Resonant Microstructures to Enhance Condenser Airside Heat Transfer

79229S Many HVAC and refrigeration equipment relies on air-cooled condensers to remove refrigeration circuit heat. The energy use of these systems is strongly dependent on the effectiveness of condenser heat transfer. In spite of significant advances in design and fabrication techniques for fins, airside heat transfer is still the dominant limitation to further improvements in condenser performance. This project will develop vibrating resonant microstructures to enhance heat transfer on the airside surface of fins by enhancing mixing between the viscous flow boundary layer and the bulk flow region. In Phase I, an experimental program is proposed to evaluate the heat transfer enhancement potential of vibrating resonant microstructures on a surface representative of a fin louver. A test fixture will be assembled to allow for the accurate measurement of heat transfer. Surfaces prepared with candidate microstructure geometries will be tested to quantify the heat transfer improvement. Commercial Applications and Other Benefits as described by the awardee: The technology should improve the efficiency and reduce the size of a wide range of existing HVAC and refrigeration products that use air-cooled condensers: residential central air-conditioners , commercial air-conditioners, room air-conditioners and packaged terminal air-conditioners, air-cooled chillers, residential refrigerators, etc. The annual sales volume of all of these products is in excess of 20 million units sold annually. Energy savings associated with the technology is estimated to be 1/3 quad of primary energy.