Hartwig M. Künzel is the Head of Department for Hygrothermics at Fraunhofer IBP in Germany, where he is responsible for hygrothermal investigations sponsored by industry and government. Hartwig’s role encompasses scientific research and model development, staff management and financial control of the department’s annual research budget. 

During his PhD work, Hartwig developed the hygrothermal model WUFI®, which has become an internationally recognised and widely applied simulation tool for moisture control in buildings. His research has helped provide better understanding of the hygrothermal conditions in building envelope systems, as well as their impact on building energy consumption, durability and human comfort.

Hartwig has worked on numerous international projects supported by the International Energy Agency (IEA), the European Commission and several German ministries. He is involved in the development of international guidelines and standards, including chairing the national standard committee on moisture control, as well as the CEN working group on hygrothermal performance of building components and building elements. 

Since 1999, Hartwig has been a member of the American Society for Heating Refrigeration and Air-Conditioning Engineers (ASHRAE), participating regularly in technical and standard committee meetings on moisture management, insulation materials and climate data. He has been a principle reviser of Chapter 25 of the internationally renowned ASHRAE Handbook of Fundamentals 2009 and 2013. He has also published more than 350 scientific articles in international trade journals, conference proceedings and textbooks. 

Hartwig holds a Diploma in Chemical Engineering from Erlangen University and a PhD in Civil Engineering from Stuttgart University. In 2016, he was appointed as an Honorary Professor by Stuttgart University. 

Presentation Overview : Healthy indoor environment through moisture control considerations during design and installation

Damp buildings are an issue of major concern because there is a strong correlation with occupants’ health problems. Excessive moisture may not only result in degradation of building materials, it can also provoke microbial growth on and in building components. Maintaining comfortable and healthy indoor conditions under all circumstances is a challenge. It requires effective quality control strategies during all design and installation stages. To realize healthy and durable buildings, an integrated envelope and HVAC design approach is essential. QE of the building fabric has to ensure that the heat, air and moisture control layers are continuous and installed according to best practice. Assembling building envelope components in a controlled environment helps to meet QE targets and minimizes adverse impacts such as rain, wind, high humidity and strong temperature swings during the construction process. This reduces substantially the risk of envelope leaks, built-in moisture or material strain. 

However, even a perfect construction may fail if its components have not been adapted to local climate conditions and intended use of the building. Appropriate moisture control must respond to the expected exterior and interior hygrothermal loads. Conventional building science design tools concentrate on energy efficiency and thermal comfort only. Moisture control issues are generally treated separately or not at all. This may prevent an optimum building performance and could entail mould growth and other moisture related problems affecting the indoor air quality and human health. Impacts from natural weathering and building operation are important loads for interior spaces and building envelope systems. Understanding the dynamic heat and moisture transfer processes in the building and in its components, facilitates the optimization of conflicting targets such as energy savings, indoor comfort (e.g. limiting overheating or overcooling), hygiene and durability.