IEA HPT Annex 59: Heat Pumps for Drying Processes

Drying processes are highly energy-intensive and widespread in industry and commerce as well as in households in various forms. In this project, the potential for energy savings in drying processes in various applications will be investigated, which can be tapped through the use of heat pumps and made available to the relevant target groups in the form of guidelines, data, etc.

Short Description


The annex aims to structure and describe the numerous possibilities and advantages of heat pump integration in dryers. Both the state of the art and innovative solutions in industrial, commercial and household applications are investigated and described. Completely different challenges apply to the sectors. In the industrial sector, there is a variety of drying processes that do not allow for a generally applicable solution. The situation is similar in the commercial sector. In the domestic sector, on the other hand, the challenges lie with heat pumps, as there are already products on the market that need to be converted to environmentally compatible refrigerants. The Annex contributes to a significant transfer of knowledge and know-how to the manufacturers, the planners, but also the operators in the mentioned sectors and is intended to raise awareness for the further use of heat pumps in the considered sectors and to reduce barriers.

The overall objective of the annex is to evaluate potentials for energy savings in drying processes in various applications, which can be tapped by the use of heat pumps. To this end, the following activities will be carried out:

  1. Compilation of relevant data on the state of the art of drying processes equipped with heat pumps,
  2. Analysis of the drying process on a theoretical level in order to identify optimizations in the process design (e.g. reduction of temperatures), in the process operation (drying time) as well as in the design and integration of the heat pump,
  3. Gathering experience from demonstration projects by monitoring and simulating the entire drying system,
  4. Development of recommendations for the design of heat pump drying systems in terms of performance, costs, etc. and comparison with conventional dryers,
  5. Development of recommendations for concepts of dryers regarding heat pump integration and operation modes favorable for heat pump operation,
  6. Dissemination of information and results on the Annex through the website, publications, workshops and reports.

Description of the national project

At national level, the consortium of AIT and AEE INTEC provides significant input to all the above objectives with a particular focus on industry and commerce. With regard to the analysis of drying processes, the collection of experience from demonstration projects and recommendations for design and operation, the aforementioned preliminary projects have a high practical relevance in terms of feasibility. Austrian knowledge is disseminated internationally, and results of the international project are disseminated with Austrian stakeholders, especially in the field of white goods.


Austria (Operating Agent), China, Germany

Contact Address

Project leader

DI Dr. Michael Lauermann
Austrian Institute of Technology GmbH
Giefinggasse 4
1221 Wien

Project partners

DI Jürgen Fluch
AEE Institut für Nachhaltige Technologien
Feldgasse 19
8200 Gleisdorf