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Homebrew Air Conditioning for Under $25

timothy posted more than 9 years ago | from the ice-is-free-after-all dept.

Hardware Hacking 832

inkey string writes "Summer has arrived, and I've been busy slowly overheating in my student house without central air. I decided to put my thermodynamics classes to work however, and produced this ~24$ homebrew air conditioner. It'll cool a room to a comfortable level in 15-20 mins, and will run for a few hours on a garbage pail full of water. It's cheap, environmentally friendly (just fire the waste water off to your garden), and makes a good one hour project for a quiet evening."

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Netcraft Confirms It... (-1, Flamebait)

Anonymous Coward | more than 9 years ago | (#12807308)

I just heard some sad news on talk radio - Singer/Entertainer Michael Jackson was found guilty in a California court room today. There weren't any more details. I'm sure everyone in the Slashdot community will miss him - even if you didn't enjoy his music, there's no denying his contributions to popular culture. Truly an American icon.

more likely (-1, Offtopic)

Anonymous Coward | more than 9 years ago | (#12807322)

"truely an American pedophile"

Re:Netcraft Confirms It... (0, Offtopic)

failure-man (870605) | more than 9 years ago | (#12807325)

The people who post shockingly-offtopic stuff as AC . . . . I've never understood them.

Re:Netcraft Confirms It... (-1, Offtopic)

Hostile_Monk (890973) | more than 9 years ago | (#12807329)

Ummm...no? Try not guilty on all 10 counts. Anyway, that's way offf topic. This sounds like a cool project, I'll give it a try! =]

Re:Netcraft Confirms It... (-1, Offtopic)

iamtom (891881) | more than 9 years ago | (#12807348)

No. Not Guilty.

stop slashdotting please! (-1, Offtopic)

Anonymous Coward | more than 9 years ago | (#12807314)

stop reloading the site on purpose.
sheesh.. 0 comments and slashdotted.

He should have built another one ... (0)

Anonymous Coward | more than 9 years ago | (#12807317)

... to cool the China Syndrome that was his server!

Its going to be hot soon (5, Funny)

Anonymous Coward | more than 9 years ago | (#12807319)

I hope his server isn't in his room, because all the thermodynamics courses in the world wont teach you about slashdotting.

Re:Its going to be hot soon (4, Insightful)

Anonymous Luddite (808273) | more than 9 years ago | (#12807355)

>> I hope his server isn't in his room

It's actually a University of Waterloo server. I'm sure the sysadmin is gonna love this sudden DDOS.

Ha Ha (0)

Anonymous Coward | more than 9 years ago | (#12807320)

You slashdotted yourself...

And you can place it... (3, Funny)

peter_gzowski (465076) | more than 9 years ago | (#12807324)

...right next to your webserver.

Re:And you can place it... (4, Funny)

Tackhead (54550) | more than 9 years ago | (#12807376)

> ...right next to your webserver.

By placing the garbage pail full of water in your garden, you ensure that within five minutes of the link going live on Slashdot, you'll have several gallons of piping-hot vegetable soup!

Re:And you can place it... (2, Funny)

Seumas (6865) | more than 9 years ago | (#12807399)

And with the money he saved, he can finally afford a maid.

Slashdoted already? (1)

homerito (591887) | more than 9 years ago | (#12807331)

Man that wsas fast.... any mirrors?

Re:Slashdoted already? (0)

Anonymous Coward | more than 9 years ago | (#12807358)

You never need to ask for a mirror. http://www.mirrordot.org/ [mirrordot.org] is all you need

Re:Slashdoted already? (1)

toQDuj (806112) | more than 9 years ago | (#12807371)

damn.
went down too fast to mirror. must be quicker than its shadow, that server.

mirrordot (5, Informative)

kryogen1x (838672) | more than 9 years ago | (#12807394)

Thank you mirrordot. [mirrordot.org]

Air Conditioning for $1500/month (4, Funny)

Geekboy(Wizard) (87906) | more than 9 years ago | (#12807332)

Move to San Francisco.

Today it hit 70F, and the news stations are talking about "the heatwave of 2005".

Re:Air Conditioning for $1500/month (5, Funny)

failure-man (870605) | more than 9 years ago | (#12807390)

Whiny bastard Californians . . . .

