Sotiris Papantoniou

Retrofitting an office building towards a net zero energy building

Energy consumption in buildings for heating, cooling and lighting is required to be reduced in all European countries in order for the goals set by the latest European Directives for reducing energy consumption by 20% and increasing the introduction of renewable energy sources by 20% to be achieved. The present paper focuses, initially, on the reduction of energy consumption of an office building in the campus of the Technical University of Crete as well as on the cover of minimized energy demands with renewable energy sources. The approach is simulation based. Firstly, the current heating and cooling demands of the building are estimated. Subsequently, some basic energy conservation techniques are applied and a detailed analysis is performed about the new energy requirements. Finally, renewable energy sources are implemented in order to provide energy to the building or directly into the grid, thus having a net zero energy building.

Adaptive lighting controllers using smart sensors

The aim of this paper is to present an advanced controller for artificial lights evaluated in several rooms in two European Hospitals located in Chania, Greece and Ancona, Italy. Fuzzy techniques have been used for the architecture of the controller. The energy efficiency of the controllers has been calculated by running the controller coupled with validated models of the RADIANCE back-wards ray tracing software. The input of the controller is the difference between the current illuminance value and the desired one, while the output is the change of the light level that should be applied in the artificial lights. Simulation results indicate significant energy saving potentials. Energy saving potential is calculated from the comparison of the current use of the artificial lights by the users and the proposed one. All simulation work has been conducted using Matlab and RADIANCE environment.

The use of algorithms for light control

Because light directly influences human health, requirements on lighting levels must be constantly fulfilled. The lighting control market represents, therefore, an innovative sector that empowers a start-ups potential and where customers are highly looking for solutions that have low costs and high life expectancy, and that are least intrusive. Consequently, the control algorithms implemented are crucial in order to maximize efficiency while satisfying all the aforementioned specifications. This chapter introduces light-control algorithms as enabler of differentiation, which is a key requirement for a successful start-up rollout. Moreover, the proposed control lighting systems are customized and implemented in three real operational environments: two hospitals and one office building, all located in the Mediterranean area. The implementations show significant energy savings with low up-front and installation costs: this demonstrates the importance of control algorithms in lighting systems as high energy savings are achieved and lighting requirements fulfilled.