| The benefits of daylight are known to most people,and it has been one of the main factors,that architects have paid their utmost attention to it through the design process of buildings for ages.Exposure to natural light helps our bodies produce Vitamin D,improves our circadian rhythms and sleep patterns,helps us to focus,enables us to get more done,and even makes us happier.Ensuring we get enough of this vital resource is key to our physical and psychological wellbeing.But according to research,we now spend close to 90% of our lives indoors-making it difficult to experience the benefits of natural light,as we simply aren’t getting enough of it.Regardless of our modern innovations,human beings are still biologically programmed to benefit from exposure to daylight.The rapid rate of technological advancement has vastly overtaken the speed of our natural evolution,and as a result of artificial lighting,we no longer experience the day and night cycles our bodies are designed to work around.Thankfully,the benefits of natural light are now well-researched and documented,and the case is clear for ensuring we all get as much access to daylight as possible.These benefits can be best understood in two distinct ways,the benefits natural lighting has on our bodies,and the benefits it has on the buildings we spend so much time in.there are strong links between the benefits of natural light exposure and our overall productivity.Particularly in the workplace,natural light has been linked to improved focus,efficiency,and less illness with reduced absenteeism.Research indicates that the benefits of daylight exposure at work included everything from improved morale to an increased ability to remember numbers backwards [1].Natural light can help our bodies realign to the natural rhythm they’re supposed to keep.Sleeping in a room with plenty of unobscured glass windows and waking up as the sun rises is a good habit to keep.Even simply getting some sunlight throughout the day can reattune our bodies to the natural rhythms of daylight,distinctly improving our sleep,and with it our effectiveness the next day.The benefits of natural light on the way we feel don’t just apply to our physical wellbeing,but also to our psychological health and mood.A lack of daylight can make us feel down,depressed and anxious,and the significance of Seasonal Affective Disorder(SAD)in the UK speaks volumes about how important daylight is to our mental wellbeing [1].It’s not just lighting that can be optimized by using daylight in your interior spaces,but heating too.It might not seem obvious at first,but by choosing the right thermal glazing products,‘solar gain’(the heating effects of sunlight on an interior space)can be regulated and controlled.Essentially,with intelligent design you can not only light up,but also heat your home using natural sunlight,while adequate insulation can ensure this interior climate is maintained.It seems though,the factor of daylight glare,hasn’t got the necessary attention,especially for library type of buildings,which glare is a significant factor that directing influences the patron’s comfort and concentration.Glare is the loss of visual performance or discomfort produced by an intensity of light in the visual field greater than the intensity of light to which the eyes are adapted.Simply put,glare occurs when too much light enters your eye and interferes with your eye’s ability to manage it.Glare can be distracting and even dangerous and can occur day or night in a number of ways.Glare may come directly from a light source or be reflected.There are four types of glare: Distracting glare,discomforting glare,disabling glare,and blinding glare.This paper with the focus on daylight glare control by designing glare-free static sunshades,tries to investigate the relationship between the amount of glare and daylight and evaluate the amount of daylight in usage of glare-free static sunshades.The whole process of the modeling and simulation is done through parametric approach(grasshopper)to ensure a relatively high accuracy in results.This research takes the University Town of Shenzhen library(UTSL)as a case study,to simulate its existing sunshades and evaluate the amount of daylight and daylight glare in its study area on the west side of the building on the third floor.The same experiment is carried out for the same space with a new glare-free designed sunshade system,to evaluate the amount of daylight in usage of the glare-free sunshades.This brought this possibility to compare the results for the both scenarios to understand if a glare-free sunshade would lead to daylight deficiency,and if it does to what extent.A glare-free sunshade system is a shading system capable of blocking the sunrays before entering the building by taking the sun as the source of glare.In this study,the amount of daylight provision is represented by DF(daylight factor)and the amount of daylight glare by DGP(daylight glare probability).The simulations are done for Solstice and equinoctial dates: 21 st Jun,21 st Dec,22 nd Sep.Timepoints are specified for each hour after which the sun starts getting angle towards the target facade.This means that only the hours of a day which sunlight will be casted over the glazing