I repeat my assertion that since 31 Octobher, 1995 (the last Oingo Boingo show) the state has had no redeeming value.

Re:Air Conditioning for $1500/month (-1, Troll)

Anonymous Coward | more than 9 years ago | (#12807415)

Isn't that where all the gays live?

Re:Air Conditioning for $1500/month (0, Offtopic)

Seumas (6865) | more than 9 years ago | (#12807436)

Hey kids! Let's all go down to South California for the day! Michael Jackson is throwing a pool party and we can all skinny dip in his pool! And if we're lucky, he might share some jesus juice and duck-butter with us at the end of the day!

Re:Air Conditioning for $1500/month (2, Funny)

MrAnnoyanceToYou (654053) | more than 9 years ago | (#12807444)

Californians buy our water, we don't mind.
Californians raise our power rates by buying ours, we don't mind.
Californians make more money, we don't mind.
Californians drive up here and buy houses at HUGE prices, we don't mind.
Californians steal our nice Oregon springs leaving us more drenched than usual, we want better environmental laws or blood.

Re:Air Conditioning for $1500/month (3, Funny)

kfg (145172) | more than 9 years ago | (#12807446)

Mark Twain once famously noted that the worst winter he ever spent was his summer in San Francisco.

KFG

At first, it looked like a great story... (1, Insightful)

rd4tech (711615) | more than 9 years ago | (#12807333)

From the article: "cheap, environmentally friendly".
From who.int: "Billions without clean water": link [who.int]
The guy has no clue how lucky he is in his "student ghettos don't have gardens" home to have clean water to throw around.

Re:At first, it looked like a great story... (0)

Anonymous Coward | more than 9 years ago | (#12807352)

You have no clue how lucky you are to have a pc with internet to bitch about some guy using clean water to cool his dorm.

Re:At first, it looked like a great story... (0)

Anonymous Coward | more than 9 years ago | (#12807389)

You have no clue how lucky you are to have hands to type on your pc about a guy who has no clue how lucky he is to have a pc with internet to bitch about some guy using clean water to cool his dorm.

Re:At first, it looked like a great story... (1)

redfieldp (549286) | more than 9 years ago | (#12807464)

There's no reason you couldn't use dirty water, as long as it was cool. Or not use water at all, for that matter - you could use cool urine. Just because he HAPPENED to use clean water, doesn't mean it's required...

Re:At first, it looked like a great story... (1)

MrAnnoyanceToYou (654053) | more than 9 years ago | (#12807392)

That's exactly what I was thinking. For an extra 20$, I'm sure you could get a bike-pump powered valve that would run the water through the tubing, a lid for the garbage can, and some duct tape to seal the garbage can in the basement so nothing got into it.... Enough extra tubing, and you're going to have a closed loop.... That way you don't even need to fill the garbage can with ice water regularly... You do have to pump up the thing every once in a while, but you never have to suck on the tube....

This is probably MORE expensive due to having to refridgerate the ice and pay for all the water.

Re:At first, it looked like a great story... (1)

malfunct (120790) | more than 9 years ago | (#12807424)

Not only this, if the freeze is in the same room as his "air conditioner" he is actually warming the room up by freezing the ice.

Re:At first, it looked like a great story... (1)

Darth Liberus (874275) | more than 9 years ago | (#12807434)

I think I'm going to turn on the tub and let the water flow right into the drain for a few hours and think about how lucky I am.

Re:At first, it looked like a great story... (1)

temojen (678985) | more than 9 years ago | (#12807454)

This design should work just as well with filtered brackish water.

damn (1)

danhm (762237) | more than 9 years ago | (#12807335)

He should have cooled his server with a few of those...

Minor nit (4, Insightful)

Roadkills-R-Us (122219) | more than 9 years ago | (#12807336)

Just great, assuming you have an infinite supply of free ice water. Add teh cost of the ice machine, and it costs a bit more than $24.

Re:Minor nit (2, Insightful)

kiatoa (66945) | more than 9 years ago | (#12807423)

Exactly, I think the financial folks talk about trading off initial costs for long term running costs. Someone is footing the bill on the electricity for making that ice. BTW the overall energy efficiency of this setup is substantially lower than the equivalent decent window air conditioner (COP of the air conditioner is much higher than the COP of an ice maker due to smaller delta T iirc).

