Evaluation of new active technology for low-energy houses
Author
Summary, in English
A water-to-air heat exchanger was developed for use in naturally ventilated buildings. This requires that the pressure drop of the air is kept close to zero. The heat exchanger comprises solar collector absorbers soldered onto a manifold. Basic heat transfer equations were used in order to optimize the dimensions of the heat exchanger in terms of heat transfer and pressure drop. A laboratory measurement showed the temperature heat recovery rate to be 80% at component level. At the same time the pressure drop was 1 Pa for the designed air flow rate. System simulations were then carried out in order to investigate the impact for a building equipped with natural/hybrid ventilation with heat recovery. A brine-based heat recovery system enables the utilization of other energy sources such as ground collectors or waste water heat recovery units. A waste water heat recovery system was built into a single-family house, and was designed to supply energy to both domestic hot water and the ventilation system. The simulations showed that a typical single-family house can reduce the heating need by approximately 600-800 kWh annually, i.e. roughly 25% of the annual need for hot water, with waste water heat recovery. The simulations showed that using ground collectors for the ventilation system has limited effects on the heating need, so the main benefit is limited to lowering the risk of frost on the heat exchanger surface. The overall conclusion from an energy perspective is that the solar window performs poorly compared to standard solar energy components. The hybrid ventilation system with the developed heat exchangers has the potential to be an interesting ventilation system when building low-energy houses or when renovating residential buildings to improve energy effi ciency.
Department/s
Publishing year
2014
Language
English
Full text
- Available as PDF - 16 MB
- Download statistics
Document type
Dissertation
Publisher
Energy and Building Design, Lund University
Topic
- Building Technologies
Keywords
- Low-quality heat
- hybrid ventilation
- heat recovery
- active house
- solar window
- PV/T hybrid
- building integration
- TRNSYS
Status
Published
Research group
- Energy and Building Design
Supervisor
- Åke Blomsterberg
- Bengt Hellström
- Björn Karlsson
- Bengt Perers
ISBN/ISSN/Other
- ISBN: 978-91-85147-56-4
Defence date
26 February 2014
Defence time
13:15
Defence place
Room A:B, A-building, Sölvegatan 24, Lund University Faculty of Engineering
Opponent
- Per Heiselberg (Professor)