Quick conclusion
No ratioThe calculation of the area of the skylight panel is correct for all factories. At first, the geometric ratio can be calculated, but the final plan must be based on illuminance targets, light distribution, glare, heat, roof orientation, optical data, fire requirements, and simulations according to local climate.
Why can't the ratio be determined based only on the workshop area?
Auxiliary requirements related to geographic location, roof orientation, operating hours, height, surface color, obstacles, transmission/diffusion level of panels, illumination requirements, glare, cooling load, and energy-fire standards. A learning ratio from another building may cause the factory to lack light or increase heat.
Area ratio is only an initial geometric index
SRR (%) = total illuminated area of the skylight / total roof plan area × 100. It is necessary to agree on using plan area or slope area; do not mix the two methods in the same calculation.
Example calculations, not design recommendations
Roof area of 2,400 m², arranged to test 96 sheets, each sheet having an effective projection area of 1m × 6m: total area is 576 m², geometric ratio is 576 / 2,400 × 100 = 24%These numbers do not indicate whether the option is good or bad; it is necessary to simulate illuminance, glare, heat, shadow areas, and check fire resistance before approval.
Procedure for determining reasonable area
- Finalize lighting tasks: area, hours of use, illuminance, and uniformity.
- Model the geometry, obstacles, surface reflections, and optical data of the panel.
- Compare rooflight distribution options using daylight simulation and heat load.
- Check fire, smoke, structure, anti-fall, and maintainability.
- Use sensors/light control if the goal is actual energy savings.
- Measure for inspection after completion and adjust operationoperation.
Evenly arranging is usually more useful than clustering together.
A reasonable distribution range can reduce overly bright and dark areas, but an increased number of joints also increases points that need leak management. Avoid placing in areas shaded by equipment or creating direct glare into the workspace; coordinate with ventilation, fire protection, solar panels, and maintenance access.
Send the roof layout, workshop height, operating hours, working areas, and lighting objectives to prepare a preliminary plan; the final quantity must be confirmed by the design unit.
Send documents to receive reportpriceReference sources and limits of use
- ASTM D3841-21: scope of classification, materials, and testing of fiberglass-reinforced polyester panels used in construction; the standard also notes that specific applications may require different performance levels.
- ISO/CIE 10916:2024: procedure to calculate the influence of daylight on building energy performance.
- MCRMA Technical Paper 1: structure, arrangement, and material selection of rooflight for metal roofing systemtype.
- NZ Metal Roofing Manufacturers – Natural Light Materials: compatible with the profile, characteristics, and differences between GRP and Polycarbonate in industrial roofing.
- Nova Construction Products – Rooflight Application Guide: focal point for guiding rooflight and self-drilling screw installation.
Technical limits: This article is used to screen options and prepare quotation data, not to replace construction drawings, structural calculations, light–heat simulations, fire regulations, or specific instructions for the actual roofing system. All thicknesses, spacing, loads, light transmission, fire resistance, durabilityChemicals, warranty, and price must be confirmed with the factory documentation of the shipment before signing the contract or starting construction.
View the product, material, and specification table at guide to choosing Composite/FRP translucent roofing sheets.
Contact Hưng Thịnh Phát for consultation on specifications and pricing at the factory.