Re:Minor nit (1, Interesting)

bhtooefr (649901) | more than 9 years ago | (#12807441)

Hmm... Gallon jugs of water in the freezer?

Still uses energy, mind you, but that takes care of the ice water.

Also, I thought that routing the water OUT was a bad idea. Why not catch the water in another bin, or in jugs, and freeze that? Makes SO much more sense...

Re:Minor nit (1)

dreamchaser (49529) | more than 9 years ago | (#12807463)

Seriously, especially since for about $120 you can get a low end window unit [thebuzzelectronics.com] .

Re:Minor nit (1)

dreamchaser (49529) | more than 9 years ago | (#12807488)

Wow, I should have looked harder. Here is one that would cool a small dorm or apartment and it's only $76 [aafeders.com] .

Re:Minor nit (1)

Tumbleweed (3706) | more than 9 years ago | (#12807499)

Many apartment buildings won't allow you to hang those things out the window, unfortunately. I have, however, seen some neat upright models at Fry's where you route a round plastic duct out the window. It's definitely on my list...

Re:Minor nit (5, Insightful)

LurkerXXX (667952) | more than 9 years ago | (#12807485)

Why you can get the ice out of the freezer/refrigerator in your kitchen. It just costs a little electricity to make. It makes it by using a condensing coil to use a gas medium to pump heat from the freezer are to coils on the back of the fridge which... then heats the room you are trying to cool. DOH!

mirror? (0)

Anonymous Coward | more than 9 years ago | (#12807337)

anyone..anyone.. it's waayy to hot in my apt. and I really want to implement this ASAP!!!!

DOA (2, Informative)

AmigaAvenger (210519) | more than 9 years ago | (#12807338)

I'm a student, with limited funds and a cheap house without air conditioning. To avoid dying this summer, I've built a primitive air conditioner. It's a basic heat pump, using water as the medium. You'll probably need to fiddle a bit with the dimensions of the supplies based on your resources and preferences.

Materials:

Salvage from around the house a:

* large fan
* garbage can

Grab from Home Depot:

* 25 feet of 1/8 inch outer diameter (OD) copper tubing (~ $14)
* 20 feet of 1/8 inch inner diameter (ID) vinyl tubing (~ $6)
* a package of zipties (~ $3)
* 2 small hose clamps (~ $1)

Here's the basic setup. The garbage can is filled with ice water, which is then fed by gravity (a siphon) through the copper tubing coiled along the back of the fan. The hot air passing through the tubing warms the cold water, cooling the air. Waste warm water is then pumped outside.

The system will cool an average room to a comfortable level in approximately 15-20 minutes. Depending on flow rate, a full bucket of water will last approximately 1-3 hours.

It doesn't rip quite as hard as central air, but for less than $30 CAD I'm not complaining.

The main factor affecting the performance is the temperature of incoming water. Cool water will work, but ice water will result in a cooler room, quicker.

Here's what the fan looks like from the back. The biggest issue in construction was uncoiling 25 feet of copper tubing in a 15 by 20 room. Just be patient and don't attempt to bend the copper too severly, it'll fold over on itself and you've effectively chopped your nice copper tubing in two.

When coiling the copper into a spiral on the back of the fan, I started in the middle and put zipties every 15-30 cm (6-12 inches). Use your discretion, you want to preserve the spiral shape and keep the tubing as close to the metal mesh as you can. If you're a bit crazy, sand the paint off the back to improve heat transfer from the metal mesh.

It doesn't really matter how it looks as long as it's reasonably spaced out and consistent. A hint for construction: prebend your zipties into a J shape. Then you can hook them easily in and back out of the metal mesh on the back of the fan. I'd suggest cutting off any extra plastic once you've got them on.

If you look closely, you can see the condensation from the incoming icewater, but no condensation on the tubing leading out. This is perfect, as it means that heat is being transferred from the room to the water.

Once you've got the copper tubing coiled, the rest is easy. Cut your vinyl tubing into 2 pieces, with one about twice the length of the other (one piece 6-7 feet, other piece 13-14 feet).

