DIY: Water Chiller for hydroponics

[OGKushman]

So I have decided to not spend the 500$ on a water chiller yet. I wanted to try this design I have been thinking of. It should cost around 100$.

Rather then explain, I drew up some plans. Feel free to comment, I will report back within a day or 2 with results.

 

[BackWoodsDrifter]

Love ya OG but out me legue friend sorry!

BWD

 

[ozzydiodude]

Using a copper coil inside the fridge would give you a better heat exchange. A small fan blowing over the coil in the fridge would also help to remove heat from the water inside the pipe.

 

[OGKushman]

Well I was thinking copper but I don't want to deal with it reacting with substances in my hydro. I use tea so there is a possibility the small copper line will get clogged. Plus it is way expensive. May get 20 feet of 1/4 inch copper for the price of 100 ft of 1/2 inch vinyl. And 100 ft of vinyl tube allowed to cool before the pump is switched on its low setting should be plenty to keep it from heating the tubing.


If the plastic tubing gets gunked up or something I can toss it and get another, plus I will not need to use one single fitting which means no possibility of a leak.

Great idea! Keep em coming please!

 

[Grower13]

The plastic tubing for the water and ice hook up for a refrigerator might work well. Smaller diameter would cool faster...... you could get as much or as little as you need to cool the water.......run it right through the side of the fridge...... tread in more if you need it cooler or vice versa.

 

[OGKushman]

See I wasn't sure if I could get ENOUGH flow from a 1/4 inch line? I would also have to reduce the size and I don't know if the tiny adjustable sump pumps would create enough pressure to pass water through 100 ft of 1/4 in line?
May have to see in the near future.

Ok so this is going quick! Just picked one up of craigslist! Must recalculate; fridge at 176 watts. 70$, BRAND SPANKIN NEW. I'm a feel bad about drilling it.

 

[The Hemp Goddess]

I think it is a great idea and I see no reason why it would not work just fine. That is how they cool the water through the door on big fridges--they have large coils of tubing hidden somewhere in the fridge. I think that a 1/2" ID line is going to be too large to cool effectively if the water is moving. I would go with either a 3/8 or 1/2" OD, although I do not believe that a 1/4" line is too small. Depending on the size line you get, you may want more than 100'. The most effective cooling will come with the most pipe in the fridge. Get the thinnest wall diameter possible as the water is not going to be under any pressure (to speak of). If you have anything large enough to clog the line (even a 1/4"), it is going to clog the pump before it clogs the lines--the lines will take a small amount of debris, the pump won't.

I'm with you on using polyethylene lines rather than copper, even if prices were the same--there is a large chance that the nutes reacting with the metal in the copper.

 

[OGKushman]

I decided to try some suggestions...1/4 inch line was too small lol

Could not get a flow going without me sucking on the end of the 1/4 in line and I'm still not sure if it was capillary action or the pump that kept it moving. I had a ~200gph pump on it and I was getting less then 1gph out of it. This will freeze in the lines and/or not flow enough to cool the res. PLUS this was only 100 feet of the 300 I was going to use.


I'm def going to get 1/2" line now. I can always add a small fitting in the 1/2 inch line reducing the size, I could crimp the line a little...lots of ways to slow flow but now I see that too much is more important than too little.

Going back to the Depot to return this stuff then off to the hydro store. BBL!


Pic 3 shows the flow rate...it's basically a fast drip.

 

[pcduck]

Just a thought, I would place the cooling coil in water.

 

[OGKushman]

I can't do that PC there is not enough room. Barely room for the line plus I couldn't imagine having an open water container in there just dripping on stuff, leaking out the bottom and needing refilling. But as I was deciding on how to coil it I realized I could run 25 feet or so inside the freezer. In doing so I discovered the cooling coil in the unit is built into the freezer tray! So yay it should freeze before it sends it into the fridge!

