Solar thermal cooling and heating: A year-round thermal comfort strategy using a hybrid solar absorption chiller and hydronic heating scheme

With over 40% of total energy use in the United States coming from buildings, it is clear that future conservation strategies must dedicate a significant focus towards the built environment. Space heating and cooling represent two of the three largest building energy loads and thus provide an excellent springboard for alternative technologies that use renewable energy as the primary energy source. One such system uses solar thermal energy as the primary driver for thermal comfort. Heat energy from the sun is absorbed and stored in water. In the winter months, the hot water is pumped directly into the building to provide space heating. In the summer, the hot water runs an absorption chiller to provide cooling to the space.;The Audubon Center at Debs Park in Los Angeles, CA uses just such a system. The off-grid, LEED platinum building is designed to first utilize passive strategies to minimize building loads. The remaining peaks are then met with the solar thermally driven system. The building uses no backup energy sources, relying on its unique system for year-round thermal comfort. An extensive network of sensors monitors the various system components in the building, providing the data used for the in depth system analysis presented in this paper.;The system performed well in the cooling season, meeting the cooling loads in the fully occupied office spaces for nearly the complete duration of the study. The heating season was drastically different, with the space too cool for comfort 40% of the time. This highlights one of the main paradoxes of a solar thermal system. Solar cooling relies on the synchronization of peak loads and peak energy availability. On the other hand, solar heating peak loads rarely coincide with peak energy availability. Various explanations of the successes and failures of the system are presented in this thesis, along with design ideas for future systems based on those conclusions. To do this, a number of different comparisons between time-matched data sets were performed to quantify the system performance under a wide variety of conditions.;The final bit of analysis concerns alternative strategies for the building that could also use renewable energy for thermal comfort. These are compared against the existing system in terms of expected performance, as well as cost and aesthetics.