Assessing Window Design's Impact on Daylight Uniformity in Classrooms in Patna, India


  • Alok Kumar Maurya Department of Architecture and Planning, National Institute of Technology Patna, India
  • Ravish Kumar Department of Architecture and Planning, National Institute of Technology Patna, India
  • Ajay Kumar Department of Architecture and Planning, National Institute of Technology Patna, India
Volume: 13 | Issue: 5 | Pages: 11898-11903 | October 2023 |


Windows play a vital role in daylight infusion, significantly impacting indoor visual comfort. Various metrics exist for evaluating visual comfort in which the uniformity ratio falls under the distribution category and is as crucial as illuminance levels. This ratio effectively reduces the likelihood of glare and the need for artificial lighting. The primary objective of this research is to assess the impact of window design on daylight uniformity ratio in a classroom setting. In pursuit of this objective, a study investigated the uniformity ratio (Uo) of north-oriented and south-oriented classrooms of Kendriya Vidyalaya (KV) Khagual, Patna. The study considered five common shapes of windows (excluding the existing base cases) at different window-sill levels. Ninety simulations were run in the DesignBuilder software under overcast, intermediate, and clear sky conditions. To assess the uniformity ratio on three dates: March 21st, June 21st, and December 21st, which correspond to the highest, equinox, and lowest solar availability during the year under intermediate and clear sky conditions at three distinct times. The omission of the specific time and date for overcast conditions and the particular year for clear and intermediate sky conditions is justified as the outcome remains consistent throughout all years. The results show that the window design and sill level significantly affect the uniformity ratio. The research findings show that window design in Case 9 at a sill of 1230 mm and lintel of 3050 mm (just below the slab) consistently produces the best uniformity ratio across all sky conditions, independent of classroom orientation. This paper offers valuable design recommendations by comparing the uniformity ratio for five commonly used window designs. This is one of the first studies of window design and position to evaluate the uniformity ratio in the classrooms at Patna.


window design, uniformity ratio, daylight, classroom, simulation


Download data is not yet available.


A. D. Galasiu and J. A. Veitch, "Occupant preferences and satisfaction with the luminous environment and control systems in daylit offices: a literature review," Energy and Buildings, vol. 38, no. 7, pp. 728–742, Jul. 2006.

Y.-W. Lim, M. Z. Kandar, M. H. Ahmad, D. R. Ossen, and A. M. Abdullah, "Building facade design for daylighting quality in typical government office building," Building and Environment, vol. 57, pp. 194–204, Nov. 2012.

F. S. Yılmaz, "Proposal of a facade design approach for daylight performance determination in buildings," A| Z ITU Journal of the Faculty of Architecture, vol. 13, no. 2, pp. 57–64, Aug. 2016.

Heschong Mahone Group, "Daylighting in Schools: An Investigation into the Relationship Between Daylighting and Human Performance Detailed Report," Pacific Gas and Electric Company, 1999.

X. Yu and Y. Su, "Daylight availability assessment and its potential energy saving estimation –A literature review," Renewable and Sustainable Energy Reviews, vol. 52, pp. 494–503, Dec. 2015.

N. S. Shafavi, M. Tahsildoost, and Z. S. Zomorodian, "Investigation of illuminance-based metrics in predicting occupants’ visual comfort (case study: Architecture design studios)," Solar Energy, vol. 197, pp. 111–125, Feb. 2020.

I. Zeghib and A. Chaker, "Efficiency of a Solar Hydronic Space Heating System under the Algerian Climate," Engineering, Technology & Applied Science Research, vol. 6, no. 6, pp. 1274–1279, Dec. 2016.

J. Yau, J. J. Wei, H. Wang, O. Eniola, and F. P. Ibitoye, "Modeling of the Internal Temperature for an Energy Saving Chinese Solar Greenhouse," Engineering, Technology & Applied Science Research, vol. 10, no. 5, pp. 6276–6281, Oct. 2020.

S. Carlucci, F. Causone, F. De Rosa, and L. Pagliano, "A review of indices for assessing visual comfort with a view to their use in optimization processes to support building integrated design," Renewable and Sustainable Energy Reviews, vol. 47, pp. 1016–1033, Jul. 2015.

S. Zanon, N. Callegaro, and R. Albatici, "A Novel Approach for the Definition of an Integrated Visual Quality Index for Residential Buildings," Applied Sciences, vol. 9, no. 8, Jan. 2019, Art. no. 1579.

Y. Zhai, Y. Wang, Y. Huang, and X. Meng, "A multi-objective optimization methodology for window design considering energy consumption, thermal environment and visual performance," Renewable Energy, vol. 134, pp. 1190–1199, Apr. 2019.

M. Qingsong and H. Fukuda, "Parametric Office Building for Daylight and Energy Analysis in the Early Design Stages," Procedia - Social and Behavioral Sciences, vol. 216, pp. 818–828, Jan. 2016.

A. Maleki and N. Dehghan, "Optimum Characteristics of Windows in an Office Building in Isfahan for Save Energy and Preserve Visual Comfort," Journal of Daylighting, vol. 8, no. 2, pp. 222–238, Jul. 2021.

S. Farivar and S. Teimourtash, "Impact of Window Design on Dynamic Daylight Performance in an Office Building in Iran," Journal of Daylighting, vol. 10, no. 1, pp. 31–44, Mar. 2023.

