Even in winter, solar heat seeps through unprotected windows, causing uneven temperatures and hot spots that create a constant battle for air conditioning systems. Solar Control window film is designed to reduce the amount of solar heat transmitted through window glass by increasing reflection and absorption through the glass. Typical colored or tinted films work primarily through increased absorption, absorbing solar energy into the glass, thus reducing direct heat transmission into a room. These films only offer marginal performance compared to metallized films or reflective films.
Reflective films are precision coated with a thin layer of vaporized metal. These metallized films are designed to increase the reflection and absorption of solar energy from the glass. Reflective films range from moderate to excellent in heat gain reduction performance and, depending on the grade of film chosen, can reject up to 80% of solar energy. The films are usually available in silver, bronze, grey, blue and green versions.
All window films have the added feature of UV inhibitors included in the laminated construction. This has the dual effect of giving the film a long life expectancy without becoming brittle and cracked and also provides additional protection for people, building contents and furnishings. In fact, some films have been endorsed by dermatologists for the protection of patients with severe UV allergies, such as lupus and xeroderma pigmentosum.
Another secondary feature of solar control window film is that it can provide excellent privacy protection. The mirror-like appearance of the films means that they are often referred to as “mirror films” which work in exactly the same way as “one-way glass”. However, what must be pointed out in this type of situation is that the unidirectional effect will only occur during the day and that during the night with interior lighting the vision towards the interior is produced.
The latest innovation in Solar Control films is the introduction of nanotechnology that allows multiple layers of different precious metals to be coated on the base polyester film. These films offer a high level of heat gain reduction with the benefit of reducing interior light levels by very small amounts.
The primary benefits to commercial end users of solar control window film are increased occupant comfort, lower heating and cooling costs, improved aesthetics, and longer air conditioning equipment life.
Solar control window film has been available in the UK since the 1960s. Since then, advances in manufacturing processes have seen the product improve in both performance and durability. Most films are protected by a scratch-proof “hard” coating, which means the expected life of the film will generally exceed ten years and can withstand the same regular cleaning and maintenance processes as ordinary glass.
The main advantages of solar control window film over more conventional methods of solar control, such as blinds, are; Low or no maintenance, durability, shorter payback periods in terms of energy savings and ease of installation.
