| Abstract |
The Lewis Glucksman Art Gallery is a cultural and educational institution promoting the visual arts at University College Cork (UCC), Ireland. Opened in October, 2004, the 2350m2 building is serviced by a geothermal heating and cooling system, which allows heating and cooling to be provided at the same time using two water-cooled heat pumps. This enables a liquid chiller installation to serve as a full service heat source simultaneously with its refrigeration function. Situated adjacent to the River Lee on UCC campus, and overlying a shallow gravel aquifer, groundwater at 12m depth and ~ 15C, is fed via an open loop collector to geothermal heat pumps through plate heat exchangers. In order to ensure the preservation and safe keeping of its art collections, critical exhibition and storage space in the Glucksman requires a highly controlled environment, including humidity control by dehumidification, which demands that heating and cooling be supplied simultaneously to closed control areas. A range of climate-control technologies connected to the heat pumps optimise energy efficiency, whilst meeting the requirements of each viewing space. Two water cooled chillers at the same time generate both chilled water at 6°C and heating water at 45°C (30°C when providing cooling only). The rejected heat from the cooling process is fed directly into the heating circuits. Excess heat or cooling is transferred to the groundwater through a plate heat exchanger, and is discharged to a holding tank for use in toilet flushing and landscape irrigation. Excess water is discharged to the River Lee. The system capacity is 170kW and 200kW for cooling and heating respectively against corresponding loads of 130kW and 190kW. In 2005 and again in mid 2008, assessments of the performance of the geothermal heating/cooling system for the Glucksman Gallery were undertaken to evaluate the operational efficiency of the geothermal system and to compare its performance to that of a conventional system. The studies also evaluated the economics and operational savings of the system relative to a conventional system and, based on fossil fuel and electricity prices over the period from commissioning of the building, estimated its payback time and future savings over the lifetime of the heat pumps. The investigations have indicated potential for considerable savings of 75% in energy consumption over that of conventionally equipped buildings. Post occupancy evaluation using recorded data from the building management system shows a remarkable correlation in energy consumed to the pre-construction design estimates. Due to significant increases in energy costs since the building was commissioned, payback time has been significantly reduced relative to pre-construction design estimates. |