by Brianna Crandall — June 3, 2011—Integral Group (formerly Rumsey Engineers), which specializes in the design of HVAC systems for critical and green building environments, announced recently that the Moraga Barn in Moraga, California, and ClimateWorks Headquarters Phase 2 in San Francisco, California, were both awarded LEED Platinum certifications by the U.S. Green Building Council (USGBC). These are the firm’s ninth and tenth LEED Platinum-certified buildings. Integral was the first firm in the United States to achieve seven LEED Platinum projects, and the group is expecting to achieve LEED Platinum with 17 more projects that are currently in design.
Built in 1914, the Moraga Barn is the oldest building in Moraga and houses the headquarters for Canyon Construction. The building’s “green” features include ultra energy- and water-efficient design, salvaged and sustainably harvested materials, and 100 percent on-site renewable electricity production.
The mechanical system features an in-slab radiant heating and cooling system with chilled water produced by a ground-source coupled chiller, and hot water by a 95 percent efficient condensing gas boiler. Natural ventilation, including operable windows and a rooftop cupola, provides a high degree of user control and allows natural night cooling. Three 5000 gallon cement tanks are buried in the courtyard and collect the rain water that will irrigate the property.
The ClimateWorks Foundation headquarters in the Russ Building—a California State Historic Landmark building in the heart of the San Francisco Financial District—makes use of many inherently sustainable features of the original 1929 building. The building’s concrete thermal mass acts like a flywheel maintaining a relatively constant temperature, responding slowly to temperature changes, and greatly reducing daytime peak cooling needs.
Natural ventilation is provided through operable windows, existing radiators were retrofitted and refurbished, and the building’s thin floorplate provides abundant natural daylight. Energy-efficient systems include a dedicated outside air system that provides excellent indoor air quality; compressor-free cooling during most of the year; daylighting and low energy lighting; a CO2 control/demand based ventilation control; low pressure drop duct design; and low pressure drop air handler design and selection.
These successful historic renovations demonstrate the attainability of sustainability in existing buildings, says the company. Integral Group strives to make sustainable and energy efficient design accessible, readily attainable and cost effective for all building types, developing innovative mechanical systems that significantly reduce building energy use. The firm says its mission is to fundamentally change building practices to be dramatically more sustainable and resource efficient.