Attach the shorter piece to the incoming side of the copper tubing. It should slide relatively easily over the copper, but be snug. Attach the hose clamp and tighten. Following a similar procedure, attach the longer piece to the outgoing side of the copper tubing. (I don't believe it really matters whether you feed cold water from the inside or the outside. It's up to you to run some numbers.)

Submerge the shorter end of the vinyl tubing in the garbage can (washed and clean). I suggest weighing down the end of the tube, to avoid it drawing in air and stopping the system. I used twist-ties to attach a thin rock to the end. If you have fishing weights, I would suggest using those.

Next, hang the longer tubing out your window. For the gravity pump to work, the end of the tubing must be below the water level of your garbage can, plus an allowance for head loss in the pipe. Just to be safe, get it as low as you can. I'd suggest arranging it so the waste water will feed into a garden, but student ghettos don't have gardens so in this picture it's being fed into a drain by the basement.

I had to poke a small hole in my screen for this to work.

To get the system started, make sure the vinyl tubing in the ice water is completely submerged. Then, bring the waste water tubing as low as you can and start sucking on the tube. If you've ever siphoned gas you know the drill.

Basically, suck as much as you can. Then plug the end of the tubing with you thumb, and repeat. You're done when you start tasting water. Just let go, and it should continue to flow normally.

Re:DOA (0)

Anonymous Coward | more than 9 years ago | (#12807364)

How about attributing what you quote? A simple "from TFA" would do.

Working Mirror (1, Informative)

Anonymous Coward | more than 9 years ago | (#12807386)

This mirror [lerfjhax.com] has the article text and the pictures that go along with it.

Re:DOA (-1, Flamebait)

Anonymous Coward | more than 9 years ago | (#12807401)

I was suprised to see this was not posted by TripFucker Monkey [slashdot.org] , the karma-whore queen.

To be pedantic... (-1, Redundant)

still_sick (585332) | more than 9 years ago | (#12807342)

This is not an Air Conditioner.

This is an Evaporative Cooler, AKA a Swamp Cooler.

No, it isn't (4, Informative)

Roadkills-R-Us (122219) | more than 9 years ago | (#12807373)

A swamp cooler pulls the air through the actual water. It uses evaporation for the cooling effect. That's rather different than this, which is just a crude radiator. effect.

Re:To be pedantic... (1, Informative)

Anonymous Coward | more than 9 years ago | (#12807378)

Read the article.

It's not an evaporative cooler. Ice water cools a heat exchanger made of copper tubing. Air is forced through the heat exchanger.

Swamp coolers increase humidity. If anything, this is going to decrease humidity due to the slight amount of condensation caused.

Re:To be pedantic... (1)

islandrain (888578) | more than 9 years ago | (#12807381)

I thought a Swamp Cooler was a can of Milluake Light?

Re:To be pedantic... (1)

javamann (410973) | more than 9 years ago | (#12807385)

Now it is not an evap cooler. It is using the 'cooler' water in copper coils to cool the air. The water is emptied outside. Also works well if your put your cold beer in the garbage can full of ice water.

Re:To be pedantic... (0)

Anonymous Coward | more than 9 years ago | (#12807402)

Actually, no, it isn't. A swamp cooler works by blowing air through a soaked pad, evaporating water into the passing air. This works by passing air between (dry) copper tubes full of ice water. Next time, be correct if you want to be pedantic. ;)

Re:To be pedantic... (1)

dioxide (149116) | more than 9 years ago | (#12807406)

This is not an Air Conditioner.

This is an Evaporative Cooler, AKA a Swamp Cooler.


Maybe.. but a far more effective method would be to make a real swamp cooler, and instead of pushing the water through a radiator, use it to wet a filter. Push the air through the filter, and you get a much more efficient evaporative cooler.

Re:To be pedantic... (1)

amliebsch (724858) | more than 9 years ago | (#12807411)

Actually, it's not even that, since the cooling simply comes from the fact that the water is colder than the air to begin with. It's just "blowing air across a cool surface". But with a siphon, to make it all science-y and energy efficient.

Re:To be pedantic... (0)

Anonymous Coward | more than 9 years ago | (#12807442)

Please re-read TFA.

