Peter Arbour thinks his patented prefabricated cladding system, with an integrated solar-energy unit, will be a winner in the marketplace, not just the winner of a design contest. The architect expects the concrete-and-stainless-steel system to make its commercial debut in a year or two, after further development of the award-winning prototype.

Prefabricated Unit Prototype Contains Solar Collector
Photo: Courtesy Of The Center For Architecture/AIA NY
Award-winning unitized cladding system needs more tweaking and testing before it is ready to be installed on a real building.
Prefabricated Unit Prototype Contains Solar Collector
Photo: Courtesy Of The Center For Architecture/AIA NY
Arbour holds a patent on the system, which is cast using 20,000-psi concrete.

“We are doing another version that includes performance and structural improvements,” says Arbour, a project manager at structural and facade engineer RFR Consulting Engineers, Paris.

An 18-ft-tall, 10-ft-wide installation of the system, which won the New York chapter of the American Institute of Architects Open Call for Innovative Curtain Wall competition, will be on display from Oct. 7 to Jan. 15 at the Center for Architecture, New York City. The concept beat 30 other submissions.

The triple-glazed, unitized system is named “Liquid Wall” because the panel’s slender frame is cast in a mold using a proprietary mix of 20,000-psi concrete. The high-performance material, named Ductal and produced by Lafarge North America, can be formed into a variety of shapes, depending on a building’s architecture.

The panel’s name also is fitting because the installed unit contains a non-freezing liquid that flows through tubes set against an energy-absorbing back pan in a glazed solar-energy spandrel cassette. The steel cassette, similar to a shadowbox, is designed to produce radiant heat and domestic hot water and to dehumidify the building’s ventilation system.

The RFR design team selected a passive solar system for simple operation and maintenance. “The cassette is as easy to replace as a window,” says Arbour.

Design and construction of the $250,000 prototype was done in four months, mostly through donated design services, materials and labor. A dozen firms were involved in the project.

Each unit consists of two concrete frames reinforced on all sides by stainless-steel tension bars. Panels are assembled using a cast-in, structural thermal break in the form of dowels made of glass fiber in a resin matrix.

The unit’s frame is seated on an anchorage affixed to the building’s structure. The anchor plate is attached to a vertical mullion below the level of the finished floor within the opaque spandrel panel.

The most difficult aspect of the prototype’s construction was the interface of the concrete and steel trades, because they “speak two different languages” and work with different tolerances, says Arbour.