An optimal design analysis method for heat recovery heat exchangers in building applications

Air-to-air heat recovery is used in buildings to reduce the energy used for conditioning the fresh air. The heat exchanger core geometry is one of the key factors that affect the overall performance of a heat recovery system. To better guide the development of high performance heat exchangers in building applications, a new analysis method is proposed in this work from the practical application point of view. The objective of the new optimization method is: at any given mass flow rate, temperature difference and desired heat recovery effectiveness, minimizing the material cost at a specified fan energy use, or alternatively, the minimizing the fan energy use at a given material cost. Different duct geometries are analyzed: equilateral triangle (Tri), circular (Cyl), square (Squ), rectangle with aspect ratio 1/2 (Rec(1/2)), 1/4 (Rec(1/4)), and 1/8 (Rec(1/8)). A novel channel structure named cross-corrugated triangular (CCT) duct is also considered for comparison. By employing this method, the manufacturing and operating cost can be considered synthetically during the optimal design.