Heating the Apple Store

December 6, 2007 12:17 PM

How does the Apple Store keep all its heat from rushing out its open doors?

I apologize if this is a New York centric question. The Apple Store on 5th ave has an entrance on the street w/ a gaping open door... you then walk down a spiral staircase to the main store, underground. (Do their other stores have this design?)

Now that it is winter, I expected to feel a draft as all the hot air rushed up and out through the doors, into the cold exterior. That wasn't happening and I couldn't figure it out. I didn't feel any major blowers pushing it down either.

Thanks for tips!
-cgs

posted by cgs to grab bag (28 comments total)

Is it an Air Curtain? Is there a big jet of air blowing down as you come in the store (we don not have the pleasure of official Apple stores in NZ unfortunately!
posted by puddpunk at 12:25 PM on December 6, 2007 [1 favorite]

Here's a photo of the entrance. It looks like the door has a glass barrier over it, maybe for this reason (or for rain). Also, there's a lot of airspace above the door. It's not really at the top of the "room".
posted by smackfu at 12:32 PM on December 6, 2007

puddpunk, an air curtain was my first thought too, but judging from this flickr picture there's no place to hide one.

My guess would be they:

1) locate the furnace intake somewhere near the entrance to recapture as much of the rising hot air as possible and

2) increase their heating budget
posted by contraption at 12:32 PM on December 6, 2007

Not only did you beat me to the punch, smackfu, you found a better picture. Curses!
posted by contraption at 12:34 PM on December 6, 2007

That's pretty cool. All four Apple Stores in Atlanta are inside shopping malls.
posted by studentbaker at 12:40 PM on December 6, 2007

I'm not an architect, structural engineer, or Apple employee.

There is an opening on the cube, but it's not at the top of the cube, and overall, it's only a fraction of the cube surface area. Not that you'd want a window open during the winter, but still.

Or maybe the big glass cube acts as a greenhouse. During the day.

Also, as you said, the store is underground. That means it's very well insulated, and they have geothermal heat, for what that's worth.

I hope someone comes along with a better answer.
posted by These Premises Are Alarmed at 12:45 PM on December 6, 2007

Another interesting photo, from below. Shows that the cube is actually much bigger than the store itself.
posted by smackfu at 12:51 PM on December 6, 2007

a few more shots of the stairwell
posted by contraption at 12:51 PM on December 6, 2007

A lot of heat just rushes out. They have heaters to put it back in. It's not very enviromentally friendly, but lots of stores do it.
posted by GuyZero at 1:17 PM on December 6, 2007

I think the fact the store is underground and low-ceilinged helps to keep the heat in.

Aside: those beautiful glass steps now have rubber treads on them, thus reducing the potential for 'trip and fall' law suits but ruining the aesthetic.
posted by essexjan at 1:25 PM on December 6, 2007

There are some excellent shots at their own gallery.

Perhaps they're pushing air up the elevator shaft (that's the tube in the middle, if I am correct) from the area below. Or perhaps they have things set up so that air tends to moves on its own. This could keep warm air moving slowly down the sides of the block, sans air curtain machine.
posted by zennie at 1:37 PM on December 6, 2007

they have a heating system in place that is calibrated to deal with the open door.

it's not environmentally friendly but it is effective to keep the place warm. Also, don't forget the fact that the lights in the store generate an incredible amount of heat and those lights are on 24/7.
posted by Stynxno at 1:39 PM on December 6, 2007

Hm. Or maybe not. That elevator is in there pretty snugly.
posted by zennie at 1:43 PM on December 6, 2007

http://www.flickr.com/photos/techsavvy/188121603/

that one shows the stairs going up to the door... i think the doors exist, i just haven't seen them closed.

in any case, i was trying to figure it out and slowly walked up the stairs waiting to feel a draft/fan/air-mover, what have you... but i never really felt the air move. i'm just curious how they do it... maybe all of the air in the cube freestanding above the door pulls the rising air past the opening to the outside?

my high school physics / chemistry is failing me... i imagined all of the air rushing out like a furnace due to the two different pressures.
posted by cgs at 1:57 PM on December 6, 2007

Also, as you said, the store is underground. That means it's very well insulated, and they have geothermal heat, for what that's worth.

Unless there's a whole bunch of tectonic activity going on in New York that the general public (i.e. me) isn't aware of, they probably don't have geothermal heating.

Also, don't forget the fact that the lights in the store generate an incredible amount of heat and those lights are on 24/7.

And it's probably full of people and a bunch of running electronic equipment. The people are probably providing more heat than the mechanical system. In fact, if the store has enough people, they'll actually be running the air conditioner, even in winter. Even more in fact, they might be leaving the doors open to mitigate their cooling costs and actually be saving energy by doing so.
posted by LionIndex at 2:08 PM on December 6, 2007

huh... interesting, LionIndex. the place is a f'ing zoo during the day... i guess the test for the people-heat theory would be to peek in at 4:00AM and see what is going on ;-)
posted by cgs at 2:14 PM on December 6, 2007

Well, I work for an architecture firm that does retail work, although mostly in California. Not once has anyone ever even raised the issue of how a space will be heated. We worry all about cooling tonnage and getting that right per the lease agreements the building owners have with their tenants, but I've never seen a thing about heating. For an electronics store, located underground with an entire building on top of it, I imagine heating is just not a concern.
posted by LionIndex at 2:25 PM on December 6, 2007

