
MIT Wristband Could Make Air Conditioning Obsolete - petercooper
http://www.wired.com/design/2013/10/an-ingenious-wristband-that-keeps-your-body-at-the-perfect-temperature-no-ac-required/
======
sn41
I live in a small "flat" in India. Without A/C in the summer (only at night),
our consumption is ~200 KWhr per month. With A/C only in one room for
something like 4-5 hours per day, it shoots up to ~500 KWhr per month. Indians
switching to A/C on a big scale will be a disaster for the world.

I believe that the answer lies in architecture, not in more energy-intensive
devices which may or may not actually work (this one fools the body - that
could be catastrophic, increasing chances for a heat stroke). India was always
hot - but older buildings used to be built (1) with high ceilings (2) with
cross-ventilation.

[http://www.architecture.com/SustainabilityHub/Designstrategi...](http://www.architecture.com/SustainabilityHub/Designstrategies/Air/1-2-1-3-naturalventilation-
crossventilation.aspx)

This contrasts with buildings in cold countries, where buildings are insulated
against winter. In the name of "better" buildings, Indians are switching to
sealed buildings working with Central A/C. Blind imitation.

On the other hand, there were builders committed to "environment-friendly",
low cost buildings (not the modern scam of "green buildings", which are
actually _more_ expensive.) Laurie Baker in South India was one - a real
unsung, and now forgotten hero:

[http://en.wikipedia.org/wiki/Laurie_Baker](http://en.wikipedia.org/wiki/Laurie_Baker)

[http://www.hindu.com/folio/fo9908/99080300.htm](http://www.hindu.com/folio/fo9908/99080300.htm)

~~~
saljam
What's particularly sad is how the vernacular architectural features, which
have evolved over thousands of years to deal with these issues, have been
largely abandoned over the 20th century. Only to be replaced by ugly concrete
buildings and AC units. These include the Malqafs[1] (windcatchers) once found
all over Arabia, Egypt, and Nubia. Also the use of underground streams[2] to
cool buildings. And generally not building huge south-facing glass windows
when you live in a place that reaches 45°C in the summer...

Also, a personal architect-hero of mine is Hassan Fathy[3]. This man inspired
generations of environment-friendly architects.

[1]
[http://en.wikipedia.org/wiki/Wind_tower](http://en.wikipedia.org/wiki/Wind_tower)
[2]
[http://en.wikipedia.org/wiki/Qanat#Cooling](http://en.wikipedia.org/wiki/Qanat#Cooling)
[3]
[http://en.wikipedia.org/wiki/Hassan_Fathy](http://en.wikipedia.org/wiki/Hassan_Fathy)

~~~
bane
It's sadly part of a growing faddishness with "Western" technology and
developments. I find it quite sad because the local solutions are often quite
elegant.

In Korea for example, they have clever traditional windows that open like
normal windows, but also draw up completely and hang from the ceiling, turning
your house or other structure into a pavilion. Large roofs provide lots of
shade.

In the winter, you literally light a fire under the floor of the building and
radiant heat warms the entire structure.

Some of these things carried over into the modern age, but many sadly did not.
They're remarkably comfortable and energy efficient dwellings.

[http://www.youtube.com/watch?v=kJ21SchGpsQ](http://www.youtube.com/watch?v=kJ21SchGpsQ)

~~~
ceejayoz
> In the winter, you literally light a fire under the floor of the building
> and radiant heat warms the entire structure.

Yeah, and occasionally die of carbon monoxide poisoning.

[http://www.ncbi.nlm.nih.gov/pubmed/22948168](http://www.ncbi.nlm.nih.gov/pubmed/22948168)

------
downandout
I live in Las Vegas. Deaths occur in homes here every summer due to AC system
failures (usually among the elderly and children that cannot easily leave and
go to a cooler place). Many more do not die because they realize it is getting
too hot and do whatever they have to do to get to a cooler place. A device
like this that changes your perception of whether it is hot or cold would
likely do more harm than good here and in other extreme climates. I can see
huge product liability lawsuits in their future.

~~~
chrisgd
I don't mean any disrepect, but this comments seems a lot like the comments on
the recent "Show HN: Dropbox" page from 2007, you are trying to think of a way
this would fail, rather than potential uses.

