DIY window AC Chiller new Version

Thread starter #1
Last year I made a chiller out of a 100 dollar window AC and a 100 Gallon Toter from Lowes. While it has held up quite well, I think it's time to replace it. Your chiller is the heart of a water cooled garden. Why not replace this vital component as often (and for less$$$) as you change your hps bulb. A failure would not be a good thing even with overheating protection.


For this chiller, I scored a barely used 6000 btu basic window unit.





the foam divider removed. Most of these parts just lift out.





Here's the heat exchanger, gently pull it out of the chassis



Slow and steady



Notice how we straigten out the bends to get length.







I have mounted the contol panel a little lower to allow the temperature probe to reach the water and put the case back on. I'm very confident this 100 dollar chiller will handle the load I'm going to throw at it.


We built this container to fit into a specific space. It is insulated with 2" of styrofoam and will hold about 60 gallons. The lid is split and will slide 4 inches apart for the plumbing and heat exchanger to drop into. The AC unit itself will sit on top of the water box.



I'll have some more photos of the completed unit in the next few days.

I have also built a new box and wanted everything fresh! My new box is 12 X 4 and is 5' tall. It is divided into an 8 x 4 flower chamber with 2 1000 watt eye hps bulbs in Fresca Sol water jackets with the large reflectors and a 4 x 4 veg, mother, clone lab. I currently have a 600wt solarmax MH conversion bulb to veg. this will be in a fresca sol soon as well. I intend to cool the interior with my chiller and an Icebox heat exchanger. They claim they can remove 100% of the heat from a 1K hps with water chilled 10 degrees cooler than your room air. A 1k HPS generates about 4000btu of energy in the form of heat. Meaning the 6" Icebox is capable of 4000btu of cooling. We'll see how it works in my next journal.
 

WheeloFortune

Nug of the Month: Mar 2010
awesome bro. I just migh do this, I have an extra AC lying around, and run a fresca as well.
 
Thread starter #3
awesome bro. I just migh do this, I have an extra AC lying around, and run a fresca as well.
Wheelo... Let me know if you have any questions. I am aware of your setup as I have followed your volksgarden journals on and off for the last year. I'm not too sure on the conversion, my iphone converts 6000btu to about 2hp. I ran 1600 watts off of a 5200btu last run as well as a water cooled co2 generator, no problems and I live in a very hot part of the country.

I'm going to be starting a new journal on my next grow. I'm just putting the finishing touches on the new box. I'll be running 2600 watts this go round. going to try bottled co2 this time and I am going to try to use the chilled water and an ice box to cool the room. I run my water at 65 degrees, it rarely moves more than a few degrees.

this box is completely sealed this go round, no leaks anywhere. the 2 chambers will have their own water chilled AC system, thermostat and Co2 controller/bottle. I may even throw a heat exchanger on my dehumidifier to remove its heat. This will be a completely liquid cooled system running about 65 watts per square foot with the ability to have flowers inches from the 1k and temps in the zone at all times. You can also buy stainless steel tubing and run a coil of 65 degree water through your rez to keep it in the ideal zone as well. If my 6k btu doesn't handle it 'll splurge and but a 12k unit for about 200.00 at walmart
 

WheeloFortune

Nug of the Month: Mar 2010
sounds awesome. yeah, i remember watching your first tek on this.

just poking around and found this one. . . very nice.

I don't want to spens 800 bucks on a 1/2 horse chiller, lol. I wish there was a way to extend the copper tubing farther out of the ac unit.

Just goes to show how bullshit inflated chiller prices are.

If I do this i'll have to build a box too. did you ever think of building a pass through box with an in and an out, say 1/2, so you could just run water through the box with a pump like a regular chiller, and then I wouldn't have to move my res. lol.

$800 for a 1/2 hp chiller is rediculous. if a 6000 btu window AC unit averages about 550-560 watts, thats about 3/4 HP. 1 3/4 hp chiller is in between $1000-$2000.
 
Thread starter #5
I like being able to buy a replacement that day, at walmart. Believe me, when you have problems with water cooled, it can be a bitch! I haven't had any problems with the chiller or any pumps, just screwed up once and cracked a fresca sol.

I have thought of using a smaller box with an in and out, but it would need to be sealed which would be a bitch, or gravity fed which would work but could take up some space. I think a gravity fed box built into a window unit, actually mounted in a window would be cool. you could also just construct a box with the water level just under your window height, and drop in the coil.

I originally thought I was going to get away with 100 gallons of water, it was 105 degrees within 24 hours. I could get it to 95 with the lid open but i would lose water through evaporation, plus it was early spring and things had yet to heat up. I needed something good, fast and cheap. Since I could only choose two, I went for fast and cheap! I've been more than pleased with the results. It was really good, fast, cheap and plentiful. I had already spent 5x my budget on my kit and just couldn't see dropping 800 bucks on a chiller.
 

