Energetic assessment of decentralized facilities for controlled ventilation with alternating operation
Duration: 2 years
- Forschungsgesellschaft HLK Stuttgart mbH
- ITG Institut für Technische Gebäudeausrüstung Dresden
Sponsors: Federal Institute for Research on Building, Urban Affairs and Spatial Development, promotional reference SWD-10-08.18.7-16.32
Thanks to the integrated heat recovery system, the controlled ventilation system has been providing a substantial amount of energy saving in residential buildings for many years. In addition, the hygienic requirements of the residential users are fulfilled by the methods used today. In addition to the well-known ventilators with a constant volume flow as defined in the standards and directives, alternating systems are increasingly being offered on the market. These alternating ventilation units are more cost-effective to purchase and install, and they can be used more easily in the field of energy-saving renovations. To date, however, there has been insufficient analysis of how the alternating mode of operation of the units (intake and exhaust function of at least two units alternately alternated) has an effect on energy consumption, heat recovery and the efficiency of air ducting in space. Therefore, these new devices can not currently be scientifically proven to be energetically evaluated because the special features of this alternating mode of operation are not taken into account in standardization. This gap in the energetic assessment of the housing ventilation is to be closed by the requested research project.
Through the three partners in the research project, investigations are carried out on the function of alternating ventilation devices based on numerical flow simulation (RWTH), as well as on the experimental evaluation of alternating ventilation devices (HVAC). The results are used to derive suitable standard values for standardization (iTG) and as suggestions for standardization work.
The simulative analysis focusses on the comparison of the ventilation quality. For the evaluation, different criteria are established. Exemplarily, one of them is the averaged time, which the air stays in the room. Depending on a series of geometrical and thermal conditions, similarities and differences between the ventilation concepts will be pointed out.