Slashdot Mirror
Homebrew Air Conditioning for Under $25
inkey string writes "Summer has arrived, and I've been busy slowly overheating in my student house without central air.
I decided to put my thermodynamics classes to work however, and produced this ~24$ 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."
... to cool the China Syndrome that was his server!
I hope his server isn't in his room, because all the thermodynamics courses in the world wont teach you about slashdotting.
You slashdotted yourself...
...right next to your webserver.
"Now gluttony and exploitation serves eight!" - TV's Frank
The people who post shockingly-offtopic stuff as AC . . . . I've never understood them.
Man that wsas fast.... any mirrors?
Move to San Francisco.
Today it hit 70F, and the news stations are talking about "the heatwave of 2005".
From the article: "cheap, environmentally friendly".
From who.int: "Billions without clean water": link
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.
He should have cooled his server with a few of those...
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.
anyone..anyone.. it's waayy to hot in my apt. and I really want to implement this ASAP!!!!
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,
You may want to post this on thinkcycle.org as additional information for some of their cooling projects
meh
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??
sorry...
Too bad it's not child compatible.
(Unless my downstairs neighbors were hoping for rain in their kitchen.
Exam 4/C again. Maybe I'll do better this time.
Next up, a $24 watercooling rig for his web server.
c 29e9dd8f982b3da/index.html
http://www.mirrordot.org/stories/5cb66a4a72a5269b
This
http://www.eng.uwaterloo.ca.nyud.net:8090/~gmilbur n/ac/
Will someone edit the submission to replace the URL, please? Sheesh.
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.
my site
/. is a commercial entity. goto slashdot.com
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?
Dude, you're in Canada. Open the window.
Now you just have to figure out how to keep the snow off of the carpet.
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.
I think my principles are reachin' an all time low
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?
The real "Libtards" are the Libertarians!
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.
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.
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!
I thought a Swamp Cooler was a can of Milluake Light?
Peace out, homies.
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.
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.
This mirror has the article text and the pictures that go along with it.
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.
Lacking <sarcasm> tags,
Thank you mirrordot.
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.
-EvilMagnus
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. ;)
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.
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.
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?
Send email from the afterlife! Write your e-will at Dead Man's Switch.
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.
If you don't know where you are going, you will wind up somewhere else.
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.
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.
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.
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.
- 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"
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)
Every experiment which ends in a big bang is a good experiment.
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.
(i.e. heat moving from air --> water --> freon in the frezzer--> air via the condensing coil of the freezer).
Cheers, ben
cheers, ben
Never miss a good chance to shut up -- Will Rogers
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...
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.
http://www.w98.us/ac/
my geeklog
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.
Q.
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.
-- Soruk
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.
Is it just my observation, or are there way too many stupid people in the world?
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...
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.
#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.
-- the cake is a lie
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.
-- Tigger warning: This post may contain tiggers! --
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.
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
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...
Isn't this just a swamp cooler? Aren't they rendered useless in humid environments? Wouldn't reading this article be a complete waste of time for the majority of us?
actually, it's not an evaporative cooler (swamp cooler), rather the heat transfer is similar to that of electric AC - a cold liquid (water in his case, refridgerent/freon in an electric AC) passes through a radiator of sorts (copper tube in his case, radiator with fins in an electric AC). Some water evaporation out of his garbage can must take place, but not much.
A swamp cooler relies on the latent heat of vaporization. This is heat from the surrounding area that must be added to water to make it evaporate. Swap coolers work well in dry environments, but don't try using one in Florida or DC.
I bought a real air conditioner last weekend for $130 + tax at Target. Ok so it was a cheapo made in china model, and whoever wrote the instruction manual obviously didn't speak English, and the thermostat on it is not too accurate, but it does actually work and blows cold air when I turn it on.
So I don't know why you'd do this when you could buy a real heat pump for not that much more.
On second thought, why go to to wal-mart and buy a real air conditioner and put it in the window where you would otherwise be wasting water?
Man, and I thought I was poor in college!
Or potentially, bury a large water resevoir, and let the ground cool the water.
Put in a pump to pump that water up to the fan and through the system.
You could even have it run through multiple fans.
Okay, sure, use the water like hell. Wouldn't it be better to use a pump to make sure you don't spoil the water. Put a Peltier kit on it (this aint exactly difficult to make, right?), and put the hot part of the peltier outside? You have power at your service, so cooling the peltier can't be that much of a hassle either.
Still is a good beginning, why don't we make some open hardware coolers?
Just stored thermal energy (cold water) and a thrown together heat exchanger.
Me thinks some efficiency improvements can be had would raising the cost substantially.
Summer hasn't arrived brah - it is here. And if you are planning on getting by with some cool trash-water, then you are woefully unprepared.
Just a hint here: but a woman is not gonna want to come over and see your sweaty fat-ass playing D&D or whatever you play.
So my advice: go down to the local utility, pay the freakin' $80 bucks and have the A/C turned on. You'd be amazed at how lower-humidity can clear acne.
Peace Out.
Air
"This isn't a study in computer science, its a study in human behavior"
Kenmore 5150 BTU Single Room Air Conditioner $89.00 new http://www.sears.com/sr/javasr/product.do?BV_UseBV Cookie=Yes&vertical=APPL&pid=04274054000&subcat=Si ngle+Room+Units
I know students are poor, but really. You can probably pick up something like this at a garage sale for $20.
A lot of people have ice makers in their home, which provides ice cheaply enough.. though one nit pick I had myself is that he wasn't adding any salt to the water!!! He could have dropped the water down at least another ten degrees, stretch out Newton's Law of Cooling the best you can.
Had a similar idea, though closed circuit, and involving an old fuel pump from a car..
"Victory means exit strategy, and it's important for the President to explain to us what the exit strategy is." G.W.Bush
i cannot see how this is possibly anymore environmentally friendly than a 80$ one room window unit
It might be cheap to construct but not to run:
- You will need a huge amount of ice that takes a lot of energy if you want to make it in your refrigerator.
- You will need a huge amount of water to run the system if using tab water $$$. - More electricity to run the fan.
If you are close to a lake or the ocean you might have an alternative but it will need a lot of piping and a pump (which usually runs on electricity).
My dad worked on a mine where they did not have electricity for refrigeration and the place was really hot (in the 40C or 105+F for the "different ones"). You would not have any cold drinks for lunch or dinner, so they would put water in bottles in a shadowed area and then cover them with wet rags. The water would evaporate from the rags taking some heat with it and cool it. It was great for drinking and taking cold showers.
You could have a system with no ice and a fan blowing on some wet rags or something. The only problem is that you would dramatically increase the humidity of the place (read as there is no free lunch... or is it beer?)
... some cold BOTTLES OF WATER in the can!!!! ;-(
;-)
Maybe this type of "concern" about the environment goes with cooling water rather than beer hand in hand?
Paul B.
Didn't anyone else figure out that you heat up the area more by freezing the water into ice than you remove with the ice melting back to water. You know, Basic Inefficiency 101?
...or by cooling one room at the expense of making the rest of the house hotter.
The only way I see this working is if freezer making the ice is outside.
Any sufficiently advanced influence is indistinguishable from control.
I don't know whats worse, the idiot parent poster who doesn't RTFA (or knows what he is talking about) or seemingly endless replies saying the same damned thing one after the other as if they were the first to point out the error and should get some sort of brownie points.
This guy just wants to cool his room; he doesn't care about the rest of the house, or he'd have one of these buckets in every room. Let the kitchen get so hot you can fry bacon on the floor, his computer room will be COOOOOOL and COMFY.
Besides the obvious efficiency issues others pointed out, it wastes the cold water after one pass through the system.
Seriously, how much heat can the ice water absorb in a single pass through the radiator? I bet it's still pretty chilly when it hits the garden.
How difficult would it be to invest in a fountain pump (maybe $20?) that circulates the water back into the reservoir?
If he's an upperclassman in an engineering program (or a physics major) he shouldn't be satisfied until he set up a closed system that includes loops in the ice water reservoir. Call it an extremely primitive heat pump.
For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
On a completely off-topic note, would you happen to have any suggestions on a particular brand or installation company for a new swamp cooler? I've been using AC all year because my ancient evap finally rotted enough that it's worthless.
I miss freezing to death. Instead, the AC's been running for probably an hour straight now trying to maintain 79.
unless the outside air is rediculously hot/humid, why not point the fan out the window and put the cooling coils where the resulting in-flow to the room occurs? that way the waste heat from the fan motor is not replacing some of the heat you have dumped into the cooling water.
SLASHDOT: news for people who can't concentrate on work or have no life at all and got tired of yelling back at the TV.
You call that innovative? This is how people cooled their buildings before in the invention of the room air conditioner. And, to be redundant, where is the cost of amking that ice water? You want innovative? THIS is innovative! And even it is old. And it will probably be cheap when it really catches on. More info, in case you're interested.
What?
I just found on online for a whopping $78: SF608R.
I'm also seeing other products by that same manufacturer on Amazon.com that include ionizing air purifiers, etc. An interesting category of product I've not noticed before.
you can find a small window AC unit that takes up much less space (and weighs less) than a 40 gallon trash-can and an oscillating fan. Cool project though...
Well, no, it's more of a heat exchanger, isn't it? Only if you include the machine making the cold water could it be considered a heat pump. This guy hasn't made an "air conditioner", he's made half of an air conditioner -- the easy half, at that. When I see the compressor and the coils discharging the excess heat outside, then I might actually call it a heat pump.
I've abandoned my search for truth; now I'm just looking for some useful delusions.
