Any idea how that system got common? NYC used to have mainly heat based on steam radiators, which are perfectly easy to control per unit by just adjusting the radiator valve. Since the 1930s, there are even &quot;automatic valves&quot; that raise&#x2F;lower the radiator inflow automatically to maintain a set temperature, like a thermostat (this is the invention that Danfoss was built on). That&#x27;s exactly the system I had when I lived in Copenhagen, and it worked pretty well. But it seems to have been largely replaced in NYC with forced-air heating that has no individual controls? So yes, to &quot;adjust the thermostat&quot; downwards, people literally open their windows in January, blowing heat into the outdoors.