Baking Below Ground, Why is the Subway So Hot?

The next time you're standing on a subway platform silently suffering and sweating from oppressive heat, take intellectual comfort in the fact that you know exactly why it's so hot below ground. The New York Times' Michael Pollak explains the situation in his informative "F.Y.I." column. Despite the fact that underground subway stations are shielded from the sun, the temperature on platforms is often higher than above ground. Pollak gives a number of reasons for the phenomena:

The "heat sink" effect, where heat is transferred from surfaces like the pavement to immediately cooler areas, like a subway station.
Air conditioning. Ironically, the subway system is heated by the energy given off by the A/C that cools the interiors of trains.
Lack of air conditioning. Subway stations are not air conditioned, with the exception of the 4/5/6 platforms at 42nd St., which tap into the A/C system cooling Grand Central Terminal.

One factor that was not mentioned is the fact that there is rarely a breeze on subway platforms. We've always found that it is somewhat cooler if you wait on the platform near an entrance or exit, where the air circulates a little more freely and it's not so hot.

(Subway Crowd, by taliashere at flickr)

Contact the author of this article or email tips@gothamist.com with further questions, comments or tips.

By Dave Hogarty in News on August 28, 2007 2:54 PM

Comments [rss]

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guest

Please post the article.

Thanks!

dadoc

In polite response to #28, of course not.

Unless resitance is applied between the hot & ground, no energy given as heat. And, should you research, you would learn about the sector concept.

Your "moron" comment is impolite, uninformed and obviously based on an uneducated need to express something without meaning.

Read, explore, study and learn, child.

Dadoc

chrisk

7 platform in GC

guest

Radiant from third rail? not likely. Rails are generally not even energized unless a train is within the signal sector.

will you test your theory out by touching the third rail? moron.

Aces N Eights

more trains more often (esp late night)and we wouldn't care a bit.

guest

All it would take are some fans to keep the air moving. Many stations used to have them, but they broke or were installed in stupid locations.

guest

its becoz of all the smokin' hot chicks in new york

MarygraceNYC

42nd Street 7 Line..... one of the hottest by far!! It is 3 stories down and no circulation.... Sucks!!

guest

How is it ironic that "the subway system is heated by the energy given off by the A/C"?

In this house, we obey the Laws of Thermodynamics!

guest

Ya ever notice how the women start covering themselves after entering the subway car with the a/c? I personally could just do with those ceiling fans they used to have. Did I just date myself - and I'm only 39...

cool

Talk to anyone who lived in the city more than 40 years ago - it's the introductin of airconditioning on the subway cars that makes the platforms so hot. So, it comes down to picking ur poison: cooler stations or cooler cars. of course, back then, you were able to open the windows, so you could get some of the tradional air cooling.

dadoc

A/C the stations? Unlikely.

With the entrances/exits & tunnel openings, you would have to consume MASSIVE amounts of energy to use A/C. Even if you had an airlock/double-door setup for the exits.

Ballasts only really heat up on the start-up discharge. Fluorescent are Way cooler than incandescent, & even compact fluorescent. And if you don't ballast each unit, if a ballast goes out you lose a whole string of lights.

Radiant from third rail? not likely. Rails are generally not even energized unless a train is within the signal sector.

People, transformers, infrastructure like steam pipes, poor air flow all contribute.

Some good venting, from above, promoting airflow from the cooler tunnels would be more effective at cooling platforms.

Any ideas?

Dadoc

guest

34st Herald Square - N/Q Line Wins hands down!

Kojak

51st and Lex where you pick up the E is almost as hot as my balls

Well... Almost

Reflect

What about flatulance radiation that has to contribute too.

Toby von Meistersinger

I recall reading in a book that the original IRT kiosks had a means of venting the stations making them cooler and aiding airflow. When they were removed in the name of progress away went the vents. The BMT and IND had no such provision.

guest

It could have something to do with being a little closer to the Earth's molten core.

guest

During the summer, the 2/3 platform at the Fulton St stop in Lower Manhattan is absolutely suffocating. I always feel like my lungs can't even breathe air that hot.