If you've got a fridge, place some copper tubing in it, and make the water flow go through it. You may have to cut some of the rubber seal off the door off the fridge to run the pipe through, but it keeps the copper cool all the time, no need to refill water bucket with ice.
I say give the OP a bit of credit. He didn't say he was solving the world's energy problems, it's just a fun hack for thrifty students to play with. I thought it was a neat article but all the comments are ripping him for scientific inaccuracies and it already being "invented". It does sound like a fun (nerdy) way to spend an evening and save your buddies from a night of intolerable heat.
Let's cut the guy some slack and give him some credit for trying, and amusing a former thrifty student.
I should really get a slashdot account...
Other than the obvious ingenuity involved in the creation of this device, the reason things like this don't exist in the real world is that they're hardly efficient. And comparing the purchase price instead of the operating costs of such a device is a sure sign you're missing something.
Air conditioners are unbelievably cheap and unbelievably efficient nowadays.
As others have said, this setup has all sorts of problems, from a reliance upon a source of ice that may very well be dumping more heat into the local environment than it saves, to wasting water.
Though this system doesn't use a pump, a recirculating system with a small electric pump could end up creating more heat than it saves.
If you're really bent upon saving energy in a cost-effective fashion, adding insulation is almost always efficient. Good blinds on the windows are also a great investment.
"I assumed blithely that there were no elves out there in the darkness"
wouldn't it be easier to just sit in the bucket?
I'm in northern vermont, and with the humidity and all, I'd rather take an ice bath than have a slightly cold breeze...
-- it's ridiculous how many people misspell ridiculous... (damn, damn, damn...)
After looking at the pictures, I keep thinking that this would make a great CPU cooler project. Nah... It's hot in California. I need to go back to the swimming pool.
Where's my sweater. O wait you havnt been to India where we dont really call it hot till it hits 45 and it wouldnt be summer without at least a week of 50 degrees plus.
Wimps!!!
**Life is too short to be serious**
If he could actually pulversize the water and spray it into the air then somehow remove it so his room doesn't drenched, he might have a much more efficient system. I saw something like that on sale somewhere - basically a fan with a hose attached to it, it is good to put by the pool in the summer or in the backyard, clearly not in the house. That is how some of those huge heat excangers for large HVAC stations work. Water absorbs heat when it evaporates, in this guy's case water only exchanges heat with the air through the small area of the tubing. Not very efficient, might as well start the shower in the bathroom and make sure it sprays a fine mist and let it drain in the bathtub, then put fans in the dorway. No need to spend any money to build, is more efficient, but still gotta pay for the water bill.
Let's see now:
- It's $24 if you don't factor in the cost of the fan and garbage; add those in and the price at least doubles
- It doesn't factor in the electricity cost of the fan (small but real) or the ice (certainly significant)
- If you're creating the ice in the same room/area as the cooler, you're creating more heat in the room then you could possibly remove via the ice, even if the system extracted heat from your room with 100% efficiency, which it doesn't.
- Because it doesn't operate at 100% efficiency, you're losing energy as cold water runs out of the tube at the waste end.
- It doesn't remove humidity from the room the same way an A/C system does, so it isn't as effective in creating a comfortable climate as an A/C
- And it's butt-ugly to boot
If he were in a thermodynamics class of mine (or engineering design), I'd fail him so fast his head would spin.
What would be better than ice water in many areas would be well water. My parents have it and its pretty cold, i would guess 60 F. you could really cool a room pretty cheap, and if you had solar panels, it would be free
number one, yes i realise that in a closed system freezing ice to cool yourself off is foolish. this is why i make ice in the kitchen, and cool my room off at night.
which addresses the why no recirculation/you need an infinite supply of ice criticisms. this was designed to cool me off before bed, so i could fall asleep without wanting to kill myself. once the bucket runs out of water/ice, it just becomes a regular fan which is fine once the house cools off in the wee hours. plus i dont have to worry about knocking anything over in a morning daze.
ive rigged it up to a slowly flowing garden hose which will keep things cool indefinitely, but i find it easier and a bit cooler to just pick up a big bag of ice and dump it in when it gets really hot.
anyways, take it or leave it. and to the graduating chemmie that said he was ashamed to call me a student - come visit me at my office by the weef lab (e2-1311), im sure i can address any of your concerns to my satisfaction.
Dehumidification is a key feature of air conditioning, not just cooling. As such, as your cooling coil chills the air passing over it, water will condense... but where does it go? Watch out it doesn't drip in the fan motor, or get sprayed around the room onto your computer or other electronics.
"No fair, you changed the outcome by measuring it!" - Professor Hubert J. Farnsworth
Why not just pump some of that ocean water from that other story a few weeks back around your house? Just need like 3 miles of copper pipe instead of 25 feet.
Put the bucket outside, in the wind, with a pump to cycle the water through the fan coil in the house, then back to the same bucket outside. Instant swamp cooler with the swamp outside and the cool inside.
It should be quite a bit more efficient than this guy's system.
Icewater is fine and dandy, but very difficult to obtain in sufficient quantities.
Now, if you simply take the hose and, instead of dunking it in the garbage can, just attach it to a faucet. Turn on the cold water and you have an infinite supply of cool water for your cooling.
It depends on where you live though. It shouldn't be any more expensive than watering your lawn, but some places have watering restrictions or expensive water. I'm lucky that where I live the water is extremely cheap and there are no restrictions on use.
I would imagine that the fact that the water isn't quite as cool could be offset by the fact that by using a faucet you can get much faster water flow. it'd really depend on how expensive your water is. If it's really cheap, you can just open the tap full bore and let the thing cool as much as it can. If your water is more expensive, you might want to restrict the flow.
Still, where I live, tapwater makes more sense than a garbage can full of icewater.
If he's getting ice from the freezer in his apartment/room, it is negating his attempt to cool his apartment/room. Heat removed from water in the freezer to make the water freeze is put right back into the house by the thermal coils on the back of freezer/refridgerator.
Have you ever been to a turkish prison?
Much cheaper: Big block of ice in a baby bath, with a fan blowing over it. (Since you are in Canada, just go outside for more ice - or you could open a window, but that won't be nearly as cool...).
Oh well, what the hell...
Looks like your bot is broken.
Or is it just some elaborate troll meant to make Canadians look stupid ? To his credit, it does cool the spot near his 'heat pump'. You can actually buy similar devices here in the states at your local hardware store ( put ice in the top, a fan blows over rotating fabric band which melting ice coats w/ cool water ), so it's not *quite* as dumb as it sounds. Well. Ok. It is, actually, unless you're just interested in cooling a single spot, and not interested in doing so efficiently. In which case, uh... small air conditioners are in fact not all that expensive.
If thats the case just run some tubing to a bucket in the fridge and hook up a cheap pump.. Pump water into and out of the fridge continuously and you will definitely keep one room cooler ;-)
J
A common farm aircon, is to put a sprinkler on the roof. That cools the whole house down.
Oh well, what the hell...
I was just in Waterloo for the CMS conference, and I was expecting a nice change from the Alabama summer that seeemed imminent, but at least we have air conditioning in our dorms!!! Hats off to you.
Karma: Bad (mostly due to all those "In Soviet Russia" jokes)
Mirror: www.138productions.com/ACMIRROR/
For things such as home brewing where the fermetning beer needs to be kept under 70 degrees this could make a good solution, one could easily cool a closet or other small room to the acceptable temperature
If you can't see the value in jet powered ants you should turn in your nerd card. - Dunbal (464142)
If you were lucky enough to have a cold water stream that went by your location you could use this idea to easily route the water from the stream through it (need a screen on the intake), through the heat exchanger, and back out to the stream. Pretty minimal impact on anything. Would be a nice method for those lucky enough to have that circumstance. A pump might be needed depending on the lay of the land, good idea to have one anyway just to keep it free of debris and stagnant water if it is out of use for a period of time.
I hope he has an ice machine that the university is paying for, otherwise this isn't going to be as cost effective for him as just getting a window unit. As corporate America would say, externalizing cost is as good as free. (sigh)
Freedom is merely privilege extended unless enjoyed by one and all.
We're scheduled to hit 36 C later this week. How do you think this setup would do here?
It's good to use your head, but not as a battering ram.
In the long run, you'll probably end up cooler and save money on your electric bill. Seriously...
Here is a cooler I use - a stationary bike turning a big fan. I get on and start pedalling - and sweating. The fan blows air across me and the sweat evaporates directly off my skin. Believe me, this can get quite chilly if you move enough air. Efficency is directly proportional to the amount of skin exposed.
Ladies, this is a sure A project in Physics. Be sure to raise you arms and twist your torso side-to-side to get an A+.
Hook the thing up to your bathroom faucet (ground water at ~20C or less, in Canada), using that 25 feet of cheap copper tube. Just get a compression fitting and an adapter, and crank it on there. No filling up the garbage can with pail after pail of water, and you can circle your tubing much more, giving you greater thermal transfer.
You can also get fancy with an evaporative cooler, using a pond pump and transmission oil cooler, but that costs more.
I'm guessing you have a utilities paid-for apartment. When the landlord sees the increase, they usually hire a plumber to go looking. I know a guy that got pissed and left the water running in his apartment, the entire last month...
"this was designed to cool me off before bed"
If you want to cool yourself, and not the room full of air, just wrap the tubing around your body.
your office is next to the weed lab?!
Dude, it is summer. You don't need the snow boots and parka anymore...
Oh well, what the hell...
???
Escher showed us you don't need no stinkin' energy-wasteful pump! Just use this arrangement:
http://diariodeumpintelhofo.no.sapo.pt/Escher.jpg
Where I live, my place heats up during the day, but it cold (outside) at night. I bet I could use this to cool the place in the late afternoons by simply catching the water in a buck in my outside basement and then swapping the buckets during the day.
