An earth energy heating and cooling system, waterless toilets and other ‘green’ innovations will result in Bellevue Community College’s newest building being one of the most environment-friendly structures in the region.BELLEVUE, Washington, US, 2001-09-27 [SolarAccess.com] The innovations are expected to save four million gallons of water, 24 million cubic feet of natural gas and US$1 million in operating costs over the 30-year depreciable life of the building, which is to be formally opened in the pacific northwest in November. The three-story 68,000 square foot wing of R Building will form the largest structure on BCC’s campus, providing 29 classrooms and faculty/staff offices to accommodate rapid growth in enrollment. The building’s geothermal heating and cooling system works by circulating water through a grid of 97 wells installed below the main entry plaza. Each well is 100 m deep, where the earth’s temperature is a constant 57oF. For cooling, the circulated water absorbs heat from the building and rejects it through the wells. When the building needs heat, cold water from the building picks up warmth from the ground. Heat pumps in various sections of the building distribute the heating and cooling energy according to the needs of each space. The geothermal system is expected to reduce energy costs by at least 30 percent compared with a conventional variable-air-volume system. That reduction will save 800,000 cubic feet of natural gas annually, while also minimizing the emission of carbon dioxide and other environmental pollutants.