9. Resources
1. http://energy.gov/public-services/homes
2. http://energy.gov/energysaver/energy-saver
3. http://www.energystar.gov/index.cfm?fuseaction=find_a_product.
4. http://info.ornl.gov/sites/publications/Files/Pub10081.pdf
5. https://www.energy.gov/energysaver/heat-and-cool/heat-pump-systems/geothermal-heat-pumps
6. https://www.energy.gov/energysaver/choosing-and-installing-geothermal-heat-pumps