Influence of shading control patterns on the energy assessment of office spaces

Abstract

a b s t r a c tThis work reviews existing models of control patterns for occupant-shading interactions in office buildings, and studies their influence in terms of energy demand when comparing transparent faç ade alternatives. It starts by establishing a review of visual comfort criteria in office buildings and of the conditions that prompt occupants to interact with shading devices and electric lighting. Given the large variety of parameters identified as primary variables in the existing literature -hence the variety of conditions considered comfortable depending on the chosen reference -a sensitivity study was carried out based on dynamic simulations. The aim of the study was to characterize the impact of choosing a given shading control model (pattern or strategy) on the calculated overall energy demand for heating, cooling and lighting, as well as the impact on choosing the best-performing transparent faç ade option for a single-occupant office. The results show that both the calculated energy performance and the ranking of transparent faç ade alternatives (glazing and shading) often vary very significantly with control patterns considered for the occupant-shading interaction. They further show that, amongst the eleven control strategies that were considered, the behavioral model based on a glare acceptability threshold (expressed as DGI > 20) is the one that, when considered individually, would most reliably express an average ranking from all considered strategies. The implications of these findings are discussed in view of their applicability to energy performance-based faç ade design choices evaluation as well as to faç ade design choices.

Solar shading control strategies in cold climates – Heating, cooling demand and daylight availability in office spaces

“…Existing studies (Dubois and Blomsterberg 2011;Silva et al 2012) have found that control strategies are not without flaws, making for higher real energy consumption than simulations have predicted. The sensitivity analysis performed in this work sheds light on how to better accommodate user behaviour in the design of shading control strategies and how to make the control strategies more robust, focusing on a cold climate.…”

Evaluating Thermal and Lighting Energy Performance of Shading Devices on Kinetic Façades

“…Previous studies have proposed various methods to reflect the movement of a shading device in an annual energy calculation [2,11,12,24,25]. The capability of accurately describing the movements and the positions of a shading device in these studies, however, was limited because they either divided the operation steps simply into "open" or "close", or they provided limited number of shading types of which the operation steps can bet set.…”

“…In the case of solar radiation reaching the façade exceeding a certain range, researchers have looked into a method of controlling solar heat gain by closing the shading device [2,24,27]. With respect to natural lighting, in the case of the illuminance on the indoor working plane of less than or equal to 1800 lux or 2000 lux, studies have been conducted to determine a control method to maintain an effective illuminance indoors [2,11]. To compare the annual primary energy according to the control strategies of an external movable shading device, three control strategies were selected on the basis of conventional studies related to solar radiation heat and natural lighting.…”

“…One of the building elements which are widely used to form a kinetic façade is the exterior movable shading devices. These devices are used on buildings and, with designated control strategies, control the solar radiation entering through the building façade, which can result in impact on energy load of a building [1,2]. In particular, the use of such devices can potentially affect the heating and cooling energy demand and lighting energy requirement within a building [3,4].…”

Modeling and Experimental Validation of a Low-Cost Radiation Sensor Based on the Photovoltaic Effect for Building Applications

“…These are placed on the roof, exterior façade, next to the windows, or inside windows surfaces to measure global solar radiation. Subsequently, shading control algorithms using the value of solar radiation to operate shading systems adjust the tilt angle of the venetian blinds [32,33], opening or closing of shutters and blinds [31,[34][35][36]. Several studies of shading control algorithms based on solar radiation measurements have shown great potential for energy savings [20,30,32,37,38].…”