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/diy/ - Do It Yourself

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File: 116 KB, 1010x701, Air-Conditioner-Photo[1].jpg [View same] [iqdb] [saucenao] [google]
248724 No.248724 [Reply] [Original]

Is it possible to construct a cheap air conditioner, that will cool a small room, by yourself?
How?

>> No.248732

please reply

>> No.248734

1) Acquire ice
2) Put it in a box
3) Blow a fan on it

>> No.248735

>>248734

But.. wouldn't ice melt away?

>> No.248747

1) Put the ice-water mixture in a cooler--add salt for extra chill
2) Get some copper pipes
3) Siphon some water through that copper pipe+hose in the ice-water cooler
4) Put fan behind the copper pipes
5) Boom, air conditioner.

>> No.248876

>>248747
Hmmm. Very interesting.

What would you suggest to use for siphoning the water.

>> No.248889

>>248724
By the time you do all that you could get a small window-type AC on sale somewhere or even used and be done with it.

>> No.248892

I remember an info pic on it but can't for the life of me find it, sorry op.

>> No.248895

>>248889

But diy AC is more environment friendly and you won't be breathing some chemical air it emits.
Also I think where I live I have to pay extra for having actual AC because of energy consumption.

>> No.248896

>>248892

That would be awesome.

>> No.248900

ITT retards. By the time you pay for ice to keep melting it to absorb heat you will be many times more in debt then just getting a little window shaker and installing it. If you need DIY help fixing a busted one or something this is a poor site for that as well. If you think making ice in your freezer is a good idea guess what, all the ice makes more heat inside your house and costs a bunch to make in juice. ( i work for york google it)

>> No.248904

>>248900

Well, I guess you do have a good point. Then again my fridge would keep working on as usual. I would just try to produce more ice. AC would just add to more power usage.

Anyways, I'll look around for some cheap ACs before making my own.

>> No.248906

>>248900
This.

>>248895
"chemical air"
?

Don't be dumb.
And it is opposite of environmentally friendly unless magical ice fairies deliver it after mining it at the north pole.

>the copper-pipe array on a fan could work if you are in a rural location and have access to a small, cold spring that is otherwise wasted or undrinkable. almost every other situation? moderate utility at best.

>> No.248910

>>248895
it doesnt emit any chemical.

>>248904
your fridge will work more, an empty fridge work more than a full one, if you are putting water to freeze it it would work more to freeze the water all day. that is a solution for when your AC is broken and you are waiting for the HVAC guy.

>> No.248913

>>248895
The same chemical reaction uses the same reactants and releases the same products and consumes just as much energy whether the machine was built by hand or at a factory. Because building by hand is sloppy compared to factory production, diy is often more inefficient, thus requiring more energy and releasing more chemicals.

Consider freon, a common chemical used in air conditioning. If you diy an AC unit, you are depending on your own expertise and arm strength to ensure all the seals on the closed-loop freon cycle are perfect. A factory that uses lasers to gauge distance and hydraulic power is going to do the job better than you. The tiniest leak will leave you with freon in your air and require more energy to push the same amount of heat out of your room.

>> No.248917

>>248906
>the copper-pipe array on a fan could work if you are in a rural location and have access to a small, cold spring that is otherwise wasted or undrinkable. almost every other situation? moderate utility at best.

so funny as that is what my friends hillbilly stepdad did. They have a little coldwater springfed .25 acre pond that drains pretty fast into a bigger lake. The water comes up nice and cold so he made a hydro loop into it and runs a couple junk car radiators with fans in the house for them. He made them look nice with nice wooden painted and fiberglass resin boxes around them and they drain condensate into a little cup if it ever happens but rarely does as the temp differential is never that great. He does get away with many days of not have to use real AC but over all if its hot for a couple days in a row they get shut off and central air goes on.

Funny how guy thinks frigdge making ice will not boost power bills. It will and every bit of ice you make will add 25% at least in more heat to the house that now you need to make more ice needing and endless 25% more every cycle to get rid of heat. IN a week you will be needing a block of ice the size of the house to cool the house daily.

>> No.248928

>>248913
if built right no refrigerant will leak. Maybe a quarter ounce or less per year tops if there is a tiny tiny leak and for the most part just being in the grocery store will expose you to more. Most refrigerant is pretty inert except 123 and nh3 that is used now. some real old ones where very deadly but not anymore.

Most decent people will be able to make one not leak if they have any backround doing car brakes or airlines then try a little DIY AC work as compressoin fitting of HIGH quality do hold up well along with WELL made flare fittings so soldering is not needed on all joints. I have built many retrofits on york units using stainless flare and compression fittings in place of soldering that held up fine for over ten years. Some areas you can not use a torch to solder so you do what you have to do even on copper.