Solving the issue of access to air conditioning or heating for the poor is a
completely seperate issue than providing a solution to help lower our use of
A/C or heating.

~~~
j_s
So tempted to go meta on how your comment seems like a lot of comments ever
since the recent re-discussion of the "Show HN: Dropbox"... where were the
nay-nay-sayers before 2 weeks ago?

Feedback such as the OP is beneficial to product development as a reminder to
cover every aspect of potential improvement and protection from liability.

~~~
chrisgd
Feel free to go meta, don't hold back. Real feedback related to improvement
and liability protection would stem from improving on the leads into the
device to prevent electrocution or something similar.

OP's comment could be said of fans not doing enough to prevent deaths during
extreme heat waves as well since the fan helps you feel cooler, but it may not
be enough to overcome ambient temperature.

~~~
slavak
A fan doesn't help you _feel_ cooler, it actually helps cool your body by
increasing air circulation and thus improving the rate of heat exchange. This
device, OTOH, is explicitly intended to trick your body, potentially
compromising its internal defenses against overheating.

OP's comment wasn't about being negative or knocking someone else's hard work;
[s]he's simply pointing out what appears to be a very real safety concern in
the system that needs to be addressed. Your suggestion that preventing
electrocution on a device presumably powered by batteries is more safety-
critical than this seemingly very real health risk that affects large parts of
the world is, quite frankly, ridiculous.

------
davyjones
I wonder how changing the perception actually impacts the body's thermostat. I
would gladly sweat and let my body do its thing than have a heatstroke while
being tricked into thinking that it is relatively cool outside.

~~~
kohanz
Agreed. I'm very wary about the affects of "tricking" a vital system of my
body for long periods of time.

~~~
petercooper
Like drinking a coffee every day.

~~~
WalterSear
There's been a bit of a precedent for that though, so we know how it works.

------
officemonkey
I originally read this as "Alternating Current" and I thought "Oh Gee, not
this shit again."

[http://en.wikipedia.org/wiki/War_of_Currents](http://en.wikipedia.org/wiki/War_of_Currents)

~~~
tokenadult
I read the headline as "alternating current" also. Usually, engineers in the
United States abbreviate "air conditioning" as "A/C," where the slash, used
contrary to the usual usage of slashes, distinguishes one familiar
abbreviation from another. I'm surprised the Wired editor didn't catch the
ambiguity.

------
nkcmr
At first I thought MIT had made AC Power Currents obsolete. An audible "no
way!" followed shortly after.

~~~
randomdata
I had the same thought, then wondered, upon seeing the title image, why anyone
would want to pass AC current through their wrist in the first place.

------
optymizer
I like the idea of cooling people as opposed to whole buildings, but I don't
like that this isn't actually decreasing your body's temperature, it just
'tricks' you into thinking it's colder/hotter outside. Perhaps it'll pave the
way for clothes that can become cool or hot, depending on the temperature
outside. I'd be very interested in those.

~~~
dannypgh
We're warm blooded. If you want to decrease your body's temperature, death is
probably the way to go.

We don't feel warm because our core temperature is above 98.6, we feel warm SL
that we are aware that we're having to work harder (typically through sweat)
to stay at 98.6.

Likewise, it seems like you could make this safe if you could measure or
estimate the user's core temperature. Should it deviate significantly from
normal, shut the device off.

~~~
Daniel_Newby
It's considerably more complicated than body temperature and sweating.

The body has ways of generating heat. If they do not turn off fast enough when
the A/C fails, you get hot. It is entirely possible that this device could
help elderly people in A/C failure, by forcing their bodies to adapt to
variability instead of constant cool air.

Likewise, sudden heat will cause the skin to flush and draw a great deal of
blood[1]. This imposes a greater workload on the heart and results in shock if
the heart cannot keep up. Constant exposure to heat, as with this device,
should force the heart to gradually strengthen as the hot season builds,
increasing heat tolerance. Likewise, variability should strengthen the heart.

[1]If you ever have to enter a machine room with failed A/C, where the heat
index is above body temperature, bundle up in heavy winter clothes over your
whole body. Otherwise a runaway flushing response will draw heat into your
body and kill you.

~~~
spbaar
As someone who doesn't want to die, could you elaborate? What temperatures are
you talking about that would cause that?

