Feasibility study on applications of solar chimney and earth tube systems for BEAM/LEED assessment

Building Environment Assessment Method (BEAM) and Leadership in Energy and Environmental Design (LEED) aim to promote better environment performance of buildings in their life time. This study explores innovative solutions to achieve key requirement of Energy Use (EU) and Indoor Environmental Quality (IEQ) from BEAM/LEED assessments by Solar Chimney (SC) or Earth Tube (ET). EnergyPlus is used to perform the simulation of building's ventilation and energy usage under the typical Hong Kong's weather data. It was found that the SC performance is affected by the building's dimension and orientation and is also determined by solar availability and absorber surface temperature. In most simulation cases, SC provided sufficient natural ventilation, but it also increased cooling load to the space when ambient temperature was higher than indoor. The ET performance was affected by the pipe dimension and buried depth. It was found that a single ET could decrease cooling load to the space in the summer design day ‘July 21’ in Hong Kong, but it could not provide sufficient outdoor fresh air. The result also demonstrated that both SC and ET systems had capabilities to help achieve on-site renewable energy requirements from BEAM/LEED because of their energy saving capacities on ventilation and thermal comfort. Because SC had higher capability to provide sufficient ventilation, SC could more significantly contribute on the sections pertinent to building ventilation in BEAM/LEED assessments. Because ET had higher capability to save cooling energy, ET could more significantly contribute on the sections pertinent to energy saving in BEAM/LEED assessments.