wall will be taken for the simulations.To ensure higher accuracy of the experiment,a row of 10 point of views representing 10 patrons have been included,throughout all the simulations.5 patrons A1-A5 are facing the North side and 5 patrons B1-B5 are facing the South side of the building.The patrons A1 and B1 has the closest distance to the glazing wall and patrons A5 and B5 are sitting the farthest distance to the glazing wall compared to the rest of the patrons.As the patrons get farther from the glazing wall their point of view changes,which means each patron will experience a different amount of daylight glare passing through the exterior static sunshades.The main reason of selecting this library as the case study for this research is its evident glare problem.In the study area usually in the afternoons,due to the sunlight penetration all the blinds are drawn down.All the simulations are done through parametric approach to ensure the highest accuracy in results.Physically photorealistic renders are produced for both existing and glare-free sunshade-equipped study areas.These renders are used to represent the both scenarios(the study area without glare and with less daylight provision,and the study area with glare and with more daylight provision)for a survey.The survey is conducted among the actual patrons on the very same study area to evaluate their preference and to make a more comprehensive understanding of the results.This research takes advantage of parametric simulation,modeling and survey method.For building modeling,daylight and glare simulation,Grasshopper,a Graphical algorithm editor which is tightly integrated with Rhino 3D,and Honeybee and Ladybug,two open-source environmental plugins based on Grasshopper platform are used.Ladybug imports standard Energy Plus weather files(EPW)into Grasshopper and provides a variety of 3D interactive graphics to support the decision-making during the design process.Ladybug provides a full range of environmental analysis in Grasshopper.The free and open nature of Ladybug democratizes environmental analysis tools,fostering the advancement of environmentally conscious designs.Environmental information becomes a design generation tool through Ladybug’s parametric diagrams,giving designers an instantaneous feedback on the effects of design modifications.A unified interface provides accessibility and convenience to users,promoting building designs that are environmentally responsible for today and for the future.Grasshopper is used as the base platform for modeling and running the simulations by ladybug and Honeybee analysis components.The location of UTSL is loaded by Ladybug and the exact sun diagram is simulated by Honeybee for daylight and glare simulations and analysis.Using a parametric approach ensures a relatively higher accuracy in results by providing all the necessary components for running glare and daylight simulations over the single platform of Grasshopper.As a result,all the components work in tandem for calculating the results.An experiment is performed to determine the variables for the simulations to reaching a glare-free sunshade for different directions and to understand that along with angle variable,if it’s the depth of the fins or the distance among them that plays the major role in providing higher amount of daylight.This experiment also reveals the relationship between fins with different depths and intervals,and how they influence the amount of DGP and DF.For this experiment a study area with the same dimensions as the USTL target study area without any interior columns and without any mullions got introduced to grasshopper to examine different variables for vertical sunshade design.Ten patrons with the same arrangement and viewpoints as the previous simulation were included for glare evaluation.For this experiment the fins are perpendicular to the glazed wall.the range for depth experiment is from 1m to 1.5m,since any fins with higher depth doesn’t seem to be practical.The experiment was run in two runs.Based on the timepoint(with high glare probability)of Jun 21 st,18:00 the first run of the experiment took the depth of1 m as a fixed parameter and tried different distances and the second run of the experiment took 1m distance as the fixed parameter and tried different depths.The start point for both of the two runs is based on fins with 1m intervals and 1m in depth.Jun 21 st 18:00 o’clock got selected for this experiment since the start point arrangement of the fins showed a high value of glare in grasshopper.The first run of the experiment started from 1m and decreased the distance by 0.1m at a time until the simulation reached a glare-free point with 0.5m interval.It showed a CR of imperceptible glare for all the patrons with a DGP of 0.174-0.237 and a DF of 2.2.The second run of the experiment started from 1m and decreased the depth by 0.1m at a time until the simulation reached a glare-free point with a depth of 1.9m.It showed a CR of imperceptible glare for all the patrons with a DGP of0.199-0.246 and a DF of 2.87.it took the depth variable to change in 10 steps until it reached the glare free point.The results clarify that although it took 10 steps for depth experiment to reach the glare-free