~~~
Daniel_Newby
I am not an expert.

This page[1] says " If the dry bulb temperature is higher than 35°C (95°F),
the hot air passing over the skin can actually make the worker hotter. When
the temperature is more than 35°C and the air is dry, evaporative cooling may
be improved by air movement, although this improvement will be offset by the
convective heat. When the temperature exceeds 35°C and the relative humidity
is 100%, air movement will make the worker hotter. Increases in air speed have
no effect on the body temperature of workers wearing vapor-barrier clothing.
".

[1]
[https://www.osha.gov/dts/osta/otm/otm_iii/otm_iii_4.html](https://www.osha.gov/dts/osta/otm/otm_iii/otm_iii_4.html)

------
georgemcfly
No it couldnt. Air Conditioning is not just about temperature but also
humidity, which this doesn't address. I think room fans would still be
necessary to keep the air moving as well. Plus, could tricking your body into
thinking its cooler than it actually is be dangerous? Make sure people don't
wear it while doing vigorous physical activity in the summer heat.

~~~
benjamincburns
I believe the idea is not that it's a nervous system trick, but by heating or
cooling a part of the body with high blood flow which occurs near the surface
of the skin, you're actually going to impart a meaningful change on overall
body temperature. Hospitals already do this for patients with
hypo/hyperthermia. This could be monitored/regulated with a second band worn
on the upper arm near the armpit which measures body temperature directly.

The question is more one of how much of an actual change can they impart (and
under what circumstances?) given the size limitations of something like a
wrist strap. My hunch is that this would need to be a fairly large system
(including its power source) to have a meaningful impact outside of sedentary
activity in an environment which is mildly under/over temperature. So good
news for people who get chilly working long hours in their cold offices (which
is a completely viable market), but not for runners looking to shed gear.
Maybe there's something there for cyclists though, but only if they're willing
to put up with a wheel generator.

Also, humidity impacts comfort largely because of its impact evaporation
rates. Reducing body temperature reduces the rate of perspiration, in turn
reducing the impact of humidity. You're right that it won't eliminate the
effects of very high humidity, but it would reduce them.

~~~
ogig
>I believe the idea is not that it's a nervous system trick, but by heating or
cooling a part of the body with high blood flow which occurs near the surface
of the skin, you're actually going to impart a meaningful change on overall
body temperature.

From the article i understand that it is a nervous system trick: "The research
suggested that anything with a temperature change greater than 0.1 degree
Celsius per second would produce the effect".

~~~
benjamincburns
Ah... I just reread, and you're correct. Apparently I shouldn't post to HN
while groggy...

------
ajtaylor
My body naturally gets very warm, very quickly, with very little exercise. If
they can make this work, I might actually be able to wear a suit all day!
Luckily I don't need to but that's beside the point.

Assuming they can get the size and look sorted so the average consumer doesn't
become a social pariah by wearing one (calculator watches come to mind), I
wonder how this is powered? And more importantly, would it last for 8-12 hours
on a charge?

~~~
nodata
Isn't this related to fitness? If you're physically fit you don't get hot so
quickly.

~~~
nrivadeneira
I haven't looked into any research about this, but anecdotally I find this to
not be true. Having peaked at 215 lbs. and ~12% body fat at 5' 11", (I'm now
closer to 195 lbs. and ~10% body fat) I'd say that I'm in the top 1% in terms
of muscle mass. I am often very hot. My theory is that because of the added
muscle mass (which requires much higher food intake), I'm metabolizing food at
a higher rate and thus generating more heat. I don't know if this is actually
the case, but it's my theory.

This may not be the case for people who are fit in a more cardiovascular
sense.

------
noptic
Interesting article - awfull title

The device can make you feel a bit better but it can NOT replace an AC.

It was never designed to replace an AC.

If this was up for purchase i would get one especialy because it is portable
and maybe it can be coupled with additional technology (measure blood preasure
, acceleration, rfid access tags,...). People have been wearing wrist bands
for ages (and even used them as currency) so it seems a good position for a
gadget.

~~~
petercooper
_Interesting article - awfull title_

Unfortunately it's the modern media's job to give things catchy titles so they
do well on the social media rounds. A lot of excellent stuff fails to do well
on HN because it hasn't got the right title (I'm an HN firehose dweller so I
get to enjoy a lot of the hidden gems :-)).

