A comparison of lighting control strategies for open offices

2019 ◽  
Vol 149 ◽  
pp. 68-78 ◽  
Author(s):  
Tatiana Lashina ◽  
Sanae van der Vleuten-Chraibi ◽  
Marija Despenic ◽  
Paul Shrubsole ◽  
Alexander Rosemann ◽  
...  
Keyword(s):  
Control Strategies ◽  
Lighting Control

scholarly journals A review on sensing-based strategies of interior lighting control system and their performance in commercial buildings

2019 ◽  
Vol 16 (1) ◽  
pp. 208 ◽  
Author(s):  
Khairul Rijal Wagiman ◽  
Mohd Noor Abdullah ◽  
Mohammad Yusri Hassan ◽  
Nur Hanis Mohammad Radzi
Keyword(s):  
Energy Savings ◽  
Control Strategies ◽  
Electrical Energy ◽  
Commercial Buildings ◽  
Current Sensing ◽  
Factors Affecting ◽  
Artificial Lighting ◽  
Lighting Control ◽  
Lighting Energy ◽  
Building Characteristics

<p>Artificial lighting consumed significant amount of electrical energy in commercial buildings. Therefore, intelligent control strategies are widely implemented to reduce the lighting energy consumption. This paper presents comprehensive review of the current sensing-based strategies (i.e. occupancy, daylight and mixed), sensors placement methods (i.e. occupancy and light) and factors affecting the performance of the lighting control strategies. Based on literature survey, the sensors placement methods can be categorized into three approaches: fixed, mathematical equation and optimization. The state-of-the-art of these approaches are discusses in details. It found that, the optimization-based approach capable to find the optimal sensor placement (numbers and positions) effectively. Moreover, the mixed strategy can be produced the highest energy savings up to 95% compared with other strategies. The occupancy pattern and building characteristics are the main factors to contribute higher energy savings of sensing-based strategies in commercial buildings.  </p>

scholarly journals Comparative Study of Energy Savings for Various Control Strategies in the Tunnel Lighting System

2021 ◽  
Vol 11 (14) ◽  
pp. 6372
Author(s):  
Li Qin ◽  
Antonio Peña-García ◽  
Arturo S. Leon ◽  
Jian-Cheng Yu
Keyword(s):  
Control Strategy ◽  
Control Strategies ◽  
Light Emitting Diode ◽  
Operating Time ◽  
Traffic Volume ◽  
Design Stage ◽  
Tunnel Length ◽  
Total Energy Consumption ◽  
Lighting Control ◽  
Electricity Cost

Tunnel lighting is the most significant component in total energy consumption in the whole infrastructure. Hence, various lighting control strategies based on light-emitting diode (LED) technology have been investigated to conserve energy by decreasing luminaires’ operating time. In this study, four kinds of tunnel lighting control strategies and the development of their associated technologies are evaluated: no-control low-consumption lamps (LCL), time-scheduling control strategy (TSCS), daylight adaptation control strategy (DACS), and intelligent control strategy (ICS). This work investigates the relationship between initial investment and electrical costs as a function of tunnel length (L) and daily traffic volume (N) for the four control strategies. The analysis was performed using 100-day data collected in eleven Chinese tunnels. The tunnel length (L) ranged from 600 m to 3300 m and the daily traffic volume (N) ranged from 700 to 2500. The results showed that initial investment costs increase with L for all control strategies. Also, the electricity costs for the LCL, TSCS, and DACS strategies increased linearly with L, whereas the electricity cost for the ICS strategy has an exponential growth with L and N. The results showed that for a lifetime equal to or shorter than 218 days, the LCL strategy offered the best economical solution; whereas for a lifetime longer than 955 days, the ICS strategy offered the best economical solution. For a lifetime between 218 and 955 days, the most suitable strategy varies with tunnel length and traffic volume. This study’s results can guide the decision-making process during the tunnel lighting system’s design stage.

scholarly journals Longer Photoperiods with Adaptive Lighting Control Can Improve Growth of Greenhouse-grown ‘Little Gem’ Lettuce (Lactuca sativa)

