This is an update of the popular direct-use guidebook, last published in 1991. All of the 19 chapters have been revised based on technical assistance experience at the Geo-Heat Center and reflecting current trends in industry. The 470-page book covers material on Lessons Learned, Nature of Geothermal Resources, Exploration for Direct-Heat Resources, Geothermal Fluid Sampling Techniques, Drilling and Well Construction, Well Testing and Reservoir Evaluation, Materials Selection Guidelines, Well Pumps, Piping, Heat Exchangers, Space Heating Equipment, Absorption Refrigeration, Greenhouses, Aquaculture, Industrial Applications, Engineering Cost Analysis, Regulatory and Commercial Aspects, and Environmental Considerations