LEUKOS
The Journal of the Illuminating Engineering Society of North America Volume 4 Number 3 January 2008
Editorial
Articles
GUY R. NEWSHAM, SANDRA MANCINI AND ROGER G. MARCHAND
Participants in an office laboratory were exposed to an initial baseline electric lighting level of 400 lx on the desktop. The electric lighting was dimmed smoothly over 10 seconds. During the dim, and for 30 seconds afterwards, the participant performed a computer-based proofreading task. The participants indicated if they had noticed the change, and whether the lighting conditions were acceptable. This was repeated over multiple trials, with dimming from 0 to 80%, and with or without daylight. The level of dimming not noticed by occupants was 20% with no daylight, 40% with relatively low prevailing daylight, and 60% with high prevailing daylight (or, alternatively, an amount which represents 20% of total light level). The level of dimming that resulted in conditions that were still acceptable was 40% with no or low daylight, and 80% with high prevailing daylight. These results may be used to develop guidelines for using lighting in demand response actions. They suggest that dimming lights can contribute large electricity demand reductions during periods of grid stress without major inconvenience to occupants.
LIPING GUO, MARJUKKA ELOHOLMA, AND LIISA HALONEN
With the development of new technologies and emphasis on energy efficient lighting, telemanagement road lighting control systems have been introduced to many countries. A telemanagement system enables the lighting system to automatically react to control parameters like traffic density, remaining daylight level, weather conditions and so on. This paper starts with introduction of the structure of telemanagement road lighting control systems, and then investigates the applicability of different control parameters and control strategies. Two examples of telemanagement road lighting control systems, Ring III and VT7 in Finland, are discussed in detail. Based on the lighting standards and current control parameters and strategies, recommendations and guidelines are given to further development of telemanagement road lighting control systems. The paper ends up with conclusions and development needs in road lighting control strategies.
ISAAC L. FLORY IV AND SAIFUR RAHMAN
The two primary performance metrics of any lamp-ballast system are lamp life and lumen depreciation. Lamp life for a particular lighting application is easily quantifiable, relying only upon the retention of maintenance records. However, the study of lamp lumen depreciation is more challenging in that lamps must be removed from installation throughout their life-cycle to allow for an accurate measurement of luminous output. In May of 1998 the lighting of the Rector Field House, located on the campus of Virginia Tech, was replaced. This upgrade was performed to not only improve lighting quality within the facility, but to also study the effects of ballast type upon the two key performance metrics, lamp life and lumen maintenance. Results of this evaluation, which concluded in May of 2002, are presented accompanied by a discussion of the factors affecting the results.
BYOUNG-CHUL PARK, AN-SEOP CHOI, AND HOON LEE
For the night image of a city, architectural outdoor lighting is an important feature of the urban landscape. Cities of developed countries already have their own distinct night images. Regarding this, the government encourages building owners to install architectural outdoor lighting on buildings in various ways. However, owners of private buildings in Korea today have not been very interested in architectural outdoor lighting beyond of the measures taken toward public buildings in our country. From this point of view, this paper identifies the economic effects of architectural outdoor lighting and suggests quantitative measurement methods for analyzing the advertising effects of such lighting. Suggested and analyzed measurement methods are the first steps toward a proper quantitative approach to the measurement of the economic and advertising effects for architectural outdoor lighting.
