Study On Daylighting And Energy Consumption Analysis Of Office Buildings

With the comparison of lighting, daylighting can not only save energy and protect environment, but also improve work efficiency, which makes it a hot and key issue in recent years. There are so many factors including sky condition, characteristic parameters and circumstance of buildings affecting daylighting, and the characteristic parameters of glazing where daylight pass through are the key affecting factors, which includes window orientation, window-to-wall ratio (WWR), figuration, transmittance and window position. Most domestic studies on daylighting are only limited to qualitative analysis with the consideration of aesthetics effect, and no detailed and systematical quantitative study on daylight utilization with the combination of daylighting and building energy consumption. Numerical simulation is used to analyze the key factors affecting daylighting such as WWR, sill, window transmittance and window orientation in this thesis. The analysis includes the influences on indoor daylight distribution, lighting saving, energy consumption of cooling and heating and their relationship. Experimental model is made for practical testing to validate the result of simulation. More detailed information about the thesis is as follows.About fifty office buildings are studied through field survey, building shop drawing analysis and related references. The investigation shows office building may be classified into five types due to the envelope, detailed see Fig. 2-6. Type â…¡ and â…¢ are more common among these five types, accounting for 68% of the studied buildings. A model of curtain wall building is established based on the investigation and calculation and analysis of the effect of WWR, sill, window transmittance and window orientation on energy consumption of cooling and heating is conducted with the usage of TRNSYS software.With the study on numerical simulation of indoor illuminance, we find CIE clear sky model and CIE overcast sky model can be used for relative precise estimation of indoor daylight distribution, meanwhile, the calculating time and PC memory space are saved. Based on the same model made for energy consumption simulation in chapter 2, a calculation and analysis of the effect of WWR, sill, window transmittance, figuration and orientation on indoor illuminance distribution is provided, and the calculating formulas of indoor illuminance for each affecting factor are obtained under regression. Four new conceptions, "Characteristic Point", "Characteristic Line", "Characteristic Distance" and "Relative Distance" are put forward for more visualized analysis of the effect of each parameter on lighting saving. With the combination of lighting, cooling and heating under daylighting, the study on the effect of the key characteristic parameters on total energy consumption is provided. The validation of the comparability of daylight distribution for building antetype and model is made through theoretical analysis and simulating calculation in the thesis. Due to the variable sky condition, daylighting factor is used for experimental validation instead of illuminance. The error analysis of several testing methods used in the experiment is conducted, followed by the experimental validation of the effect of WWR, sill and transmittance on daylighting factor distribution.