Plastic skylights are cheap, resistant to shattering and lightweight; and there are now new polycarbonate skylights, incorporating aerogel insulation, able to overcome part of the disadvantages of traditional plastic units.
Plastic skylights are usually made with acrylic and polycarbonate materials. Acrylic skylights are more resistant to UV (ultraviolet radiation), but they aren't as sturdier or lasting as polycarbonate skylights.
New polycarbonate skylights with aerogel insulation can overcome the disadvantages of traditional plastic units and can be much more energy-efficient.
Plastic Skylights Materials vs. New Units
Typical plastic skylights do not last as long as glass skylights, and are more prone to scratching. They tend to lose qualities - including part of their light-harvesting capacity - and to discolor with time. And they are more vulnerable to ultraviolet rays and oxidation.
Their lifespan varies widely, and depends largely on the quality of their materials but also on construction details. The frame, the frame cap thickness and dimensions, or the glazing and the sealants they use are critical. Prefer UL listed skylights with engineered thermoplastic molded sealing.
These plastic skylights come in very different colors, though mostly in white and transparent plastic (the best options to soften the light and to prevent glare). Many of them are curved-shaped: arched, pyramidal and warped-plane.
Traditional plastic skylights are mostly used in garages and non-residential buildings, and can involve large surfaces. Their low price and light weight, and their resistance to shattering are important advantages…
Polycarbonate skylights with aerogel - The advantages
But there are important developments underway... Extremely resistant plastics are now being tested, combining with materials like aerogel insulation.
Polycarbonate skylights with aerogel (manufactured by Wasco and Bristolite, in North America) can provide an U-factor close to 0.2, which is excellent to avoid heat loss and very difficult or impossible to achieve with glass coatings.
Aerogel is an environmentally-friendly thermal insulator, and one of the best performing daylighting products available on the market, excellent to reduce energy costs. Plastic skylights with aerogel can also provide glare-free and moisture resistance, and their performace is expected to be consistent over time.
Polycarbonate skylights with aerogel - the disadvantages
Polycaborbonate skylights with aerogel are not transparent. They are translucent, which can be a downside.
Besides, they aren't as tried-and-tested as glass skylights.
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