>> No.248929
File: 549 KB, 600x1300, 1319430077135.jpg [View same] [iqdb] [saucenao] [google]
248929

I hope this is the right image. Too lazy to check the thumbnail.

>> No.248937

OP, everyone else in this thread seems to be retarded.

http://en.wikipedia.org/wiki/Stirling_engine

You can think of it like this if you're stupid: A stirling engine basically has 2 modes of operation.

1. It can move heat from its hot intake to its slightly less hot exhaust and output mechanical energy from its piston, or
2. It can take in mechanical energy from its piston and move heat from its intake to its exhaust.

2 has the effect of causing the intake to become extremely cold and the exhaust to become extremely hot. Modern cheapass air conditioners and refrigerators have stirling engines filled with refrigerant (because it expands and contracts more efficiently than normal air), a heater coil at the intake that cools the air, and a fan that blows the cooled air out. There's also a heater coil at the exhaust that vents heat to the exterior.

There are just too many moving parts and too much complexity to DIY a modern air conditioner for less money than it would cost to just buy one

>> No.248980

>>248937
i dont think you really know how the stirling engine work.

>> No.249057

>>248937

Yeah, you're a crackpot. Stirling engines run on temperature differences, not strictly heat. Its quite possible to run one using ice and room temperature air. It uses the expansion and contraction of the air, or whatever working gas you've selected, inside the pistons to generate work. Using work to run the engine instead will not then make the working gas hot or cold. No more then spinning an empty steam engine will make steam.

>> No.249101
File: 9 KB, 216x246, striling.cryocooler.jpg [View same] [iqdb] [saucenao] [google]
249101

>>248937

No idea if someone actually makes Stirling air conditioners, but all the air conditioners I've seen this far have used vapor compression cycle, just like normal fridges and freezers.

>>249057
> Using work to run the engine instead will not then make the working gas hot or cold

You're wrong. Cooling is an important application for Stirling cycle machines. Not in houses, but in applications where liquid air (and lower) temperatures are required. Pic related.

>> No.249110

>>249101
No, anon was right, you are wrong. You can not use the work to load to generate the needed energy to compress those gasses. You need to spend a little time on your thermodynamics reading.

>> No.249144

>>249110

You could just google it. There are even videos available showing you that you can use a Stirling engine to produce cold.
It is possible because all the processes in a Stirling engine are reversible.

>> No.249153

>>249144
do share.

>> No.249154

take a piece of old canvas a little larger then the window you are putting it over, and slice it so that it is strips but the top and bottom are not cut.

attach the bottom and sides to the window sill, place the top in a vessel that contains water.

the canvas will get wet, warm air blows in water evaporates, air gets a bit cooler.

it wont work anywhere near as good as a real AC but you also wont be producing heat by making ice.

>> No.249155

>>248724
not that is cheaper and works better than the $100 recirculating-phase-change ones you can buy at wal-mart

using a stirling to cool is bullshit, as far as i've ever seen

peltiers are expensive and don't have very long lifetimes unless they are turned on and never turned off.... the expansion & contraction from cooling down and warming back up eventually destroys them

there are vortex tubes, but they require compressed air and are noisy
http://en.wikipedia.org/wiki/Vortex_tube

there are also standing wave/acoustical compressors that can be designed to produce thermal differences
they can be even more efficient than a normal recirculating heat pump, but only over a smaller temperature difference
only seen these at university, but I was told there are industrial ones used for particular reasons

this is all the refridgerators I can recall at the moment

>> No.249157

if you hook the fucking output shaft of your stirling engine up to an electric motor one side of it will get hot and the other side will get cold

if you don't believe me then go fucking try it

>> No.249159

if you have the time and inclination build a 10'x10'x100' sealed and insulated. At the top allow a 2' gap between the roof and the end of the walls and fill the gap with filter media, under the gap put run off trays, a sump, and a small solar panel powered recirculating pump and put a 6'x6' hole in the one side at bottom of the tower. Enjoy cool air.

>> No.249160

>>249159
and of course a distribution rail for the water to be pumped to across the top of the filter media

>> No.249161

>>249153

Dunno why I bothered, but here's some hobbyist's PoS machine cranked with a small electric motor: http://www.youtube.com/watch?v=5ImmaKORSII

Some company's ad for their free piston Stirling cooler. This looks quite different than the simple prime movers, but it's still based on the same principle: http://www.youtube.com/watch?v=Ig3PrQBdf2c

>> No.249162

>>249157
Yes, we understand using the unit as a pump. That's what it is, a differential heat pump. What you fail to understand is the fact that A LOT of extra energy is required to generate that cold and it's not very efficient, you could not use the heat/cold difference that the engine generates to run the engine, something else has to do the work. You really really need to read more about thermodynamics.

>> No.249171

You guys are doing this far too complicated.