What LionIndex said. Have you ever noticed how much heat an iMac generates? Hint: It's a lot. My office is quite toasty in the winter between my MBP and iMac, even while the rest of the house is cold.
posted by SpecialK at 2:31 PM on December 6, 2007

Actually, the slots at the bottom of the glass walls in the cube look air-curtain-ish to me, but I think they probably have more to do with the cooling system than with heating.
posted by LionIndex at 3:19 PM on December 6, 2007

Maybe their heating system also pressurizes the air so that it is as dense as the cold air outside. Okay, probably not, but it's one possible explanation.
posted by gauchodaspampas at 3:35 PM on December 6, 2007

Maybe their heating system also pressurizes the air so that it is as dense as the cold air outside. Okay, probably not, but it's one possible explanation.

No, it's really not possible. "Pressurizing" the air would only force it out through the open doors quicker.
posted by LionIndex at 3:53 PM on December 6, 2007

Now I'm interested to find out whether there are any perceptible drafts near the door. Most atmospheric heat exchange in rooms and other enclosed spaces involves convection currents. Since the door isn't at the top of the cube, rising warm air won't be especially forced outside; the main current will simply rise inside the cube to the top. Given that the damn thing is made of glass and is ginormous, I bet the store is losing a significant amount of head through conduction. The most significant actual exchange of air at the door is probably the currents people entering and exiting induce by pushing the air along with their bodies; that amount isn't going to increase that much just because the doorframe is actually open. (Unless, that is, the seductively open doorway draws more people into the store.)

Neat question, cgs!
posted by grimmelm at 6:15 PM on December 6, 2007

hey grimmelm- i hear you regarding the height of the cube pulling the air up... however, if the air outside is so much colder than the air inside, won't the door (despite being positioned at the bottom of the cube) still suck the air out?

w/ the air inside being like 60 degrees different, i picture it like a hole in a balloon...
posted by cgs at 9:22 AM on December 7, 2007

LionIndex: I find it hard to believe that a store, even an electronics store, with a ceiling that effectively has a large hole in it open to the Manhattan winter, would not require any heating at all.

I still suspect that the main intake for the forced air heating/cooling system is located somewhere near the top of that stairwell (maybe the slots LionIndex pointed out) in order to recapture as much of the rising warm air as possible before it escapes through the doorway. Actively removing air in this way would effectively lower the pressure within the cube, bringing it close to the pressure of the colder outside air and preventing a draft. If you wanted to be really slick you could even put electronic barometers inside and outside, and dynamically alter the fan speed to make them match.

You can pull a lot of air out of a space before it causes a noticeable breeze (sucking is more omnidirectional than blowing,) and doing it this way will also capture any air coming in from the street so that it can be run through a filtration system, removing any NYC aromas that might otherwise drift downstairs and spoil the carefully constructed ambiance. It's more expensive, ambitious and prone to failure than just closing the damn door, but this is Apple we're talking about.
posted by contraption at 12:00 PM on December 7, 2007

What slots? I see slots for the glass panes, and a little row of lights, but absolutely nothing recognizable as ventilation on the inside of the cube. The grid on the outside appears to be drainage.


Didn't notice before, but the link to the Apple gallery I posted earlier gives you a virtual look into the entryway, as though you're on the landing between the closed outer doors and the elevator.

If anyone really wants to do the math, here are some of the details from the designer's company:

The 10m (32.5 ft) glass cube entrance stands on the refurbished plaza and appears to punch up through the sidewalk. It is structured with multi-laminate glass beams and columns stabilised by the glass walls, all connected by discrete stainless steel fittings. The roof beams have a lamella-type structural arrangement such that each beam spans between the centres of the two adjacent orthogonal beams. At the centre of the roof hangs an 2.4m (8ft) illuminated Apple Logo.

And more about the Apple's patented glass staircases.
posted by zennie at 1:02 PM on December 7, 2007

zennie: in this photo and in the QuickTime panorama you linked, narrow black slots are visible between the rows of recessed lights and the outer glass walls.

Also, that panorama clearly shows a set of glass doors, which I now realize can be seen propped open in other pictures as well.
posted by contraption at 1:47 PM on December 7, 2007

Ooh... yo'ure right, contraption. Too much glass for my depth perception skills!
posted by zennie at 1:56 PM on December 7, 2007

I still suspect that the main intake for the forced air heating/cooling system is located somewhere near the top of that stairwell (maybe the slots LionIndex pointed out) in order to recapture as much of the rising warm air as possible before it escapes through the doorway. Actively removing air in this way would effectively lower the pressure within the cube, bringing it close to the pressure of the colder outside air and preventing a draft. If you wanted to be really slick you could even put electronic barometers inside and outside, and dynamically alter the fan speed to make them match.

I kind of doubt that those slots would lead to return ducts--they're just too small. Return ducts and registers are usually monstrous, and with the amount of air they'd have to be sucking to make any difference at the glass walls, slots that size would start whistling. Seriously. The slots are, however, perfectly located for air conditioning, which is typically located in front of windows just like that.

I'd still bet on the "heating costs are much less than you think for crowded buildings" theory.
posted by LionIndex at 5:39 PM on December 19, 2007