Data logger analysis case studies: Residential Construction Demonstration Project Cycle I.

摘要

A set of 12 homes with advanced heat recovery ventilation systems located in Washington, Idaho, and Montana are monitored under the Bonneville Power Administrations Residential Construction Demonstration Project. Five of the homes are equipped with exhaust air heat pumps. Two different types of EAHP systems are monitored. The first type, which is installed in three houses in Washington State, provides space and water heat and extract energy from the exhaust air stream only. These heat pumps achieved overall coefficients of performance (COP) between 3.1 and 2.5 and ventilated the homes well above the required 0.25 mechanical air changes per hour during the heating season. COP is a ratio of the energy extracted from the exhaust air and the energy required to operate the system. Total energy recovered from exhaust air by these three heat pumps ranged from 1,733 to 3,300 Btu/hr for the entire monitoring period. COP is adjusted downward due to excess ventilation. Efficiency of these systems may be increased through better system controls and operation. The second type of EAHP that is installed in two Montana homes extracted energy from both exhaust and supply air streams. These heat pumps achieved considerably lower COPs. COP for these two homes are 1.8 and 1.7. The systems are operated less often and did not provide the recommended air change rate. Seven houses are ventilated with air-to-air heat exchangers with special measures to heat supply air before delivery. Four heat exchanger systems are integrated with forced air electric furnaces of heat pumps and three systems used duct heaters to preheat incoming air. These systems saved between 162 and 1,172 Btu/hr over the entire monitoring period.