The Chicago Center for Green Technology
General Information
Location Chicago IL
Owner City of Chicago, Department of Environment
Architect Farr Associates
Engineer   Mechanical - IBC Engineering
Electrical - Spectrum Engineering
Completed   January 2003
Building Use   Commercial office, Industrial, Assembly
Size   32,000 SF
Stories   Two
Cost   $5,400,000 (excluding land cost)
Occupancy   Typically occupied by 35 people, 50 hours per person per week; and 100 visitors per week, 2 hours per visit
Relevant codes   City of Chicago Building Codes
Mixed-Mode System
Mixed-Mode Strategy   Concurrent system. As a 1950s office building, the structure had been designed for natural cross ventilation as well as daylighting using narrow wings extending out from a common circulation core. The renovation took advantage of this existing condition to retain operable windows while adding a mechanical cooling system. The primary strategy relies on cross ventilation rather than stack effect or other techniques to maintain natural ventilation.
Natural Ventilation Details   Operable windows are awning type, crank operated set below fixed vision glazing. Insulated, spectrally selective, low-e glazing was installed throughout the facility.
HVAC System Details   A ground-source heat pump system provides all space cooling and most of the space heating. System includes 28 vertical wells drilled to a depth of 200 feet. Although a cooling tower was incorporated to assist during the cooling season, it did not operate at all during the first summer, all cooling came from the wells. At the beginning of the cooling season, glycol from the earth entered the heat pumps at a cool 55∞F allowing them to run at very high cooling efficiencies. By the end of the summer, this glycol was still below the 90∞F threshold that would have required cooling tower operation. During the winter months, heat from the heat pumps is subsidized by heat from a natural gas-fired, high-efficiency, condensing hot water boiler.
A run-around heat recovery loop, tied to the heat pump system, recovers heat/cool energy from exhaust air and uses that energy to preheat/cool incoming ventilation air. Extensive daylighting displaces the need for some artificial lighting. A 25% savings in lighting energy is expected over standard systems. At times of high-electric demand (such as hot summer days), the building management system is programmed to prevent demand spikes. It reads the load required and temporarily offsets mechanical startups to save demand costs.
The building is divided into seven (7) zones. One (1) zone is a large assembly area and each of the other six (6) zones is an office area. Operable windows were not a factor in selecting the zones. Zones were selected based on activities and exposures (North, South, East, West).
Duct distribution design was determined by air volume requirements, displacement ventilation requirements (many diffusers are located under desks), and space restrictions (this was a retrofit of an existing shell). Operable windows were not a factor since the system has to provide complete heating and cooling when the windows are closed. Peak heating and cooling demand tends to occur during extreme weather when windows should be closed. Windows are used for providing additional ventilation during days where the outside air conditions are comfortable; therefore, they don't really affect system sizing. Windows may actually increase peak heating and cooling demand because of leakage around the seals. For this building the effect was probably very small.
The building surpasses the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard 90.13 by 405, which means that the Center uses 40% less energy than a minimally code-compliant building of the same size, saving an estimated $29,000 each year.
Configuration & Control   The building has a complete building automation system which takes information from building thermostats, the ground loop temperature, and the peak electric demand to optimize the running of the heat pumps. The building operator has complete control of the HVAC from a PC station located in his office. There is no active or passive connection between the windows and the mechanical system. Occupants are free to open/close windows at their own discretion.
Building Design Process
Time Line   1999-2001
Design Tools   The U.S. Green Building Council's LEED Rating System was used in setting goals for the project before the design commenced. The LEED Platinum rating was identified as the final objective by Owner and influenced all choices of major components including mechanical, electrical, and ventilation options.
Energy Analysis   DOE-2 software was used for energy analysis. Energy modeling expects the building to surpasses ASHRAE 90.1 by 60%, an energy savings of approximately $21,000 per year. These savings are generated through a combination of the heat pumps, solar shading, controls, daylighting, and building envelope.
Commissioning   Commissioning was provided by IBC Engineering, the mechanical engineers for the project. The mixed-mode strategy was identified in the first design intent and remained constant through the project. The minor changes in the execution of the ventilation system that took place during construction and commissioning were necessitated by code requirements (see below).
Code Conflicts   When air conditioning is provided in commercial buildings, the City of Chicago code requirements do not allow for natural ventilation to be included in total ventilation requirements. Mechanical ventilation systems are therefore designed as if no natural ventilation existed. During construction the City code inspectors required additional through-the-wall powered vents be provided in those spaces identified for light manufacturing. While not necessary for the natural ventilation design, they in effect provide for an additional economizer cycle when windows are opened and the wall vents are activated.
Building Performance
Outdoor Air/Noise   The site is adjacent to a commuter rail route, but due to the density of the rail system in Chicago this is not an uncommon occurrence and users are relatively habituated to the noise. See post-occupancy evaluation results below.
