Holistic evaluation of conventional and innovative ventilation systems for the energy retrofit of residential buildings

The research presented in this Dissertation has been performed at the Fraunhofer Institute for Solar Energy Systems (ISE) in the department Thermal Systems and Buildings and supervised by the Institute of Fluid Machinery of the Karlsruhe Institute of Technology (KIT). The implementation of ventilation systems is addressed within the context of energy retrofits of residential buildings. Indoor air quality is a parameter of crucial importance when the airtightness of the building envelope is increased. A mechanical ventilation system is required and its influence on the energy demand of the building and on the user comfort can become a source of dissatisfaction. The performances of market available systems are extremely variable and a precise definition of criteria and of an evaluation method is necessary. Conventional as well as innovative systems are evaluated according to the following criteria: energy performance, hygrothermal comfort, indoor air quality, costs and eventual user disturbances during installation work or maintenance operations.