Solar Control Window Film in Philadelphia

Solar Heat Gain in Philadelphia Commercial Buildings

Philadelphia's commercial building stock ranges widely. There are glass towers built in the past few decades, mid-century office blocks with ribbon windows, early twentieth century masonry buildings converted to offices and apartments, and newer mid-rise residential buildings with large window walls in Fishtown, Northern Liberties and along the river.

Most of them have the same summer pattern. The south and west faces collect heat through the afternoon, while the north side stays comfortable. Mechanical systems are sized to handle the peak, and on the hottest humid days some struggle to keep sunny zones at setpoint. Older single-pane or uncoated double-pane glass makes the problem worse.

Apartment buildings add another layer. Tenants on the sunny side of a building in July may run window units or cranked-up mini-splits, while those on the north side barely use cooling. When the building pays for central cooling, those sunny units drive the bill. Treating the south and west glass is a targeted way to bring them closer to the rest of the building.

How Commercial Solar Control Film Reduces Heat

Solar control films lower the solar heat gain coefficient of the glass by reflecting and absorbing part of the incoming solar energy. Reflective films reject the most heat and give the building a mirrored look by day. Spectrally selective products target the infrared part of sunlight and pass most of the visible part, which suits buildings that want to keep daylight and a neutral exterior.

We compare options using published performance data for film applied to glass like yours: solar heat gain, visible light transmission, interior and exterior reflectance, and shading coefficient. Your engineer or energy consultant can use the same data to estimate the effect on cooling load.

Before recommending a film, we confirm the glass type, check that the film is approved for that glass, and look for conditions such as partial shading or tight frames that raise thermal stress risk.

Solar Control Film and Philadelphia Building Energy Programs

Philadelphia's benchmarking law requires owners of large commercial and multifamily buildings to report energy and water use each year, and the city's building performance program asks larger buildings to complete tune-ups or show high performance. Solar control film is not a required measure, but reducing perimeter heat gain is a direct way to lower cooling energy.

Thresholds, deadlines and compliance paths are set by the city and can change, so owners should confirm current requirements with the Office of Sustainability. We provide film performance data and installation records for your reporting and consultants.

Solar Control Film for Historic and Older Commercial Buildings

Center City and Old City include many older commercial buildings that are designated or fall inside historic districts. Highly reflective film can change how a historic facade looks, which may require review by the Philadelphia Historical Commission. Spectrally selective films with low exterior reflectance are the usual choice on these buildings, and owners should confirm with the Commission before installing.

Older buildings also tend to have a mix of original and replacement windows. We survey the glass by elevation and floor, then propose a film that will look consistent across the different window types.

Where a building has steel or bronze framed windows from its original construction, we pay close attention to the frames as well as the glass. Old glazing compound and tight steel sash can limit how close film can come to the edge, and we adjust trimming to protect the existing seals.