Stellwagen Bank National Marine Sanctuary headquarters
offices are located in Scituate, Mass. The facility consists
of the main building, a meeting annex, and a boathouse with
dock. The main facility is a three-story building, holding
staff offices, a small conference room, and the South Shore
offices of the Massachusetts Environmental Police and the
Massachusetts Coastal Zone Management Office. The meeting
annex has been designed to fit 30 at tables or 75-80 in theater-style
seating. The boathouse is presently used for storage, with
berthing for the sanctuary's research vessels, MEP patrol
boats, and guest research vessels (with prior approval).
renovation of the Scituate buildings, which had formerly
served as a U.S. Coast Guard Station, was completed in
The doors and windows of the Annex were blocked with snow drifts after a major storm in early 2005.
The facility was the third NOAA building in the nation to incorporate a geothermal heating and cooling system. This HVAC system reduces our dependency on fossil fuels by using the earth as a heat source in the winter and a heat sink in the summer. The subsurface soil, groundwater (salt and fresh), and bedrock maintain a constant temperature of around 54 degrees Farenheit. What drives the system is the difference in temperature between the 54 degree earth and the ambient air. In winter the system draws heat from the ground and transfers it to the building space through water source heat pumps. In the summer, it extracts heat from the building's interior and transfers it to the ground. In our case, we utilize the earth's energy source through two 740-foot wells, which are tapped into deep saltwater veins. Submersible pumps pump the 54-degree water into the building.
This is where the workhorses of the system, the water source heat pumps, take over. Their basic function is not to create heat but to move it from one place (earth) to another (the building). Similar to a refrigerator, they do this by pumping a refrigerant (we use an environmentally friendly type) through a closed loop. However, the difference is that the heat pumps have a reversing capability (valving between the built-in evaporator and condenser coils allows their function to be reversed) so that they can take heat from a warm area and exchange it to a cooler area and vice versa. The refrigerant transfers heat (extracts it in the winter and discharges it in the summer) from the saltwater to the forced air which is then circulated throughout the building via air ducts.
The combination of the special chemical properties of the refrigerant and the relatively high, year-round difference in temperature between the refrigerant and ground temperature enable this efficient heat transfer rate. The bottom line is that the geothermal HVAC system is 50-70% more efficient at heating and 20-40% more efficient at cooling than a conventional, fossil-fuel fired system.
Ben Cowie-Haskell, SBNMS operations and program coordinator
Photos from the files of the US Coast Guard and Mass GIS show First Cliff, where the sanctuary headquarters buildings are located. The top left photo shows the area a half century ago; top right shows the building after a fire that destroyed the widow's walk and damaged the second floor; the bottom left photo provides a recent aerial perspective from the state's Geographic Information System (GIS) program.