No electricity!
I got the idea when i noticed the refrigerator was cool...
That site that explains the home airconditioner is ugly as sin...
Why doesn't someone put it on:
http://www.ifabricate.com:8080/
I FABRICATE!!
I must say i either STUMBLED on that site (www.stumbleupon.com/ )
or randomly came upon it
I'm not an operator or owner, but i think it is damn cool
When will people start using these great tools.
I didn't know about
stumble upon this week
delicious till January this year
wikipedia 2 years ago
slashdot 3 years ago
google 4 years ago
WHY DON"T PEOPLE AGRIGATE These sites better?
Is that the semantic web?
could have come up with a better cooling rig. But thanks for a demonstration of U-Waterloo's engineering abilities!!
60% RH is a dry day in Dallas....
SIGSEGV caught, terminating
wait... not that kind of sig.
WTF? Where the hell do you live? Anything above 40 C is hot even by Indian standards. 45 C is when people start dying of heatstroke.
Time flies like an arrow. Fruit flies like a banana.
Side note, if any of you hosers don't have a Chillow ( http://www.soothsoft.com/chillow.htm/ ) , you should check it out. My face gets hot when I sleep and I love this thing. The only hard part is explaining to strange chicks why I have a big plastic thing in my pillow.
You can get 'em at your local Walgreen; look hard.
If you had another garbage can outside collecting the used warm water, you could use that later to recool.
Envirmonmentally this is hilarious. Technically it would work once a day, then you would have to use the freezer(s) to refreeze your ice, but you would use far more electricity.
To be fair, even though all us techo/scientific nerds are laughing heavily at this, we all know there may be a point in our lives where we NEED to resort to this... ie "if only we could get a weak AC on it for 3 hours or so that did'nt require electricity".
Move along... there is no sig here.
The store needs to make a profit on top of the cost of the electricity to maintain the machine, and the ice...
...supplied by the ice company which bought the machine, maintains it, and freezes the ice, and trucks it to the store from their "plant"...and make a profit.
You do realize that 1kW/hr costs about 22 cents, whereas a 20lb bag of ice costs about $5, right?
You have to move 330J of energy to freeze one gram of water, basically. We'll assume a 50% efficiency here (pretty poor, I believe). A bag of ice, say, 20lb- would need about 3 million joules (watt-seconds), or 6 million watt-seconds of electricity. That's 1662 Watt-hours, roughly.
Or about 36 cents.
#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
Most refrigerators are virtually incapable of pumping that much heat (there's a reason they're insulated), and furthermore, are designed to work at a temperature range 60-90 degrees cooler than what you're asking of it. Ever noticed that a fridge takes forever to get from room temperature down to operating temperature?
This idea is so stupid, I can't believe I just wasted 5 minutes on this post. I want that 5 minutes of my life back.
Please help metamoderate.
I bet his parents are SO proud. I mean come on, its a very simple radiator. Big whoop. He could've at least made an evaporative cooler or something, but no, its instead a lame siphon deal. Makes me glad I never went to college.
Now, it would've been cool (no pun intended) if he had figured out a way to run the hose down to the fridge and run some tubing of equal or greater length inside the freezer. Of course then you'd just have a very rudimentary air conditioner going that would waste more resources than it saved, but still, it'd be better than a bucket full of ice water.
Maybe he could've even made it with a little pump, to keep the water recirulating, or maybe more coils until the water actually came out warm by some degree.
I can't believe this cheap college 'hack' even made slashdot. C'mon editors, don't you have something better to do?
Nobodies Prefect
Tidbits for Techs Technology Blog
I had never heard of a swamp (evaporative) cooler until I moved to AZ. At first, I didn't like the idea of adding a ton of humidity to the air in order to cool some space, but when I bought my first house, I learned that I LOVE swamp coolers.
Newer homes never have them, but the older house that I bought (built in 1979) had a monster one installed on it. During the early parts of summer (when the humidity is low) I can keep my house at 72 degrees when the outside temp is about 100 and my electricity bill is $65/mo.
If I ran my AC unit and kept the house equally as cool with it, I would be looking at no less then a $150 in early summer and $200+ as the temp gets into the range of 110+.
At this point, what I would love is a thermostat that runs both my swamp cooler and AC unit and can determine when to use one versus the other and switch automatically between them. Anybody know of such a device?
cheers.
"Perhaps most amazingly, votaries of 'diversity' insist on absolute conformity." -- Tony Snow
A bunch of work was done in the 70s to develop cheaper methods of air conditioning.
One was ice ponds. Freeman Dyson and (mind fart) Taylor worked on them, as I recall.
Roughly put: You would build, while laying out an office building's parking lots, several big pits lined with pipes.
After snow falls, plows pile the snow and ice scaped off of the walks and driveways into the pits, which can be covered to keep out sun and rain.
If sufficiently insulated, the pits will remain full of ice and snow well into summer. The building's air conditioning system uses the pits as a heat sink, greatly reducing the energy required to cool and dehumidify the air.
I imagine the melted snow could be used to water the lawns and landscaping . . . a small but important win.
Stefan
I almost live in Canada (in Maine, about a 15 minute drive away from NB)
And while this isn't totally on topic.. Damn I need A/C. I'm going to die.
Does anyone know of a fairly inexpensive (read: less than $500) AC unit that fits into a crank-out window?
Our apartment's got 3 huge bay windows.. all with crank-out windows on the side. I haven't found a useable AC unit that's affordable that doesn't require me to route plumbing and vent heat through a drier vent type hose.
Suggestions would be very welcome.
Spend another $26, and buy a real airconditioner for $50 at CostCo.
It's $99.99 with an instant $50 off rebate at the register.
Less work too.....
"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..."
He isn't buying ice, he's only wasting water. University of Waterloo has icecold water around the dorms. The pipes are underground where its very moist and cold. His tap water is like ice water, right out of the tap! Don't even need ice to make ice tea!
Now, all he needs to make a system that is water-use-friendly, 2 trashcans, 1 sump pump, and a full thing of powder chlorine (for the algea you know)
Then, he can put the trashcan outside, put the water exiting the house near nearby ground, bury some copper pipes around in the backyard to cool it down underground (works for the water to the house, should work that way too) then have the water exit in a waste trash can.
Have the sump pump pump the new cold water back up in to the room after the siphoned water fills up said trash can (they're pumps made to kick in when water gets to a certain level.. in this case to the top of the waste trash can)
Add chlorine in to the system to keep it clean of microorganisms.
Presto! You have a completley self contained system that only uses electricity to pump water back upstairs when the waste trashcan gets full (e.g. when the trashcan in his room is almost empty)
This would be considered 'Green' would be if heAfter all that shopping and sweating in that "hot" room he should have stopped over analyizing a solution and go back to basic. Fill the garbage can with ice water, get naked and jump in. Will drop body temp at a much faster rate and will mostly likely last just as long. Hell, get a $20.00 inflatable pool for Toy's 'R' Us and invite over a few friends to discuss the nipply occasion. WARNING: Above events may cause uncontrollable shrinking of your 'package'. Please wait 30 minutes before checking if you can find your jewels and have begun to drop. Repeat this step every 30 minutes for up to 2 hours. If jewels are unable to locate your balls and they seem to have totally disappeared.. call 911 immediately!
Never try to beat a professional at his own game!
Ice cooling - OLD - before modern AC was invented, this was fairly common - in fact, most AC units (larger than window) are rated in TONS - as in tons of ICE melted in N period of time (I think its per day - don't remember)
I have seen an "Interesting" energy saver unit - When does a building need it's max cooling? During the afternoon. If you are on demand metering - when is electricity the most expensive? During the day. What this unit did was run at night, and freeze water, and during peak load, you melt the ice - the place I saw it was even more fun - a church. All week, you have almost NO load on the system, but on Sunday AM, you need a LOT of cooling - rather than install huge coils, compressors, etc - they installed a smaller system, and made ice all week - on Sunday, they blew air over the ice, and melted it
-- 73 de KG2V For the Children - RKBA! "You are what you do when it counts" - the Masso
Here in San Francisco Bay Area, most of the warm half of the year you can get by with opening the windows at night and closing them during the day, with a few weeks when it's actually worth going to the office instead of telecommuting.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
This is in no bloody way clever, and cooling a room like this has occurred to everybody on the planet with an IQ greater than 40 at one point or another, none of whom ended up doing it because either (1) they are the ones paying for the ice/water/electricity and realize it's cheaper to buy an A/C; or (2) they have access to free utilities but realize that it is a huge fucking waste of water and energy and therefore completely irresponsible (and certainly not clever enough to warrant ignoring that fact).
This is totally unworthy of a /. story. The guy should buy a goddam $100 air conditioner and quit wasting water and electricity on his fake "heat pump." Eventually his university will come across his self-satisfied little post and put an end to it, at which point he will simply have found a way to cool his room for $28 for two days and make a tool of himself to everybody on the web who knows any physics.
With all the amazing hacks out there that don't get posted here, why do we hear about this kid who didn't even understand the undergrad thermo class he keeps telling us about?
I don't know if this guy ever took shop class, but the simple old trick of filling the part of the copper tubing to be bent with sand will help prevent it from collapsing from a too-tight bend.
At least in my house, the automated switch wouldn't work because of the block I have on the return to keep air from blowing backwards through the AC and filter. Besides, I would only use it twice a year.
On the other hand, it's a good idea to use a cheap indoor/outdoor thermometer with humidity sensor to keep an eye on the discharge temperature, since that gives you a good advance clue when the dew point is headed towards "miserable."
