O'Connor Company is a mechanical contractor that provides heating, ventilation and air conditioning systems for residential, institutional and commercial construction projects. Its equipment division offers a variety of products that delivers economical solutions for customers. It provides technical assistance to various professional consulting engineers, mechanical contractors and building owners. The company provides installation services for heating, ventilation and air conditioning equipment. Founded in 1970, O'Connor Company is located in Sioux Falls and Rapid City, S.D. It is owned and operated by the O'Connor Group. The group also operates G&R Controls division and Balancing Professionals, a testing and balancing division.