erc: who: United States. Department of Energy. Office of Energy Efficiency and Renewable Energy. Office of Industrial Technologies. what: American Water Heater Company: Compressed Air System Optimization Project Saves Energy and Improves Production at Water Heater Plant when: 20031101 where: https://digital.library.unt.edu/ark:/67531/metadc1404676/ erc-support: who: University of North Texas Libraries what: Permanent: Stable Content: when: 20081203 where: https://digital.library.unt.edu/ark:/67531/