point,compared to the distance experiment with 6 steps,it still owns a higher DF value.Hence,this research takes angle and depth variables as the experiment variables.This finding can also help architects in the design process of sunshades for different buildings by giving more priority to increasing the depth of the vertical fins than the intervals,with the aim of more daylight provision.After determining the variables,a simulation is performed base on the baseline model and the existing sunshades that were introduced to Honeybee,and according to each timepoint for the ten defined patrons.For each patron and each timepoint the DGP and DF values are produced.The results show that for December 21 st 16:00 o’clock glare analysis component showed a comfort range of Intolerable Glare for patron B3,with a glare probability of 0.468.And for June 21 st 18:00 o’clock for the patron A1,showed a glare probability of 0.482 with a comfort range of Intolerable glare.For the rest of the timepoints imperceptible amount of glare were shown.Whilst the daylight factor showed the value of 0.5 for the existing sunshades.This indicates that the existing sunshade system not only is incapable of providing a glare-free interior but also its incapable of providing a daylit interior space.With the aim of evaluating the amount of daylight glare probability and daylight factor for the UTSL’s study area with static glare-free sunshade system a glare free sunshade system has been proposed and the amount of DGP and DF values for the study area has been produced.In this experiment a new sunshade system is calculated and simulated based on the exact orientation of the UTSL’s study area’s glaze wall.Then daylight glare probabilities and DF value will be produced in grasshopper.The simulation results show that a sunshade system with a set of vertical sunshades with an angle of 30 degree and a depth of 1.4m along with the two rows of horizontal sunshades resulted from the formula with a distance of 1.13 m from top and a depth of 1.21 m,proves to provide a glare-free interior with a DF of 0.148%.The results indicate that the glare-free sunshade with a produced DF of 0.148%caused only 0.352% less DF value compared to the existing sunshades producing 0.5%DF.Which means regarding daylight availability,both scenarios have an almost similar daylight effect,and both of them suffer from a high daylight deficiency,whereas the second scenario provides a glare-free interior space.To show that the designed glare-free sunshade is still preferred despite the fact that the DF is reduced,a survey is conducted based on physically photorealistic renders for both of the scenarios in the same study area.95% of the participants preferred the glare-free study area,despite its less daylight availability.The results indicate,that although,glare-free static sunshades lower the amount of daylight,they are an appropriate strategy for controlling the daylight glare,and it clarifies the higher priority of the glare control over the daylight provision and exterior view for a study area.Additionally,to make a more comprehensive understanding of this research;this paper also explores the relationship of glare and daylight by including three western directions: South West,West and Northwest directions;based on the same time points,with the aim of getting hands on a more general findings that could apply to any library facing these three directions.A building with the same dimensions but in a generic situation and without interior columns and window mullions got introduced to grasshopper.10 patrons among whom A1-A5 facing North side of the building and B1-B5 facing South side of the building with the same desk’s arrangement as the last experiment,were included in this experiment.Staring from the West direction and by trying different angle and depth variations through Grasshopper and producing DF and DGP values for each one of the simulation runs,a set of 160-degree vertical fins with a depth of 1.4m proves to be glare-free whilst providing a DF of 0.58%.For southwest oriented study area,a set of sunshade system with two horizontal sunshades with a depth of 1.21 m and an array of vertical fins with 1m distance and a depth of 1.4m,slanted to 60 degree proves to be glare-free whilst providing a DF of 0.584%.For Northwest oriented study area,110-degree fins with 1.4m depth with a DF of 2.984% proves as the glare-free sunshade solution.It is found that the amount of daylight availability for a study area with glazing wall,facing southwest direction reaches 0.58% DF and facing west direction reaches0.584% DF.The result for both directions is quite similar and for both of them there is a high daylight deficiency.However,the situation is extraordinarily better when the glazing wall facing the northwest as the amount of DF reaches 2.98%,almost 5 times higher than the formers.The result means,it is considerably important to consider the designed glarefree sunshade systems when the glazing wall is facing northwest,and according to the survey result,although for west and southwest directions,the daylight provision from glare-free sunshades is low,glare-free sunshades are still preferable. |
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