This article provides an overview of the various equipment components that are used in most geothermal direct-use project. Following, are articles describing in more detail five major types of equipment: well pumps, piping, heat exchangers, space heating equipment and absorption refrigeration equipment. These five articles are condensations of chapters written by Kevin Rafferty and Gene Culver, mechanical engineers with the Geo-Heat Center, that appear in the 3rd edition of our “Geothermal Direct-Use Engineering and Design Guidebook” (1998)