Master's Thesis Anna Dorothea Schiffer


Energy Efficiency of Ventilation Systems at RWTH Aachen University - Analysis, Assessment and Suggestions for Improvement

Primary energy demand from heat Copyright: EBC Primary energy demand from heat for improvement measures in the field of mechanical ventilation systems for the relevant buildings on the RWTH Aachen University

This thesis investigates the potential for improvement of mechanical ventilation systems at RWTH Aachen University. The premises of the RWTH Aachen University consist of a large number of buildings with different building types. They differ in usages, year of construction, physical condition and sometimes show considerable potential for energy optimization. This is also true for ventilation systems. In particular, the numerous institute buildings, with significant requirements of qualitative air, demand a large part of the energy supply for the operation of ventilation systems.

The total stock of ventilation systems at RWTH Aachen University is analyzed. Criteria for the energetic relevance are developed, on which the plants suitable for improvement measures are identified. The affected buildings are divided into clusters based on the type of usage, proportion of aerated net floor area, treatment functions and capacity of the ventilation system. A total of 14 sample buildings are considered and missing information is collected by means of on-site inspections.

A classification of possible measures to increase the efficiency and an assessment of the applicability to the facilities of the RWTH Aachen University is proposed. Scenarios for reduced operation and the installation of heat recovery systems are developed and simulated for the sample buildings. According to the formed clusters, the quantified possible energy savings in terms of heating are transferred to the relevant buildings.

In the subsequent economic and primary energy assessment, considerable potential savings will be demonstrated. The greatest possible savings result from the combination of the installation of a heat recovery system and reduced operation during nights and weekends. For this scenario, primary energy savings of around 57 % are achieved in the form of thermal energy for 54 buildings of the RWTH Aachen University. The improvement measures are recommendable from an economic point of view. An annual saving in energy accounts around € 1.45 million which will result in a capital payback time of less than ten years for the replacement of existing ventilation systems.