International Ground Source Heat Pump Association (IGSHPA) - Find answers to GeoExchange questions, plus links to more detailed information covering topics such as project financing, case studies, and the technical aspects of GeoExchange.

GeoExchange Information Center - Information on ground-source heat pump technology, including case studies of applications. Maintained by the Geothermal Heat Pump Consortium (U.S.).

Fine-Wire Heat Exchangers - Heat exchangers and improved fans to improve the performance of heat pumps. Site has information about low-temp heating, energy storage, and heat pump technology.

International Energy Agency (IEA) Heat Pump Centre - The HPC is the IEA's information center for heat pumping technologies, applications, markets. Operates worldwide via a network of national teams in its member countries.

Econar Energy Systems, Corporation - How geothermal works, case studies, publications and manuals.

Geothermal Systems - Information on the process of geothermal heating, benefits, how does it heat and cool .

Water and Energy Systems - Technical papers, case studies and FAQs relating to the standing column well geo-earth coupling method.

Geothermal Heat Pump Heating and Cooling Systems - For homes and businesses anywhere on Earth. Energy efficient, these ground coupled systems use the Earth as a source of heat and cooling. By Trane.

Geothermal Heat Pump Energy -- How It Works - Primer on the subject, by Sunteq/Enviroteq.

Continental Services: Geothermal FAQ - Questions and answers on geothermal heating systems.