What I miss is a sensor that would let the sucker blow cool, dry nighttime air in to chill the house during the spring and fall without adding water. Just turn off the pump, not the fan.
Lacking <sarcasm> tags,
Instead of all this malarkey, why not go to Wal*Mart and pick up a window air conditioner? I saw a 5000 BTU air conditioner for $78 this weekend. It's probably about as efficient (500 watts) as running that fan all the time and the extra load on the freezer...
...to cool a room, as has been noted repeatedly, a few refinements that can be done easily and cheaply:
:)
1) Get a second trash can. Drain to trash can number 2. This will allow you to save water, plus:
2) Put salt in the water. The ice and chilled water mixture gets colder with salt.
You probably don't want to drain salt water to the yard.
You can run from one trash can to the other, then when it's done draining, swap one can for the other and ice down the other can. If you've got some freezer space to dedicate to the project, the bottles of ice are probably an excellent idea-- have a set in the freezer and one in the heat pump.
Is this a joke or something? This has nothing to do with the way air conditioning works. And it actually ends up using a lot more power than a real AC.
This is like saying "how to build a car that runs without gas", and then describing how to tack 4 wheels onto a board that you can sit on while it's pulled by a real car. Well, duh!
Basically, set up a closed loop heat exchanger system by leaving the coil he already has set up on the fan, and set up a similar coil in a large diameter PVC pipe or box of some type (made from fiberglass, or resin coated wood, or something similar). This second box needs to have a fan that will draw air thru the coil and out the side of the box. The bottom of the box is a water resevoir (holding a couple of inches, like a swamp cooler). Water is then pumped and "misted" or "dripped" over the coil. As it "waterfalls" down the coils, some of it evaporates, picking up the heat in the coil. This evaporation is also helped by the fan in the box/tube (with a long tube, you could mist from the top and let it evaporate on the way down - some guy a few years back set up such a system to cool his CPU with - it was basically what I am describing here, but smaller for a CPU). Set this system outside, run the intake/output lines into the house to the coil fan.
What this system is, is essentially a low-cost (and probably fairly inefficient) "chiller" unit - larger versions of these are used in industrial settings, as well as "pre-coolers" for air-conditioning systems. They actually work pretty well, depending on humidity. Basically, you can figure you will get the same cooling as you would with a swamp cooler, but instead without all of the extra humidity a standard swamp cooler pumps into the house. The closed loop of the chiller water recirculation unit keeps the water usage inline (basically making it about as cheap to run as a swamp cooler).
Honestly, you could probably even repurpose a regular side or bottom-draft swamp cooler for this - just let the air vent to the outside, and mount the chiller coils in place of (or in addition to) the pads on the unit...
Reason is the Path to God - Anon
Or, you could plant a tree or two for shade. We're one of the few houses in my neighborhood near Los Angeles that doesn't have A/C, and we don't need it. Sure, it gets warm at times, but with open windows a light breeze will take care of excess heat. The water used is no more than our neighbors pour onto their sparse lawns. Even outdoors, the temperature drops about ten degrees when you walk past our house. Unfortunately, the neighbors' A/C noise still negates the effects of my quiet PC.
-- I prefer the term "karma escort."
He goes to Waterloo, they don't know how to drink there (except for one week in Oktober)
If you add a bunch of rock-salt to the water/ice mixture, the temperature will go below freezing, as long as the ice isn't close to being completely melted (this is how ice-cream makers used to work). Of course, this air-conditioner will probably only be able to cool until the dew-point anyways, but if you have a closed-off room, this air-conditioner could also act as a dehumidifier. And since the reaction is endo-thermic, the total system (not including the ice-maker) temperature will decrease (as opposed to the case of a mechanical dehumidifier, where the total system temperature increases).
Also, you could buy ice from an ice-house. Ice-houses used to chop up huge blocks of ice from rivers and lakes in the winter time and put them in huge insulated sheds to sell to people who had ice-boxes. So, this cheap air-conditioner isn't necessarily required to be dependent on electricity.
And, if you have a handy-dandy glacier around, then you have free "environmentally-friendly" ice. If you live near tall mountains, you enviromentalists can go ahead and get your ice from some glacier up there.
(I live in MN and some years we still have frozen ice and snow in mall parking lots even into the month of May. During the winter, most of the area of parking lots is cleared of snow which is piled by big trucks onto enormous house-sized snow-piles.)
BTW, we made ice-cream using the ice-and-salt method a month ago for my physics dept's annual end-of-the-year picnic.
Initially, not only does your water have to be cooled but you aren't running that fan with a handcrank either, are you? You're powering that fan with electricity which has to be generated from somewhere else as well.
;)
Environmentally friendly? Not really. Ingenious solution for a college student without A/C? Yep.
Methinks the author is a marketing major!
I like my women how I like my sugar.. granulated.
is the current title of this guy's homepage. Perhaps this should've tipped off the submitter to do a little more checking into this "engineer's" idea, which turns out to be little more than the thermodynamic equivalent of cooling yourself down by drinking cold beer that you stole from your neighbor.
Personally, I always thought the dehumidifying aspect of AC was just as important as the actual temperature of the room. Still, its better than nothing.
Yeah, but does it run Lennox?
Dude... your office is next to the weed lab?!
The Kruger Dunning explains most post on
Using that in a car..mmm... Since I got no A/C and I stick to the seat after 1-2hrs drive from work I might try buildng such a system. It might be trickier though as one has to use a lid for the bucket (damn potholes), punch a hole in it and seal w/ silicone or something; find a custom 12V fan that plugs into the lighter; also hmm a hole on my floor...but I still think it's worth a try...
Normally you need to refill the garbage can. Now that is a nasty thing to refill every hour. So what you need is a semiautomatic refiller that refills when almost empty.
Also not everybody has the possability to let the water flow outside. SO you need another way to get rid of the water that is lower than the refiller.
The solution? Your toilet. Get the water out of the watertank. When it is lower then a certain level, it will refill.
The toilet itself is perfect to get rid of water. The wtare itself is clean and just as clean as the water that comes out in the kitchen. (In Europe that means drinkable)
Don't fight for your country, if your country does not fight for you.
Bwahahahahaha! .. *sniff*
Hello, and welcome to last century!
Pretty Pictures!
Where I live the humidity is often around 100% although it gets "only" into the nineties most Summer days. Swamp coolers are awesome, but they won't work here.
But what DOES work is... taadaah! An amazing electrical appliance commonly known as an AIR CONDITIONER. In my case it is a GoldStar unit purchased for $98 at Wal-Mart two years ago. It still works fine albeit a bit noisier than when new and it actually costs LESS to keep this thing running in my bedroom 24/7 than it cost last month to run that Intel 3.2GHz tower with the two big fat SATA hard drives and the GB of RAM.
Imagine that... go to the store, buy a box for a hundred bucks and get a cool room! If this kid would have put off that last big fat hard drive upgrade maybe he wouldn't have to worry about mopping up 25 gallons of icewater due to someone bumping over his "room cooler."
Cry much?
If you live somewhere that it gets significantly colder at night than in the daytime, that works.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Get out of the basement sometime, and stop playing Doom III all day. Perhaps read a book. That's bound to bring the temperature of your room down.
It may be more efficient to just put the fridge in doorway, seal the sides and keep the refrigerator door open all day.
On his page, he says this is a heat pump. A heat pump moves heat from a low temp-reservoir to a high-temp reservoir (i.e., against the temperature gradient) with a work (or electrical power) input. This does not do that; it merely transfers heat from the air to the colder ice water. This is nothing more than a heat exchanger.
Also, it's the kind of application where wimpy American-style canned beers work fine (or whichever of Labatt's or Molson in cheaper in Waterloo) - you want something cold and quick-drinking, not something like the Guinness I'm about to go open a bottle of :-)
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Assuming you can get the permits and own a house. You could allways drill a 65 foot hole and run copper pipe down and up and use geothermal temps to cool a water supply. not cheap to set up but cheap to run.
In my old house in Arizona, we had a swamp cooler which uses a turbine fan to pull outside air through wet pulp mats, evaporating the water, cooling the pads, and thus the air. This is a lot more efficient than a freon pump, but it has a lower dynamic range (only works for a limited range of temperature), and it only works in very dry climates. It works very poorly in places with higher humidity.
I have seen a design for multi-stage evaporation, where the evaporation of each stage might be limited by temperature or humidity, but each cumulative stage adds a little bit of heat removal, with the delivered air being quite effective.
Whatever methods we use in the near future, we need to try to do whatever we can to approach using as close as possible to only the amout of enthalpic energy needed to produce the desired effect. And not expend a lot of extra energy doing it.
Can anyone give me advice for how to cool an interior room? Standard air conditioners won't work, because there's no window for me to run an exhaust out of. Evaporative coolers won't work either, because the air isn't low humidity. Am I limited to fans (which don't work well)?
Convolutus Counter Flow Wort Chiller: The inner tube is made from 12' of 5/8" convoluted (twisted) copper which continually turbulates the wort as it flows through. The outer tube is made from 7/8" copper. The Convolutus chiller allows you to pump wort through without having to restrict your pump to slow down flow. Use 1/2" line to connect to wort in and out feeds. The water connections are male and female hose connections.
You could use this beer making technology to improve the design of this system.
Check out the lighted makeup mirror on the desk.
:)
Ok.. Ok.. Maybe I'm being the one who is stereotyping. He can wear all the rouge he wants to, it's no skin off my nose.
god i hate that guy.
why, ME TOO!!!
I rent a very small, one-story house. It used to get SO hot in the evenings -- much hotter than outside, and opening the windows just didn't seem to help much.
