Comparison of control parameters for roller blinds

Roller blinds can reduce the heating and cooling building energy consumption required to maintain thermal comfort. The effectiveness of roller blinds is influenced by the strategies and input parameters for their control. This study is the first to identify the most effective of seven alternative control parameters to control roller blinds. It further defines the benefits from using paired control parameters to maximise energy savings and optimise occupants' comfort. For the particular case studies and conditions examined, it is concluded that operating roller blinds using indoor air temperature as a single control parameter with rule-based controller provided, 16 %, 19 % and 45 % in heating, cooling and lighting energy savings in Dublin, Berlin and Madrid respectively compared to a window without roller blinds, with an average 51 % daylight discomfort reduction. Using both internal temperature and outdoor ambient temperature to control the roller blinds had little effect on energy need, with only a further 0.6 %, 0.5 % and 0.3 % energy savings and an average of 2 % reduction in daylight discomfort achieved compared to using solely indoor temperature as the control parameter.