“Japan’s leading diversified materials manufacturer Nitto Denko Corporation developed a novel transparent window film featuring the industry’s highest-level thermal insulation along with solar heat rejection, which allows users to achieve energy savings year-round, the company announced today. When applied to glass windows, this film product rejects approximately 40% of solar heat as well as 99% of UV, so that cooling load would be greatly reduced in summer. Moreover, the product’s unique feature is that it can reduce heat flow through windows by approximately 35% and help maintain indoor warmth during winter. The product can be used for windows of residential homes and office buildings, in addition to display chillers and transportation vehicle windows. The company will engage in product test marketing in the first half of fiscal year (FY) 2012, which will lead to an official product debut in the latter half of the year.”

Japanese climate is on average a bit colder than in the USA. The comparable climate for the Japanese Islands would be similar to the region from Nova Scotia, Canada to Maryland. Summers may be quite hot, but long cold winters are also a normal.

Window film traditionally does the best during summers by rejecting solar heat. During winter, although there are some insulation properties to average window film, it’s performance is not as strong.

There are a couple window films in the domestic USA market that have insulating thermal properties for colder climates.

Nitto Denko’s product performance seems to be similar to Sungards Low E with solar rejection percentages around 40% and thermal insulation percentage of 35%. The US window film manufacturers traditionally use the U Value to measure how well building element (like windows or window tint) conduct heat.

The film has a U Value of .75. Standard single glazed window with normal glass typically have U Value of around 5 and high performance windows with double glazed glass and Low-E Argon gas filling has a U Value of 1.5.

Installing this form of at .75 U Value represents halving the heat loss of even high performance insulated windows.