(As an aside, why is this? How can the temperature continue to climb after the sun goes down? I never really figured that out. My guess is that the air in the attic was superheated, and as it cooled at night would slowly come down out of there. But I digress.)
So I was out watering the lawn one day and out of curiousity pointed my hose up on to the roof. The water came out of the hose very cold, and came off the roof as hot as a very hot shower.
So I got one of those self-irrigating garden hoses and ran it right along the crest of my roof. Now when it gets hot I just turn the hose on. It works OK, though not as well as I had hoped. Plus it's kind of nice to sit in my house with the sound of rain falling all around me in the background.
- Alaska Jack
Not only is ice not free, but the refrigerator (being a non-ideal, non-reversible thermodynamic entity) is putting off MORE HEAT than what it is cooling (the same is true of an A/C unit... that's why they are located outside). Since he is in a dorm room, the freezer is located in his room, the constant cooling of additional water in addition to his normal "load" will actually cause his room to head up more. If he gets the ice from a common machine down the hall then yes, the bucket itself is pretty efficient, but the machine as a whole (which must include the production of ice) sucks it bigtime compared to a commercial air conditioner.
Moral of the story: "The laws of science be a harsh mistress" -Bender, Futurama
-philski-
In Australia we have a drought and water restrictions, you insensitive clod.
Save the waste water in a bucket and feed it back into the garbage pail. Save water.
MOUNT TAPE U1439 ON B3, NO RING
I was thinking about the project where they use Lake Ontario water cool downtown Toronto buildings. What if you used the water from your tap that has been cooled in the ground on its trip to your house?
Take the difference in temperature from your tap water to a comfy room temperature (65 to 75 degrees). The amount of energy from the amount of tap water I use in a day (a few hundred gallons) would be equivalent to the cooling that a room air conditioner could do in a couple of hours. Not enough to make a dent in a house's A/C costs.
You'd have to do something with evaporation before it would start to pay. In fact, this guy would have better luck with cooling his room if his copper tube leaked a little.
Exactly. This thing is neither an air conditioner nor a heat pump. It barely uses principles taught in a decent thermodynamics class.
That that is is that that that that is not is not.
Most people have a basement. If you invested in a few more Garbage cans of water you could effectively reuse the water by dumping into an empty can in the basement. With a little bit of elbow greese you could use a pump to refill the bucket upstairs in your room. If you could do this with say 6 cans of water that would effectively give you 18 hours of cooling. By the next morning the water would be back to a 55 - 60 Degree water and you could start the process a new. You would probably want to invest in some bleach as well to prevent critters from a growin'.
Neat Idea, funniest thing I've read all day
But this is slashdot after all, why not rig up a butane refrigeration unit (realatively low psi--it's easy enough to build a wankel engine efficient enough for compression) and a turbine water pump (plug the wiring into a box and you can honestly say it runs linux).
The guy just found a great excuse to keep a trash can full of ice water in his dorm room.
"It's an air conditioner honest. I have no idea why it smell like cheap beer in here."
You may think poverty is temporary, but it doesn't get any easier after college. Get used to rigging your own water cooled fans. Maybe Canadia has it easier. If you're one of the suckers who joins u.s. down here you'll be rigging a lot more on the long, hot road of survival.
http://www.lowes.com/lowes/lkn?action=productDetai l&productId=84590-48713-HWF05XC5&lpage=none
And not much more expensive.
If you could reason with religious people, there would be no religious people
This guy must have some source of free ice. If you have to pay market rates for ice, this is a terrible idea.
it hit the mid 30s in the North Bay, and high 20s-low 30s in the East Bay today. Hot enough to be #@$@# annoying. Of course, today, it was probably raining or something in San Francisco proper.
--
alex
The revolution will be mocked
Errggh.... no it doesn't
Salt in the water just allows it to be a liquid at a lower temp. Salt does also add a little more heat mass to the water. However, neither of these changes makes the solution 'colder'.
The reason you use ice in an icecream maker is to allow better thermal conduction to the container with the ice cream. You want the whole surface area to be below freezing. Not just the points where icecubes are actually rubbing against the container. Having the liquid state gives you 100% surface area contact instead of just those points.
Telcos have alot of dark fibre in the States. Most people assume that's optical fibre...but it's actually moral fibre.
Years ago, during a heatwave in Oakland, I built a homebrew swamp cooler with some muffin fans and a mist nozzle from McMaster (like 32215K11).
From thermodynamics, the say you have 1kg of water to work with:
Changing it from ice to water: 334kJ
Raising it from 0C to 25C: 104kJ
Converting from liquid to vapor: 2,260kJ
Compared with vaporizing water, melting ice is trivial.
For swamp coolers to work, the humidity has to be low--if it's high the ice bucket trick is a good one. But for those in dry hot climates, a swamp cooler works well.
I connected mine to a hose spigot with 1/8" tubing, which supplied a continuous flow of water to the mist nozzle, which was mixed with a good flow of hot dry air from the fans, and resulted in a good flow of cool slightly damp air.
Only when I read /. these days...
I think my way is much more efficient and more environmentally friendly. I just hooked my freezer up to my perpetual motion machine and leave the door open. Infinite cold air, and no puddle of wasted ice water outside my window.
I live in the Central Valley of Northern California. It regularly hits > 100 degrees (f) in the summer. Go down 20 feet, though, and you have well water at a nice, comfy 67 degrees year-round.
So, why don't I see any fridges that use that cool water? I would think that a closed-loop system were set up, pumping costs should be minimal - set up a nice, big heat exchanger, and pump cold water out of the ground, thru the exchanger, and back (probably into a different well)
Why wouldn't this work? Why hasn't it been done already?
I have no problem with your religion until you decide it's reason to deprive others of the truth.
if you add salt to the mix of water/ice, you'll get a much faster cooling effect
This is all very well and good, but he's missing one thing - capacity.
Air-conditioning systems are sometimes rated in "tons". That's "how many tons of ice required to melt in a 24hr period to get the same cooling effect."
Surprisingly, in AC terms, a ton is not a very large unit. A typical car air-conditioner is about 2-2.5 tons. This size AC is capable of cooling about half a house. So, a 5kg bag of ice? Forget it. Go buy a real air-conditioner. Scrounge around - 30 bucks can buy a decent old second-hand unit.
You are in a twisty maze of processor lines, all alike.
There is a lot of hype here.
Isn't there some irony in that Waterloo has met its waterloo? No, I suppose its perfectly apt.
In Texas, our office AC went out one weekend, but the ice machine down the hall was still working.
I didn't care how hot the place near the Ice machine got, but damn if I was going to live with 100F+ temperatures at my desk.
Bucket + extremely powerful fan + towel + ice == 20 degree drop in temp. However, when the Ice machine was empty, we were screwed.
Laugh while you can, monkey-boy!
Ground water from a tap is usually around 6C - 8C depending on where you are, etc. I knew a guy who did this type of thing except used a radiator from a car and the cold source was his cold water tap. Warm water was vented down the drain. Worked fine. Till his landlord wanted to know how he was using so much damn water...
But if you live in a large apartment block chances are nobody would ever be the wiser...
I've got a even cheaper and simpler idea: leave your fridge door open and set a fan in front of it.
why not it work well both ways, only not cheap to build
I have a better plan, and a cheaper one too. Big block of ice + fan = AC. Just cause he has high tech ice... and his keeps your floor dry...
Cold water can make air colder. Woohoo!
1 lb. of water
Changing it from ice to water: 144 btu
Raising it from 32F to 75F: 43 btu
Converting from liquid to vapor: 970 btu
Is that a real poncho? I mean, is that a Mexican poncho or is that a Sears poncho?
"The MUCH better systems are 'split' ... But... this was Australia... I've NEVER seen a model like that here in the US."
m ay_port_dual.htm
There's things like this:
http://www.fedders.com/catalog/appliances/portac/
It's basically the same thing as your standard in-window unit, except that rather then putting the whole thing in the window, you just put a couple of flexible air ducts (hoses) in the window, and put the unit on the floor. You still get the compressor noise, of course, but you do get a good amount of cooling without needing any special installation. They cost a bit more then an in-window unit, but not too too much. I've used them to cool computer rooms before.
dragonhawk@iname.microsoft.com
I do not like Microsoft. Remove them from my email address.
Lucky me I just came from Seattle and I am hiding in AC'ed offices, server rooms, and am making my landlord poor because utils are included. But I plan to be nice to him and upgrade the 70's era AC units with modern ones. How do I know they are 70's era? Who pray tell uses brown plastic anymore??
Sorry about the writing. Robot fingers, you know? Cliff Steele in DOOM PATROL #23
...misattribution than Mark Twain have been greatly exaggerated. -- Benjamin Franklin
Yeah, suck up that power to freeze ice, pump that electric fan, and the increased heat out your window and into your garden. With energy sucking friends like those, the environment doesn't need enemies.
--
make install -not war
Ice Expeditioner: You gotta start charging more per bag, we lost 4 men on this expedition!
Apu: If you can think of a better way to get ice, I would like to hear it!
Back in college when we used to fill a kiddie pool in the yard with hot water from upstairs using this gravity feed method, rather than suck starting it, we would crimp the low end of the hose and pitcher water in at the high end to get it started.
Perhaps you meant "I suggest that you start with capital letters" or "I suggest starting with capital letters"... It might be a good idea to choose a single qualifier, as well. Beginning one clause with "if" and the following with "perhaps" just doesn't read nicely.
;)
Clumsy grammar is not terribly persuasive. Perhaps you can join him in his English studies - that'd likely help with the quality assurance needed for your technical writing.
