Investigating the effect of shading material on the amount of incoming light and indoor heating conditions (Case study: dezful city)

Introduction
Theuseofsunlightasarenewablesourcehasalwaysbeenconsideredimportantbydesigners.Ithasalwaysbeenconsideredasoneofthemainfactorsinthedesignandformationofarchitecturalspaces.Optimaluseofnaturallightin order to achieve highlightefficiencyrequiresacorrectunderstandingofthecharacteristicsandfactorsaffectingit.Therefore, sunlightisdividedintothreeregionsintermsofspectralregions:ultraviolet(ultraviolet),visible,andinfrared(infrared).Thevisiblepartofthespectrum,whileilluminatingtheplace,alsohelpstoheatit,whiletheinvisibleinfraredrayshaveonlythermaleffects.Sowindowtransmittancesurfacesplayanimportantroleinenergyconsumptionofthebuilding.Theflowofheatthroughthepermeablesurfacesincreasestheheatandthusthecoolingload.Therefore,bycontrollingtheheatfromthesunontheexternalopenings,thecoolingloadofthebuildingcanbesignificantlyreduced.Oneofthemeasuresconsideredinthisfieldistheuseofshadowsontheexternalwindows.
Materials and methods
In this research, in the first step, the range of requirements for shade and sun in Dezful city is determined according to the climate needs calendar of this city. Using Ecotect 2011 software, optimal shading is designed for glazing in the south, north, east and west. In the next step, using Design Builder software version 6 with Energy Plus engine 8.9, the effect of shading material (acrylic, wood, glass, aluminum, and steel) on the amount of solar gain, daylight factor, and daylight autonomy indoors on the fronts is investigated. South and east are given as examples.
Discussion and results
 According to the research findings, the amount of solar gain, daylight factor and autonomy of daylight in the interior space have the lowest quantity in acrylic shading while glass and wood have the higher values and aluminum and steel are maximum. Shades of wood and glass with similar values can create a better balance between light and heat than other indoor shades. Finally, between the two options of glass and wood, glass can be a more suitable option for designing shades on different fronts due to its elegance, beauty, moisture resistance and increasing field of view.
Conclusion
Theformandtypeofshadingdevicesareamongtheparametersaffectingtheamountofincominglightandcontrolofindoorheatingconditions.Bychoosingtheappropriateshadingdevice,thermallycomfortableconditionscanbeprovidedforindoorspaces.Themainpurposeofthisstudyistoachievethedesiredbalancebetweenthermalcomfortandlightdistributioninspace.Oneofthemainconditionsforprovidingthermalcomfortinwarmclimatesistoprovidesuitableshades.Therefore,inDezfulcity,duetoitslocationinhotand semi-humid climatesandduetohightemperaturesinmostmonthsoftheyear,theneedforshadeandshadingelementsisinevitable.