Interestingly, this is often by design: https://www.npr.org/2020/12/10/945136599/how-spanish-flu-pandemic-changed-home-heat-radiators#:~:text=CHANG%3A%20This%20

Interestingly, this is often by design: https://www.npr.org/2020/12/10/945136599/how-spanish-flu-pandemic-changed-home-heat-radiators#:~:text=CHANG%3A%20This%20design%20philosophy%20took,from%20coal%20to%20other%20fuels https://www.npr.org/2020/12/10/945136599/how-spanish-flu-pan....