WheeloFortune

Nug of the Month: Mar 2010
thats sweet. and your not even using what would be the most useful part to my grow op. Putting it in the window!!

mounting it in the window would let me keep all the hot air out of. . . well the air. right now my small chiller pumps out hot air into my grow room. . . it's ventilated which helps, but keeping it out in the first place would be better. mounting the AC in the window would solve this problem. . . . its awesome, a chiller with an out door exhaust for $100. can't beat it.
 
Thread starter #8
thats sweet. and your not even using what would be the most useful part to my grow op. Putting it in the window!!

mounting it in the window would let me keep all the hot air out of. . . well the air. right now my small chiller pumps out hot air into my grow room. . . it's ventilated which helps, but keeping it out in the first place would be better. mounting the AC in the window would solve this problem. . . . its awesome, a chiller with an out door exhaust for $100. can't beat it.
Here's a clever solution to that problem!





This was lifted from here:
420 Magazine ®
 
do you need to have anything exhausted out the window? or can you just pop the ac in the room and let if fly? i have a 1000 fresco setup and need a cheap alt chiller for my res this looks awesome just not sure about if anything needs to go out a window
 

WheeloFortune

Nug of the Month: Mar 2010
take a look at the pics above akia, BDR just has it in the room. . . a chiller would also vent into the room.

it depends on how big your room is and what else is in it. are you going to put it in a small room with most of it taken up by plants? probably not a good idea IMO as it would make your room hot. if its an open basement or a big space, yeah it should be fine to run in the room.

I think that the ability to remove the heat out the window might be the best feature of this whole thing. a chiller doesn't do that.
 
Thread starter #13
If I had a window to install this thing in I would very securly install it in the window with the coil hanging out of the front. I would then build a rez that would fit under it and allow the coil to be submerged in the water. In my case, I have no windows and I'm in a very large building with little to no occupancy. The space can easily absorb the heat this generates. You could also do the DIY venting of the AC unit found on this site.

It would also be very easy to put this thing in a dog house or some small storage box right out side your space.
 
Thread starter #14
Your correct on the copper. Now this chiller cools my lights not my nutrient rez. When I need to chill my nute rez, I run a seperate pump circuit out of the chilled water, through a stainless steel or titanium coil in the nutrient water. this will chill a nute rez nice. If you just need to chill your nutient rez and no lighting. Use a camp type ice chest for your chiller water and run a pump circuit through your chiller water. You can keep the chiller water much colder.
 
well just went to the store and bought a 100 ac unit and tore it apart. so far so good oh i see why you need to keep the fan on :) don't take the fan off you need to something blowing on the heater coils...i wasn't thinking.
 
Thread starter #17
I haven't fired this system up yet but I would venture to guess that the insulation will make a difference in the heat if the summer.

I would recommend using a water filter before your fresca and RO water. My pump has a UV bulb in it as well. Make sure to take any foam filters off of your pump as it will likely dissolve if you use chlorine in your water to keep it clean. My last run was with tap water, the calcium in the tap water hardens on the coils. The bottom of my rez had about 1/2" of these calcium deposits that had formed and then fallen from the heat exchanger. This was after a year of use. Also be sure to PH your water to 8. Lower ph levels are more corrosive, the water will eat the powder coating off the fixture after a while.
 
Thread starter #18
$800 for a 1/2 hp chiller is rediculous. if a 6000 btu window AC unit averages about 550-560 watts, thats about 3/4 HP. 1 3/4 hp chiller is in between $1000-$2000.
Do you know how this is rated? Is it motor hp or thermal energy that is used for this calculation? I am clueless about this stuff. Seems like the increased effeciency of coupling with water vs air would change the rating. I mean have you seen the titanium coil in some of these commercial units, they're tiny!
 

WheeloFortune

Nug of the Month: Mar 2010
The British thermal unit (BTU or Btu) is a traditional unit of energy equal to about 1.06 kilojoules. It is approximately the amount of energy needed to heat one pound of water one degree Fahrenheit.

This is an intrinsic property and can be easily converted to other units.

This is not the conversion I used, this is from google.

* 1 watt is approximately 3.41214 BTU/h[4]
* 1000 BTU/h is approximately 293.071 W
* 1 horsepower is approximately 2,544 BTU/h
* 1 "ton of cooling", a common unit in North American refrigeration and air conditioning applications, is 12,000 BTU/h. It is the amount of power needed to melt one short ton of ice in 24 hours, and is approximately 3.51 kW.

but like you said you have to worry about efficiency too.

the numbers I used, was I looked up a 6000 btu air conditioner, looked up the spec sheet and just used those numbers. YMMV depending on name brand.