Due to energy consumption increasing and building internal comfort requirements, the application of design strategies is mandatory in order to improve lighting efficiency and to use daylighting techniques. For new and existing buildings, the challenge becomes the achievement of both maximum lighting efficacy and maximum energy-efficiency, according to law’s specifications. In recent years, daylighting algorithms incorporated in building energy simulation programs have become increasingly sophisticated in their abilities to predict the illuminance, light power reductions, and associated thermal load interactions. The aim of this paper is to analyse simulated light levels of a non-residential building. An existing multifunctional building was investigated and in particular the offices placed at the second floor (with a large glazing system in the south façade); a model was implemented in DIALux. It was calibrated thanks to in-situ measurements: the daylight illuminance was monitored by illuminance meters in a typical office. After the model validation, illuminance was simulated with different glazings: standard double-glazing system, systems with granular silica aerogel in interspace, double-glazing with sunlight control films and the influence of blind systems on the glazing facade was also evaluated. Furthermore different lighting plants were implemented, in order to compare a traditional solution and a LED lighting system, in terms of illuminance distribution and operating cost. Results showed that the best solution in terms of natural lighting is the standard glazing with blind systems: the shading device allows the entry of the natural light for many hours during the day, avoiding also glare problems. Considering the solar control films and the aerogel system, the turn-on periods of the lighting system during a day is too long. Concerning the lighting systems, LED lamps have a lower rated power and therefore a saving in terms of energy absorption. Despite the higher luminous flux turns out to be that of compact fluorescent lamps, LED lamps have more luminous efficiency and a longer service life.
Natural lighting in glazed buildings: energy balance
BURATTI, Cinzia;BELLONI, ELISA;
2016
Abstract
Due to energy consumption increasing and building internal comfort requirements, the application of design strategies is mandatory in order to improve lighting efficiency and to use daylighting techniques. For new and existing buildings, the challenge becomes the achievement of both maximum lighting efficacy and maximum energy-efficiency, according to law’s specifications. In recent years, daylighting algorithms incorporated in building energy simulation programs have become increasingly sophisticated in their abilities to predict the illuminance, light power reductions, and associated thermal load interactions. The aim of this paper is to analyse simulated light levels of a non-residential building. An existing multifunctional building was investigated and in particular the offices placed at the second floor (with a large glazing system in the south façade); a model was implemented in DIALux. It was calibrated thanks to in-situ measurements: the daylight illuminance was monitored by illuminance meters in a typical office. After the model validation, illuminance was simulated with different glazings: standard double-glazing system, systems with granular silica aerogel in interspace, double-glazing with sunlight control films and the influence of blind systems on the glazing facade was also evaluated. Furthermore different lighting plants were implemented, in order to compare a traditional solution and a LED lighting system, in terms of illuminance distribution and operating cost. Results showed that the best solution in terms of natural lighting is the standard glazing with blind systems: the shading device allows the entry of the natural light for many hours during the day, avoiding also glare problems. Considering the solar control films and the aerogel system, the turn-on periods of the lighting system during a day is too long. Concerning the lighting systems, LED lamps have a lower rated power and therefore a saving in terms of energy absorption. Despite the higher luminous flux turns out to be that of compact fluorescent lamps, LED lamps have more luminous efficiency and a longer service life.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
