The Effect Of Exterior Shading On Energy Consumption,Indoor Thermal And Visual Environment In A Building

Shading is an effective mean to reduce energy consumption and improve indoor thermal and visual environment.In this context,the impact of external louvers and electrochromic windows on energy consumption,indoor thermal and visual environment are studied.External louvers can prevent solar beam radiation from entering the room and reduce energy consumption in summer.Besides,external louvers can also reduce glare and improve the visual environment.To study the influence of the external louvers,the EnergyPlus software was employed to predict the energy consumption、thermal and visual environment of a representative office,as a model,with external louvers on each oriented facades in Shanghai.The results show that the facade’s optimal slat angle was 50°～900°、400。、50°～900°、1200°for the east oriented facade,500°、30°、50°、60°、for the west orientation,50°～01100°、400°、500°、60°for the south oriented facade and 60°～1200°、400°、60°～200°、100°for the north facade respectively,at all seasons.It is concluded that the best positive results are obtained when smart external louvers are used in the west facade,followed by the south facade.For the east and north facades the results show no significant advantages in using smart external louvers.Electrochromic(EC)glazing can prevent solar radiation from entering the room in summer and let solar radiation in during heating period by changing its optical properties.The thermal and visual environment of a representative office and a representative hotel with electrochromic window located in Shanghai and Guangzhou,are modeled and implemented in the EnergyPlus building simulation program.The results show that electrochromic window can improve thermal and visual environment significantly,but the parameters of the indoor environment are almost the same when different control strategies of EC window are used.Different lighting requirements and air conditioning opening time are the main reasons contribute to the difference of energy consumption.The energy saving is more significant when EC windows are used in a hotel than in an office.