PROJECT: John Fox Towers Retrofit

National manufacturer Crystal Window & Door Systems delivered cost and time savings on a recent Philadelphia window replacement project. Crystal provided a curtainwall retrofit alternative for John Fox Towers.

The 17-story brick 1960s-era apartment building located at 22 South 22nd Street in central Philadelphia underwent a major interior and exterior renovation in 2017. A significant challenge for the renovation was the planned replacement of 17 narrow vertical full building height curtainwall bays or ribbons which provided the bulk of the building’s fenestration. The building owner, general contractor and architect faced an expensive, complex and time-consuming curtainwall replacement effort.

“Recognizing the fenestration challenges the project team faced, Crystal Windows stepped forward to assess the situation and develop a creative alternative solution,” said Rob Dorsky, Crystal’s regional sales manager.

The crux of the Crystal solution lay in leaving the curtainwall structure and spandrel panels in place, removing the existing vision glass sashes and using custom accessories to install new windows and new insulated panels over the original spandrel ones.

“With the Crystal solution, the curtainwall look was maintained, but the time, effort, expense, disruption, and impact on tenants was avoided,” said Vincent Grieco, Crystal’s technical manager and key driver behind the plan. “To successfully and safely achieve this goal, the full talents and resources of Crystal’s engineering, production and professional affiliate and building materials partners were employed.”

First, Crystal brought in the noted building structural analysis firm Porcello Engineering of Pine Brook, N.J., to perform in collaboration with the project general contractor and architect a comprehensive assessment of the existing curtainwall structure’s integrity. The engineering analysis involved detailed on-site inspection of exposed areas and probes within the hidden wall interiors of the curtainwall system. Key to the assessment was the engineering determination that the current structure could carry the additional load of new aluminum windows and panels plus installation accessories.

Crystal’s in-house engineering staff worked to design new special mounting brackets, interior trim pieces and exterior covers for the new Crystal aluminum slider windows and second-generation insulated panels. The company’s 3-D printing equipment provided samples and models of the various new components to assure the architect and the fenestration contractor the installation would be safe, secure, and expedient. Crystal also had Porcello Engineering review and approve the proposed installation materials and methods. Then Crystal’s aluminum extrusion affiliate, Gateway Extrusions in Union, Mo., stepped up to cut new dies and extrude the custom-designed aluminum components.

Laminators Inc. of Hatfield, Pa., supplied the 455 second-generation aluminum insulated panels. The panels feature a polypropylene corrugated core sandwiched between 0.32-inch aluminum skins which were finished in a custom “Coppertone” color paint. Two panels were used per replacement window to match with the unequal offset sashes of the sliders. With new additional 2-inch thick DOW Super TUFF-R polyisocyanurate insulation sandwiched in between, the new panels were installed over the original curtainwall panels using a custom fabricated clip system.

Crystal supplied 338 new aluminum heavy-commercial windows for the John Fox Towers project. The majority of the window units supplied were Series 5600 aluminum 2-lite sliders. This 3-¼-inch jamb window is AAMA AW-PG40/AW-PG50 rated and features sash clip locking pull rails. Adding to the building’s architectural aesthetics, the slider windows were specified with unequal sash widths to match the configuration of the new insulated panels. The new windows were secured to the existing curtainwall structure and mated with the new panels using custom fabricated installation accessories.

For the building’s staircases and hallways, the Crystal Series 5500 aluminum double-hung window was employed. This 3-¼-inch frame depth window is AAMA CW-PG60 rated and features full width top and bottom rail sash clip locks. These windows were specified with ¼-inch laminated glass insulating glass units for safety and ultra-lift balances for ease of operation.

All the new Crystal replacement windows were supplied with 2-½-inch face flange frames and metal sash stops, and they were finished with an environmentally sustainable durable AAMA 2604 bronze powder coat paint finish. The energy efficiency of the 1-inch double pane insulated glass units for all the windows was further enhanced by the use of Vitro Solarban 60 glass and Argon gas filling. The standard and custom-fabricated installation and finishing trim included L-clips, H-mullions, special trim covers, flashing and historic and regular profile snap trim. All the exposed accessory surfaces were finished with the AAMA 2604 bronze powder coat paint finish to match the windows.

John Fox Towers originally was named Sidney Hillman Apartments for the legendary garment workers’ union leader and was built in his honor by the Amalgamated Clothing Workers Union in 1967. The residential building offers affordable senior living with 273 apartment units. It is located in the heart of the museum district in Center City Philadelphia, with convenient bus and light rail service nearby. The building was completely rehabilitated inside and out to improve energy efficiency, with new climate control systems, exterior lighting, new Crystal fenestration, roofing and water heating systems. To encourage residents to get out of their apartments more, the developer renovated common areas with a gathering space, computer and library center and an indoor community garden.

The new owner and developer of The John Fox Towers building is the Vitus Group of New York. Apollon Contracting of Rosyln Heights, N.Y., was the General Contractor and the fenestration and panel installation firm was Eureka Metal and Glass Service of Philadelphia. Kramer + Marks of Ambler, Pa., was the project architect. Porcello Engineering supplied special fenestration engineering services, and the Laminators insulated panels were supplied through A-Porcel Distributors of Bronx, N.Y.