..Don't they all live in igloos in Canada anyway? (kidding, I'm living in Canada right now. If you'll excuse me, I'll ride away on my dogsled.)
It's a neat hack, but I seriously doubt it is cost effective, and it certainly is less environmentally friendly, compared to just running an air conditioner. Now hey, maybe you have other reasons not to run an air conditioner. But pointing out the cost and the environmental issues in the writeup led us to believe that you had invented something which was either cheap or environmentally friendly compared to buying an air conditioner.
It's not at all "environmentally friendly" because that ice maker or refrigerator uses just as much electricity and nasty ozone-hostile refrigerants as any AC unit ever did.
If he's using his refrigerator to make the ice, he's not being efficient at all. He's moving heat from the water to the room's air to make ice, then from the room's air to the water to cool off the room he heated up while making the ice.
If he's taking the ice from a common ice-making machine, he's being a parasite on the rest of the student housing population.
take off your clothes. Don't drink beer. Put your fridge outside. Don't cook. AND TURN OFF YOUR COMPUTER and read a book, the bible. Death, destruction, monsters, sex, it has it all. It makes L. Ron Hubbard look like an opportunistic Scientologist. Poor Kaite Holmes. Poor red headed Austrailian pragmatist who married Tom Cruise.
At any rate, I love PHP and Java and LINUX!
If you payed a different rate during the off-hours than the on? Then his plan would actually work by evening out the work needed to cool the place. Props if he uses cooler night-time air to reduce the ambient room temperature before engaging cooling.
One can make a more extreme version, by using better temperature storage cells with a greater differential between what you want and what you have.
That's why you need a doctor's note* that says you have "allergies" and need an air conditioner.
:-)
*I mean, I think just about everyone has an allergy to something and to some degree. YMMV convincing your doc of that.
A preposition is a terrible thing to end a sentence with.
At first glance I thought it said "Hebrew AC for under $25". I was just about to say, "Boy, are those hebrews smart.
Table-ized A.I.
Agreed. That guy is a total prick.
It's really obvious that if he makes his own ice using a fridge that's in the same room that he's cooling then the machine won't get him net cooling.
But where did it say that?
Maybe he has a big old chest freezer in his garage - the garage gets unbearably hot - but he doesn't live in his garage.
Maybe there is a free ice-maker in his apartment complex.
Maybe he buys bags of ice from Kroger. ($1.40 buys 10lbs of ice - that'll get you a big bucket of ice-water).
Maybe he makes ice in his fridge all day when he's at work/school - then opens all of his doors and windows to let the hot air out and get the room back to ambient before turning on the home-made A/C unit to chill things down when he's at home.
There are LOTS of ways that this could actually work.
But since cheap A/C can be had for $100 and is pretty much guaranteed to be more efficient and less hassle - I don't think this is such a wonderful device.
www.sjbaker.org
"you could use cool urine"
Don't you mean... frosty piss?
+++ATH0
You need a FREE iPod Nano
You are forgetting the anti-freeze to kill off those nasty algae.
But then again...after you dump the warm water outside, you can probably kiss your lawn goodbye.
Perhaps, but then you've salinated the waste water. That's hardly something you want to dump in your garden.
You are checking your backups, aren't you?
I live in a 500 square foot loft in my parents house (go figure). The loft is on the 3rd floor, and in the summer, the temperature and humidity are unbearable. It's a good 10-15 degrees hotter then the house (normally around 20 celcius). The central air condioner isn't able to get cold air all the way to the ducts in my room. Currently, I just have 3 large fans pointed at me running all the time, and I sit in my underwear, sweating like a pig.
I'm gonna try this homebrew system out and hope that it works. My poor body, and more importantly, my computer, can't handle this heat. My friends hate hanging out in my loft in the summer, because it's like a sauna.
This is a swamp cooler. Nothing new. Popular in places where they have dry heat (southwest US). But not very efficient, and almost useless in humid weather. Really, this isn't much of an invention and shouldn't be a slashdot article.
if you get your ice water from an un-electric fridge.
http://www.walkingtaco.com
My college residence had free (pre-paid un-metered) hot/cold water, then this could work as a low cost heater also. (electricity was metered, but the water heater was gas)
The problem with normal air conditioning is that it requires a massive amount of electricity to be used during the hottest hours of the day. This results in everyone drawing a huge load of power at the same time, resulting in strains on the system and so forth.
Rewind to a conservation/proof of concept idea from Alabama Power back in the early 90's: Make a lot of ice at night, when it's cooler outside and much less electricity is being used. Since there is excess generation capacity at night, this power costs less to use. (Err, especially if you're the power company.) During the day, use the ice to cool the building.
Assuming your local power company would install a second meter for you that lets you pay less for electricity -- but only at night -- you could make ice at night to cool yourself off during the day. Run it through a few calculators, but eventually the electricity savings would pay for the equipment. (Including the ice machine...)
I've never understood people who reply to shockingly-offtopic posts logged in, knowing they'll be modded offtopic for it.
How about a lithium bromide absorption chiller, then? That is, if you have a free gas stove to boil off the water & recover the lithium bromide.
This device may actually result in a long term reduction in room temperature by eliminating one source of heat -- you.
What I think we're missing is the principle behind it all. This guy had a need and instead of just running out and buying an air conditioner, he designs and builds something that meets his needs (cooling off the room before bed). It's not perfect but he used his ingenuity to build a cheap air conditioner rather than just throwing a fistful of dollars at the problem. I wonder what this world would be like if we took the initiative to do things like this more often?
But watch out - evaporating lots of chlorinated water releases chloroform-related gasses..
Also, swamp coolers dont work in high humidity - for obvious reasons..
Perhaps a Peltier device might work better?
Thats what my next personal cooler project is going to be based on..
This is a hell of a long way from an "excellent idea".
All you are essentially doing is opening the door to your freezer. Homer Simpson comes up with better ideas than this...
You are dramatically stortening the life of your freezer, making it use significantly more power, and are only transfering the heat. Your freezer will output more heat into your house than the ice it produces will be able to cool.
Purpose-built air conditioners have the hot side mounted outside your house. If they were like freezers, with the heat going out into your house, they wouldn't possibly be able to cool your house one bit.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
Clearly he has a particular room besides the kitchen in mind for cooling.
So he is cooling another room at the expense of the kitchen, which should be OK if the room is closed-off.
We have temparatures soaring to 45+ degrees C in india, and AC's cost in the region of about 15000rs(380$). Most people go in for these coolers which cost around 30$. They have a water pump which deposit water on the mats and the fan directs the air. The power consumtion is around 200W, compared to 1900W of AC. So if humidity is not too high, they do an excellent job. The branded ones which are factory made are expensive at around 150$, but the local electircal shop will get you the 70-80$ one.
My Aurora : http://www.youtube.com/watch?v=o91ZsGwJYyg
FB : https://www.facebook.com/TanveersPhotography
For a moment I thought you were a WEEF TA. I was going to laugh my ass off. Then I realized that wasn't the right room#, and read the sentence again.
Why don't you just sleep in the Comfy? :)
...it looks like something Red Green would come up with!
The race isn't always to the swift... but that's the way to bet!
Which means he probably doesn't pay for Water or Electricity. And my guess is he gets the ice by the bag from some place other than his own freezer. So quit saying how inefficient this is. For $25 and the cost of ice, this guy's room is going to be nice and cool. It's that simple.
I have been too lazy to work out the thermo equations (ok, too stupid), but had been contemplating avariation of your chiller. I have an unused well under my property, and was considering pumping water from it onto my roof to cool the house on hot days. Jet pumps are pretty efficient, and I figured I could redirect the downspouts to the well head to ensure what didn't evaporate partially closed the loop. Silly? Impossible?
I hoped the cool roof would result in a current cooling the entire house.
>>Put salt in the water. The ice and chilled water mixture gets colder with salt.
:}
>Errggh.... no it doesn't
Errgh.. yes it does.
Salt in the water just allows it to be a liquid at a lower temp.
Which means what? It means that you've shifted the equillibrium between ice and water to a lower temperature. Which will lead to the ice melting faster until the depressed freezing-point is reached. (after which the melting will actually proceed slower than before since the whole solution is colder)
The reason you use ice in an icecream maker is to allow better thermal conduction to the container with the ice cream.
I assume you mean 'salt in an icecream maker'. And that is wrong too.
But if you don't take my word for it (although you should; I've got a degree in physical chemistry), then perhaps you should go look at this entry in the General Chemistry Online FAQ, which adresses exactly this.
Perhaps you should read the whole thing before you start correcting people on basic chemistry.
Build a shelf in front of your window to mount your AC unit on, then make some side panels that conform to the angular shape of your cranked open window.
Even if aren't the least bit mechanically inclined you can get any hardware store to custom cut a piece of plywood for the AC shelf, and fill in the gaps with some cardboard.
Divide by zero hurts my brain.
I was sure someone else said this, but no and not so clearly...
This is a heat exchanger, NOT an A/C (heat pump).
I am soo unimpressed with this, I forgot to post.
MAKE YOUR TIME
I dont see any reason why this wouldn't work
here in australia i have a few mates that have set up sprinklers on top of the shed, can easily drop the temp inside by a few degrees which makes all the difference on a 40deg day
You use the clear ice instead.
Dumbass.
-- Ender, Duke_of_URL
yes, clearly if you are a phd you have a grasp on thermodynamics far beyond that which our eleventh grade physics teachers taught us, but you missed the lesson where you would have been taught to address basic criticisms of your design right at the top of your webpage, or at least list the cost of producing ice in your cost summary.
