Comments on: Some like it hot

Question: Some like it hot

nyterrant — Thu, 28 Jul 2005 12:33:10 -0800

Why are New York subway platforms so hot?

I know it's summer, but yikes. NYC subway platforms are at least 10 degrees hotter than above ground. I've been on many subways in many cities, and never have I experienced the furnance-like tempertatures found in New York. Can anyone point to a reason it's so hot down there?

By: Mo Nickels

Mo Nickels — Thu, 28 Jul 2005 12:36:50 -0800

I had some subway geek try to convince me once that it was all due to heat released by the brakes on the subway cars, but that's pretty much rubbish. There are three main causes of the heat:

1. Exhaust from the air conditioning units on cars.
2. Steam pipes that use the same tunnels or space.
3. Heat radiated downward from the surface streets that have absorbed it.

By: Mo Nickels

Mo Nickels — Thu, 28 Jul 2005 12:37:38 -0800

...air conditioning units on subway cars...

By: reverendX

reverendX — Thu, 28 Jul 2005 12:44:28 -0800

I've noticed some of the really deeper lines are noticably cooler... that makes it seem more like a surface street issue.

By: Pollomacho

Pollomacho — Thu, 28 Jul 2005 12:47:13 -0800

Steam pipes are operating during the summer? What for?

I think sewage lines giving off heat may also add to the misery, but that's just speculation.

By: true

true — Thu, 28 Jul 2005 13:00:54 -0800

Why steam in the summer? Cooling! Steam air conditioning in NY.

By: dame

dame — Thu, 28 Jul 2005 13:11:59 -0800

I do believe it is the brakes, but I can't prove it. It is coming from the trains in any case. You'll notice that the more trains using a platform (and the more often the train comes), the hotter the platform. That is, at Union Square, the 4/5/6 platform is *much* hotter than the L, and at Lorimer-Metropolitan, the L is much hotter than the G.

Unlike others above, I've found deep lines hotter, with stations that have the vents to the street cooler.

By: Mo Nickels

Mo Nickels — Thu, 28 Jul 2005 13:21:37 -0800

That is, at Union Square, the 4/5/6 platform is *much* hotter than the L, and at Lorimer-Metropolitan, the L is much hotter than the G.

This doesn't prove anything, since the 4/5/6 platform is much closer to the street than the L, and so more susceptible to heat radiating from the street.

By: dame

dame — Thu, 28 Jul 2005 13:24:08 -0800

This article may shed some light on it, if anyone can get it (bug me not isn't working). Another from the Washington Post about their metro, does indicate that train brakes add heat.

And Mo, actually Union Square is a bad comparison because the L has fans--I forgot. But my L stop is very close to the street & is very cool--much cooler than any express-local stop I've ever been at.

By: darksquirrel

darksquirrel — Thu, 28 Jul 2005 13:27:44 -0800

Not sure but I'd bet part of the problem is ventilation. All that air is just stuck down there and insulated by surrounding dirt etc. Nowhere for the heat to go.

By: dame

dame — Thu, 28 Jul 2005 13:28:45 -0800

Also, from the little bit of that Sun article that shows up on google, there seems to be something to do with circulation: so perhaps it is hot if it is close to the street but not vented and cooler if it is both close to the street and vented.

But now I'm way past speculation, so I'll shit up and see if someone can get into the Sun.

By: Leon

Leon — Thu, 28 Jul 2005 13:46:20 -0800

Hmm. A human body kicks out, what 100 watts? Call it 4 million journeys a day with an average, of, say, 20 minutes per journey? I make that 133 megawatts per day.

My math is probably completely wrong, but I bet that heat radiated from bodies is a significant factor. Anyone care to guess at how much heat is generated by braking?

By: Leon

Leon — Thu, 28 Jul 2005 14:19:46 -0800

Although now I think about it, human-generated heat (and the extra heat caused be shifting it around with A/C) probably pales into insignificance when compared to sunlight heating the ground above.

By: wackybrit

wackybrit — Thu, 28 Jul 2005 14:35:44 -0800

I've been on many subways in many cities, and never have I experienced the furnance-like tempertatures found in New York.

You've not been to London? It's insanely warmer in the Tube than above ground 99% of the time.

By: nyterrant

nyterrant — Thu, 28 Jul 2005 15:15:33 -0800

I used to live in London. But the heat in the Tube is nothing compared to what you have to face in New York.

By: bcwinters

bcwinters — Thu, 28 Jul 2005 15:47:59 -0800

Try the 9th street PATH station some time if you want to REALLY bake. It's unquestionably the hottest station I've been in anywhere in NYC.

I shudder to recall how many summers I spent commuting via that station. Gah.

By: scazza

scazza — Thu, 28 Jul 2005 16:25:24 -0800

And Mo, actually Union Square is a bad comparison because the L has fans

But I swear the L is still roasting. I was at 6th Ave the other day and it was the hottest platform I've ever experienced. frankly, I'd think the 4/5/6 would be waay cooler since their ceilings are usually higher and the heat has more room to rise away from the platform. I think we need to follow North Korea's example of air conditioned subways.

By: blag

blag — Thu, 28 Jul 2005 16:29:16 -0800

By: ikkyu2

ikkyu2 — Thu, 28 Jul 2005 17:53:29 -0800

a) NYC subways use partially-regenerative brakes. Everything that's not regenerated becomes heat. That's a LOT of kinetic energy.

b) The motors produce a considerable amount of heat, as do any/all electric motors.

c) If deeper lines are really cooler, the 168th st 1/9 stop - 150-180 ft underground by my estimation - really didn't get the memo. It's frequently 100+ degrees down there in summertime.

By: dame

dame — Thu, 28 Jul 2005 18:15:45 -0800

Wait, blag's link says the trains in London aren't air-conditioned. Is that true? Because in New York, it's just the platforms. It also says that only new systems have AC in the trains, and I know that's a lie--we have it.

Anyway, scazza, the Union Square L is nothing for the 4/5/6, I promise. In summer, if I'm going downtown, I'll take the N/R just to avoid that platform of doom.

By: fvw

fvw — Thu, 28 Jul 2005 19:19:32 -0800

Yup, no AC on the tube. There are plans to install AC units on certain lines I believe, but nothing soon.

By: five fresh fish

five fresh fish — Thu, 28 Jul 2005 19:23:12 -0800

And here I thought it's because the deeper you go under New York, the closer to hell you get...

By: GreenTentacle

GreenTentacle — Thu, 28 Jul 2005 21:27:27 -0800

I wish the MTA would search a few less bags and divert the money to investing in big, powerful, "blowy" portable A/C units like they have in Newark Penn Station. Would make waiting for the subway oh so much more comfortable.