A flooded, abandoned, underground zinc mine in Tennessee is used to provide the heating, ventilating and cooling at Samaritan House, a short-term shelter for families and single women. The building has a system of water-to-air heat pumps with its closed-loop piping lowered into the mine's water. Using the mine shaft as the "borehole" resulted in considerably lower initial costs than a conventional borefield and in a first-year annual energy use intensity of 27.5 kBtu/ft² (312 kJ/m²).