Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture; and, (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1986. / Typescript (photocopy). / Includes bibliographical references (v. 2, leaves 288-292) / A study of the energy system at the Massachusetts State Transportation Building was conducted. This innovative energy system utilizes internal-source heat pumps and a water thermal storage system to provide building heating and cooling. The potential benefits of this type of system include both energy savings and operating and equipment cost savings when compared to more conventional building heating and cooling systems. The study involved monitoring of equipment performance, computer simulation of the building energy system dynamics, and analysis of actual and modelled system efficiency. It was found that the building is presently operating as a 'low energy' building, despite a number of factors which have limited the heat pump system's capability to entirely meet winter heating requirements. Significant additional operation efficiency and cost savings are potentially available if a variety of measures are undertaken, including: stratification of the thermal storage system, utilization of demand management controls, and increased lighting system efficiency. / by Abbe Ellen Bjorklund. / M.S.