HortScience ◽  
2020 ◽  
Vol 55 (4) ◽  
pp. 573-580 ◽  
Author(s):  
Geoffrey Weaver ◽  
Marc W. van Iersel
Keyword(s):  
Lactuca Sativa ◽  
Energy Use ◽  
Control Strategies ◽  
Leaf Size ◽  
Dry Weight ◽  
Photon Flux ◽  
Lighting Control ◽  
Content Index ◽  
Supplemental Lighting ◽  
Greenhouse Growers

Supplemental lighting can improve the growth of greenhouse crops, but the electricity required for supplemental lighting can be a significant expense for greenhouse growers. Lighting control strategies that use the dimmability of light-emitting diodes (LEDs) have the potential to decrease this cost. In our experiments, we tested the hypothesis that providing ‘Little Gem’ lettuce (Lactuca sativa) plants with the same daily amount of light, spread out over a longer photoperiod and at lower average photosynthetic photon flux densities (PPFDs), would improve growth because light is used more efficiently to drive photosynthesis at lower PPFDs. We conducted two greenhouse experiments wherein supplemental light was provided to reach a minimum daily light integral (DLI) of 17 mol·m−2·d−1 with a 12, 15, 18, or 21-hour photoperiod using adaptive lighting control of LED lights. As the photoperiod for supplemental lighting was increased and supplemental light was provided at lower average PPFDs, plant dry weight increased. Conversion efficiency, the estimated increase in dry weight per Joule expended on supplemental lighting, increased as the photoperiod was extended from 12 to 21 hours. Leaf size and chlorophyll content index increased with longer photoperiods. The number of plants with symptoms of tipburn, including apical and marginal necrosis, also increased as the photoperiod was extended. These results demonstrate that adaptive lighting control can be used to increase the growth of ‘Little Gem’ lettuce and the energy use efficiency of supplemental lighting by providing supplemental light at relatively low PPFDs.

scholarly journals Photochemical Characterization of Greenhouse-grown Lettuce (Lactuca sativa L. ‘Green Towers’) with Applications for Supplemental Lighting Control

HortScience ◽  
2019 ◽  
Vol 54 (2) ◽  
pp. 317-322 ◽  
Author(s):  
Geoffrey Weaver ◽  
Marc W. van Iersel
Keyword(s):  
Chlorophyll Fluorescence ◽  
Lactuca Sativa ◽  
Control Strategies ◽  
Photon Flux ◽  
Production Cycle ◽  
Light Use Efficiency ◽  
Lighting Control ◽  
Fluorescence Measurements ◽  
Use Efficiency ◽  
Supplemental Lighting

Plant light use efficiency decreases as light intensity is increased, and a better understanding of crop-specific light responses can contribute to the development of more energy-efficient supplemental lighting control strategies for greenhouses. In this study, diurnal chlorophyll fluorescence monitoring was used to characterize the photochemical responses of ‘Green Towers’ lettuce (Lactuca sativa L.) to photosynthetic photon flux density (PPFD) and daily light integral (DLI) in a greenhouse during a production cycle. Plants were monitored continuously for 35 days, with chlorophyll fluorescence measurements collected once every 15 minutes. Quantum yield of photosystem II (ΦPSII) decreased exponentially with PPFD, whereas electron transport rate (ETR) increased asymptotically to 121 µmol·m–2·s–1. Daily photochemical integral (DPI) is defined as the integral of ETR over a 24-hour period; DPI increased asymptotically to 3.29 mol·m–2·d–1 with increasing DLI. No effects of plant age or prior day’s DLI and a negligible effect of PPFDs 15 or 30 minutes before measurements within days were observed. Simulations were conducted using the regression equation of ETR as a function of PPFD {ETR = 121[1 – exp(–0.00277PPFD)]} to illustrate methods of increasing photochemical light use efficiency for improved supplemental lighting control strategies. For a given DLI, DPI can be increased by providing light at lower PPFDs for a longer period of time, and can be maximized by providing light with a uniform PPFD throughout the entire photoperiod. Similarly, the DLI required to achieve a given DPI is reduced using these same methods.

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