The Carnegie Institute for Global Ecology
General Information
Location Stanford, CA
Owner Carnegie Institution of Washington
Architect Esherick, Homsey, Dodge, and Davis
Engineer   Rumsey Engineers
Completed   April 2004
Building Use   Research Laboratories, Offices, Greenhouses
Size   11,000 SF
Stories   Two
Cost   Unknown
Occupancy   45 full-time researchers and staff
Relevant codes   California Building Code
Mixed-Mode System
Mixed-Mode Strategy   The Carnegie Institute for Global Ecology uses both a zoned and concurrent system. The center’s functions were zoned into separate categories requiring different levels of ventilation and cooling. The offices can be naturally ventilated, while the laboratory areas require higher levels of ventilation and cooling. The second floor is entirely naturally ventilated which combined with radiant slab heating and cooling allows for the elimination of ducts and fan energy use on the second floor.
Natural Ventilation Details   The building is oriented to take advantage of the prevailing winds to catch breezes for effective cross-ventilation. Some stack effect is created through the clerestory windows on the second floor. The radiant system was chosen as the best match for the naturally ventilated second floor to allow occupants to open windows and not lose the effectiveness of the mechanical system.
Approximately half the clerestory windows are operable awning-type ganged to hand cranks. The operable windows at occupant level are casement-type with the operable direction oriented to catch the prevailing breezes.
The lobby is an unconditioned outdoor space much of the year, with a passive cooling tower providing increased comfort on hot days. To improve comfort on hot days when the lobby is in “outdoor” mode, the cool tower captures breezes from above the roof line. The wind-catcher at the top of the tower catches breezes from any direction and directs them down to the lobby. Atomizing spray nozzles in the tower evaporatively cool the air, creating a thermally-driven downdraft in the absence of wind to carry cool air into the lobby areas.
HVAC System Details   Heating is supplied by a high efficiency condensing gas boiler at 110°F (instead of 180°F). The lower temperature allows the boiler to operate at 93% efficiency instead of a typical 80% efficiency. Chilled water for cooling is provided without air-conditioning compressors by using a “Night Sky” roof spray system. It creates a thin film of water on the roof at night using small sprinklers. The water is cooled primarily through radiation to the deep space cold night sky. The water is collected via the roof drainage system into a 12,000 gallon storage tank. Chilled water is supplied at 55-60°F using only 0.04 kW/ton, and using half as much water as a conventional water-cooled chiller. An existing 20 ton air cooled chiller is used to provide additional cooling on the hottest days.
All air supplied to the labs is 100% outside air at the rate of six room air changes per hour. Most of the exhaust from this space is room exhaust (not fume hood exhaust), and is run through a heat pipe heat exchanger to preheat or precool the incoming outside air. Late at night, when the lab is unoccupied, the rate of outside air is reduced. This is also the peak heating time. Using this night setback and heat recovery allows the boilers to be much smaller and therefore inexpensive condensing boilers were able to be used.
The building is zoned into four areas on the first floor and three areas on the second floor that correspond to the functional uses. As a simple building, the natural ventilation did not affect the decisions to zone the building.
Configuration & Control   The building has a complete building automation system which takes information from building thermostats, night sky cooling system, and the peak electric demand to optimize the running of the building. There is no active or passive connection between the operable windows and the mechanical system. Occupants are free to open/close windows at their own discretion.
Due to the environmental knowledge of the scientists and staff that work in the building, the owner chose to use education and experimentation to determine the integration method for the HVAC and natural ventilation system. Through trial and error the occupant as a group has established a culture that understands the building, its reaction to weather conditions and acts accordingly to control their environment. They have learned for example, that during summer heat spells the windows must be closed by 9:30AM to trap the cool air in and prevent the hot breeze from quickly heating the building, and negating the effect of the thermal mass and radiant cooling system.
Building Design Process
Time Line   2002-2004
Design Tools   Heliodon sun model and shading testing.
Energy Analysis   EnergyPLUS was used for energy analysis.
Commissioning   The project was not commissioned. The mechanical engineer did provide some fine-tuning services upon completion of the project to correct malfunctioning valves and miswired lighting controls.
