Discussion about calculation method of light transmission efficiencies of elbows in cylindrical light pipes

Wang, Chun-Yuan; Gao, Qinglong; Gao, Weijun; Ouyang, Jinlong

doi:10.1016/j.solener.2022.04.024

Cited by 4 publications

(8 citation statements)

References 12 publications

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“…The elbowed pipe has to redirect the light ux from the vertical pipe to the diffuser or the straight pipe with an angular [15,24]. Recently, several experimental methods [25] and analytical solve methods [13,14,24,26] for evaluation of light transmittance through an elbowed light pipe. It is also di cult to accurately predict light transmissions in elbowed light pipes because they are affected by more variable.…”

Section: Aims and Motivationmentioning

confidence: 99%

“…It is also di cult to accurately predict light transmissions in elbowed light pipes because they are affected by more variable. Suspecting the analytical calculation method used in previous studies, the study [14] develops a solution thorough some formula derivations to calculate elbow light transmission e ciency. This elbow pointed out by Wang et al (2022), is also used in this study and new models are developed.…”

Section: Aims and Motivationmentioning

confidence: 99%

“…Suspecting the analytical calculation method used in previous studies, the study [14] develops a solution thorough some formula derivations to calculate elbow light transmission e ciency. This elbow pointed out by Wang et al (2022), is also used in this study and new models are developed. Pipes with two elbows angled at 45° are also used in commercial productions [27] and are estimated with analytical calculation method [2].…”

Section: Aims and Motivationmentioning

confidence: 99%

“…The introduction of elbows will increase the aspect ratios of light pipes [2,13]. That case reduce the overall light transmission e ciency in most cases [14]. However, since it still provides different usage advantages, many studies have been conducted on light pipes with elbow in different methods [14][15][16].…”

Section: Introductionmentioning

confidence: 99%

“…It is necessary to determine the daylight it transmits indoors to adapt and use in complex building. In light pipe studies, many analytical calculations [2,14,15], experimental measurements [17,18] and simulation software tools [10,19,20] were used methods in order to determine the light transmission of different cases. The analytical calculation method is based on assumptions on the light transmission e ciency of pipe components and is inadequate to characterize complicated systems [20].…”

Section: Introductionmentioning

confidence: 99%

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Light Pipe Configurations Based on Daylight Simulations; Straight and Elbowed Pipe Models

Atalay,

Kurtay

2023

Preprint

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Light pipes are one of the most effective ways of transmitting daylight deeper into buildings, away from facades and windowless areas. To adapt in complex building structures, one or more elbows must be used to change the direction of light, however, an elbowed pipe is known to cause more light loss than a straight pipe of equal length. This paper presents a research study on different configurations for straight and elbowed light pipes via the accurate simulation tools, which is another light transmission efficiency method. Case study is defined in three main stages: identification of the optimum model by trying different elbow models; comparison of light pipes, which are generally used straight, and the elbow model attached to bottom interface of the pipe at an angle of 45°; comparison of double elbow light pipes with 45° and 90° elbow angles. Basic software series consist with 3D-based Rhinoceros, algorithmic graphical editor Grasshopper, simulate daylight Ladybug and Honeybee plugins. The analyzed parameters are maximum and average illumination level, Daylight Factor (DF) and Daylight Autonomy (DA). According to the illumination levels, DA and DF results, in overcast sky conditions, it is possible to provide approximately 50% of the required light level for the space with daylight using light pipe systems.

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Section: Aims and Motivationmentioning

confidence: 99%

Section: Aims and Motivationmentioning

confidence: 99%

Section: Aims and Motivationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Light Pipe Configurations Based on Daylight Simulations; Straight and Elbowed Pipe Models

Atalay,

Kurtay

2023

Preprint

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Analysing light pipe two-side aperture in dense population housing to improve the visual and thermal condition

Hanjani

Dewi

Putra

2024

Energy and Built Environment

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Daylight Performance of Elbow Geometry in Light Pipe Models

Atalay,

Kurtay

2023

Period. Polytech. Arch.

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Light pipes are innovative daylight lighting systems often used linearly which transmit light through reflections on carrying surfaces. However, in order for the system to be used in more complex buildings, it should be possible to integrate one or more elbows into the system if needed with the purpose of deliberately change the direction of light transmission. In this study, attention is drawn to the assumption that the light carried in the elbowed light pipes is related to the design of the elbow geometry as well as variables such as pipe length, diameter (aspect ratio), reflectance and transmittance values of the components, sky conditions, solar angles, latitude-longitude data, elbow angle, etc. The purpose of the study is to investigate the daylight performance of elbowed light pipe system and different elbow geometries. In this respect, the models used in scientific studies and commercial products were compared and new elbow models were proposed. Daylight levels (lux) and Daylight Factor (DF) achieved through a numerical simulation software based on a correct method and well-established algorithm were evaluated as performance measures. Whether the light levels reached as a result of the analyses alone are sufficient to illuminate the space varies depending on the dimensions, function and duration of use of the space.

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Discussion about calculation method of light transmission efficiencies of elbows in cylindrical light pipes

Cited by 4 publications

References 12 publications

Light Pipe Configurations Based on Daylight Simulations; Straight and Elbowed Pipe Models

Light Pipe Configurations Based on Daylight Simulations; Straight and Elbowed Pipe Models

Analysing light pipe two-side aperture in dense population housing to improve the visual and thermal condition

Daylight Performance of Elbow Geometry in Light Pipe Models

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