Uniformity Ratio Of Illuminance Research Articles

Daylighting performance improvement of a light-shelf using diffused reflection

A light-shelf is a highly efficient daylighting system about which a great deal of research has been performed. However, improvements to the daylighting performance of light-shelves have been limited, because light-shelves could introduce external natural light into the interior space through specular reflection, rather than into a specific region of the interior environment. In this study, to improve the performance of a light-shelf, a light-shelf using the principle of diffused reflection was proposed, and its validity was verified through performance verification. The conclusions of this study are as follows: (1) The optimal angles of a flat type light-shelf and a light-shelf using diffused reflection could vary depending on measurements taken in different seasons. (2) With the installation of the light-shelf using diffused reflection in the summer, the uniformity ratio of illuminance could be improved by 29.9%–34.3% with the external type and by 10.4%–13.7% with the internal type compared to the existing flat type light-shelf. (3) For the light-shelf using diffused reflection, the lighting energy could be reduced by 7.98%–13.3% in the case of the external type and by 1.8%–4.4% in the case of the internal type compared to the existing flat type light-shelf.

Lighting Control System Based on the RTP of Smart Grid in WSN

This paper proposes a lighting control system based on RTP to save lighting energy cost by utilizing daylight while maintaining target luminance suited to the purpose. DR is a mechanism which transmits load by changing power use pattern depending on the user and receiving power charges signal at real time so that power demand would not exceed supply. However, DR is not actually implemented in an effective way due to a burden on the participants in the program to respond voluntarily towards pricing signals. In this paper, power charge process is categorized into three stages according to power load and proposes an LED control system based on WSN which automatically responds according to power demand. Daylight is controlled with a venetian blind, but it is controlled at the highest angle of uniformity ratio of illumination per time zone to maintain the uniformity of natural lights. This study establishes two test beds having the same environment. Further, illumination cost and power consumption of testing group that provides service with variable target illumination according to RTP as well as control group that serves with fixed target illumination regardless of power consumption were measured and energy saving by both conditions was compared.

Wpływ metod oświetlania wnętrz na poziom równomierności oświetlenia płaszczyzny pracy wzrokowej

Wpływ metod oświetlania wnętrz na poziom równomierności oświetlenia płaszczyzny pracy wzrokowej

The energy-saving effect and prediction method under various illuminance distribution types

This study employed the method of constant stimuli to obtain the equivalent illuminance and energy-saving effect of 14 illuminance distribution types. Among 14 types, the type T09 with only one luminary was the most energy-consuming, and T03 was the most energy-saving, the difference of their equivalent illuminances was 23%. When indoor illumination has the same average illuminance, but different Illuminance distribution, the overall indoor equivalent illuminance differs as well. When the illuminance distribution is more uniform, the equivalent illuminance is lower, and the perceived brightness is higher. This indicates that, at a fixed overall average illuminance of indoor space, or energy consumption of lighting, the illuminance redistribution can improve the brightness effectively. On the contrary, to maintain the equal brightness, illuminance distribution can be adjusted to lower the average illuminance, and reduce the energy consumption of lighting. Additionally, this study found that, symmetric luminary configuration usually leads to lower equivalent illuminance, and higher perceived brightness. This study further established a simple prediction equation for energy-saving effect of lighting. The above results indicated that, the illumination type of “one-room-one-light” commonly seen in houses may have latent energy waste. If adjusting it to “one-room-multiple-lights” illumination, then the uniformity ratio of illuminance can be improved, facilitating energy-saving of lighting.

Light and noise conditions of buildings for breeding dairy cows

Check measurement of the illuminance, the uniformity ratio of illuminance and noise level was made in the selected stable building to prove quality of lightning both for service workers and the cattle. The measurement discovered that the noise level, the day lighting and artificial lighting do not satisfy valid health standards and can have harmful effect upon human and cattle organism. In the monitored stable building the permissible hygienic limit of noise was exceeded only during distribution of feed and bedding and it only for the short time.

농촌 청소년 공부방의 조명환경 실태조사

This study investigated the actual conditions of the illumination environment from agricultural youth study room. The result, average space of the study room was 11.42[]. The illuminant uses the fluorescent lamp mainly, Method of using illumination was only general illumination the case which uses 73.8[%]. Method of light distribution was a direct lighting mainly. The house which has a stand illumination was also 45.7[%], The percentage using the stand illumination which was a local illumination was nothing but in 20[%] of the whole subject of investigation, therefore eye work could not effective. The internal illuminance was average 131.82[lx], the desk illuminance was 253.64[lx] which was the minimum permitted limit and poor. Uniformity ratio of illuminance appeared with average 35.61[%]. The satisfaction with 3.93 points to be high for illumination environment, therefore it was thought that the recognition of illumination was very insufficient.