I was driving in the city yesterday and all of the manholes had smoke, or steam coming out of them. What causes that?
2007-04-01 11:37:57 · 8 answers · asked by Ash 5 in Cars & Transportation ➔ Other - Cars & Transportation
Warm moist air in the under ground coming into the cooler air at street level.
2007-04-01 11:43:01 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Same answer as the rest. The warm moist air in the sewer, rises to meet the colder dry air above the manhole and it forms a little cloud. It is a mini-fog just like the big ones you see when you get a rain and a cold front comes in and the ground is warm, you'll see the steam coming off the grass.
2007-04-01 18:50:34 · answer #2 · answered by Fordman 7 · 0⤊ 0⤋
Generally speaking, if a Manhole is smoking it is part of an underground steam pipe system or a sewer. Either of which will vent out steam. It could also be an nderground water supply and if it's real cold out. The water generally traveling underground is usually about 56 degrees and if its cold the water vapors leaking out will condense and make steam
2007-04-01 18:48:23 · answer #3 · answered by jan t 2 · 0⤊ 0⤋
NYC, Boston, DC all have steam pipes underground. Some of the steam is used for heating, not entireloy certain on what the other uses are, but it is not uncommon to see steam escaping from standpipes, subway vents and manhole covers in older Northeastern cities.
2007-04-01 18:49:27 · answer #4 · answered by Porterhouse 5 · 0⤊ 0⤋
All good answers, plus in some cities there is centrally distributed steam for heat and that steam both escapes and in traveling heats the air underground.
2007-04-01 18:46:09 · answer #5 · answered by Mike1942f 7 · 0⤊ 0⤋
It really depends on the city. First possibility is that the drainage running under the streets is warmer than the street level air. Also, the city could use heat/steam and their just vents.
2007-04-01 18:42:54 · answer #6 · answered by Vincent C 3 · 2⤊ 0⤋
warm moist air fro underground meets the colder dryer air, causing steam/ condensation
2007-04-01 18:41:28 · answer #7 · answered by Anonymous · 1⤊ 0⤋
They were all influenced by cigarette advertising at a very young age, now they smoke, every last one of them.
2007-04-01 18:45:05 · answer #8 · answered by Anonymous · 3⤊ 0⤋