Environmental Leader

Sears Tower, the tallest building in the Western Hemisphere, is about to get a $350-million makeover that is designed to significantly reduce its energy use by up to 80 percent and cut its CO2 emissions. The retrofit project, over the next five years, includes major upgrades to windows, heating and cooling systems, lighting, elevators, restroom fixtures and condensation recovery systems, along with wind and solar installations and a green roof.

The energy savings will equal 68-million kilowatt hours annually or 150,000 barrels of oil every year. The majority of the energy savings will be realized in approximately five years, say planners. The sustainability project will also create more than 3,600 jobs.

The building, which already meets Leadership in Energy and Environmental Design (LEED) criteria, will implement sustainability initiatives above and beyond those used by the United Stated Green Building Council to rate a green building.

Building upgrades, designed by Chicago-based Adrian Smith + Gordon Gill Architecture (AS+GG), include:

• Efficiency improvements to the building’s exterior and windows that will save up to 50 percent in heating costs.
• Mechanical systems upgrades including new gas boilers that use fuel cell technologies, that deliver heating and cooling at as much as 90 percent efficiency, new high-efficiency chillers and upgrades to the distribution system.
• Upgrades to the tower’s 104 high-speed elevators and 15 escalators to achieve 40 percent reduction in their energy consumption.
• Water conservation initiatives through upgrades to restroom fixtures, condensation recovery systems and water efficient landscaping, which will reduce water usage by 40 percent and save 24 million gallons of water each year.
• Lighting that will be upgraded through advanced lighting control systems and daylight harvesting, an advanced lighting control system that automatically dims lights in tenant spaces based on the amount of sunlight entering through the windows, which will save up to 40 percent of lighting energy consumption.
• Use of renewable energy, which include wind and solar installations.

On the roof, architects plan to test wind turbines and green roofs that can sustain high-altitude conditions. Green roofs will be tested to reduce storm water runoff, improve insulation, help mitigate the urban heat island effect, along with providing pleasant views for tenants overlooking the areas, say planners.

Standing at 1,450 feet and 110 stories tall, the Sears Tower, which opened in 1973, is much larger than the Empire State Building which is undergoing a $20-million energy efficiency overhaul that should result in a $4.4-million energy savings annually, or a 38-percent energy reduction. The energy upgrades are part of a larger $500 million refurbishing of the building.