Sustainability and the concept of green buildings have been moving to the forefront of the building industry for quite some time and have now taken center stage. But while maximizing energy efficiency remains a worthy goal, the latest buzz involves the concept of zero-energy buildings. The combination of rising energy prices, improving technology and concerns about global warming have leaders in the industry establishing a new goal: net-zero energy buildings.

When former President Clinton spoke at Greenbuild 2007, he predicted: “In five years, anyone would be crazy to design a building that isn’t green. But Greenbuild will be about zero-net energy buildings, and about technologies to increase the amount of excess energy building owners can sell on the grid.”

The first net-zero energy commercial office building is already here. It opened in San Jose, Calif., on October 6, 2007. The new building is the headquarters of Integrated Design Associates (IDeAs) Inc., and it showcases what is possible when cutting-edge solutions and technologies are used to maximize efficiency. IDeAs is a consultancy that provides electrical engineering and lighting design services to help architects design energy-efficient facilities. Staying true to the company’s vision of sustainability, Principal David Kaneda saw an opportunity to bring the concept of a net-zero energy, net-zero carbon emission building to life when he purchased a 7,200-square-foot former bank branch to house the company’s new headquarters.

The goal was to transform the windowless concrete building built in the 1960s into a highly sustainable facility, while keeping construction costs comparable to a more traditional design. The result: the first commercial office building in the United States to reach a net-zero energy/net-zero carbon emissions goal. Coined the Z2 building, the new IDeAs headquarters uses renewable energy solutions to meet 100 percent of its energy requirements, burns no fossil fuels and produces no net greenhouse gas emissions.

How did they do it? Through the combination of an innovative HVAC system, a photovoltaic energy source, and a slew of sustainable design technologies. “All of the technologies we are using are readily available. Some of them are more expensive from a first-cost standpoint, but the reduction in energy use will pay long-term dividends,” says Kaneda. “And, it’s the right thing to do from the standpoint of reducing our impact on the environment.”

HVAC System Helps Maximize Efficiency

With an HVAC system designed to maximize performance, IAQ and efficiency, a geo-thermal heat pump system (shown) circulates either warm or cool water through the concrete floor slab, creating radiant heating and cooling. Photo by Joseph H. Mayton III.

With the help of Johnson Controls, the building’s HVAC system was designed to maximize performance, indoor air quality and efficiency. In fact, the energy efficiency for the HVAC system is an estimated 40 percent below 2005 California Title 24 energy requirements.

The design incorporates a ClimateMaster geo-thermal heat pump system that, depending on the season, circulates either warm or cool water through the concrete floor slab to create radiant heating and cooling. Pipes laid under an open landscape area behind the building transport the water into the facility. There, a heat exchanger collects heat from the water in the winter and pulls the cooling effect from the water in the summer. A radiant floor system with cross-linked counter flow tubing uses the water to heat and cool the space.

Using water to convey heating and cooling instead of a traditional forced air system requires less energy and provides the same level of comfort. The in-slab radiant system uses higher water temperatures to provide effective cooling and lower water temperatures to provide effective heating.

A Metasys building management system controls the floor heating and cooling rates to provide maximum performance, while using the least amount of energy and the most efficient water temperatures. Floor condensation is prevented by the system, which monitors the floor temperature and the room dew point air temperature. When needed, dehumidification is provided by an outside air handler that uses chilled water and concurrent condenser water for temperature control.

The air handler, with high-performance filtration and constant temperature control, also provides ventilation for the building. In addition, operable windows and doors with adjustable openings were installed throughout the building, allowing occupants to manually adjust the temperatures to their comfort levels.

An Array of Sustainable Features

The facility’s energy source is an integrated photovoltaic system, which uses solar roof panels to convert sunlight into electricity. The electrical system is tied into the grid. During the day, the solar panels generate electricity for the facility, consistently generating more energy than needed. When this happens, excess power is delivered back to the grid. A small amount of power is drawn from the grid at night, when there is no available sunlight.

In addition to these renewable solutions, the IDeAs building also uses traditional energy conservation techniques. From lighting to office equipment, simple switches are made to boost the building’s overall energy savings.

Skylights take advantage of natural light. High-efficiency windows allow light to shine through, while blocking out infrared and ultraviolet rays to keep the office cool. Traditional computer monitors are replaced with LCD-flat screens, which consume 50 percent less energy, and low-energy florescent bulbs take the place of standard lights throughout the building.

The building is outfitted with multiple sensors to automatically turn off lights in empty rooms and shut off select fixtures when sufficient daylight is available. In addition, the building’s security system is integrated into the office equipment, automatically shutting down computers when the system is armed.

With these energy saving measures, an innovative HVAC system and unique renewable energy solutions, the IDeAs headquarters has set a precedent for the future of green building and facility operations. By showing what is possible when sustainable technologies are implemented, IDeAs has paved the way for other companies to follow suit.

Facility Overview

Integrated Design Associates (IDeAs) Inc. Z2 Building
Size: 7,200 square feet
Location: San Jose, Calif.

Materials & Resources

HVAC
Heat Pump: ClimateMaster
Water Circulation Pump: Taco, Inc.
Metasys Controls: Johnson Controls, Inc.
Dual Coil Air Handler: Trane


Glazing
Electrochromic Glass Panes: Sage
Electrochromics, Inc.
Spectrally-Sensitive Glass: Solarban 70XL Solar Control Low-E Glass / PPG Industries

Lighting
Light Fixtures: Ledalite; Finelite; Litecontrol; Alkco; Prescolite; Zumbtobel; Elliptipar; Metalux; Strand; Surelite; Isolite; AAL; Shaper; and Invue; Wattstopper; Lutron; Square D

Power
Power Control and Metering: Square D
Inverter: Xantrex Technology
Photovoltaic System: Open Energy Corp.
Roofing Membrane: SolarSave
Solar Cells: SunPower A300
PV Glass: SolarSave Architectural
Floor Boxes: Wiremold
Line-Voltage Wiring Devices: Pass & Seymor
Walker Duct: Wiremold

Plumbing
Sensor-controlled Faucets: Sloan
Dual-flush Toilet: SmartFlush by Caroma

Data Center
Data Rack, Cable Tray: Chatsworth
Telecom Equipment: Leviton
CAT 6A Cable/Patch Cords: Superior Essex