Agricultural engineers at the University of Minnesota have spent the better part of a year capturing a snapshot of the energy-saving capabilities of a one-of-a-kind, 900-sow, breed-to-wean facility fitted with matching sets of five geothermal heat exchangers on both sides of the structure. The relatively simple design allows outside air to be pulled through each of 10 heat exchangers to temper air (heat in winter, cool in summer) as it enters 8-ft.-wide hallways that serve as inlet air-mixing chambers.