Circular radiators date back to the early 1900s. They were assembled as one whole radiator or as halves for the purpose of encircling columns. When they were in halves, each half became an independent radiator. In this video, Dan Holohan tells us about a circular radiator that was still in operation in Washington, DC.
Want to learn more? Read Dan Holohan’s book The Lost Art of Steam Heating Revisited.