Evaluation Methods And Application Of Daylight Glare

The prevention of daylight glare is an important part of daylighting design.National standards in China had already established certain requirements on glare prevention,suggesting using DGI as glare index to evaluate glare effects.However,there is no clear definition of simulation boundaries of DGI,without which glare prediction is baseless and lacks interoperability.Therefore,this paper did some numerical simulations to find out how DGI was affected by all the boundary conditions.First,this paper recommended principle theory of glare calculation as well as some most cited glare indexes.Though parameter attribution,7 considerations of daylight design are characterized into 2 categories: space size,fa?ade material,window design,and room orientation are classified into design variables,while sky model,simulation time,and measuring point/direction are classified into boundary conditions which we were about to discuss.Second,this paper sorted out some popular daylight-simulating software,and came up with a dynamic glare calculating platform,which consisted of Rhino,Grasshopper,Diva,Radiance,and Evalglare.Third,a reference building model was built to help testing glare performances of 2 CIE sky models,3797-time points,42 measuring points and 12 measuring directions.All these 38313 sets of data were plotted in several timing diagrams,which revealed the relationship between glare index and the 3 boundary conditions.With the regular pattern of boundary conditions,based on the principle of the worst-case scenario,this paper came up with methods to define boundary conditions for each design practice.And also with these patterns,this paper put forward several design strategies on glare prevention.