The setup cools by transferring heat to water, then draining the heated water away through a tube. Evaporation is not part of the process.

Re:To be pedantic... (1)

ben_white (639603) | more than 9 years ago | (#12807443)

This is not an Air Conditioner.

This is an Evaporative Cooler, AKA a Swamp Cooler.
No, an evaporative cooler uses transfer of heat necessary to evaporate water to cool the air. There is no evaporation in his design. He has just made a simple heat pump, transfering heat to water cooled with ice. I guess this is an airconditioner using his freezer as the primary coil and a two stage transfer
(i.e. heat moving from air --> water --> freon in the frezzer--> air via the condensing coil of the freezer).

Cheers, ben

Re:To be pedantic... (1)

chudgoo (812186) | more than 9 years ago | (#12807450)

Go check your texts again, Mr Pendantic...

It's a heat pump.

Swamp coolers require water to evaporate to fucntion. (Hence the "evaporative" part) What exactly is evaporating here?

So much for your book learning...

Re:To be pedantic... (1)

Quikah (14419) | more than 9 years ago | (#12807458)

Swamp Coolers work by passing air through a moist pad. The water in the pad is evaporated cooling the air. This works by passing air through a cooled coiled tube, no evaporation occurs during the cooling process.

Re:To be pedantic... (1)

Soruk (225361) | more than 9 years ago | (#12807460)

An evaporative cooler uses the evaporation of water to cool the air. That's not how this thing works. This is just an elaborate transfer of heat from the air to a stream of cold water.

Re:To be pedantic... (1)

Overzeetop (214511) | more than 9 years ago | (#12807462)

Well I didn't RTFA, but based on the text someone posted here (just above you) this is not a swamp cooler. Those work by an evaprative process where the temperature of the air drops as it passes over a wet wick. The evaporation removes energy from the air, reducing the temperature. Unfortunately, they also add moisture to the air, so you get a cooler, more humid environment. They also don't work when the humidity is high (saturation=no evaporation). They're good for desert climates, but not good anywhere else.

This is a simple energy transfer - he's using a bucket to store sub-room temperature water, then passing that water past a fan through a coil (hey, fan-coil...that sounds catchy). The air flowing over the coil gives up some of its energy to the water, which is "circulated" and disposed of via gravity.

What I didn't see is whether he set his heat excnager up to maximize his return. Specifically, did he have the "beginning" of the coil closest to the fan? With this setup, the air temperature will be as low as possible - theoretically it can be very clost to the water temperature. Reversing the coils, so the outlet (to the drain) of the coil is closest to the fan, the best temerature you can hope to achieve is (mdot*T1+mdotT2)/2. With balanced mass flow, that means only half way to water temperature, even if it was perfect.

Boy, that was a waste of time.

Re:To be pedantic... (1, Interesting)

Anonymous Coward | more than 9 years ago | (#12807490)

Did you bother checking where the link points to?

This is Waterloo, Ontario, Canada. Normal RH is 60% or more in the summer.

A swamp cooler simply won't work, period. They don't even sell them here because it's pointless. The air is so chock full of water it's just going to generate heat, if anything.

Since he said it works, it must be moving the heat instead.

Thinkcycle (2, Informative)

bigattichouse (527527) | more than 9 years ago | (#12807345)

You may want to post this on thinkcycle.org as additional information for some of their cooling projects

Why no pump? (2, Interesting)

pirho666 (153073) | more than 9 years ago | (#12807347)

Gets good points in my book, but it would be infinately cooler with a pump to circulate the water and then you could just add more ice from your freezer to get it cooler again.

I know that the freezer will put out more heat than you will get from the ice but this is more likely to be used to keep a single room cool and not an entire house.

Shouldnt be that much to add a small pump to the mix??

Siphoning (2, Funny)

sxltrex (198448) | more than 9 years ago | (#12807349)

It certainly does suck!


sorry...

Pretty Cool (1)

QMO (836285) | more than 9 years ago | (#12807353)

Too bad it's not child compatible.
(Unless my downstairs neighbors were hoping for rain in their kitchen.

