The Ultimate Window Film Choice
Spectrally Selective (premium) window films are unique due to their relationship between high visible light transmission (vlt) and high heat rejection. These films can appear practically invisible to the naked eye with excellent heat protection. For even better performance, this same technology is produced in darker versions. Darker premium window films provide better glare control and even higher heat rejection without making your glass look mirrored. In addition to glare and heat, darker versions provide increased fade protection. Although, we are not stating that we always recommend a film of this class for ‘every’ situation, precious metal films do have unique qualifications that no other product can possibly match.
Generally the rule of thumb for heat rejection is the darker the better. Spectrally Selective window films break this rule by allowing the most light in while blocking most of the heat. “Spectrally Selective” window film technology is the most common term used in our industry that defines the ability of a particular product to reject a high amount of select spectrums of the suns electromagnetic spectrum. To be selective.
One of the most difficult tasks of a window film manufacturer is to create such a film that will allow practically all the light in but reject most of the heat. Hence the name, “spectrally selective”. The most popular and effective spectrally selective window film products are manufactured with precious metals. Yes, there are traces of gold in these films, imagine that! Synonymous with such terms as high performance & precious metals, spectrally selective window films are the pinnacle in window film technologies. If you are in the market for this type of product, we recommend you choose a product that filters out as much of the infra-red radiation (I/R) spectrum as possible. Within the solar spectrum near infra red radiation falls in between 780 nm to 2,500 nm. The I/R band is known to be 1,720 nm wide. In other words, this is the time you really want to read the fine print, don’t worry, we have you covered. One popular brand name is known to market incredibly high I/R rejection numbers on their sample spec cards but unfortunately these numbers only represent a large number of a very small chunk of the I/R spectrum as noted in their fine print.
However, I/R is not the only spectrum responsible for the cause of heat. The visible light spectrum is responsible for some of this heat as well because 44% of solar energy consists of visible light. For the ultimate in heat control with no added reflective appearance, darker shades of this technology are available.
In most cases, these products are low-reflective but reflective versions of another common technology is available for unique circumstances such as a product that offers the following three features, high visible light transmission/daytime privacy/high heat rejection. This accomplishes most of what was discussed above except the product is reflective therefore offering added ‘daytime privacy’.