Oklahoma State University

A ventilation system that provides fresh outdoor air to building spaces. In this study, a DOAS was installed to serve both floors of the test building.

An underground heat pump system at Kameha Grand hotel in Germany that uses six geothermal wells at 28 meters depth to provide heating and cooling for 80,000 square feet of building space, supplying all cooling and 70 percent of heating needs while saving approximately 1,700,000 kWh annually.

A heating and cooling system that uses variable refrigerant flow technology to condition building spaces. Commonly used in commercial buildings as an alternative to geothermal systems.

Georgia

A two-year research project comparing the energy performance of geothermal heat pump systems versus variable refrigerant flow systems in a commercial building. The study involved renovation of a 1960s-era building and installation of over 1,600 sensors to monitor HVAC operations.