Congrats on making your PH.d. pay for itself! (4, Insightful)

jeffmeden (135043) | more than 9 years ago | (#12807360)

But sadly this isnt that revolutionary, nor is it very 'green'. It takes a cold source of water to work, and if you have none in your area (tap water wont cut it unless you happen to get fed from a pipe running through a glacier) you have to get cold media from your local refridgerator/freezer. Why not instead rig a direct cycle through your cooling appliance of choice to offer a small, localized cooling effect? It also wouldn't waste water. Just remember, don't try to cool the room with the freezer in it.

Re:Congrats on making your PH.d. pay for itself! (1)

Spy der Mann (805235) | more than 9 years ago | (#12807430)

Well, you could put the heated water on the boiler - there! You save your self the heating, too! :)

Re:Congrats on making your PH.d. pay for itself! (1)

Overzeetop (214511) | more than 9 years ago | (#12807494)

Depends. Around me (and it's nearly 90 outside today) the groundwater temperature is about 59 degrees (both in F, of course). Even the taps come out low 60s year round, once the slug of heated water in the house is gone.

Not green, as the water is just getting wasted, but it may be cheaper for the water than the electricity + air conditioning. Especially if you're not paying for the water bill ;-)

Mirror is located at (1)

Tairan (167707) | more than 9 years ago | (#12807362)

my site [johncglass.com]

fridge (0)

Anonymous Coward | more than 9 years ago | (#12807365)

I thought this was going to be some neat contraption that didn't even use electricity. Why not just open the fridge door and stick the fan in there if it requires ice?

Canada (4, Funny)

Geekboy(Wizard) (87906) | more than 9 years ago | (#12807366)

Dude, you're in Canada. Open the window.

Now you just have to figure out how to keep the snow off of the carpet.

Re:Canada (4, Informative)

RobinH (124750) | more than 9 years ago | (#12807448)

Dude, I'm in Canada... was 92 fahrenheit here on the weekend. Plus humidex.

Re:Canada (1)

lurch84 (889236) | more than 9 years ago | (#12807480)

So am I (Toronto) and it's been 30+ for the last week with the humidity well over 60%. I'm seriously contemplating building this thing just so I don't have to drop $130 on a real air conditioner

Re:Canada (3, Informative)

Quasar1999 (520073) | more than 9 years ago | (#12807487)

It's currently 28 degrees outside... check for yourself (http://weather.uwaterloo.ca/ [uwaterloo.ca] ), if you can make snow at that temperature, I'd be impressed.

Evaporative cooling doesn't work everywhere (0)

pctainto (325762) | more than 9 years ago | (#12807367)

The site seems to be slashdotted, but I'm assuming that he's using an evaporative cooler. These are very cool, but you can't use them in the east. You have to have pretty arid conditions for enough evaporation to occur to actually make a difference. Very cool idea though -- just wish I could do it in my background.

Re:Evaporative cooling doesn't work everywhere (1)

insanecarbonbasedlif (623558) | more than 9 years ago | (#12807429)

Now, he's basically made a heat exchanger - a radiator type of thing. Pump cold water by the fan circulating air, dump the waste water outside.

Environmentally friendly? (4, Insightful)

whoever57 (658626) | more than 9 years ago | (#12807369)

It's cheap, environmentally friendly (just fire the waste water off to your garden)
So, if it is environmentally friendly, just where did the "ice water" come from?

Unless you have a solar or wind-powered refrigerator, I suspect that the overall system is not actually all that environmentally friendly. What is the energy efficiency of the system?

Beer (5, Funny)

supe (163410) | more than 9 years ago | (#12807380)

I think that his garbage can full of ice water should at least have a few cold beers. I mean really, he's in college!

Looks Like a Ruby On Rails Design (0)

Anonymous Coward | more than 9 years ago | (#12807382)

Come on, you need to carry a bag of ice to it every 3 hours. This is neither practical nor cheap when you factor in the cost of ice.

Give me a real cheap a/c that will work in Houston's climate: 50% humidity and 90+ degrees temperatures. No evaporation units, please, they don't work here.