Code Conflicts   None. The building used a simple shallow floor plate which did not impede the use of natural ventilation and HVAC integration.
Other Design Issues   The mechanical system was somewhat unusual (such as the combined forced air and radiant system in the laboratories), which added cost to the project. But due to the clients experience with such systems, they were not afraid of the added risks. The clients had slight concerns regarding the systems ability to provide comfort to the conference room where not habituated guests would be using. The mechanical engineer provided some calculations showing the hours/year that the space may not meet comfort desires and additional cooling was added to counter that discrepancy.
Building Performance
Outdoor Air/Noise   The building is sufficiently located away from local streets and activity to cause no concern.
Occupant Satisfaction   The University of California Berkeley Center for the Built Environment administered a web-based Occupant Indoor Environmental Quality (IEQ) survey at the Center for Global Ecology. The survey addressed general building satisfaction, general workspace satisfaction, office layout, office furnishings, thermal comfort, air quality, lighting, acoustic quality and cleanliness and maintenance. Survey results are currently being analyzed and will be posted at a later date.
Actual Energy Data   In progress
Additional Building Features
Sustainable Sites   • Drought-resistand oaks, chapparel, and grasses will mature into a native habitat supporting wildlife with minimal demands on precious water resources.
• Existing irrigated grass turf was replaced with native planting to offset building water consumption.
Water Efficiency   • Dual-flush toilets
• Low-flow faucets
• Waterless urinal promise
• Prediction are for a 40% water savings over conventional practices.
Energy and Atmosphere   • Two major energy uses for buildings are electric lighting and cooling.
• Solar gain through windows is a major cooling load.
• Direct solar gain on long north/south windows can be avoided through shading, while still admitting indirect daylighting.
• The chilled or heated water used to condition the building is pumped through polyethylene tubing in the radiant floor slabs and ceiling panels, and the forced air system in the lab.
Materials and Resources   • Structure, layout, and furnishings are designed with flexibility in mind to accept changes over time.
• An open lab with suspended shelving and movable workbenches and a highly-efficient, free-span structural system on the second floor allow reconfiguration in the short and long term.
• Future modifications can proceed with minimum of demolition and waste.
• Nearly all concrete used in the building and site contains 50% fly ash replacement for cement.
• Salvaged materials and elements were used to reduce the waste stream going to landfills.
• Salvaged lab casework and faucets were located and installed as-is.
• Solid wood doors were transformed into desks and worktables for the lobby and offices.
• Fallen urban trees were milled and shaped into conference tables and lobby furniture.
• Old-growth redwood from old Sebastiani wine vats were re-milled to form exterior siding.
Indoor Environmental Quality   • Natural light reaches into the building double the window head height, daylighting the full 40’ width.
• Super-efficient lighting includes occupancy sensors as well as photo-sensors that dim lights when there is adequate daylighting.
Project Team
Architect   EHDD (Esherick, Homsey, Dodge, and Davis) Architecture
500 Treat Avenue
San Francisco, CA 94110
Mechanical, Electrical, & Plumbing Engineer   Rumsey Engineers
9 Linden Street
Oakland, CA 94607
(510) 663-2070
Electrical Engineer   Engineering Enterprise
1305 Marina Village Parkway
Alameda, CA 94501
Civil Engineer   BKF
4780 Chabot Drive, Suite 104
Pleasanton, CA 94588
Structural Engineer   Rutherford & Chekene
427 13th Street 2nd Floor
Oakland, CA 94612
Landscape Architect   Lutsko Associates, Landscape
2815 18th Street
San Francisco, CA 94110
415-920 2800
Additional Information
Awards   • R & D Magazine 2004 Laboratory of the Year Special Mention.
Sources   • Carnegie Institution Department of Global Ecology website
• Esherick, Homsey, Dodge, and Davis Architecture website
Contact   Primary Contact
Scott Shell, Project Manager
EHDD (Esherick, Homsey, Dodge, and Davis) Architecture
500 Treat Avenue
San Francisco, CA 94110
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