Indeed, I'm pretty sure there's room for an "off HN" type site that solely
focuses on the best HN submissions that didn't make it for whatever reason.

------
bagosm
Thank you MIT for this opportunity to be found frozen to death and smiling
happily

------
nathas
Heh, I tackled the same problem a few years back in college, but with robotics
and computer vision. I prefer this approach.

~~~
stedaniels
You made a robot that followed you around and fanned you?! Very impressive, is
the source on GitHub? ;-)

~~~
nathas
It actually detected any life forms in a room with medical grade temp sensors
coupled with a kinect and then found 'hot spots'.

It wouldn't follow you (although that could be done); it was stationary and
one of the big requirements was safety (don't want a robot arm slapping you in
the face while coding).

Unfortunately no, the source isn't on github, although I should put it up
there.

------
ctz
Peltier heat pumps are inefficient; typically wanting a whole bunch of watts
for achieving a small temperature gradient. So I'm wondering about the
practicalities of powering this thing such that it could be worn as a personal
item.

~~~
vidarh
That doesn't seem to be much of a problem as the point is not to _actually_
cool you, but to apply a temperature change of a fraction of a degree to a
tiny part of skin to trick you into _feeling_ colder.

------
randywaterhouse
This is interesting, and in my opinion definitely deserving of the prize they
got for it.

But I think it's real value (in contrast to "replacing A/C") is in developing
markets, where a little wristband could really improve quality of life (in the
sense that one isn't sweating to death in their shanty-town hut). Not only
could it improve QoL, but it would also be much cheaper to install than a
central air unit, and also much more feasible: everyone has a wrist, not
everyone has an insulated home with consistent electrical service that could
provide the power for a central air unit. Cool stuff!

~~~
rytis
But that wristband doesn't actually reduce your body temperature, sweating
does. Unless I'm missing something obvious here??

------
ChuckMcM
I think the article gets it wrong. Sorry.

Having your body think that it is comfortable, especially when the environment
is hazardous, would be a lose. Like filtering out the sound of smoke detectors
so you can sleep easier.

That said, this would be quite useful in office situations like ours where
some people whine that 75 is too hot and other complain that at 70 they need
mukluks. In that situation where the office is actually at a livable
temperature, if we could adjust individual perceptions to be comfortable then
it would be quite useful.

------
robomartin
On a tech front, it's an interesting use of a peltier junction device. They
are horribly inefficient yet really interesting. It is, effectively, a heat
pump. It will make one side colder than the other. And that part is key. You
must take away energy on the hot side or the entire thing will get hotter and
hotter. Without heat removal on the hot side it would get hot enough to burn
you very quickly. The article says they are using pulsed heat which might
presumably deal with this issue.

As others mentioned already, tricking the body like this could have negative
consequences. I wonder if any studies exist on this (ice bags on the wrists or
some such thing).

It brought back memories of going sculling at the peak of winter. Due to the
danger of falling into extremely cold water [0] I experimented with wearing a
kayaker's dry suit. It worked reasonably well. A surprising find was that
wearing a wool head-cap made me overheat. It was really amazing how quickly
this would happen too.

I can see this MIT gizmo having some effect because our skin is sensitive to
heat flow, not absolute temperature. Not sure I'd like to trick my body that
way though. What are the consequences of messing with the mechanism that
maintains proper thermal balance?

[0] There have been many incidents of rowers drowning in cold water within
swimming distance of the shore. Swimming in cold water while wearing thin
clothes and your heart pumping hard due to the physical exertion of rowing is
extremely dangerous because hypothermic effects can be greatly accelerated.
Even accomplished swimmers can drown fifty feet from shore.

------
paul_f
Hopelessly naive. An air conditioning system is used to cool spaces yes. But
where I live, it is just as important to lower the humidity. This device will
not help with that.

~~~
fsckin
Naive? This is a proof of concept, and it makes people feel cooler.
Dehumidifiers use _significantly_ less power than cooling. The peltier they're
using with a 30% duty cycle would require about 30W per person.

Dehumidify a typical room: 500W Cooling a typical room: 2000W

------
ianbicking
This is like a placebo, intended to trick you into perceiving cold or less-
cold when it isn't there. But when there's a real matter at hand placebos only
work very temporarily – then eventually reality catches up to you. So if it's
actually hot, and my body needs to react to that to regulate my temperature,
this doesn't change that. But I suppose it would let you turn the temperature
up a couple degrees.

