History of District Heating in the United States

| Chronological List of District Heating Systems in the United States |

District Heating in Oklahoma City, Oklahoma

Thermal Systems, Inc., a wholly-owned subsidiary of Oklahoma Natural Gas Company, built heating and cooling plant in downtown Tulsa and Oklahoma City. The Oklahoma City system began service in 1971. The system was sold to Trigen in 1989 and to Vicinity Energy in 2019.

.References
1970 "New Heating-Cooling System being constructed in Oklahoma," District Heating 55(3):17 (Winter 1970)
Oklahoma City, Thermal Systems, Inc. subsidiary of Oklahoma Natural Gas Company