Application potential of solar air-conditioning systems for displacement ventilation

Solar air-conditioning can have higher application potential for buildings through the strategy of high temperature cooling. In recent years, displacement ventilation (DV), which makes use of the indoor rising plumes from the internal heat gains, provides a more effective supply air option than the traditional mixing ventilation (MV) in terms of both thermal comfort and indoor air quality. As it is possible to raise the supply air temperature to 19 °C for DV, it would enhance the competitive edge of the solar air-conditioning against the conventional vapour compression refrigeration. Through dynamic simulation, a solar-desiccant-cooling displacement ventilation system (SDC-DV) was developed for full-fresh-air provision, while a solar-hybrid-desiccant-cooling displacement ventilation system (SHDC-DV) for return air arrangement. The latter was further hybridized with absorption chiller (AB) to become SHDC _AB-DV, or adsorption chiller (AD) to be SHDC_AD-DV, in order to be wholly energized by the solar thermal gain. Benchmarked with the conventional system using MV, the SDC-DV had 43.3% saving in year-round primary energy consumption for a typical office in the subtropical climate; the SHDC_AB-DV had 49.5% saving, and the SHDC_AD-DV had 18.3% saving. Compared with their MV counterparts, the SDC-DV, the SHDC _AB-DV and the SHDC_AD-DV could have 42.4%, 21.9% and 30.3% saving respectively. © 2011 Elsevier B.V. All rights reserved.