• International Ground Source Heat Pump Association, http://www.igshpa.okstate.edu/
• Geothermal Heat Pump Consortium (GHPC), http://www.geoexchange.org
• WaterFurnace, http://www.waterfurnace.com/
• Trane, http://www.trane.com/Commercial/Equipment/ProductDetails.aspx?prod=232
• U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy,
  • Consumer's Guide, http://www.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12640
  • How to Buy an Energy-Efficient Ground-Source Heat Pump, http://www1.eere.energy.gov/femp/pdfs/groundsource_heatpumps.pdf
    

  
  

Geoexchange Research:

• Ground Source Heat Pump Design , http://www.geokiss.com/
  
  
• Oklahoma State University Geothermal Heat Pump Links, http://www.igshpa.okstate.edu/geothermal/links.htm
  
  
• Oak Ridge National Laboratory (click on "geothermal heat pumps" link) http://www.ornl.gov/femp/
  
  
• ASHRAE (use the search box to find articles), http://www.ashrae.org/
  
  
• Oregon Institute of Technology, GEO-HEAT CENTER, http://geoheat.oit.edu/
  
  
• Air-Conditioning and Refrigeration Institute (ARI), http://www.arti-research.org/index.php