Occupant Satisfaction   The University of California Berkeley Center for the Built Environment performed a web-based occupant Indoor environmental quality (IEQ) survey at the Chicago Center for Green Technology. The survey addressed general building satisfaction, general workspace satisfaction, office layout, office furnishings, thermal comfort, air quality, lighting, acoustic quality and cleanliness and maintenance.
Occupants reported being satisfied or very satisfied with all categories but with more neutral comments in thermal comfort and acoustic quality. Thermally responses showed that occupants often find the building too cool in both warm and cool seasons particularly in the afternoon. This dissatisfaction was attributed to a lack of accessibility and control of thermostats. In acoustic quality the responses showed that the open plan cubicle workspaces were not providing enough privacy for occupants.
Actual Energy Data   (In progress)
Additional Building Features
Sustainable Sites   • Located within 1/2 mile of a Metro Rail station and within 1/4 mile of two bus lines.
• Majority of the material accumulated on the site was recycled or salvaged for reuse.
• Bike storage, showers, and changing facilities for bicycle commuters.
• Recharging stations for electric vehicles
• Preferred parking for carpools.
• The brownfield site, which had been turned into a dumping ground for construction and demolition materials, was cleaned by the city at a cost of nine million dollars.
Water Efficiency   • Four water-storage cisterns catch rainwater used for irrigation, reduce flow into sewers, and have a combined capacity of 12,000-gallon.
• Native plants minimize maintenance and water needs
• Green roof on a portion of the project also reduces stormwater runoff.
Energy and Atmosphere   • Extensive daylighting displaces the need for some artificial lighting
• Expected 24% savings in lighting energy over standard systems.
• Insulated, spectrally selective, low-e glazing.
• Heat and air conditioning registers are located near occupants with low velocity output.
Materials and Resources   • No CFCs are used in any building materials or systems.
• No HCFCs are used in any building materials.
• Recycling center encourages occupant participation.
• 100% of the original building's structural shell was retained in the rehabilitation.
• 84% of all construction waste was diverted from the landfill.
• 36% of all building materials have recycled content, including: drywall, cellulose insulation, linoleum, ceiling tiles, rubber flooring, gravel, fill materials, steel, tile, MDF board, and fireproofing.
• Over 50% of the building materials (excluding mechanical and plumbing systems) were manufactured or assembled within 300 miles of the construction site.
• The elevator runs on canola oil.
Indoor Environmental Quality   • A construction indoor air quality management plan was designed and implemented by the contractor .
• Low-VOC materials.
Project Team
Architect   Farr Associates, Architecture and Urban Design
53 West Jackson Blvd., Suite 650
Chicago, IL 60604
Mechanical, Electrical and Fire Protection Engineer   IBC Engineering
217 Wisconsin Avenue, Suite 300
Waukesha, Wisconsin 53186
Electrical Engineer   Spectrum Engineering
633 Skokie Boulevard, Suite 305
Northbrook, IL 60062
Civil Engineer   Terra Engineering
505 N. LaSalle, Suite 250
Chicago, IL 60610
Structural Engineer   Tylk, Gustafson, Reckers, Wilson, Andrews
407 S. Dearborn, Suite 900
Chicago, Il 60605
Landscape Architect   Site Design Group
8 South Michigan, Suite 1007
Chicago, IL 60603
Cost Estimating   Construction Cost Systems
200 West Lombard, Suite 209
Lombard, IL 60148
Construction Waste Management   Micheal Roy Iversen Architects
144 N. Lombard Ave
Oak Park, IL 60302
Computer Energy Modeling   Prisco, Serena, Sturm
3351 Commercial Avenue
Northbrook, IL 60062
Efficient Lighting Design   Sieben Energy Associates
333 N. Michigan Avenue, Suite 2107
Chicago, IL 60611
Public Health/Indoor Air Quality   O'Donnell, Wickland, Pagozzi and Peterson
111 West Washington, Suite 2100
Chicago, IL 60602
Additional Information
Awards   • USGBC LEED Platinum Rating (2003)
• 2003 AIA Top Ten Green Building Award
• 2003 Chicago Building Congress Green Building Award
Sources   Green Technology Center to Open: Collaborations Build Environmental "Brightfield" on Chicago's Industrial West Side by Middendorf, Bobbye Conscious Choice (April 2002).
Chicago Green Tech Center Receives Platinum LEED Rating from U.S. Green Building Council (November 14, 2003) This press release, available on-line, announces the presentation of a LEED Platinum award to the Center for Green Technology. The release includes comments from Mayor Daley and a description of the project.
• Emerald City by Kamin, Blair Chicago Tribune (May 6, 2002).
Spire Solar Chicago Celebrates the Opening of Its Plant At Chicago Center for Green Technology (May 6, 2002).
How Green Can You Get? by Harold Henderson Chicago Reader (May 3, 2002).
• U.S. Department of Energy High Performance Buildings Database.
Contacts   Primary Contact
Carol McLaughlin
Farr Associates Architecture and Urban Design
Monadnock Building
53 West Jackson, Suite 650
Chicago, IL 60604
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