High Performing Buildings - Winter 2008 - (Page 32)

CASE STUDY The Condé Nast Building at 4 Times Square An early, high-proﬁle building that is often cited as being one of the pioneers in the high performing building movement is our Condé Nast Building at 4 Times Square in New York City. In response to growing interest in the measured energy performance of green buildings, as well as increased interest from tenants about relative energy use/costs as energy prices have risen dramatically over the last several years, we reviewed energy use at 4 Times Square and compared it to other buildings in our portfolio as well as the broader population of peer buildings in New York. Table 1 shows how the 4 Times Square energy intensity, in kBtu/ft² per year, compared with other Durst buildings, and with what the EPA ENERGY STAR® Portfolio Manager calculates to be the annual site energy intensity for an averagerated building (50th percentile) with the use characteristics of 4 Times Square. Source energy includes the energy consumed at the building itself—or the site energy—plus the energy used to generate, transmit and distribute the site energy. TA B L E 1 C O M PA R I S O N O F 4 T I M E S S Q U A R E E N E R G Y P E R F O R M A N C E T O B E N C H M A R K S kBtu/ft per year Source Energy Site Energy 4 Times Square 244 120 The table demonstrates that 4 Times Square is significantly more energy efficient than the median New York City office building, but that it is not the lowest in energy intensity among the Durst portfolio. Some of the reasons for higher energy intensity at 4 Times Square relative to other Durst buildings include: • Significantly higher amounts of outside air (twice the prior New York City industry standard practice) are delivered to the tenant floors by a dedicated outside air system. This additional outside air requires additional fan and chiller energy use to deliver and condition the air. In addition, the outside air is filtered to a higher level (85%) than older buildings with the additional filter resistance, adding to fan energy consumption. • The Times Square redevelopment district requires a specified amount of exterior signage and lighting as the minimum, process energy that was not taken into consideration while setting performance goals. This lighting consumes substantial additional energy. • The principal tenants of the building, a publishing house and a law firm, both have significant after-hours operations, often until 1 a.m. The building is available for tenants 24/7. • A broadcast antenna atop the building with transmitter facilities for radio and television stations uses significant process energy. Some of these facilities operate 24/7 and require continuous operation of the building cooling plant. • Two corporate cafeterias with commercial kitchen facilities use significant amounts of process energy. • Finally, direct gas-fired absorption chillers, selected by the design team primarily for their lack of impact on the electrical grid, favorable operating costs, and lack of harmful refrigerants, are not the most efficient choice with respect to overall net site or source energy use. If the building had been built with electric chilling, the site energy intensity would be substantially lower. Best Durst Building 213 76 Durst Fleet Average 239 107 50th percentile per ENERGY STAR®(with the use characteristics of 4 Times Square) 366 180 32 HIGH PERFORMING BUILDINGS Winter 2008

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High Performance Buildings - Winter 2008 Passing On the Gift: Heifer International Headquarters Head of the Class: University of Florida’s Rinker Hall How Far Can You Go? Pearl River Tower The Proof Is Performance: How Does 4 Times Square Measure Up? Lighting the Way: Two Guilford County Schools Montreal’s Retail Example: Mountain Equipment Co-op® (MEC)

High Performing Buildings - Winter 2008

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