Workshop lighting and building retrofit for visual quality and usability efficiency: case study of welding and sheet metal workshop, Phrae Technical College


  • Kanokkarn Vungmanee Faculty of Architecture, Silpakorn University
  • Tharinee Ramasoot Faculty of Architecture, Silpakorn University


natural light, illumination, glare, workshop, light uniformity


Good lighting is essential to perform activities successfully and safely. Inadequate artificial or natural lighting level may lead to errors or injuries. Lighting, therefore, plays an important part in the design of high risk areas such as metal workshops in technical colleges where vision is very demanding. At Phrae technical college, the workshops on floor 1 and 3, which are designed in accordance with the vocational education commission’s standard, were found to have problems with insufficient illuminance levels. The amount of natural light and artificial light in the workshops are far below the recommended levels in standards. This study aims to explore the natural lighting and artificial lighting strategies to increase the amount of light in the workshops to meet the standards. DiaLux Evo, a lighting simulation software, was used as a tool to simulate lighting in the workshops throughout the operation times on 4 key dates. The study found that the maximum amount of natural lighting is achieved by the combined design of the light shelf, the fiberglass shading, the change from aluminum to glass louvers and the flat ceiling. In the workshop on floor 1, the amount of light is increased by 172 Lux or 283%. In the workshops on floor 3, the amount of light is increased by 447 Lux or 103%. For artificial lighting, refitting the lighting with the arrays of 104 LED lamps results the amount of light is increased by 419 Lux or 157% increase in illuminance with only 13% increase of energy consumption on floor 1 and the amount of light is increased by  503 Lux or 190% increase in illuminance with only 19% increase of energy consumption on floor 3. But not enough for requirements lighting , floor 1 at 300 Lux and floor 3 at 500 Lux. In summary, despite the building retrofit, the quantify of natural lighting alone is not adequate to accommodate workshop activities, efficient artificial
lighting is needed. The best result of the improvement is the installation of fiberglass awning at a distance of 1.10 meters, 0.85 meters in size, changing the aluminum sheet to clear glass. Install an external light shelf size 1.10 meters. Install a flat type ceiling. And changing the artificial lighting system into a 27 27-watt LED lamp. This new artificial lighting system results in a slight increase in energy consumption but the quantity and quality of lighting is very much improved. The results from this study can be applied in other metal workshops to improve lighting conditions.


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