What makes the LEED silver certified residence halls “green”?
Many components of Osher and West, including the materials, heating system and rainwater system all contribute to the overall sustainability of the buildings. Features include:
Each of the above components garners a certain number of LEED credits, when added up earned the buildings silver certification.
Who was involved in the project?
The College administration adopted the principle of sustainable building design in December of 2003. Bowdoin had been planning to build new housing for many years, but the main motivational force behind the project was the need for alternative housing during the renovations of the original first-year dorms. Architects from Kyu Sung Woo designed the new buildings, with input from the Bowdoin residential life staff, students and LEED consultants. Harriman Associates provided the energy and engineering aspects of the project, while Barr and Barr Inc. served as the general contractor. From Bowdoin’s own staff, Greg Hogan, Capital Projects Manager, provided leadership from start to finish.
How does the heating and cooling work in the residence halls?
The residence halls are heated and cooled by a geothermal heating system, which eliminates reliance on heating oil. There are seven wells evenly spaced around the two buildings. Because the wells are up to 1500 feet deep, they tap into the bedrock crevices filled with groundwater. The groundwater is well insulated, and remains at a fairly constant temperature of 48-50 degrees Fahrenheit year-round. The wells bring the groundwater into the buildings, where heat pumps extract 15-20 degrees to heat or cool the building, depending on the time of year. A heating/cooling loop system takes the heated and or cooled water and circulates it through the building to individual dorm rooms. The water then returns to the ground, where it is naturally re-heated. As Bentson explains, “Basically, you are getting energy out of the ground for free.” The geothermal heating system allows Bowdoin to save over 40% of the energy per year that students would normally consume in a residence hall. While the initial cost is more than that of a normal heating and cooling system, the savings generated by features such as the geothermal system and the rainwater collection system are expected to be paid back in three to four years.
How do the residence halls conserve water?
The West dorm contains a 2100-gallon tank, which stores runoff rainwater from the roof. Normally, rainwater runs into a storm sewer, which eventually carries the water to the ocean. The pipes and collecting tank reuse this water. The tank water is then purified with an ultraviolet purifier and pumped upwards for use as toilet water. The use of rainwater in toilets conserves treated potable water. Additionally, the plumbing fixtures in the dorm bathrooms are “low-flow”, meaning that they use less water then typical fixtures. The toilets only use 1.6 gallons per flush. The faucets use 2.2 gallons per minute and the showers use 1.8 gallons per minute. The rainwater system and low-flow fixtures allow Bowdoin to save about 20% of the water a typical dorm uses in a year.
Where do the building materials come from and what are they made of?
Many of the materials come from within 500 miles of Brunswick, Maine, and most of them contain a large percentage of recycled content (by weight). Some examples include the reinforcing steel in the concrete (rebar), which is 90% recycled steel and came from Sayreville, NJ. The rest of the steel used in construction is also 90% recycled, and came from Kingfield, Maine. The gypsum wallboard is 98% recycled material and came from Montreal, Quebec. The window glass in the dorms also came from Montreal, and is 20% recycled, while the aluminum around the glass came from Wausau, Wisconsin, and is 32% recycled. The precast concrete, containing 2% recycled material, came from Epsom, New Hampshire. The carpet in the dorms is 41% recycled, and came from Dalton, Georgia. Even the toilet partitions are recycled! They come from Moosic, Pennsylvania, and contain 20% recycled material. The majority of the tile in the dorms (white) is 46% recycled and comes from Dallas, Texas. The green, yellow and red tile in the buildings is composed of 50% recycled material, produced in Monterrey, Mexico. Unfortunately, the blue and dark blue tile from Olean, NY and Jackson, TN contain no recycled material.