3 ms·

If anyone in your building turns the valve on their radiator off (because their space is overheated) then the water will condense and when they open it again th

by nkurz 8y ago

If anyone in your building turns the valve on their radiator off (because their space is overheated) then the water will condense and when they open it again the entire system will hammer, forever, until the building engineer drains it. Theoretically, I don't think this is correct. And in practice, I'm sure it's not always true. That is, I've tuned up a steam system using Holoway's advice, and there was no problem with turning individual radiators on or off. In normal operation, the steam is condensing in the radiator, and then draining back to the boiler by gravity. Opening the valve after a period of nonoperation is not significantly different than the rush of condensation one gets at system start up when the radiator is cold. If the pipes are layed out correctly, when the valve is opened the water will drain back to the boiler with no outside action required. What is true is that the standard "one pipe" steam radiators work poorly when the user decides they want half the heat, and turns the steam valve halfway. In this case, the higher speed of the incoming steam through the smaller opening prevents the water from flowing out, and the radiator works poorly. The correct approach to variable heat on one-pipe steam systems is an adjustable exit air valve. Still, this should also "fix itself" quickly as soon as the shut-off valve is fully opened.

Kadin 8y ago
> The correct approach to variable heat is an adjustable exit air valve. I always wondered why the radiators in some buildings had two apparent temperature controls, one at the bottom of one side (generally a big gate valve) and another at the top of the other side (which I presume is the "exit air valve"). As a student, nobody ever told us how to actually regulate the heat, so there was a lot of randomly opening and closing valves until the thing either got hot or cooled down as needed. Or, more commonly, you just ran the thing full blast all the time and opened a window when it got too hot, titrating the cold air from outside against the overwhelming heat from the radiator. A couple of laminated instructions stapled to the wall near each radiator probably would have made the system perform much better.

by nkurz 8y ago

Kadin 8y ago

> The correct approach to variable heat is an adjustable exit air valve. I always wondered why the radiators in some buildings had two apparent temperature controls, one at the bottom of one side (generally a big gate valve) and another at the top of the other side (which I presume is the "exit air valve"). As a student, nobody ever told us how to actually regulate the heat, so there was a lot of randomly opening and closing valves until the thing either got hot or cooled down as needed. Or, more commonly, you just ran the thing full blast all the time and opened a window when it got too hot, titrating the cold air from outside against the overwhelming heat from the radiator. A couple of laminated instructions stapled to the wall near each radiator probably would have made the system perform much better.