Study On Efficiency Evaluation And Optimization Of The Light Wells In Underground Parking Garage In Guangzhou Residential

Typically well-designed light wells can improve the luminous and thermal environment in the enclosed parking garage, and they are of vital importance to human health and energy conservation in residential buildings. With combined methods of field test and simulation analysis, this paper selects the underground parking garage of a residential district in Guangzhou as an example to study its luminous and thermal environment and assess its light well design in terms of energy efficiency. After that it discusses some major designing defects and concludes with an optimization proposal in the end.Specifically, there are altogether four parts to unfold.In the first part, a literature review is carried out of home and abroad researches on lighting and ventilation in the underground garage, and light wells built for this purpose are categorized and summarized.The second part mainly elaborates the field test on and simulation analysis of the luminous environment in the underground garage of Lingnanwan Pan Estate in Guangzhou. Such problems as excessive illumination, unreasonable lightwell design, improper lighting control and the like are discussed and dissected. With the field test of a series of lighting coefficient obtained from a light well, ECOTECT lighting simulation software stands as practical and effective, and it is then applied to analyze the luminous environment in the underground garage. Such simulation analysis shows that natural lighting shall be deployed in the lightwell design to the effect of energy conservation.Part Three illustrates the thermal experiment on that same garage as what has been tested in Part Two. Parameters of the wind velocity at the height of 1.5 meters in the garage, air temperature, wall temperature and CO density demonstrate that vehicular radiation has a great influence on the underground thermal environment, which can be improved by pressure-driven flows through the light wells. Obviously, natural ventilation alone can expel all the CO contents in the exhaust emissions. With the test-proven method of value simulation via FLUENT software, thermal analysis shows that natural ventilation can meet the required standards set for the underground garage during the peak time of traffic flow in summer. Hence, ventilators become unnecessary to save mechanical ventilation and energy consumption.In the last part, a close study is conducted on the radius of radiation and lighting performance of square-shaped light wells in different sizes, and a total of five optimization schemes are proposed to solve the current lighting issues in the underground parking garage of Lingnanwan Estate. With the application of ECOTECT simulation analysis, all the proposals are measured for the best one whose ventilation effect is further evaluated by FLUENT software. Finally some suggestions are offered on the design of energy-saving light wells and alterations available are also presented.