i live at alumni hall on 3rd ave and 9th st facing 10th street. all day we can see steam coming past our windows? where is it coming from and why?
Con Ed has been selling steam for over a century to be used for heating buildings. Some of it vents off of the pipes used to deliver it to customers.
I’ll second DrFidelius. Either that, or you have a dryer vent near your window.
Tripler
Look out your window. Do you see any pipes? What do they look like?
Staff Report: Why does steam rise from manholes in the U.S.?
Steam is invisible! Trust me on this.
What you see is water vapor.
The vapor phase of water.
A mist of cooling water vapor.
Pressurized water vapor used for heating, cooking, or to provide mechanical power.
The power produced by a machine using pressurized water vapor.
Steam heating.
Power; energy.
Sorry, Reeder
People call royal gelatin jello too.
But it ain’t.
According to David Letterman, it’s radioactive steam.
So, you’d better run for it.
I think water vapor is also invisible since steam is just water vapor. The dividing line between calling something water vapor or steam is hazy. Vapor is usually used, I think, to describe water that evaporates naturally without the addition of heat to the liquid. Steam is the stuff that comes off when you heat water and capture the vapor under pressure in a closed system. But I don’t think there’s anything hard for fast about that.
Merriam-Webster’s Collegiate says that steam is a vapor arising from a heated substance.
What is seen is a mist of excedingly fineof water droplets. When the visible stuff disappears into thin air by evaporation, that’s water vapor.
Technically, steam is invisible. But so is water vapor (do you see any hanging in the air around you?)
Both can be seen as droplets condense and become large enough. As a general rule, if these droplets are hot, they’re called “steam” and if they’re cool, they’re called “water vapor” or “fog.”
It is not a precise definition, but no where is it required that language always be precise.
This thread is so SDMB!
[nitpick] Or maybe not so nitpicky. Once droplets condense it is no longor vapor. It’s water.[/nitpick]
As a native New Yorker, I’ve always wondered about this too.
Is Con Ed making steam just to be distributed? Or is it a byproduct of burning oil (or whatever they burn) in their power plants, where they’re recapturing some of the energy as heat and converting it to steam - a win-win situation. Because if it’s not a byproduct, it would seem incredibly inefficient.
But wouldn’t the steam cool off a lot by the time it got to the building? **How do they keep it hot **as it travels the many miles underground from the powerplant to the buildings?
Yes, it’s made with waste heat from ConEd’s power plants. This used to be the normal practice in most cities until they started building larger power plants further away from urban centers which made steam distribution unprofitable. Most big power plants in rural areas just, err, waste their waste heat now.
I imagine it does lose a lot of its heat as it travels, but the pipes are all buried underground so there’s some natural insulation. And the steam is highly pressurized so it moves fast.
BTW: Here are some interesting statistics all about ConEd steam.
Since when did we abandon the dictionary?
Steam has several definitions/meanings. Steam can be used to refer to the invisible vapor, but it can also be used to describe the visible droplets, etc.
So, lighten up. “Steam” is not exclusively the invisible vapor.
Steam engines spew water droplets and invisible vapor. In terms of the dictionary and communication from one english speaking human to another, saying “steam” to describe what one can see from the stack would be correct in terms of the dictionary definition and would constitute effective communication.
Abandoning those correct uses would fly in the face of the definition in various dictionaries and would be contrary to how people communicate.
Steam can be used to describe the visible and/or invisible.
I’ve seen steam rising from residential neighborhood storm sewers in Houston on cold days. What’s up with that? Nobody’s delivering steam to them.
Actually, it’s one of the many special effects New York priovides to make us all look Fabulous:
• Romantic, flattering steam to emerge through, as people gasp at their sudden sight of you (or to vanish into, in a film noir kind of way)
• Reflectors on skyscrapers and glitter in the sidewalks for that perfect lighting.
• Vague miasma of pollution to give you that “Cybill Shepherd in Moonlighting” soft-focus effect.
• Equal breezes from the East and Hudson rivers to keep your hair full and windswept.
• And you know about subway gratings and skirts . . . .
I have to admit, it bugs me when the ConEd site describes steam as a “clean, efficient energy source”. Heated water isn’t an energy source, it’s the by-product of the use of a real energy source, which presumably is a ConEd coal- or oil-plant which does, in fact, pollute.
Sure, “steam” is the popular term and won’t be replaced. However, we do have a perfectly good word, “mist,” that describes precisely what we are seeing, viz. “… water in the form of particles floating or falling in the atmosphere.” If we want to be accurate we should use that term and not “steam.”
Oops. My big nose just got struck by a windmill.