Experimental investigation on indoor daylight environment of building with Cadmium Telluride photovoltaic window

Photovoltaic(PV)windows have received more and more attention in recent years since their active energy-saving advantages.Considering the surface covered with solar cell modules,the indoor daylight environment of PV windows is obviously different with clear glass windows.However,despite many scholars have studied the indoor daylight environment of PV windows,there few investigations study it from the perspective of human subjective visual perception.In this paper,the indoor daylight environment and human visual comfort of building with Cadmium Telluride Photovoltaic(CdTe-PV)window were investigated.Firstly,the parameters of indoor daylight environment and subjective questionnaires in rooms with CdTe-PV window and clear glass window were analyzed respectively.On the basis of this,combined with indoor working surface illuminance and results of subjective questionnaires,the daylight illuminance threshold of human visual comfort was investigated by the method of Mean Bias Degree(MBD).Finally,an evaluation model for indoor daylight environment of buildings with CdTe-PV window was developed by Fuzzy Comprehensive Evaluation Method.The results showed that the working surface illuminance of CdTe-PV window was lower than that of clear glass room,the CCT of different windows room had a minor gap and the CdTe-PV window room was closer to the recommended range that was 3300-5000K.As for CRI,both the CdTe-PV window room and the clear glass room could meet the visual comfort requirements of office staff.Furthermore,it was found that the requirement of human visual comfort was met when indoor working surface illuminance varies between 500-2200lx in the room with CdTe-PV window.At last,according to the comprehensive evaluation model proposed in this paper,it was found that the indoor daylight environment of buildings with CdTe-PV window was excellent in the present experiment.

Multi-objective optimization of building design for life cycle cost and C0_(2) emissions:A case study of a low-energy residential building in a severe cold climate

Currently,building construction and operation are responsible for 36%of global final energy usage and nearly 40%of energy-related carbon dioxide(CO_(2))emissions.From the sustainable development perspective,it is crucial to consider the impact of construction material on the achievement of life cycle benefits.This study proposed a simulation-based multi-objective optimization method to minimize both life cycle cost and CO_(2) emissions of buildings.We built an energy simulation model with hybrid ventilation and light-dimming control in EnergyPlus based on an operational passive residential building in a severe cold climate.Next,this investigation selected insulation thickness,window type,window-to-wall ratio,overhang depth and building orientation as design variables.The study ran parametric simulations to establish a database and then used artificial neural network models to correlate the design variables and the objective functions.Finally,we used the multi-objective optimization algorithm NSGA-Ⅱ to search for the optimal design solutions.The results showed potential reductions of 10.9%-18.9%in life cycle cost and 13.5%-22.4%in life cycle CO_(2) emissions compared with the initial design.The results indicated that the optimization approach in this study would improve building performance.The optimal values of the design variables obtained in this study can guide designers in meeting economic and environmental targets in passive buildings.