMEL)

Project management:
Fachagentur Nachwachsende Rohstoffe e. V. (Agency for Renewable Resources, FNR)

FNR Funding code:
22005615

Duration:
1.4.2016 to 31.12.2019