This application guide is written to assist the designer in Geothermal heat pump design. It is a companion guide to McQuay’s Catalog 330-1, Water Source Heat Pump Design Manual, which discusses Boiler/Tower heat pump design. It can be downloaded from or contact your local McQuay representative. For the most comprehensive guide to Geothermal heat pump design, it is recommended that designers refer to Ground-Source Heat Pump Systems: Design of Geothermal Systems for Commercial and Institutional Systems , available from the American Society Of Heating, Air- conditioning and Refrigeration Engineers (ASHRAE) at