Full Description

A study of the energy system at the Massachusetts State Transportation Building was conducted. This innovative energy system utilizes internal-source heat pumps and water thermal storage to provide building heating and cooling. First opened in December1 983, the State Transportation Building is a 901,000 square foot( 83,700m²) office building located in Boston, which also includes garage and retail space.

The post-occupancy study evaluated the performance of the energy system in the context of both operation and design-related factors. The study involved monitoring the dynamics of the building’s energy system over a range of ambient and occupancy conditions and analyzing actual and modeled system performance.

It was found that the building is presently operating as a "low energy" building, despite a number of factors that have limited the capability of the heat pump and thermal storage system to entirely meet winter heating requirements as the designers had anticipated. These factors, including reduced building occupancy, excessive air infiltration, and system design issues, are discussed in terms of their effects upon energy system performance.

Units: Dual

Citation: ASHRAE Transactions, 1987, vol. 93, pt. 2, Nashville, TN