Lighting Energy Saving with Light Pipe in Farm Animal Production

Daylight plays a significant role in achieving energy saving and comfort in buildings. It is in accordance with the human circadian rhythms and allows the best visual conditions in work environments and residential buildings. Recently, numerous researchers have focused their attention on the performance of technological devices able to increase natural light availability in interior areas of buildings. Among them, light shelves are commonly used with the aim of improving the depth of daylight penetration, trying to reduce the nonuniform diffusion of light entering from vertical windows. In this paper, the authors propose six different configurations of an internalexternal light shelf and analyse their performance using the experimental scale model approach under real sky. Although the method is not very accurate as deduced from literature on this topic, the authors still demonstrate its usefulness in examining different geometric configurations of light shelves. In fact, even if the results highlight inaccuracies in the method used, which are accentuated under direct sun light, they are useful for considerations in the comparative analysis, particularly in regard to data logged under partially completely cloudy skies albeit with the awareness that light shelves' effectiveness is improved under direct sun light. Despite its limits, the method is simple to use and can be considered efficient in allowing the authors to carry out considerations regarding the performance of the system analysed. Among the six different configurations proposed two seem to be the most efficient and are characterized by the presence of an internal highly reflecting surface applied on the ceiling and an external one with two different inclination angles (10° and 20°).

Section: Introductionmentioning

confidence: 99%

Experimental Analysis of the Performance of Light Shelves in Different Geometrical Configurations Through the Scale Model Approach

Zazzini¹,

Romano²,

Lorenzo³

et al. 2020

“…This could mean that sensor errors for low illuminance conditions would be larger. However, recorded data seems to have a linear response to increased illuminance [10].…”

Section: Variability Of Measurementsmentioning

confidence: 90%

“…Midday solar altitude ranges from 11º on December 21 to 58º on June 21. The description of houses, light pipes, and measuring system are described in [10].…”

Section: Methodsmentioning

confidence: 99%

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Daylight Utilization with Light Pipe in Farm Animal Production: A Simulation Approach

Diéguez

Gentile²,

Wachenfelt

et al. 2016

Self Cite

Light pipes offer a passive way to bring daylight inside deep buildings, such as agricultural buildings. However, the lack of reliable performance predictability methods for light pipes represents a major obstacle preventing their widespread use. This paper evaluates a simulation approach for performance prediction and identifies key light pipe design parameters affecting their daylight transmission performance. The study was carried out through continuous monitoring of daylight in two full-scale, identical pig stables fitted with two light pipe systems, Solatube ® and Velux ® . The experiment included three continuously measuring sensors in each stable and an outdoor sensor during 2013 and 2014. A forward raytracing tool, TracePro ® , was used for illuminance prediction and parametric simulations. The simulation results for overcast skies indicated discrepancies between the simulated and average measurement results below 30% in all cases. The discrepancies for clear skies were somewhat higher, i.e., below 30% for 67% of the cases. The higher discrepancies with clear skies were due to the overestimation of absolute sunlight levels and absence of an advanced and detailed optical characterization of the dome collector's surface. The parametric results have shown that light pipes' performance is better during summer time, in sunny climates, at low to mid-latitudes, which provides higher solar altitudes than during winter and cloudy climates at high latitudes. Methods to improve the luminous transmittance for low solar altitudes occurring in Scandinavia include: bending or tilting the pipe, increasing the aspect ratio, improving the pipe specular reflectance, tilting the collector to the south, and using optical redirecting system in the collector.

“…Electric lighting energy was reduced in farm animal production using daylight transmission through light pipe [16,17]. Light pipe designs gave better results with a tilt angle of 6 degree, which was achieved through simulation [18].…”

Section: Introductionmentioning

confidence: 95%

Heliostats Daylighting System for Multi-floor Buildings

Ullah

2019

Daylighting has been considered as a major part of sustainable buildings for saving electric lighting and providing benefits such as, health, visual comfort, and productivity of the occupants. A daylighting system enables the sunlight to capture and deliver it in the interior spaces that cannot be illuminated through windows. Previously, small-scale daylighting systems have been presented using active and passive techniques. This paper presents a daylighting scheme to illuminate the interior of a multi-floor building. Traditional light pipe-based systems are lacked to achieve a high concentration of sunlight for illuminating the interior of a multi-floor building. Here, a highly concentrated light pipe-based daylighting system is presented using heliostats. The daylighting system includes heliostats, light pipe, and light guide to collect, transmit, and distribute the light in the interior of the multi-floor building, respectively. The light guide is made of a reflective film and a prismatic optical film for distributing the light in the interior. Heliostats track the sun and reflect the light towards a circular flat mirror, which inserts the light into the light pipe. To transmit a portion of the light into the light guide for illuminating the interior of each floor, a redirecting mirror is placed at the inlet of the light guide inside the light pipe. Simulation results have shown that an efficiency of 40% is achieved providing almost uniform illumination in the interior.