Who Needs Central Heat When You Live Above a Subway Shaft?

Among all of their other byproducts – in economic benefits, time savings, reduced emissions – subway systems also happen to generate a lot of heat. You've probably felt it standing in an underground subway stop in the dead of winter. Trains generate heat when they brake. The lighting in subway systems creates heat, too. As do all the passengers (another phenomenon you've undoubtedly experienced in a packed train car).

Much of this heat is discharged in pretty concentrated quantities out of ventilation shafts, where it dissipates into the air. In theory, though, we could actually do something with it. Like heat nearby homes.