~~~
donutdan4114
I don't think it's that much like a placebo. A placebo literally has no
effect. This device actually has a cooling/heating effect that your body just
perceives as being greater than it actually is.

------
cpncrunch
Am I the only person who is skeptical about this? I don't see any published
research. It sounds like their device just temporarily distracts you from
noticing the heat or cold, in the same way that poking needles into random
parts of your body distracts you from pain (aka acupuncture). I would like to
see a placebo-controlled study where they having people sitting in a 35C room
all day.

------
ealloc
Interesting idea. I though it was going to be more like the 'cooling glove'
[1] which actually cools you down, rather than just making you think you're
cooler. Hairless skin on the hands and face has blood vessels close to the
surface, and cooling those parts is proposed to quickly cool your blood and
core temperature.

It looks like the energy and space requirements for such cooling glove are too
large to make it portable, however, and it also doesn't work much better than
simply holding an ice pack! So, for portable devices, it seems like at most we
can only trick ourselves into thinking we're cool.

[1][http://www.slate.com/articles/technology/future_tense/2012/0...](http://www.slate.com/articles/technology/future_tense/2012/09/avacore_technologies_magic_cooling_glove_from_stanford_won_t_transform_your_workout_.2.html)

------
Morgawr
At first I thought this thing hooked into your blood flow to actively cool
down your blood, like watercooling does for computers, it would've been a much
cooler idea (no pun intended)

EDIT: fixed autocomplete phone typo

------
uptown
Reminds me a little of this, though this uses a constant fan rather than a
pulsing schedule of cooling jolts. I've used one before, and it works
surprisingly well for such a low-tech contraption.

[http://www.sharperimage.com/si/view/product/CoolWare-
Persona...](http://www.sharperimage.com/si/view/product/CoolWare-Personal-
Cooling-System/100849)

------
DavidWanjiru
Unless my high school biology teachers lied to me, feeling hot or cold is not
a mere perception; it's homeostasis, a complex mix of body temperature
control, early warning system and pre-emptive shutdown all rolled into one. I
don't see how useful tricking this system is, and I also fear it is dangerous
to do it, if at all it's possible to successfully do it.

------
erikb
I'd say the biggest market now or at least 10 years later will be China. They
don't use them just for cooling but also for heating because the southern half
of China has no public heating system. But that's just my instinct. Might be
completely off and people in Brazil might actually use them much more.

------
ogig
Body temperature comfort is subtle. Is not the same 24ºC with an AC than by
the sea shore, under a tree shadow with warm, slow wind.

For some reason i don't think a heat sink tricking my physical feelings will
do for my quality standards regarding temperature control. I already detest
AC, as in, I can't stand in ACed places.

------
Zak
I don't imagine this making AC obsolete. It might marginally reduce demand for
AC, especially in cooler climates where AC might only be used occasionally if
installed.

If made in to a product, I expect it to be popular for outdoor use. I find it
appealing enough for that use case that I'm contemplating building one.

------
jagtesh
How does fooling the body into thinking the temperature is higher / lower
affect the real temperature of the body? The article fails to explain that.

This is like putting a frog in gradually boiling water. The frog cannot sense
the increasing temperature, so it stays in the water until its dead.

~~~
mhb
Snopes says the frog jumps out:

[http://www.snopes.com/critters/wild/frogboil.asp](http://www.snopes.com/critters/wild/frogboil.asp)

------
breakbread
Yeah, I definitely don't see this as making AC "obsolete" so much as perhaps
raising the threshold of when you turn on the AC. As a resident of the Deep
South, this could potentially make sitting outside during the height of the
summer a more pleasant experience.

------
Mustafabei
This is not news. Sharper ımage already has a product like that in the market
for years.

[http://www.sharperimage.com/si/view/product/CoolWare-
Persona...](http://www.sharperimage.com/si/view/product/CoolWare-Personal-
Cooling-System/100849)

------
euroclydon
So it's a trick? I'd rather see a thermal device that makes contact with a
larger surface of one or more of my body's high-blood-flow areas and actually
cool or heat it.

I've found it efficient to cool or heat myself by letting cold or warm water
run over my hands.

