Solar Thermal Project at Massachusetts Maritime Academy
Weston & Sampson was contracted to provide turnkey design and construction of a solar water heating system at Massachusetts Maritime Academy (MMA). The solar thermal system is designed to provide primary heating for heat domestic hot water, with auxiliary heating for the indoor swimming pool in the Alumni Gym Building. The system consists of 24 Apricus AP30 evacuated tube collectors and is expected to produce 156,000 MMBTU or 1,560 Therms per year of useful heat energy.
This system is designed as a “drain back” system. This allows the heat transfer fluid (glycol) to drain out of the collectors when there is insufficient sunlight for heating. This avoids issues with glycol degradation, which occurs with stagnation temperatures. In order to optimize overall solar energy gain, the system has the flexibility to direct energy to either the pool or the domestic storage tank in response to continuously changing solar and domestic hot water load conditions. The Data Acquisition System (DAS) also allows the facility to access the solar thermal system over the Internet.
The project also included the complete replacement of the existing tar and gravel roof with a new fully adhered PVC Membrane Roofing System Roof covering 10,000 square feet over the natatorium section of the building.
The project received a grant from the Massachusetts Clean Energy Center and a utility rebate from National Grid for the gas savings attributed to the additional roof insulation that was added as part of the roof replacement.