EMPIRE STATE BUILDING A MODEL OF EFFICIENCY

Empire State Building Retrofit Surpasses Energy Savings Expectations

Kelly Vaughn, May 31, 2012 (Rocky Mountain Institute)

"...[For the] energy efficiency retrofit of the Empire State Building…owner Tony Malkin, in an effort to revive the 2.7 million-square foot New York landmark, assembled a team of leading organizations…to develop a retrofit program that would not only maximize energy savings, but build a strong economic case, saving 38 percent of the building’s energy and $4.4 million annually—and created 252 jobs to boot…[Last year] the building exceeded its energy-efficiency guarantee by five percent, saving $2.4 million and establishing a commercial real estate model for reducing costs, maximizing return on investment, increasing real estate value, and protecting the environment…

"What ultimately set the Empire State Building apart are integrated design, and a ‘right-steps in the right-order’ model that can be applied to any building of any size…

"In dense urban settings like New York City, commercial buildings account for up to 75 percent of energy used. If every commercial building in New York City followed this blueprint, carbon emissions would be reduced by 4 million tons—the equivalent to that generated by a typical coal-fired power plant…"

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"Several measures in particular helped to ensure an informed financial decision-making process and ensure a sound economic outcome. These included:

-The use of Life Cycle Cost Analysis

-Piggybacking energy upgrades on planned improvements

-Incorporating energy modeling into the design process to identify options of energy efficiency measures

-Using a hybrid of the ESCO model and owner investments to finance the upgrades Incorporating tenant energy reduction measures..."

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"A total of eight efficiency measures performed jointly by Johnson Controls and Jones Lang LaSalle were responsible for a total first-year savings that added up to $4,393,796:

1&2-Radiator Insulation and Steam Trap Savings

Total savings: $491,191

More than 6,000 insulated reflective barriers were installed behind radiator units located on the perimeter of the building. Prior to this upgrade, about half of the heat radiated into the usable space, while the other half helped to heat New York City. This barrier reflects back most of the heat into occupied space—where it is intended to go.

2-Windows Retrofit

Total savings: $338,508

The buildings 6,500 existing double-hung windows were dismantled and rebuilt onsite to include [advanced glazing,] a suspended coated film and gas fill. This more than tripled the insulating value of each window, increasing occupant comfort, blocking winter heat loss three-times better than the old windows, reducing heating and cooling loads, blocking ultraviolet rays to protect occupants and furnishings, and enhancing daylighting…[They] cut the building’s peak cooling load by one-third. The old chiller plant could then be renovated, rather than replaced and expanded—saving more than $17 million of budgeted capital expenditure. That capital cost savings helped pay for other projects and cut the overall incremental simple payback for the retrofit to three years.

3-Direct Digital Controls and Demand Control Ventilation

Total savings: $858,305

This measure involved upgrading the existing piecemeal and primarily pneumatic control systems at the Empire State Building to comprehensive, consistent digital controls, and the installation of CO2 sensors for control of outside air introduction to the air-handling units. Benefits include reducing cooling and heating demand, monitoring of indoor air quality, increased occupant comfort, and reduced energy bills.

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4-Chiller Plant Retrofit

Total savings: $675,714

The chiller plant retrofit project included the improvement of four industrial electric chillers in addition to upgrades to controls, variable speed drives, and primary loop bypasses.

5-Tenant Energy Management

Total savings: $386,709

This project provides tenants with access to online energy and benchmarking information, as well as sustainability tips and updates. Tenants in the Empire State Building have access to a digital dashboard showing energy use in real time, and comparing it to past use and other tenants.

6-Tenant Daylighting, lighting and plugs

Total savings: $940,862

This measure—the biggest energy saver—reduced lighting power density in tenant spaces, by installing dimmable ballasts and photosensors for perimeter spaces and provided occupants with a plug load occupancy sensor for their personal workstations. Benefits include reduced utility costs for tenants, lower cooling demand due to less heat from electric lights and equipment, and improved visual quality.

7-VAV Air Handling Units

Total Savings: $702,507

As tenant turnover occurs, existing constant volume units are replaced with variable air volume units, using a new air-handling layout (two floor-mounted units per floor instead of four ceiling-hung units). VAV air handlers are more intelligent, and provide greater control—leading to not only costs savings, but also other benefits including greater occupant comfort and control, and reduced electricity demand…"

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