New York City operates the largest commercial steam system in the world, pushing boiling vapor through more than a hundred miles of subterranean pipes to heat iconic skyscrapers and sterilize hospital equipment.

A closer look

New York City operates the largest commercial steam system in the world, pushing boiling vapor through more than a hundred miles of subterranean pipes to heat iconic skyscrapers and sterilize hospital equipment. The dramatic white plumes you see billowing out of those orange and white plastic funnels on the streets are just pressure release valves keeping the antiquated underground infrastructure from exploding violently. Tourists love to photograph these misty street vents because they look like gritty, cinematic smoke straight out of a classic noir film or an aggressive eighties action movie. In reality, you are just taking a romantic selfie in front of literal boiling water exhaust that is actively preventing the entire island of Manhattan from becoming a catastrophic, pressurized crater of angry rats and expensive real estate