~~~
joezydeco
There's a similar technology already being tested on athletes:

[http://corecontrolcooling.com/](http://corecontrolcooling.com/)

------
pawn
Cool idea. If you attached a wristwatch to the outside face, I think that'd
help it take off.

------
moocowduckquack
Don't make AC obsolete, make it as efficient as you can and then power it from
solar. The kind of people who will wear a heat pump on their wrist to try and
save electricity, are not the people who run the most AC units.

------
g8oz
Anyone had experience with Phase Change Material (PCM) clothing? Here is one
supplier:
[http://www.outlast.com/en/technology/](http://www.outlast.com/en/technology/)

------
vayarajesh
I think it is the concept "anything with a temperature change greater than 0.1
degree Celsius per second would produce the effect" is very interesting.
Building a device to do that is not a big deal..

------
dharmach
I have nothing against all the energy efficiency development however many
articles display a tone that everything was going well before but now due to
emerging countries we are facing this havoc. Pathetic.

------
bjoernw
Hasn't there been one of these in SharperImage and Skymall for years?

------
ajb
This may not replace AC, but I wonder if (in colder countries) it would help
with dieting. Want to lose weight, just turn your thermostat down by a degree
and use this device to help you adapt to it.

~~~
eru
Are there any indications that turning thermostats down (or up) impacts
weight?

~~~
evacuationdrill
Maintaining body temperature takes energy, so being in a cooler environment
would help, but it would be minimal, I'm fairly sure. Air has a much lower
specific heat than water, and I remember reading a reddit discussion about
drinking ice water all day to lose weight versus room temperature water. I
don't remember what the result was, but it didn't take as many calories to
heat the water as you'd think.

~~~
InnocentB
Well a calorie is the amount of energy to raise a gram of water by one degree
Celsius, so if you're drinking 2 litres of water a day and it's 0 degrees vs
20 degrees, you'll burn around 20,000 calories a day from the difference.

Note though that that's calories, and not kilocalories, which is what we
generally talk about for dietary purposes. So ~20kcal a day, which would
represent about a 1% change for the average person. Not a huge gain.

~~~
eru
Also, people might just eat a spoonful of more food, if they need 20kcal more
per day.

------
mgraczyk
How about a solar powered thermoelectric mesh woven into a short that cools my
body off? Can I have a wired article if I build one, even when it doesn't
work?

------
stevewilhelm
If the MIT team had just printed their device on a 3D printer, their article
would have knocked the Nexus 5 release off the front page.

------
richiverse
I read this as MIT wristband would make 'Atlantic City' obsolete. Perhaps some
kind of card counting helper. ;)

~~~
frezik
MIT has worked on that as well.

------
gpvos
If your body continually feels like you are jumping into cold or hot water,
wouldn't that induce stress?

~~~
Oculus
I think that was a layman way of explaining the technology rather then how you
actually feel.

------
peter303
It could kill people. If you dont thermoregulate properly then you will die of
hyperthermia.

------
swamp40
Those wires are going to cramp some people's style, though.

------
ChristianMarks
Can't wait for the FDA trials.

~~~
andyakb
Why would their be FDA trials for this?

~~~
ChristianMarks
It could be classified as a medical device under FDA
regulations:[http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidanc...](http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/Overview/ClassifyYourDevice/ucm051512.htm)

------
jokoon
so if I have such a copper heat dispenser I got from taking a laptop apart, I
can feel cool ?

~~~
bnegreve
It's not just a heat dispenser, it's a peltier [1] a device that can produce
cold from electricity.

[1]
[http://en.wikipedia.org/wiki/Thermoelectric_effect](http://en.wikipedia.org/wiki/Thermoelectric_effect)

~~~
AUmrysh
Well, it can transfer heat when electric current is applied. They used these
for processor coolers in the 90s, I remember my father had one and it broke
one day and so his processor let out the blue smoke.

~~~
bnegreve
I had one as well. Same experience with a brand new AMD Athlon XP 1800+.

------
brador
I invented this exact concept 2 months ago. Heat sink on a wrist band. I did
nothing with it, good luck to these guys.

