Lighting Energy Savings From Daylighting Through Skylights for Warehouses

2007 ◽  
Author(s):  
Aymen Mechergui ◽  
Moncef Krarti
Keyword(s):  
Calculation Method ◽  
Open Space ◽  
Energy Use ◽  
Energy Savings ◽  
Control Strategies ◽  
Simulation Based ◽  
Simplified Method ◽  
The World ◽  
Lighting Energy ◽  
Simplified Calculation

The paper provides the results of a simulation-based analysis to estimate the potential savings in electrical lighting energy use associated with daylighting controls using skylights for open space warehouses. First, the effectiveness of daylighting controls is investigated for several skylight opening areas, glazing types, control strategies, and several locations in Tunisia. A simplified calculation method is then developed to estimate the annual savings in electrical lighting energy use due to daylighting controls in warehouses. The simplified method has been developed and validated for several locations throughout the world.

Analysis of Electrical Energy Savings From Daylighting Through Skylights

Solar Energy ◽  
2005 ◽  
Author(s):  
Abdelkarim Nemri ◽  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Simulation Analysis ◽  
Control Strategies ◽  
Electrical Energy ◽  
Office Building ◽  
Analysis Tool ◽  
Energy Saving Potential ◽  
Lighting Energy ◽  
The Impact

This paper provides a simplified analysis tool to assess the energy saving potential of daylighting for commercial buildings through skylights. Specifically, the impact of daylighting is investigated for various fenestration opening sizes, glazing types, control strategies, and geographic locations. A top floor of a prototypical office building has been considered in the analysis. The results obtained for the office building can be applied to other types of buildings such as retails stores, schools, and warehouses. Based on the simulation analysis results, it was determined that skylight to floor ratio more than 0.3 does not affect significantly the lighting energy savings. An optimum value of skylight to floor area ratio was found to be 0.2 to minimize the annual total building energy use.

Roof Cover Impact on Cooling Energy Use of Office Buildings

2014 ◽  
Author(s):  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Simulation Analysis ◽  
Calculation Model ◽  
Office Building ◽  
Climate Zones ◽  
Building Energy Use ◽  
Detailed Simulation ◽  
Simplified Calculation ◽  
The Impact

This paper analyzes the impact of roof covers on office building energy use for representative US climate zones. In particular, the study presented in the paper investigates the potential annual cooling energy use savings that roof covers could provide using whole-building simulation analysis to evaluate the performance of a 2-story office building in five US locations. Three parameters of the roof covers including their size, height, and transmittance, are considered in the analysis. The simulation results indicate that while roof covers had similar affects on buildings in all climate zones, their impact in reducing cooling energy usage is different and is more pronounced in cooler climates. Specifically, roof covers could potentially achieve cooling energy savings of up to: 25% in Houston, 33% in Atlanta, 31% in Nashville, 38% in Chicago, and 41% in Madison. Based on the detailed simulation analysis results, a simplified calculation model is developed to help the estimation of cooling energy savings as a function of the roof cover size, height, and transmittance.

scholarly journals A Basic Study on the Performance Evaluation of a Movable Light Shelf with a Rolling Reflector That Can Change Reflectivity to Improve the Visual Environment

2020 ◽  
Vol 17 (22) ◽  
pp. 8338
Author(s):  
Heangwoo Lee
Keyword(s):  
Performance Evaluation ◽  
Energy Use ◽  
Energy Savings ◽  
Luminance Contrast ◽  
Visual Environment ◽  
Basic Study ◽  
Lighting Energy ◽  
Save Energy ◽  
Indoor Spaces ◽  
A Performance

In recent years, the need for comfortable visual environments in indoor spaces has increased energy use in buildings. There have been diverse studies on using a light shelf to solve this problem. It is an effective system that allows external natural light deep into indoor spaces through reflection. However, prior studies have used light shelves with a fixed reflectivity, and there are few studies on improving the visual environment through light shelf control. Therefore, this study proposes a movable light shelf with a rolling reflector that can change the reflectivity. To achieve these objectives, we conducted a performance evaluation of the system’s ability to save energy and improve the visual environment. This study built a real scale testbed and conducted a performance evaluation by deriving values for lighting energy consumption, uniformity, and luminance contrast depending on the light shelf variables. We conclude that (1) the light shelf system achieved an energy savings of 13.6% and 5.7%, respectively, compared to a fixed type light shelf, whose reflectivity cannot be changed, and a traditional movable light shelf; (2) in terms of improving the visual environment, results suggest that the visual environment could be improved using a light shelf by deriving light shelf variables that disturb indoor uniformity; and (3) the results verified glare generation conditions by deriving luminance contrast caused by the variables of light shelf angle and its reflectivity.

Photoelectric control: the effectiveness of techniques to reduce switching frequency

2001 ◽  
Vol 33 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Paul J Littlefair
Keyword(s):  
Time Delay ◽  
Energy Use ◽  
Control Strategies ◽  
Control Mode ◽  
Switching Frequency ◽  
Adaptation Level ◽  
Lighting Energy ◽  
Frequent Switching ◽  
Save Energy ◽  
The Cost

Photoelectric switching has the potential to save energy by turning off lighting when daylight illuminances are adequate. However one problem with this control type is frequent switching, annoying occupants. This paper examines three types of control algorithm which can reduce the number of switching operations. Under differential switching, the lighting is switched on if the illuminance falls below a critical value Eon, but not switched off again until the illuminance reaches a substantially higher value Eoff. Another option is the use of a time delay. The final control mode is solar reset where the lighting can only be switched off at certain set times of day. Operation of the various controls was simulated using model room illuminance data recorded every minute. The analysis reveals that solar reset gives the fewest switching operations but at the cost of increased energy consumption. A time delay, where the daylight illuminance has to exceed a target value for a set time before switching off can occur, gives the fewest switch offs for a given lighting energy use. However differential switching ensures that switching off occurs at a favourable adaptation level. The paper outlines ways to predict lighting energy use under the different control strategies.

