Conference Paper

Proceedings of BSA Conference 2017: Third Conference of IBPSA-Italy

Effect of Blind Control Strategies on Energy Demand of Office Buildings and Melanopic Effect for Occupants

Daniel Plörer, Matthias Werner, Martin Hauer, David Geisler-Moroder

Abstract: The total energy demand of buildings consisting of heating, cooling, and artificial light demand is strongly depends on solar gains resp. daylight passing the façade. To prevent glare issues and overheating in summer, shading systems are widely used especially in office buildings. The majority of such systems involve venetian blinds. To provide a satisfying operation of the blind systems, the decision whether the façade should be opened or closed has to be based on live measurements of the external situation in terms of solar radiation, illuminance, and ambient temperature. The most commonly used control strategies operate rudimentarily, and often choose only between the two façade states, retracted blinds and deployed at a certain angle, mostly around 45°, based on simple criteria depending on single values of external sensors. This paper introduces a novel control strategy, which simulates the necessary artificial light and heating or cooling demand for each possible blind position in real time depending on external boundary conditions. This allows the determination of the best blind angle in terms of minimal total energy demand. The results show that these elaborate strategies can have a remarkable influence on the total energy demand of buildings. The evaluated test scene shows 30 % savings in terms of total primary energy demand could be achieved compared to conventional sun protection control strategies. In addition, daylight exposure of the occupants’ faces can be improved and this represents an important factor for the melanopic effect. Two new strategies are applied to three different façade setups for a single office scenario and compared to a hypothetical reference system, which represents the state of the art.
Pages: 201 - 208
Paper: