1. In galvanized steel roofing and wall projects, what main equipment is typically needed to achieve ventilation and lighting functions?
In modern light steel structure factory buildings, the common solution is to use integrated ventilation and lighting roof ventilators (also known as ventilation louvers or ventilation skylights). This is a large roofing device mainly composed of a steel structure frame, skylight panels (usually FRP skylight panels), and galvanized steel profiled sheets (serving as rain protection and enclosure), simultaneously meeting the four major needs of ventilation, exhaust, smoke extraction, and lighting. Commonly used ventilator types include streamlined roof ventilators (low wind resistance, strong wind resistance) and thin roof ventilators (low profile, low wind load), and manual, electric, or fire-fighting linked opening and closing valves can be selected according to specific needs.
2. How to effectively connect and seal ventilators and skylights with galvanized color-coated steel roofing panels to prevent leaks?
A: This is a core challenge in roofing systems. Ensuring leak-proof operation hinges on "compatibility" and "multiple lines of defense." First, skylights with a coefficient of thermal expansion similar to that of galvanized color-coated steel roofing coils should be selected. The coefficient of thermal expansion of FRP skylights (approximately 2.2 × 10⁻⁵ /℃) is very close to that of steel (approximately 1.5 × 10⁻⁵ /℃), far superior to that of PC panels, fundamentally reducing sealing failures caused by temperature-induced deformation. Second, all metal components (framework, connectors) must be hot-dip galvanized for corrosion protection, with a zinc coating thickness of no less than 50μm to prevent rust from damaging the waterproof structure. In terms of installation, the overlap between flange connections and the steel roofing sheet must be fully welded and sealed with weather-resistant sealant to ensure a smooth weld. Flashing and built-in gutters should also be installed to direct rainwater to the roof downpipes. Finally, when laying the skylight panels, the spacing between the self-tapping screws of the special sealing ring should be maintained at 150~200mm, and it should be fixed with aluminum pressure plates or rubber pads to avoid directly cracking the panels.
3. Can skylights be used to replace some of the galvanized color-coated profiled sheets to simultaneously solve the lighting problem and be used in conjunction with ventilators?
A: Yes, this is a commonly used and economical approach for achieving long-distance ventilation and lighting in large-span factory buildings. You can replace some of the ordinary color-coated sheets on the roof with FRP (fiberglass reinforced polyester) skylights to create horizontal or vertical transparent lighting strips. Regarding ventilation, the ventilators installed on the roof not only expel hot air and smoke from the room, but their rain shields can also be made of FRP skylight material to further increase the amount of light entering the room, avoid glare, and make the indoor lighting more uniform. By rationally planning the area and spacing of the skylights, it is possible to achieve complete natural lighting during the day, forming a highly efficient and energy-saving combination of "smoke exhaust + lighting" in conjunction with ventilators.
4. What are the principles for the layout and use of galvanized color-coated steel sheet projects when comprehensively designing these systems?
A: The principle of overall layout planning is usually "natural, efficient, and complementary." For ventilation, ventilation towers should be arranged along the highest point of the factory roof (ridge line) as the main axis to facilitate the automatic upward flow of hot air to exhaust and remove polluted air; at the same time, auxiliary ventilation windows should be designed on the gable walls of the building to create convection. For lighting, it should be combined with the layout of the ventilation system, with ventilation towers, side lighting, and replacement lighting panels forming a three-dimensional array. In addition, complete inspection and maintenance passages must be reserved, and personnel are strictly prohibited from walking or standing directly on the lighting panels. All inspections must be carried out by walking on safety hooks within the grooves of the roof steel plates to avoid breaking the panels and causing safety accidents.
5. Regarding material selection, what coatings and platings should be chosen for the matching ventilators and skylights?
A: Based on the reliability principle of "matching corrosion resistance lifespan within the same region," the steel frames of the roof ventilators and skylights should use hot-dip galvanized or hot-dip aluminum-zinc coated substrates of the same grade as the main roof panels. It is recommended that the aluminum-zinc coating amount be ≥150g/㎡, the yield strength ≥280Mpa (meeting the unit requirements for material matching), and a double-sided coating of 0.5mm thick plates. For rain covers (outer protective panels), color-coated steel plates with anti-corrosion coatings on both sides must be used. The surface of exposed metal profiles should be protected with a fluorocarbon coating layer that is UV-resistant and aging-resistant. For FRP skylights that integrate lighting and rain protection, it is required to add a Melinx UV-resistant film and a weathering-resistant resin layer to ensure that their weather resistance coefficient for 10 to 15 years is roughly the same as that of the main steel panels.