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 Recent Advances in Internet of Things (IoT) Infrastructures for Building Energy Systems: A Review

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2152
Author(s):  
Wahiba Yaïci ◽  
Karthik Krishnamurthy ◽  
Evgueniy Entchev ◽  
Michela Longo
Keyword(s):  
Internet Of Things ◽  
Energy Use ◽  
Energy Savings ◽  
Control Strategies ◽  
Building Energy ◽  
Sensors And Actuators ◽  
Energy Applications ◽  
Building Energy Use ◽  
Detailed Assessment ◽  
The Many

This paper summarises a literature review on the applications of Internet of Things (IoT) with the aim of enhancing building energy use and reducing greenhouse gas emissions (GHGs). A detailed assessment of contemporary practical reviews and works was conducted to understand how different IoT systems and technologies are being developed to increase energy efficiencies in both residential and commercial buildings. Most of the reviewed works were invariably related to the dilemma of efficient heating systems in buildings. Several features of the central components of IoT, namely, the hardware and software needed for building controls, are analysed. Common design factors across the many IoT systems comprise the selection of sensors and actuators and their powering techniques, control strategies for collecting information and activating appliances, monitoring of actual data to forecast prospect energy consumption and communication methods amongst IoT components. Some building energy applications using IoT are provided. It was found that each application presented has the potential for significant energy reduction and user comfort improvement. This is confirmed in two case studies summarised, which report the energy savings resulting from implementing IoT systems. Results revealed that a few elements are user-specific that need to be considered in the decision processes. Last, based on the studies reviewed, a few aspects of prospective research were recommended.

Estimation of Lighting Energy Savings From Atrium Daylighting for Office Buildings

2014 ◽  
Author(s):  
Moncef Krarti
Keyword(s):  
Energy Savings ◽  
Office Buildings ◽  
Energy Reduction ◽  
Passive Heating ◽  
Heating And Cooling ◽  
Light Levels ◽  
Surface Finishes ◽  
Lighting Energy ◽  
Simplified Calculation ◽  
Story Building

Atria can offer several benefits to deep plan commercial and office buildings. This includes passive heating and cooling, ventilation, and daylighting. In order to use daylight effectively in atrium buildings, the characteristics that affect the light levels and distribution must be taken into account and analyzed. These elements include roofs, shapes, well geometries, surface finishes, and glazing types. The analysis outlined in this paper shows that a larger atrium area, higher window-to-wall ratio, clear windows, and a multi-story building provide the highest energy savings. The paper also presents a simplified calculation method to determine the percent lighting energy reduction attributed to atria in office buildings with continuous dimming. The lighting energy savings due to daylighting from atria can be up to 40%.

scholarly journals Controlling Switchable Electrochromic Glazing for Energy Savings, Visual Comfort and Thermal Comfort: A Model Predictive Control

CivilEng ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 1019-1053
Author(s):  
Abolfazl Ganji Kheybari ◽  
Tim Steiner ◽  
Steven Liu ◽  
Sabine Hoffmann
Keyword(s):  
Model Predictive Control ◽  
Thermal Comfort ◽  
Predictive Control ◽  
Energy Savings ◽  
Control Strategies ◽  
Temperate Climate ◽  
Base Case ◽  
North East ◽  
Simulation Based ◽  
The Impact

Dynamic façades play an important role in enhancing the overall performance of buildings: they respond to the environmental conditions and adjust the amount of transmitted solar radiation. This paper proposes a simulation-based framework to evaluate the energy and comfort performance of different control strategies for switchable electrochromic glazing (EC). The presented method shows the impact of a model predictive control (MPC) on energy savings and on visual and thermal comfort for different orientations compared to other strategies. Besides manual operation and conventional rule-based controls, the benchmark in this study was a simulation-based control (multi-objective penalty-based control) with optimal performance. The hourly results of various control cases were analyzed based on the established performance indicators and criteria. The cumulative annual results show the capabilities and limitations of each control strategy for an EC glazing. For a temperate climate (Mannheim, Germany), results showed that an MPC for EC glazing provides visual and thermal comfort while saving energy of up to 14%, 37%, 37%, and 34% respectively for facing north, east, south, and west relative to the base-case.

Optimal Control Strategies for Switchable Roof Insulation Systems Applied to US Residential Buildings

2020 ◽  
Vol 1 (4) ◽  
Author(s):  
Ammar H. A. Dehwah ◽  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Control Strategies ◽  
Residential Buildings ◽  
Residential Building ◽  
Building Envelope ◽  
Optimization Techniques ◽  
Optimal Controls ◽  
Insulation Systems ◽  
Rule Sets

Abstract Switchable building envelope systems, including passive and active systems, have recently seen an increase interest in the literature. Unlike static insulation, switchable insulation systems (SISs) have the ability to adjust the thermal properties of envelope elements. Advanced control strategies for SISs are evaluated in this analysis using genetic algorithm-based optimization techniques. In particular, this study investigates the potential heating and cooling energy savings for deploying optimal controls specific to SIS technologies when applied to residential roofs located in representative US climates. Moreover, energy use and peak demand savings obtained by optimal controls are compared with those obtained from the 2-step rule-based controls. Overall, the analysis results indicate that the maximum monthly additional savings obtained by optimal controls can reach up to 32% compared with 2-step rule sets when an annual analysis is conducted for a residential building located in Golden, CO.

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