Z. S. Zomorodian, S. S. Korsavi, and M. Tahsildoost, "The effect of window configuration on daylight performance in classrooms : A field and simulation study," International journal of architectural engineering and urban planning, vol. 26, no. 1, pp. 15–24, 2016.

B. J. Futrell, E. C. Ozelkan, and D. Brentrup, "Bi-objective optimization of building enclosure design for thermal and lighting performance," Building and Environment, vol. 92, pp. 591–602, Oct. 2015.

X. Liu, Y. Sun, S. Wei, L. Meng, and G. Cao, "Illumination distribution and daylight glare evaluation within different windows for comfortable lighting," Results in Optics, vol. 3, May 2021, Art. no. 100080.

S. Carlucci, G. Cattarin, F. Causone, and L. Pagliano, "Multi-objective optimization of a nearly zero-energy building based on thermal and visual discomfort minimization using a non-dominated sorting genetic algorithm (NSGA-II)," Energy and Buildings, vol. 104, pp. 378–394, Oct. 2015.

I. Acosta, M. A. Campano, and J. F. Molina, "Window design in architecture: Analysis of energy savings for lighting and visual comfort in residential spaces," Applied Energy, vol. 168, pp. 493–506, Apr. 2016.

F. Kharvari, "A Field-validated Multi-objective Optimization of the Shape and Size of Windows Based on Daylighting Metrics in Hot-summer Mediterranean and Dry Summer Continental Climates," Journal of Daylighting, vol. 7, no. 2, pp. 222–237, Nov. 2020.

B. Lartigue, B. Lasternas, and V. Loftness, "Multi-objective optimization of building envelope for energy consumption and daylight," Indoor and Built Environment, vol. 23, no. 1, pp. 70–80, Feb. 2014.

A. Zhang, R. Bokel, A. van den Dobbelsteen, Y. Sun, Q. Huang, and Q. Zhang, "Optimization of thermal and daylight performance of school buildings based on a multi-objective genetic algorithm in the cold climate of China," Energy and Buildings, vol. 139, pp. 371–384, Mar. 2017.

A. Toutou, M. Fikry, and W. Mohamed, "The parametric based optimization framework daylighting and energy performance in residential buildings in hot arid zone," Alexandria Engineering Journal, vol. 57, no. 4, pp. 3595–3608, Dec. 2018.

C. E. Ochoa, M. B. C. Aries, E. J. van Loenen, and J. L. M. Hensen, "Considerations on design optimization criteria for windows providing low energy consumption and high visual comfort," Applied Energy, vol. 95, pp. 238–245, Jul. 2012.

I. Acosta, C. Munoz, M. A. Campano, and J. Navarro, "Analysis of daylight factors and energy saving allowed by windows under overcast sky conditions," Renewable Energy, vol. 77, pp. 194–207, May 2015.

S. Saadi and A. Chaker, "A Numerical Simulation Approach for Sunspot Area Calculation," Engineering, Technology & Applied Science Research, vol. 8, no. 3, pp. 3013–3017, Jun. 2018.

S. Kumari, A. Kumar, R. Kumar, and A. H. M. Fetais, "Assessing residential satisfaction parameters and its socio-economic characteristics of low-income group public housing in Lucknow city," International Journal of Indian Culture and Business Management, vol. 29, no. 3, pp. 335–352, Jan. 2023.

S. Kumari, A. Kumar, and R. Kumar, "Regression model for residential satisfaction in low-income group public housing in Lucknow, India," International Journal of Indian Culture and Business Management, vol. 1, Jun. 2022.

S. Darula and R. Kittler, "CIE general sky standard defining luminance distributions," in Proceedings of eSim 2002 The Canadian conference on building energy, Montreal, Canada, Sep. 2002.

R. Perez, R. Seals, and J. Michalsky, "All-weather model for sky luminance distribution—Preliminary configuration and validation," Solar Energy, vol. 50, no. 3, pp. 235–245, Mar. 1993.

N. A. Khan, P. Malik, and B. Bhattacharjee, "Identifying the design skies for Indian tropical climatic conditions," Current Science, vol. 119, no. 3, pp. 473–484, 2020.

V. Costanzo, G. Evola, and L. Marletta, "A Review of Daylighting Strategies in Schools: State of the Art and Expected Future Trends," Buildings, vol. 7, no. 2, Jun. 2017, Art. no. 41.

BS EN 12464 1 (2021),Light and lighting — Lighting of work places,Part 1: Indoor work places. London, UK: British Standards Institution, 2021.

D. Loe, N. Watson, E. Rowlands, K. Mansfield, B. Venning, and J. Baker, "Lighting Design for Schools. Building Bulletin 90," The Stationery Office, London, UK, Building Bulleting 90, 1999.

K. Butcher, Lighting Guide 5: Lighting for Education. London, UK: Chartered Institution of Building Services Engineers, 2011.


How to Cite

A. K. Maurya, R. Kumar, and A. Kumar, “Assessing Window Design’s Impact on Daylight Uniformity in Classrooms in Patna, India”, Eng. Technol. Appl. Sci. Res., vol. 13, no. 5, pp. 11898–11903, Oct. 2023.


Abstract Views: 371
PDF Downloads: 236

Metrics Information

Most read articles by the same author(s)