Get a small fridge
Use ducting to guide the hot air from the compressor out the window. Use two ducts so that you have an input and an output so you're sucking away cold air while you're venting.
Open door
Turn on

You may want a small fan in the ducting. Water will collect inside it so have two towels. One towel is the working towel, absorbing water, and the other towel is dried outside by hanging in front of the ducting outlet.


If you get a stirling engine, connect it to a solar-heater or something neat like that.

>> No.249174

>>249171
Water will collect inside the fridge, not the ducting.

I should have proof-read that before posting.

>> No.249172

>>249171
*so you're not sucking away cold air

>> No.249173

>>249162

Of course it needs power to operate, just like all the other heat pumps. The thing is, the Stirling engine is theoretically ideal, achieving 100% of the Carnot efficiency (even in cooling applications). Of course, reality is different and "100% of the Carnot efficiency" isn't that much, but still. However, at low temperatures, where Stirling coolers are commonly used, their efficiencies are reasonably good in comparison to the other heat pumps.

> You really really need to read more about thermodynamics.

You should try it, too.

>> No.249252

>You could just google it. There are even videos available showing you that you can use a Stirling engine to produce cold.
>It is possible because all the processes in a Stirling engine are reversible.

gawd /diy/ is ignorant sometimes.

A Stirling engine is nothing more than a pump...it just uses external heat to expand a gas which moves a piston. Cool that gas and piston returns to starting position.

Now instead of using external heat to expand that gas, use external mechanical energy to compress it, and viola compressed gas/liquid (depending on the pressures and fluid/gas you have in the system)...

Just about any cylinder/piston setup can be made to run in a Stirling cycle, you just need the proper valves and timing for it all. Compact all in one designs are necessarily reversible because the valves are built as part of the unit, much like 2 stroke engine.

>> No.249259

>>249155

An ammonium phase change system would work well provided you have a high temp heat source.

I never really understood the desire to run a compressor off the motor in a car, when you could design the unit to use waste heat from the exhaust as the energy source. In a home environment unless you room for a solar collector or something it's not going to fly.

https://en.wikipedia.org/wiki/Einstein_refrigerator

>> No.249436

>>249252
how is that guy ignorant? It looks like you're backpedaling from here. Nothing you said disagrees with him. It's obvious if you compress the air at the exhaust and decompress it at the intake the intake will get cold

so what exactly do you have up your ass

>> No.249519

>>249436
>so what exactly do you have up your ass

The inability to read the whole thread before I posted...

Kind of like the others directly above me, it was a general comment toward all those who don't seem to have a clue of how a Stirling engine works.

>> No.249598

>>248913
It's highly illegal for anyone to handle freon, unless you're a licensed, qualified technician. The fine is a real bitch, to the tune of about $25,000 or more.

Making ice actually helps save energy, as it fills up your freezer. A fridge/freezer works harder with less stuff inside, as it has to cool more air. People actually make ice in large containers, to fill up space and save energy.

>>248735
It's the melting of the ice that makes the cooling action. However...if you're in a humid climate, that melting could actually make your room more humid and uncomfortable. The best way to tell is just to test the fan/ice combo in your own surroundings, to see if it's effective.

>> No.249613

I'm kinda curious randAnon. Could you use a weed-wacker engine to power an AC that you hang out a window, even if you had to start it outside?

>> No.249614

I learned an AMAZING trick from some polish people. They are pretty intolerant to the heat and they have been doing this for years in my area:

Make hundreds of ice cubes in your freezer. Once they're made, dump them into a trash bin or plastic bin of some kind.
Place a fan blowing across the ice. It will cool down an entire apartment in several minutes and will bring the temperature all the way down from intolerable to comfortable.

Depending on how much ice you have, this can last from several hours to an entire night. It works and you can save yourself all of the risk and hardship of sweating to build something that will probably be too inefficient and noisy to be of real value.

>> No.249620

If you have the money to pay for parts and then all of that electricity, then you've got the money to buy a damn air conditioner off of craigslist. If electricity isn't a concern because someone else is paying for it then use the ice-in-a-bucket method.

Either way OP, you'd be embarking on a technical DIY challenge that appears to be so far out of your league that the summer will be over before you get close to finishing it.

>> No.249627

If you have a house, run your water thru a radiator when you water your lawn. Blow a fan through it.

>> No.249700

Swamp Cooler.

Next question

>> No.249715
File: 42 KB, 960x639, alexandermarcus why.jpg [View same] [iqdb] [saucenao] [google]
249715

>>248724
Google earth tubes OP its interesting reading but I don't know how practical it actually is in the end. Please google it quick before these guys get into a knife fight over stirling engines. lol. I'm glad we don't have more trolls on DIY than we do or this board would be intolerable. good luck op