2010-06-172010-06-171994https://hdl.handle.net/10365/9632The topic was the usage of 'salvaged' heat from exhaust air in the dairy barn. Rocks would be used to collect and to hold waste heat from the vents. This article discusses a heat exchange method tested in a small barn and used successfully in the large (l20-cow) freestall N DSU dairy barn. The ventilation system uses field rocks to absorb the heat from the exhaust air and return it to the barn in the intake air by reversing the ventilating fan.North Dakota State UniversityWheatSoil erosionCrop productionArticle