Re:Looks Like a Ruby On Rails Design (1)

faeryman (191366) | more than 9 years ago | (#12807440)

Won't happen. I've lived in the Houston area and the Waterloo area, and the Texas humidity and heat can only be beaten with central air ;)

Congratulations (5, Informative)

overshoot (39700) | more than 9 years ago | (#12807388)

At first I thought you'd reinvented the swamp cooler [arizona.edu] . On RTFL, however, I find that you've actually reinvented the 18th-century icehouse cooler, which is notably less efficient (like, where does the heat from the icemaker go?)

It didn't seem all that likely that most /.ers would care about evaporative cooling, since even in Arizona they only work part of the year (like now, although today the Phoenix dew point got up to 10C. I woke up just knowing it had gone up because the cooler was blowing full speed and it still wasn't all that cool.) Never mind next month when the monsoons start. AC time then for sure.

Swamp thing? (0)

EvilMagnus (32878) | more than 9 years ago | (#12807398)

How is this different from a swamp cooler?

I can't read the original article (/.ed), but he mentions thermodynamics and water, so I immediately think it's in the same league.

Runs on water?!! (0)

Anonymous Coward | more than 9 years ago | (#12807407)

It'll cool a room to a comfortable level in 15-20 mins, and will run for a few hours on a garbage pail full of water.

Wow, How did he get an Air Conditioning unit to run on water?!! if that technology could be applied to other devices... it could change the world.

Fan? (1)

Poromenos1 (830658) | more than 9 years ago | (#12807410)

Correct me if I'm wrong, but wouldn't just leaving the bucket with the ice in there (or, well, even just the ice) cool the room down as much as making all this? I mean, all the difference in temperature comes from the volume of the melting ice, and that's not changing, is it?

Indoor humidity level? (1)

rhakka (224319) | more than 9 years ago | (#12807412)

evaporative cooling is great, as long as you aren't jacking up your indoor humidity levels which can cause all kinds of nastiness like mold that can kill you or get your building condemned.

If you do this in a non-arid climate, you're asking for trouble, IMHO.

Environmentally friendly? (1)

iamdrscience (541136) | more than 9 years ago | (#12807416)

I'm not sure whether this would be more energy efficient or not, but I would bet not. I mean, really it's using electricity like an air conditioner would -- it takes electricity to make the ice in your freezer (or make the ice you buy from the store).

However, he did say it worked alright with cold water as well and water is included with rent in my apartment whereas electricity isn't. I think I might have to try this.

environmentally friendly? (1)

choongiri (840652) | more than 9 years ago | (#12807421)

that is neat, but i would argue just how environmentally friendly it is. there's the electricity required to run the fan, and also to freeze the water for ice. and even if you can buy renewable electricity / green-tags, there's still the issue of the embedded energy in the water supply and considerable water waste. that said, it really is neat. i'd be interested in a comparison between this and a regular ac in terms of total energy usage (inc water) and cooling efficiency.

thermodynamics? (4, Funny)

csimicah (592121) | more than 9 years ago | (#12807425)

Wait... this retard thinks that using his fridge, inside his house, to produce ice... then cooling with the ice... is going to make his house cooler? He could accomplish the exact same thing by just opening his freezer door, right? I hope this kid's Thermo professor sees this and kicks him out of school.

hmmmm.... (4, Insightful)

MarcoAtWork (28889) | more than 9 years ago | (#12807476)

#1 you can buy a bag of ice at the gas station/convenience store, not free but then neither is the electricity to run your freezer.

#2 even if you used the house freezer, you shut the door and basically you're pumping heat away from the bedroom into the kitchen, obviously you won't get huge temperature differentials, but 5-6C feels very noticeable when you're trying to fall asleep and it's too hot to do so.

Other Uses (1)

Paperweight (865007) | more than 9 years ago | (#12807427)

- Cooling his slashdotted server

- Making tons of cash in Home Depot product placements

- Proving once again that Canadians can invent good cheap stuff, besides grow-op tech. No wait...

