Daylight trough system illuminating a tropical office interior

Harnessing Daylight: Can Light Troughs Brighten the Future of Sustainable Office Design?

"A case study in Malaysia explores the potential of daylight troughs to revolutionize office lighting, reduce energy consumption, and enhance visual comfort in tropical climates."


In the quest for sustainable architecture, daylighting has emerged as a crucial strategy, particularly with the rise of green building initiatives worldwide. While research often focuses on temperate climates, the unique conditions of tropical regions demand innovative solutions. This article explores one such solution: the daylight trough.

Daylighting offers a wealth of benefits, from improving the visual experience of occupants to reducing reliance on artificial lighting. Studies have shown that daylighting can lead to significant energy savings, with some reporting reductions of up to 87%. But conventional fenestration systems often fall short, distributing daylight unevenly and limiting its reach within a building.

This article dives into a case study of a daylight trough installed in a Malaysian office building, examining its performance, practicality, and potential for broader adoption. We'll explore how this system effectively delivers natural light deep into the office space, reduces lighting energy consumption, and the challenges encountered during its implementation.

Daylight Troughs: A Tropical Solution for Deep-Space Illumination

Daylight trough system illuminating a tropical office interior

Conventional windows often struggle to distribute light evenly, typically reaching only 1.7 times the window's height into the room. However, innovative techniques for redirecting and reflecting sunlight have greatly extended daylight's reach. One such approach is "light guidance," which uses collector devices to capture sunlight and transport it to deeper areas within a building.

The daylight trough (DT) is an example of a light guidance system. Researchers investigated a DT system installed in Menara Mustapha Kamal Block D, a 21-story office tower in Damansara Perdana, Malaysia. They used simulation software (Radiance IES) and field measurements to evaluate the DT's performance, focusing on daylight factor (DF), illuminance distribution, and potential energy savings.

  • Simulation Parameters: The team meticulously modeled the building and surrounding structures, accounting for material reflectance, specularity, and visible light transmission.
  • Field Measurements: Illuminance loggers were strategically placed to record light levels, both indoors and outdoors, to determine the actual daylight factor and assess the sky conditions.
  • Energy Savings Calculations: The study compared lighting power density (LPD) with and without the DT to quantify potential energy savings.
The results showed that the DT effectively delivered daylight up to 6 meters into the office space, achieving an average illuminance ratio improvement factor (IRIF) of 17.16 and 5.87 for the south- and north-oriented offices, respectively. This resulted in a lighting power density of 1.90W/m² with the DT, compared to 5.25W/m² without it. This translates to a 39.2% and 13.9% reduction in electrical lighting for South and North oriented offices. A total savings of 25.18% overall.

Practical Considerations and Future Directions

Despite the promising results, the implementation of daylight troughs also presents challenges. The initial design required adjustments due to constructability issues, and maintenance considerations led to further refinements. For instance, the design was modified to accommodate existing mechanical and electrical components, and a system for cleaning the troughs was developed using telescopic mops instead of robot vacuum cleaners, which presented warranty and liability concerns.

The economic analysis revealed a payback period of 20.4 years, considering the cost of materials and installation, as well as energy savings and lamp replacement cost reductions. However, this calculation doesn't fully capture intangible benefits such as improved employee well-being, reduced carbon emissions, and enhanced corporate image. Factoring these elements could significantly shorten the payback period.

Further research is needed to fully understand the long-term performance of daylight troughs and optimize their design for different building types and climates. Post-occupancy surveys should be conducted to assess occupant satisfaction and visual comfort. Additional studies should also investigate the integration of daylight troughs with artificial lighting systems to create a more seamless and energy-efficient lighting solution. Ultimately, daylight troughs offer a compelling strategy for achieving sustainable and human-centric lighting in tropical office environments.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1051/matecconf/20166600032, Alternate LINK

Title: Practicality And Performance Of Daylight Trough In The Tropics: A Case Study

Subject: General Medicine

Journal: MATEC Web of Conferences

Publisher: EDP Sciences

Authors: Lim Gene-Harn, Gregers Reimann, Gunaseelan Bhaskaran, Michael Hirning, Morten Christensen

Published: 2016-01-01

Everything You Need To Know

1

What is a daylight trough and why is it important in the context of the article?

The daylight trough (DT) is a light guidance system. It is a key element in the context of sustainable office design, specifically in tropical climates, as a means of redirecting and reflecting sunlight to illuminate deep spaces within a building. This helps to reduce reliance on artificial lighting and offers a pathway to reduce energy consumption and enhance well-being of occupants.

2

What is daylighting, and why is it significant in the pursuit of sustainable office design?

Daylighting is the practice of using natural light to illuminate a space. Its importance in this context lies in its ability to improve the visual experience for occupants, reduce energy consumption, and support green building initiatives. The article highlights how conventional fenestration systems often fail to distribute daylight effectively, especially in tropical climates, making innovative solutions like the daylight trough essential for achieving these benefits.

3

How did researchers evaluate the performance of the daylight trough in the Menara Mustapha Kamal Block D study?

The study in Menara Mustapha Kamal Block D employed several methods. The simulation software (Radiance IES) modeled the building's performance, accounting for material properties. Field measurements, using illuminance loggers, recorded light levels. Energy savings were calculated by comparing lighting power density (LPD) with and without the daylight trough. These methods were crucial for evaluating the daylight trough's effectiveness in delivering natural light, reducing energy consumption, and determining its potential for broader adoption.

4

What practical challenges were faced during the implementation of daylight troughs, and why are they important?

The challenges encountered during the implementation of daylight troughs included design adjustments due to constructability issues and the need for maintenance solutions. The design was modified to accommodate existing mechanical and electrical components. The study developed a cleaning system utilizing telescopic mops for the daylight troughs, replacing robotic vacuum cleaners. These considerations are important because they highlight the need to balance innovative design with practical application and maintenance to ensure the long-term viability and effectiveness of the daylight trough system.

5

What were the key results of the daylight trough study, and why are they significant?

The study's findings showed that the daylight trough effectively delivered daylight up to 6 meters into the office space. It achieved significant improvements in illuminance ratio improvement factor (IRIF) for both south- and north-oriented offices. This resulted in substantial reductions in lighting power density, leading to a total overall savings of 25.18%. These results are significant because they demonstrate the daylight trough's ability to enhance daylighting performance, reduce energy consumption, and contribute to a more sustainable and comfortable indoor environment.

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