I just googled it and ran across some guy's description of how he converted an a/c unit to a chiller for his saltwater fish tank.

Any window a/c should work. My donor a/c was a 20+ year old 8000btu unit that was destined for the dump.

The basics of it are that you disassemble enough of the casing to get to the low pressure coil - that's the coil that gets cold when the coolant expands and has air blowing over it to make cool air.

Once you expose the coil, you remove any brackets holding it down, and simply unbend it ever so gently and then rebend it such that you can dunk it into whatever you want to cool.

I recommend exercising a bit of caution here. Unbending tubing requires no special dexterity or skill - just patience. Do this outside and wear eye protection in case you break the tubing.

All a/c units have a thermostat - whether or not you can set the unit to a specific set temperature.

I poked a hole in the wall of my res, shoved the thermostat probe into it, and hot glued it.

The thermostat limits the low temp to about 65f. Before I routed the thermostat and it ran wide open, it was pulling down into the 50's.

Again, that's 70+ gal of water that would otherwise be heated by the pump to about 90F.

Why not do this?

It throws off a fair amount of waste heat, and it's as noisy as the a/c unit you start with. It does use power.

It's also nearly free, outperforms units costing hundreds, and you save an a/c from the landfill.

Hi,
Just a couple of thoughts for you. If you use an external pump (outside the res) you won't heat up the nutrient nearly as much as with the submersible.
Secondly, I just wonder about putting copper coils in nutrient solution. I have always understood that stainless steel tubing was best, as other metals tend to react with the solution.
Kudos to you though for an excellent re-cycling idea.

Is RO water really needed? Or is it just possible to use tap water etc? Any advice or is it a better idea to attempt to find an RO system in general. I don't know a WHOLE lot about it, so this is more so why I'm asking - in case I should study up. What are the pro's and cons of having it? What about letting tap water sit for 24 hours to take out the chlorine etc? Advice anyone? I love this type of set up, but I keep running into this situation. So, if it's possible to have the system without RO it would be much easier to get into it.

Whether you can use tap water or not depends on the purity. If you have an EC meter, or ppm meter, you can measure your tap water to determine total dissolved solids. The lower the reading the better. Personally I use water straight out of a mountain stream, with ppm of 20 and PH of 7.2 (Just lucky I guess)
And if you do find your tap water is suitable to use, it's a good idea to let it stand for 24 hours to get rid of the chlorine

some cool setups... I like the chiller idea...
one thing i would be scared of is leaks... all that unrolling of that copper pipe has got to weaken it...
i could imagine that freon cant be good for roots....

also I have heard that copper in the res..is very bad...

dont know how true it is... but from what i understand the city actually raises that waters PH so that the low PH water doesnt corrode the copper pipes...
if you can get a trouble free harvest off,using that small res.. I say forget about it... and keep it rollin

BTW ... the lucas formula is the best nutrient program known to man.... saves you money and a hell of alot of time changing res;s..
BUT ..you r hydro store dude will hate you,since you will only be buyin micro and bloom from now on... mine is always cryin he dont see me anymore...
especially when it seemed like I was droppin a grand every cpl days runnin soil....

Here is some info some of you have been asking for.


RO machine, and RO rez plumbing. $250



Chiller and meters. $750


Spray pump, and associated plumbing. $200


Chiller pump and float valve. $80


Essential tools. $40


Drain and associated plumbing parts. $80


Pump and water hose for drain system. $90


Two powerheads. $40


6 inch tubes, (2)epoxy, (4)bulkhead fittings, (3)blue tubs. $200




Insulation and Fans. $120



Many trips to homedepot and the plumbing supply. $40

Somewhere around $1900, not including lights and nutes.
.

The grommets, 1/4" vinyl hose, and the green spray jets,
can be purchased here. about $30
Click on the picture.


Click on the picture.

I have what is probably a very stupid question.



why are there two reservoirs in this system?

bump because this is informative

awesome! set up im learning soooooooooo much from all of you . thank you.

Impressed with the simplicity of aero. You said you run the misters or now "flow" all the time. Do you mean 24 hours a day, or all the time when the lights are on?