A daylight factor model under clear sky conditions for building: An experimental validation

Sudan, Madhu; Tiwari, G.N.; Al-Helal, I.M.

doi:10.1016/j.solener.2015.03.002

Cited by 34 publications

(19 citation statements)

References 22 publications

(27 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From an energy perspective, it is also used in the new daylighting European Standard EN-17037:2018 [65] for evaluating daylight penetration of buildings. Standard sky for DF calculation (overcast sky) has been defined as the most conservative, and from an energy point of view, this is very useful since it represents the condition of peak energy consumption for artificial lighting [65][66][67][68].…”

Section: Verification On Indoor Illuminance Prediction Methods (Cie Ovmentioning

confidence: 99%

Development of Sky Luminance and Daylight Illuminance Prediction Methods for Lighting Energy Saving in Office Buildings

Kim

2019

Energies

View full text Add to dashboard Cite

Accurately predicting indoor illuminance from daylight during the early stages of building design is an important factor in saving energy and the costs associated with lighting. The objective of this study was to predict sky luminance distribution using the Commission Internationale de l’éclairage (CIE) standard sky model, and propose a method that can be used to predict indoor illuminance. Results obtained from the proposed prediction method were compared and verified with simulation values obtained by Desktop Radiance. From the CIE overcast sky, the zenith/horizon ratio was 3:1. From the CIE clear sky, the luminance value was highest around the sun. In contrast, the luminance value was lowest in the opposite direction of the sun when the angle between the sun and sky elements was 90°. In addition, this study suggested an indoor illuminance prediction method by applying the effects of sky luminance, direct sunlight, and wall reflection elements. When the proposed equation’s calculation results were compared with Desktop Radiance simulation’s value in overcast and clear sky, all statistically analysis (R2, MBE, Cv(RMSE), t-value, p-value) satisfied each standard and showed high correlations. Consequently, it was established that the predicted indoor illuminance obtained from the proposed prediction method was accurate and can be used to predict the level of indoor illuminance. The results further revealed that it is possible to calculate indoor illuminance when installing blinds, by substituting variable values of visible light transmittance (VLT).

show abstract

Section: Verification On Indoor Illuminance Prediction Methods (Cie Ovmentioning

confidence: 99%

Development of Sky Luminance and Daylight Illuminance Prediction Methods for Lighting Energy Saving in Office Buildings

Kim

2019

Energies

View full text Add to dashboard Cite

show abstract

“…The device was able to maintain the visual comfort of occupants and reduce the reliance on artificial lighting in the internal space with the validation from both computer simulation and experiments [14]. Theoretical daylight model was developed to estimate the daylight factor, sky component and internally reflected component for rooms which were validated by measurement data with an error of 5.1-7.9% [18]. The study also identified the south orientation and upper wall positon as favorable window designs.…”

Section: Daylight Studiesmentioning

confidence: 99%

“…where SC, ERC and IRC are the sky component (direct light received only), the external reflected component and the internal reflected component respectively [18]. Therefore, the amount of daylight available for specific internal space is related to: window and room geometry, room surface finishes; sky obstruction due to the shape of the building and its neighbourhood; and glazing transmittances.…”

Section: Daylight Simulationmentioning

confidence: 99%

Combined thermal and daylight analysis of a typical public rental housing development to fulfil green building guidance in Hong Kong

Chen

Yang

2015

Energy and Buildings

View full text Add to dashboard Cite

“…The calculation of daylight availability and its impact on energy savings are presented in Reference [72][73][74]. Factors that have an impact on daylight performance such as weather, architecture and location of the building are presented in Reference [75][76][77]. A simulation result [78] using different weather data has revealed that weather has a significant effect on the illuminance value through the condition of the sky.…”

Section: Literature Reviewmentioning

confidence: 99%

Feasibility Study and Impact of Daylight on Illumination Control for Energy-Saving Lighting Systems

Bunjongjit

Ngaopitakkul

2018

Sustainability

View full text Add to dashboard Cite

The main goal of energy conservation should be reducing the consumption of energy resources. Due to energy and environmental concerns in recent years, to reduce energy consumption in a lighting system, which has been one of the prime targets of energy saving, daylighting has been investigated and has become one of the energy-efficiency techniques widely applied in buildings. This paper presents an analysis of T5 fluorescent luminaire lighting control using daylight in a building. The study is conducted in two parts; simulation of a lecture room using the daylighting function of the DIALux program is performed to estimate the effect of daylighting on a task area (workplane). Another part is an experimental setup to evaluate the performance of a lighting control unit that is installed for a T5 fluorescent luminaire with a dimmable electronic ballast. The efficiency of the lighting control in term of illumination on the task area and energy consumption are also evaluated and compared with the standard case. The simulation results show that daylighting increases illuminance on a task area, especially on the window side, so the lighting system can significantly reduce its power consumption compared with a standard case (without lighting control). The experimental result shows that upon installing the lighting control with daylighting, both the average illuminance and the energy consumption in each time period are decreased compared with in the standard case. Lighting control with daylighting tries to set the average illuminance on a task area to less than 500 lux, corresponding to the amount of daylight passing through window shutters. The obtained results are useful for the design of a T5 fluorescent luminaire with lighting control using daylighting in a building lighting system for energy efficiency and reducing energy consumption, including the average illuminance on the task area, according to a relevant standard.

show abstract

A daylight factor model under clear sky conditions for building: An experimental validation

Cited by 34 publications

References 22 publications

Development of Sky Luminance and Daylight Illuminance Prediction Methods for Lighting Energy Saving in Office Buildings

Development of Sky Luminance and Daylight Illuminance Prediction Methods for Lighting Energy Saving in Office Buildings

Combined thermal and daylight analysis of a typical public rental housing development to fulfil green building guidance in Hong Kong

Feasibility Study and Impact of Daylight on Illumination Control for Energy-Saving Lighting Systems

Contact Info

Product

Resources

About