An intervention study on automated lighting control to save energy in open space offices

Abstract

We present intervention study on energy saving investigating the benefit of controlling ceiling lighting based on occupant presence information obtained at each desk. We show that fine-grained sensing and control is particularly beneficial for lighting control in open plan office spaces. Our intervention was conducted in a 63.8m2 modern open office space over a time of 1.5 months. Ultrasound sensors were installed to obtain presence at each desk. Self-dimming ceiling lights were made individually controllable and a novel building management system (BMS) was implemented. Every two desks and a nearby light were grouped in a cell, implicitly defined by rules of the BMS. Based on the intervention, energy savings of up to 19.01 kWh/m2·year were obtained. Recorded presence and power consumption values were used to simulate alternative lighting control strategies with reduced sensor numbers to further explore energy saving benefits.