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References

Hearst Tower, New York, New York

Project Facts:

  • New York, USA
  • Office building
  • Completion: 2006

Uponor involvement

  • 13935 m²
Hearst Tower – First Green Office Building in Manhattan The 46-story Hearst Tower in Manhattan is a soaring compilation of innovation, beauty and attention-grabbing architectural features. Uponor provided the radiant heating and cooling to this stunning glass and metal-skinned tower built atop the company’s 1928 headquarters. The third level of the media giant’s headquarters building, which contains a cafeteria and other amenities, has a radiant floor with water-filled polyethylene tubing (PEX-a tubing) manufactured by Uponor, buried in the concrete topping slab. The slab is thermally controlled to keep the space comfortable even in the humid Manhattan summer. Radiant Cooling is Cool “The unique aspect of the system is the cooling,” says David Cooper, managing director of the New York City office of WSP Flack + Kurtz, the consulting engineer for Hearst Corp.’s tower. Cooper says the building was the first commercial high rise in the U.S. with a radiant cooling system in the lobby. The radiant floor was the first in New York City, too, he added. The 856,000-sq-ft development, which incorporates Hearst’s 1928 landmark headquarters and adds a Norman Foster-designed tower, was engineered to use 25% less energy than a building that meets minimum requirements of prevailing codes. Some of the efficiency is in the radiant floor, combined with displacement ventilation. Radiant Radiates Surfaces Radiant floors take advantage of “effective temperature,” says Cooper. The true perception of comfort is a function of radiant surface temperatures, air temperature, air velocities and moisture levels, he explains. In most buildings, the only variable controlled is the air temperature. The radiant-floor system takes advantage of the phenomenon that the sun’s rays coming in through the skylight only warm up the surfaces they hit, not the air. The heat never really enters the space. With radiant cooling, the sunlight hits the floor and heat is taken away by circulating water in the embedded pipes, spaced 9" on center. “Because the slab never warms up, the solar energy never becomes a load in the space,” says Cooper. Radiant cooling takes advantage of the fact that it is more efficient to remove heat from water than to remove it from air, he adds. The energy required to pump air is more than the horsepower to pump water to remove the same quantity of heat. The challenge was to ensure that there was never condensation on the floor under any circumstances. The trick was to keep the surface temperature of the floor above the dew point of the lobby air. In the worst humidity of summer, “we were able to maintain great comfort and no condensation was observed,” says Cooper. Radiant floors do not come with a cost premium, says the engineer. The system is also less visually intrusive because there is no ductwork. “When you factor in the cost of space for mechanical equipment and ductwork, it probably costs less than a conventional system,” says Cooper. The owner is very satisfied with the entire system. “The radiant floor works exceptionally well in that it both heats and cools,” says Brian Schwagerl, Hearst’s vice president of real estate and facilities. “Having a 10-story atrium is quite dramatic but making it comfortable at all times is equally as important, and we’ve been successful at achieving that.”

Project Information

Address
300 West 57th Street 10019 New York

Country
USA

Website
Hearst Tower, New York

Completion
2006

Project Type
New Build

Building Type
Office building

Partners

enduser
hearst corp

contractor
Turner Construction Corp

architect
Foster + Partners

specifier
Flack + Kurtz

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