PS no one has mentioned that not only did you do this for 24 dollars, you did this for 24 Canadian dollars, which is what, like seventy-five cents? god i love Canadian money, it's like spending tickets at Chuck E Cheese's.
If you have a fan only setting on your thermostat then go down into the basement and bypass the air return ducks so that it's sucking in cold air from the basement. think of your concrete foundation has a big ass heat sink.
Oh yeah.
Why does yahoo do this
2: On-Demand, CNG water heater (i.e.: no tank to keep warm)
Even better, get a solar water heater. This is how it works: you install these tubes on your roof facing in the normal direction of the sun (not too many can heat lots of water). You have two tanks for water (both well insulated). The first tank brings water from the mains and has a coil in it. A pump sends ethylene glycol through the pipe to the tubes on the roof and back down and through the first tank. The substance has a high heat capacity, so it can move energy well. You also have another well insulated tank (both can be fairly small) that heats the water conventionally if the solar heat isn't enough. When the difference in temperature between the first tank and the roof fluid temperature is great enough, the pump automatically turns on to heat the water.
I had a chance to see one of these systems here in Seattle. The tubes aren't very big or noticeable (they can be put on the side of the house as well, if you get enough light there). They can produce heat most days (even here in dark Seattle), even when it is below freezing outside (the tubes contain a vacuum, so the light radiation comes in, but there is very little way for the energy to come back out (no convection through atmosphere)).
I can find more info if you like.
Andrew
If you had a 80 kilometres, or so, of tubing you could pump cold water from Lake Erie or Ontario through the copper coil and cool your room that way. Like what them folks at Enwave are doing in downtown Toronto. ;-)
Why cant he get into the refrigerator and sit there sometime !
Why does yahoo do this
have a closed loop of pipe filled with water.
Run this pipe (in a nice bendy formation to increase surface area) through the cistern of the toilet
Preferably a toilet above you with a 1-way valve in the pipe so the hot water at the bottom will pump itself to the top. Else use an electric/wind pump
It won't do nearly as much cooling (and the amount of heat it can take away is dependent on how often people go to the toilet) but it's free to run and doesn't produce any extra heat to get rid of.
It takes a few degrees from your room (maybe only 1 degree) and who cares if the water you flush your toilet with is a bit warmer?
FGD 135
If you buy an air conditioner, when the air conditioner breaks, you have all that chemical stuff you have to take care. So in that sense it is more environmentally friendly.
I'd actually be interested in seeing this. I've got a few spaces that could use some A/C on the cheap.
Who cares about the ozone layer?...thanks to CFC's I can write my name......IN CHEESE!!!
>>> "Since very few residential customers in the city get billed for water usage, this would be a PERFECT solution"
... but do you Americans ever look beyond the dollar cost of anything?
I think you need to check your definition of perfect there. Wasting water has huge environmental impacts.
Not wanting to make huge stereotyping statements
Where he of course met Guinan and Data and was almost killed by time shifting aliens that were attempting to steal our souls. Wouldn't that be anyones worst season?
"Genius may shine aloof and alone, like a star, but goodness is social, and it takes two men and God to make a Brother."
to cool the body?
Drink a lot of water and eat alot of hot peppers. This makes you sweat. Add a fan to aid in evaporation and whammo, you're cool.
would operate a normal friggin proxy, using whatever port their friggin corporate firewall has open, and the access the coral cache from there....
/. from Work ?
Btw, u r surfing
Heretic !! Burn, Burn !
(yeah, I'm unemployed.... does it show ?)
I put in a geothermal heat pump in my new home (2001), with it's capacity spec'd about a ton over the recommended size for my house volume. No problem cooling or heating the place.
pros:
1. no outside condenser unit (noise, ice buildup, landscape around)
2. no resistive heating when outside temps drops into the 20s
3. SEER16 all year round, not just at that test temp for the SEER rating.
4. essentially mortgaged some of my heating/cooling bill with the upfront expenses
cons:
1. builder had never installed one before and turned the issue over to me
2. upfront cost of 3 200' wells for the closed loop has to be amortized into my savings
3. holes in my basement wall leaked in big storms from that direction, but then most of them did at one point or another.
As an aside I've noticed that late-afternoon sunlight heats my western side of the house, probably about the same time as the attic heat starts penetrating the R-38 insulation. Attic vent fan helps a little bit. Also electricity costs about 25% higher during summer months here in Virginia, so it's important to design for cooling.
Is it a rule, that there's an exception to every rule?
This is not really Air Conditioning. The heat will not transfer from the water that fast, because it is not going with the water for a long time.
What this thing is doing is adding lots of miniscule Cold water droplets to the air. This helps by cooling the air, but increases the moisture. It is a great method for reducing temperature during hot and dry conditions, but very bad for hot and humid conditions.
In our place we use this till July, then when monsoon starts the only recourse is an Air Conditioner. But Air Cooler is very cost effective compared to Air Conditioner, and IMHO also more environment friendly.
Ofcourse you don't need ice from the Freezer, simply using tap water is enough.
Anti-freeze is usually Ethylene-glycol. You are correct that it is quite toxic.
in thermodynamics class, were they...
Well, if you ran the water through a coil inside your house with a fan blowing across it and then ran the warm water back into the well, you would have built yourself a heat pump of sorts. We had a house with this in Washington state when I was a kid, except that we had two wells - pumped out of one and into the other. It worked fine for cooling, but not so well at warming.
Add salt to the ice, and the water flowing will be much colder in the copper pipes.
Of course, this doesn't take into account the cost of producing the ice at all.
Depending on the local humidity levels, a swamp cooler (straw pads kept wet with a small drip pump with a fan passing air through) would be more effective and predictable. Won't work here in new england where temperature and dew point are nearly the same on hot days, but its a staple of life in Arizona (or was when I was there).
Now -- if only you had a nearby source of inexpensive cold water.
The problem with quotes on the internet, is that nobody bothers to check their veracity. -- Abraham Lincoln
Great idea ..... except in the end you're going to spend more money just on freezing the ice to run the thing. And guess what? If the fridge you use to freeze the ice vents into the room you're trying to cool, it'll never work. Frankly I'm amazed fridges don't have proper outside flues, but maybe in the winter you want the excess heat from your food.
A proper, two-unit air conditioner is the way to go if you want something cheap to run. A single-unit air conditioner is generally a poor substitute, because the air used to cool the evaporator {the bit that chucks out the waste heat} is usually drawn from the room. However, if you can find a way to modify it so as to make the evaporator draw its cooling air from outside {another length of Kopex and a fancy homebrew adaptor} then you can improve its efficiency somewhat.
I had a wild idea to replace my gas boiler with something like a beer cooler, and pump icy cold water around the radiators. However, I don't know how well this would work in practice: my own heating system runs the circulating water at about 80 degrees, just to heat the rooms to 20 degrees. So to get the same differential temperature, you'd need to cool the radiators to -40!
Je fume. Tu fumes. Nous fûmes!
Actually, if you want to solve at least a few of the problems that some have pointed out, a supply of free ice would be a good solution. But where do you get free ice? Well, back in high school, my friends and I used to always fill up our beer cooler by stopping by whatever fast-food joint we would come across, and just ask them if they could fill us up. You might think that they wouldn't do so, but, as they have to clean out their ice machines often anyway, they are often glad to do it. They're just going to empty out the machine anyway -- wasting the ice. Granted, you have to be nice, and catch them at a slow time, but we never had trouble finding someone who would hook us up, even on road trips through random small towns. Also, if you're in college, there's a good chance that you know someone in the food service industry who can supply you. Granted, this assumes that you have a car to trasport the ice, but it also allows you to make a change to the system. Rather than using an open-top trash-can, you can use a large cooler with a drainage spout, which can be placed somewhere less obtrusive. You can also put it up on a shelf (or more likely a dresser due to weight), making it easier to find a drainage solution (set it up near a bathroom or kitchen). Of course, it requires making daily (or nightly) stops at some restaurant, a friendly manager (or managers) who will supply you regularly, a way of transporting the ice, and a bit more effort, but it makes your system much more plausible.
Our supermarket (Kroger chain) sells el-cheapo appliances from China like $70 ACs, $30 microwaves, and $25 TVs. They arent top of the line, but I wish these prices were around when I was a starving student.
It doesn't get colder -- it freezes at a higher temperature.
There's a *huge* effect difference.
High-temperature ice is still high temperature.
- Michael T. Babcock (Yes, I blog)
better yet, make the water run through some sort of porous pad. The fan will vaporize the water and you will have a swamp cooler, which will work better than the device you just described.
...and it's the middle of frikkin' winter over here! :-)
;-)
Yes, that's right, it was 79 F today, and we're 10 days from the winter solstice. Yes, it was a warm day for winter, even in Brisbane.
My point is that your perception of temperature is very, very relative. 30C is a warm day, but not hot. We don't think it starts to get hot until it's approaching 35...
Right now it's officially 18C in Brisbane. Cool by our standards - you might not agree, but when you're living in a house, with no central heating, designed for 35C summers, it gets cool in winter. Internal temps around 10-15C are normal for us in the mornings. What's your thermostat set to?
Not wanting to make huge stereotyping statements ... but do you Americans ever look beyond the dollar cost of anything?
Why bother? If we run out of water, we'll just take yours.
What he could do to make this even more efficient is to dig a 6-8 foot hole in the yard. Bury a series of coiled copper tubing in the hole with the two end going back up into the bucket. Buy a simple and cheap garden electric pond pump or fish tank pump to pump the water contantly from the bucket to the earth to the bucket. The ground at that depth is always at roughly 50 degrees. Then use the same system attached to the fan with suction but have the other end return the water directly back into the garbage can. The water bottle could still be utilized to increase effectiveness. This makes it into a cheap geothermal system that utilizes the same water over and over again. Also, to prevent even further loss due to evaporation, put a lid on the garbage can.
don't waste water please.