- Making me go back to the suspicious Home Depot people for supplies for another "project"

gah (1)

toQDuj (806112) | more than 9 years ago | (#12807438)

most stupid construction ever. I'm ashamed to call him a student.
This is no more than a construction to waste water. He could have ripped a few radiators from a garbage belt to greatly increase the cooling surface (not, as he suggests, pumping more water through it). Also he does not consider the energy it takes to make ice water, and absolutely doesn't consider that that energy is dissipated in his student house.
I wonder if this guy had any thermodynamics lesson at all. Hell, you can even get more thermodyn. from Irregular Webcomic (www.irregularwebcomic.com).

sheesh.
B. (graduating chem.eng. student)

Neat, but probably not very effecient. (1)

Zerbey (15536) | more than 9 years ago | (#12807452)

I don't think this would be very helpful in Florida, but you never know. I wonder if the inventor has tried it in 100% humidity/100F+ weather? :-) The major sticking point is needing the ice water to begin with of course.

Being without A/C for a week after the hurricanes last year was no fun at all! I'm just glad our generator had enough juice to power a window air conditioner (but the gasoline cost a fortune :().

Building a home brew A/C that was energy effecient would be a very useful project this year, methinks.

mirror, just in case (1)

w98 (831730) | more than 9 years ago | (#12807456)

Bah! Put that reservior in the fridge and recirc! (1)

wernst (536414) | more than 9 years ago | (#12807470)

Not a terrible bit of redneck engineering (and I mean that is a positive way), but I can't imagine anyone having a limitless supply of ice and water.

Not that the idea I'm about to present is any better, but this guy really needs to make this a closed system. Put that bucket'o'water in the refridgerator (or freezer), get an aquarium pump, and run the pickup line to the bottom of the bucket and the return line on the top of the bucket. Cut out the door gaskets to allow the lines to go through, and just add some ice cubes every so often as needed.

Sure, you'll be wasting electricity and may burn out the refridgerator compressor because its running all the time, but at least you won't be buying bags and bags of ice and wasting water.

And hell, if the landlord is paying for the fridge, you're home free!

The problem here is that I can't tell if I'm being sarcastic...

Re:Bah! Put that reservior in the fridge and recir (1)

csimicah (592121) | more than 9 years ago | (#12807498)

I know you were being semi-sarcastic, but the problem is, because the fridge sinks heat to the room, you're going to have a net result of warming the room. You've got the heat you took out of the water, PLUS the heat from the inefficiency of the fridge.

It's the same thing as running a room air conditioner in the middle of the floor in your living room. Ooh! Cool air from the front! Just don't go behind it...

I had something similar to this... (1)

Frangible (881728) | more than 9 years ago | (#12807475)

And with ordinary tapwater, it didn't produce much cooling at all. With ice, it produced some effect, but a very small one. And this was just in the heat produced by only two computers. The bottomline is the room was still too hot. Also, most people don't get water for free. The unit claimed up to 12 degrees, but I couldn't detect such a change, especially near the computers. I would strongly urge anyone considering such a thing to save themselves the headache and just go buy a cheap $99 air conditioner at Walmart or something. I'd bet when you consider the energy and water consumption of evaporative coolers, the air conditioner is cheaper and more environmentally friendly to operate. And infinitely more effective in my experience.

Most enviro friendly method to not overheat (2, Interesting)

WillAffleckUW (858324) | more than 9 years ago | (#12807486)

is just to replace the standard incandescent lightbulbs in your house with compact flourescent bulbs.

this will result in you using about 1/8 the electricity to get the same light, but drop the heat output from lighting - a major contributor to household heat - to virtually nil.

I used to have a problem in my new house with having to get a fan until I realized it was mostly heat from lights that was making it hotter than a normal open window breeze could cool. Then I replaced my incandescent bulbs (well, most of them) with flourescent bulbs and suddenly it was cool enough I didn't even need a fan at all.

Now, if the external temperature is above about 98 degrees Fahrenheit (30 C, I think), you may still need to do the water evaporator you describe, but the energy used by it will still be lowered by switching to compact flourescent bulbs for lighting.

Oh, and get a flat panel LCD monitor - that will save a lot of energy usage and heat output as well.

Save the fan to cool off your computer, not your room.

momd 3own (-1, Redundant)

Anonymous Coward | more than 9 years ago | (#12807491)

other5 wHat to

Walmart or GoodWill (1)

mikejz84 (771717) | more than 9 years ago | (#12807496)

In a related story in stead of paying $24 why not spring $90 and get window unit from Walmart? I bet you could find a used A/C unit at goodwill for around $25-$40
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