Window Film Shading Coefficient

Shading coefficient a ratio derived from dividing the amount of solar heat gain passed through the window film by the same amount that occurs through a normal untinted window.

Window film shading coefficient. One of the more common terms used by power companies to describe a window films performance value is its shading coefficient. The properties of a given glass can be altered by tinting or by applying various coatings or films to the glass. Specifically the shading coefficient is the ratio between the solar heat gain for a particular type of glass and that of double strength clear glass. The lower the window shading coefficient the less solar heat it transmits and the greater shading ability it has.

The ratio of heat passing through a filmed window to heat passing through clear unfilmed glass. Windows and window films have 3 key specifications that correlate to the amount of energy that a building uses visible light transmission vlt solar heat gain coefficient shgc and u value. 3m window films are designed to upgrade existing windows at a fraction of the cost of replacing the windows by helping to reduce the shgc u value. The window shading coefficient of window blinds or shades is directly proportional to the solar heat of the shade it transmits.

Solar heat gain coefficient shgc is the total percentage of solar energy at a window opening that is either absorbed and reflected into a building or directly transmitted through the window. Most standard window films are 1 5 mil thick while a safety film is typically 4 mil thick or greater. The shading coefficient for window shades is expressed as a number between 0 and 1. Shading coefficient sc is an alternative measure of the heat gain through glass from solar radiation.

Window film is a popular choice in many homes and office buildings where certain areas of the space are prone to strong glare from the sun making it uncomfortable to work or relax. Shading coefficient sc is a measure of thermal performance of a glass unit panel or window in a building. The lower the shgc the better the film is at blocking heat gain. It is the ratio of solar gain due to direct sunlight passing through a glass unit to the solar energy which passes through 3mm clear float glass it is an indicator of how well the glass is thermally insulating the interior when there is direct sunlight on the panel or window.

Sc is an older term being replaced by solar heat gain coefficient shgc. The higher the vt the more potential for daylighting. It includes the solar heat gain coefficient shgc and visible transmittance vt of the window film both numbers between 0 and 1. In cold climates however a higher shgc helps reduce energy costs.

Tints color and coatings. In hot climates like arizona a low shgc helps reduce energy costs.