What he could do to make this even more efficient is to dig a 6-8 foot hole in the yard. Bury a series of coiled copper tubing in the hole with the two end going back up into the bucket. Buy a simple and cheap garden electric pond pump or fish tank pump to pump the water contantly from the bucket to the earth to the bucket. The ground at that depth is always at roughly 50 degrees. Then use the same system attached to the fan with suction but have the other end return the water directly back into the garbage can. The water bottle could still be utilized to increase effectiveness. This makes it into a cheap geothermal system that utilizes the same water over and over again. Also, to prevent even further loss due to evaporation, put a lid on the garbage can.
What he could do to make this even more efficient is to dig a 6-8 foot hole in the yard. Bury a series of coiled copper tubing in the hole with the two end going back up into the bucket. Buy a simple and cheap garden electric pond pump or fish tank pump to pump the water contantly from the bucket to the earth to the bucket. The ground at that depth is always at roughly 50 degrees. Then use the same system attached to the fan with suction but have the other end return the water directly back into the garbage can. The water bottle could still be utilized to increase effectiveness. This makes it into a cheap geothermal system that utilizes the same water over and over again. Also, to prevent even further loss due to evaporation, put a lid on the garbage can. I would be interested to see pics if this upgrade is implemented.
What he could do to make this even more efficient is to dig a 6-8 foot hole in the yard. Bury a series of coiled copper tubing in the hole with the two end going back up into the bucket. Buy a simple and cheap garden electric pond pump or fish tank pump to pump the water contantly from the bucket to the earth to the bucket. The ground at that depth is always at roughly 50 degrees. Then use the same system attached to the fan with suction but have the other end return the water directly back into the garbage can. The water bottle could still be utilized to increase effectiveness. This makes it into a cheap geothermal system that utilizes the same water over and over again. Also, to prevent even further loss due to evaporation, put a lid on the garbage can. Post an update on slashdot to see how your geothermal systems works out....
What I was expecting was something more like they had about 2000 years ago. The Romans, Greeks used the fact that when water evaporates, it absorbs energy (i.e. thermaldynamic law I had hoped he would use). I used this back in the 1970's to cool beer^h^h^h^h Cokes down. Put newspaper on top of them, pour water on that and 15 minutes later they are much cooler.
Of course the energy you want to absorb is the heat in the Cokes and not the sun. So while the sun would evaporate the water quicker, it would also defeat the purpose. Another old trick is to force air over the water to evaporate it.
Of course we could come forward into the early part of the 20th century that had closed cooling systems. One part could be heated and the other side would get colder. This is how gas refridgerators work. Yes there is such a thing, they can often be found in campers today. They use propane.
Which is why I'm going to go out and build one of these. No sense in having my $90 (no CostCo here) A/C unit confiscated by bureaucrats. Let them pay for the extra utility costs of an ice-based system. The fridge is not in my room.
Thank you, inkeystring.
I spent a year in various Asian countries and they all had those wall-mounted on-demand water heaters and they satisfied my "American" style of showering just fine. In fact, they were too hot. One of my friends had a bath tub and the wall-mounted heater was capable of filling that with hot water. I'm not too sure what you're basing your "first gallon" idea on.
In Japan, they had a smaller version attached to the kitchen sink and produced temperatures that could be used for cooking noodles or making tea.
Ground at that level is always at 50 degrees until you heat it up. Geothermal cooling requires HUGE transfer area due to the low thermal conductivity of the ground. I don't think you will upgrade to a working system for the $30 the original system cost (well, $30 plus a heck of a lot of ice :)
so
1: be a dirtbaggy college student
2: invent the already invented swamp cooler
3: take credit for it
4: ??
5: profit!
This is great for those in Chicago where cold water from the tap is free. Maybe our taxes go to pay for the water, but at least each house is not individually billed. Just hook a water pipe up and let the city pressure do the work.
Nicely done. There are restrictions on water use in the city, but that doesn't seem to bother you. http://www.city.waterloo.on.ca/DesktopDefault.aspx ?tabid=1256
As long as you need to fill the garbage can with water, why not just run the input tube straight from a slow running faucet?
Sure it isn't ice water, but in my area the water pipes are buried deep enoug so they are cold.
You won't use any more water, and you don't need the impressive garbage can in the living room any more.
Buy a new one at home depot for less than $60 when fall clearance sales arrive. Then like an intelligent little squirrel, put it away until needed next year.
Is that 28 degrees Kelvin, Rankine, or Reaumur?
Contribute to civilization: ari.aynrand.org/donate
i am a weef ta.
that is the right room number... come visit, im next to lorie.
Buy a fan.
Not from around here, are you? I think the nearest frozen lake is a two-day drive.
Lacking <sarcasm> tags,
When I return home to Las Vegas in two weeks, putting in a swamp cooler (aka evaporative cooler) is one of the first orders of business.
:(
It seems to me that before my exile, they had about a 4:1 cost advantage. Probably not as much now, as 10% humidy has become downright common
I'm trying to find out if I can connect it to my central air system. Ideally, the real air condidtioner would only kick in when it was failing to get enough done (e.g., run have the swamp coooler try to maintain 78F, and kick in the AC if it hits 81F).
hawk
My local Fry's store is advertising a $60 window unit. I think it's a 5K BTU model. Should easily keep a single room cool all day without having to refill a water tank every 1-3 hours.
Basically, this guy moved his landlord's icebox "heat sink" into his room...
If you don't have a Fry's, you've probly got something else similar near by.
And what about when your freezer breaks?
Most people have a freezer regardless if they use it or not. If you move into an apartment, the freezer is there. An air conditioning unit is an additional purchase on top of the freezer. Now if someone does not have a refrigerator/freezer and is considering whether to get an airconditioning unit or using this freezer hack. Of course this is ridiculous.
Thanks so much for the directions for the home-made air conditioner. I was dying during summer classes in my dorm room and was really excited to see a cheap alternative to AC. It took a day to buy and assemble but that night it was cool enough to party!! Thanks again!!
I think you need to check your definition of perfect there. Wasting water has huge environmental impacts.
You missed some tongue-in-cheek impacts there, paco. Fucking Canucks and Euros take everything so goddamn seriously, if there's a chance to dog-pile on Americans.
And FWIW, as other posters have pointed out, most NYC residents are apartment renters. Therefore, the landlord pays the water bill and tucks it into the rent, without metering individual units for it (unlike gas and electricity, for instance). Why? God only knows, I'm sure there's a reason.
Point is, if anyone gets too out of control on usage, their landlord will come-a-knockin' and ask some pentrating questions about reasonable water usage. So it's not like there's a massive tragedy-of-the-commons happening.
Also, NYC rarely has water problems, mostly due to the fact that it has a generally adequete water supply at present, and it's highly unlikely to grow its residential population anytime in the next several decades--living here is so fucking expensive that it's tending to scare as many out as the nice parts attract. Even a 0.1% annualized population growth would be highly surprising, in the next 20 years.
Most people have a freezer regardless if they use it or not.
And if they don't use it, it isn't likely to break. And if they use it more than normal, it's likely to break sooner.
>>Errggh.... no it doesn't :}
>Errgh.. yes it does.
Adding salt however would porbably not change the total amount of heat that could be removed from the air much though. Basically you are taking heat from the room and dumping it into the water/ice mixture which is then being ejected. Anything that you can do to get the ejected water temp to be as close as possible to the room temperature will improve efficiency - longer cooling pipes, more airflow, etc. Dumping in salt will drop the solution's temperature by causing the ice to melt faster (heat is absorbed in the phase change), and perhaps the colder brine will absorb heat from the air slightly easier, but the total heat absorbing capacity of a chunk of ice from the freezer is unaffected by the addition of salt.
would have made a lot more sense if he lived in a dorm (apparently he doesn't). I considered doing something like this at Fordham when I desperately wanted air conditioning but the fuckers at Res Life wouldn't let us install it. At that point I didn't care about efficiency, I just wanted my room cool in a way that got around Res Life's "no air conditioner plugged into our electrical system" rules.
+++ATH0
So is that a yes?!
You claimed air conditioners were "unbelievably efficient". I endorsed your statement by disbeleiving it.
Ceci n'est pas une signature.
If you have a forced air furnace and it's located in a basement, you have the the necessary stuff to circulate (somewhat) cooler air. First check to see that the furnace doesn't have air conditioning already. Second, make sure there are no stink sources in that basement. Remove smelly hockey equipment, rotting garbage, etc. Remove the door on the furnace that allows access the insides where the blower motor and fan are located. Somewhere on the frame of the door is a 'push-button' switch that prevents the furnace from operating with the door removed. Wedge this switch so that it is pushed in so that the furnace thinks the door is back on. Set the thermostat to the lowest setting to prevent the burner from turning on. Set the fan switch to 'ON'. ( If there is no fan switch, you will have to hot wire the blower. This is easily accomplished by any nerd by running an extension cord and plug to the blower connector after disconnecting this from the furnace. This should be self evident. ) Now we have the blower running and sucking cooler air from the basement and blowing out the registers! In my house the basement is usually 15 degrees F cooler than the first floor and 20 degrees less than the second floor, however, in Michigan where I live, we also have humid summers. Warm humid air condensing in a cool basement creates dampness and mustyness so a portable de-humidifier is a must. These things, naturally, blow out dryer AND COOLER air. Place this to blow into open furnace for max effect!