So I returned the 1/4" and got 100 feet of 1/2" Food Grade, a 396GPH pump and a 1/2" in line valve for the cold drain to limit flow if needed.

COILING THE 100' WAS A HUGH PAIN IN THE BOOTY! Had to do it so door would shut.

Just finished...Ill report back in 24 hours. If it all succeeds I'll rewrite the original post and put these pics in place, if it doesn't work I will leave the thread as is for others to see how badly this failed lol.

Current Reservoir Temp: 71 degrees F
Current Ambient Temp: 76 degrees F

 

[OGKushman]

*let me note that my res temp may be 71 now, but we have had a few days of heat already this last week and my res was tipping 80. It just happened to cool down and drizzle here in SoCal today, the day I decide to tackle it. Hahaa

 

[pcduck]

OGK My thinking was 41 degree water would cool the liquid in the cooling coil faster then 41 degree air, thus not having to run/use so many coils to cool to desire temp. I was also thinking if heater cores or radiators might work instead of coils.:confused2:

Good luck hopes it works because it would be a great alternative to high price chillers.

 

[OGKushman]

Oh i know a cold bath would cool the coil faster, but once the whole system has reached equilibrium it shouldn't make much of a difference as long as the water exiting is the same temp as the inside of the fridge. But if I had a huge fridge id fill a 5gallon and submerge the lines in that. Just no room and trying to keep electrical costs down using a dorm fridge.

I was also looking into using an old Volvo intercooler I have sitting. But the openings are 2.5 inches which makes for a crappy time to try and convert it to 1/2"... and it had air sucked through it for 90,000 miles from god knows where. I did think that a heater core from an old small car would work but again I didn't want to buy a 100$ car part and didn't want to use old used parts from a pick a part.


Ideally if you could get a a huge fridge and not have to hand coil it would work best.


I believe* that switching on the fridge first with a full line and not running the pump until the fridge cools the whole line down will be a key to starting the process. Also you must purge ALL the air out of the lines or it will only trickle. Gotta do the old gas hose siphon sucker trick:rofl:

 

[The Hemp Goddess]

I would get rid of the brass pieces if you have nute solution running through them. You can get all of those fittings in a high density poly. I'm also a little confused with having to purge all the air from the lines....submersible pumps should not need to be primed.

 

[OGKushman]

What brass? It's all 1/2 inch line and a pump...

That was an old post and the 1/4" line and reducer setup didn't work.

If you don't pull all the air out you are left with air gaps and bubbles in the line, if the flow is not fast enough to push the air out so when it rounds a vertical piece of tube it won't circulate the water. It just sits behind an air bubble. Your not priming the pump your priming the line.

 

[Growdude]

Plastic tubing is not going to be the best at heat transfer, especially just a big fat roll like that.
What you need is a finned coil that allows space for air between each turn, this allows for the cool air to contact the warmer coil, its all about surface area.

Use stainless if your worried about contamination.
They sell a radiator thing I think its called the ice box, it goes in the fridge.

Also what might help the setup is a thermostat valve that would hold that water in the hose long enough to get it cold. Like the cold water dispencer THG mentioned because it only needs to fill a glass or 2 then has time to chill down again.

If all fails you can allways hxxp://www.kegerator.com/RCK-LC-V-Value-Door-Kegerator-Conversion-Kit/RCK-LC-V,default,pd.html?cgid=Draft_Beer_Components-Kegerator_Conversion_Kits

 

[OGKushman]

GREAT IDEAS^^^^!!!!


Lights on tonight...It works!

Reservoir: 59 degrees! (I turned the fridge thermostat down a little)
Ambient temp: 71


Gonna take some fine tuning but 62-65 is my range with the root issues I've had in the last few grows...more to come

eace: :48:

 

[Growdude]

Im glad to hear its working.

 

[brandylorton]

Well nice to see this kind of system working for the hydroponics gardens . this really saves alot of amount of money so we can spend that much money for the expansions our project.