What are the advantages of glass film compared to other types of glass?
1) Comparison with Regular Glass:
Some public buildings have window-to-wall ratios exceeding 20%, with energy consumption through windows accounting for approximately 50% of the building's total energy use. About 75% of energy losses through windows are attributed to glass, especially for windows with a shading coefficient (SC) of around 0.8 or higher. This leads to what is commonly referred to as the "greenhouse effect" due to the excessive introduction of solar energy. Energy-efficient renovation in public buildings, particularly window and façade upgrades, is crucial for energy conservation. Glass retrofitting for existing buildings offers two main options: replacing existing glass with energy-efficient glass or applying architectural insulating safety film. The latter is a faster, more convenient, and effective solution.
2) Comparison with Laminated Glass:
Laminated glass is typically used in banks and offers protection against break-ins and bullets. However, it has relatively poor thermal insulation properties and does not effectively block ultraviolet (UV) rays. Laminated glass has complex production processes and high technical requirements. Moreover, the cost of the PVB material used for interlayer lamination is significantly higher than the cost of the glass itself. Architectural film for glass is easier to install, more cost-effective, and offers good performance in terms of thermal insulation, light transmission, and UV protection. After applying the film, the strength of the glass can be increased by 4 to 40 times or even achieve bullet-resistant effects, comparable to laminated glass.
3) Comparison with Coated Glass:
Coated glass involves applying one or more layers of metal, alloy, or metal compounds to the glass surface to alter its properties. Depending on their characteristics, coated glass can be categorized as heat-reflective glass and low-emissivity (Low-E) glass. Heat-reflective glass, also known as sunlight control glass, features a thin film composed of metals or their compounds (e.g., chromium, titanium, or stainless steel) on the glass surface. It provides vibrant colors, suitable visible light transmittance, high reflectance in the near-infrared spectrum, and low ultraviolet transmittance. However, it has a minimal impact on the U-value, which measures thermal conductivity. Low-E glass is coated with multiple layers of silver, copper, tin, or other metals or compounds, offering high visible light transmittance and high reflectance in the infrared spectrum, excellent insulating properties, but is generally used in insulated glass units (IGUs) due to lower coating strength. Low-E glass is susceptible to oxidation over time, forming black oxide deposits, which significantly affect both light transmission and the overall appearance of buildings.
4) Comparison with Composite Glass with Coatings and Insulation:
This category includes combinations like heat-reflective coated insulated glass and low-E coated insulated glass. The former improves both the U-value and SC simultaneously, while the latter offers good light transmission. However, using three panes of glass and coatings can significantly increase the cost compared to regular glass.
In summary, architectural glass film for retrofitting existing building windows has the following six advantages:
a) More cost-effective: Retrofitting existing clear or tinted tempered glass with heat-reflective or Low-E films is about 50% more cost-effective than replacing it with heat-reflective glass. Similar cost savings can be achieved with other scenarios, such as retrofitting existing insulated glass with heat-reflective or Low-E films to upgrade to insulated heat-reflective or Low-E coated glass.
b) Faster: Applying glass film is quicker and less labor-intensive compared to removing and replacing glass.
c) Environmentally Friendly: Glass replacement generates a significant amount of construction waste, increasing transportation and landfill costs. In contrast, glass film utilizes existing glass, enhancing thermal and safety performance. It also prevents fading of indoor carpets, curtains, fabrics, paints, etc., protecting indoor furniture and office equipment and extending their lifespan.
d) Safer: Architectural films offer some safety enhancements, particularly when professionally installed. They can hold shattered glass pieces together and provide enhanced security, surpassing the safety of tempered glass.
e) Healthier: Glass films contain UV-absorbing agents that block 98% to 99% of UV rays.
f) Lighter: Replacing glass with insulated glass or Low-E glass increases the total weight of the glass by at least twice or more, significantly increasing the building's load.
