Window film is only for old buildings.

False! Window film is not just for old buildings, just like it’s not just for old windows.

Window film can reduce the Solar Heat Gain Coefficient (SHGC) and U-Value of any type of glass, whether new or old. An older, yet highly efficient building may not need window film as much as a newer, yet highly inefficient building. (In fact, it is not uncommon for older buildings to have higher Energy Star Portfolio Manager scores as compared to newer buildings.)

Office buildings with floor-to-ceiling windows are becoming more popular. The associated benefits of an all-glass curtainwall include greater daylight and upgraded curb appeal. This recent architectural trend is made possible by the significant advancements in glazing technology that have made windows more energy efficient than their predecessors. (The same technology has also made tempered glass more unstable and prone to break.)

An all-glass façade means that the ratio of glazing to curtainwall is significantly higher than it is for buildings constructed in the past. Despite the increased efficiency, windows are still inefficient in comparison to other construction materials that may traditionally comprise a building envelope (brick, limestone, plywood, insulation, and drywall).

It is not uncommon for a recently constructed building of this design to have tenant comfort issues, whereby occupants are simply too hot during the cooling season (April through October). There are usually two outcomes to this problem:

• Air conditioning bills are sky high
• The HVAC system simply can’t keep up

Building engineers are at a loss as they face one tenant complaint after another.

Window film is a great solution because it can reduce a window’s SHGC (and U-Value), thereby increasing the amount of the sun’s energy that is rejected before it ever enters a building. That helps lower utility bills, prolong HVAC life, and increase tenant comfort.

Ultimately the appropriateness of window film depends on many factors, including existing glass type, the HVAC system, internal loads, building usage, and tenant expectations/requirements.