Electric Lighting Predictions in the Energy Calculation Methods

Abstract

Electric lighting is one of the major factors for energy consumption of buildings. The European Directive 2010/31/EU states that from 31 December 2020 all new buildings will have to be nearly-Zero Energy Buildings, thus improving electric lighting energy performance is a key issue. The article presents a study and energy figures of power density and electric lighting annual consumptions for different types of buildings, office, commercial and educational, in the northern European country Estonia with the scope to quantify energy savings when using different types of high-efficiency luminaires, occupancy and dimming controls, lighting groups, and daylight contribution. The study has been conducted in relation to the energy performance regulation for new buildings in Estonia. The scope is to develop methods for electric lighting and daylight calculations to be used in compliance assessment with energy requirements. Using different validated software for electric light and daylight simulations the study analyzes three cases for office buildings, single office, open office and meeting room, and one case for both commercial and educational buildings. Results show that average installed power density can be as low as 3.17 W/m2 for office rooms, 3.22 W/m2 for commercial buildings and 2.09 W/m2 for classrooms. The reduction of energy consumption comparing tabulated values can be up 93.3% for office rooms. Also for commercial and educational buildings energy saving are consistent, up to 72.2% and 87.2% respectively. The article presents as well electric light and daylight model specifications and parameters and the different control settings and relative performance.