Building a DIY AC chiller & multi functional watercooling system

Ok guys, stay tuned, I just received a lightly used Samsung 6300 window unit. Was thinking about using as is (through wall or duct mod,etc)to switch from my current passive setup, but then I got to thinking..

I will only need to cool a smaller 7.5 x 6.5 x 6.25H sealed flower room with two 500-1100watt dimmable air cooled HPS lights, containing 2 separate 30 gallon 6 site RDWC systems, and also another small 20 gallon AERO/NFT/DWC hybrid system sitting in a passive veg cabinet with an 8 lamp t5 thats nearby.

I have a space in mind to place the unit, in a open faced cabinet thats right next to the flower room, perfect size and it already has a big vent leading outside at the back. Here is the awesome part, the vent (which is my old main outside air intake for flower room, w/ light proof box & filter) is lined up and exactly the size of the AC unit! If i remove my filter box contraption, that's not really needed anymore, I could slide the whole unit right in so the back would sit flush against the wall and damn near sealed into the inside lip of the vents frame, so that it exhaust straight out the wall. The intake would then be the cabinet itself sucking ambient lung room air in through the units factory vents instead of hanging outside. I would leave the housing on or make a custom one to direct the air out better and help trap any stray light that might escape through the back of the unit and outside the vent just in case. From outside if I put a better flowing mesh instead of the louvered grill I have it would look pretty cool I think seeing just the back of the unit.. through doubled up bug screen or something with a nice frame, not that that matters too much. Plus even better yet, inside just before the cab face frame I can drop the evaporator coil straight through a slotted cutout and down below the cabinets shelf and into a low profile foam board insulated RV water tank res I was going to make that would fit perfect. Its about thirty gallons short but long. I could possibly find something bigger or even add a reserve tank next to it later for more capacity.

Now.. If I go regular air cooled with the AC Id have to take up some space and box up a portion inside the already small flower room space, and flip the unit 90 degrees so it aims towards the same cabinet + vent.. or somewhere else and do extensive re-work to duct it through the wall and whatnot. I really don't have much room but could make it work. I know I don't want the unit to hang outside either. The worst part about this way to me is the fact that after all that work I would still have to build or buy a chiller & res.. which takes up more space, and is just 1 more unit that I almost don't even need except summer.

..So anyways I was thinking the conversion to a chiller (basically 6300 = 1/2HP) and centralizing all my cooling needs with one easily replaceable AC unit I have would be a nice way to go. I would build a multi panel with a bunch of cheap digital STC-1000 temp controllers for each pump in the the chiller res. 3 going to the 3 hydro systems with stainless coils, 1 going to a heater core hooked up to my 50 pint to blow thru, and 1(the main biggest line) going to a custom air handler and or ice boxes I will build.. from either triple stack heater cores, bigger alum radiator/tranny coolers, or just buy a nice sized exchanger.. whatever I find works best to cool the room itself and drain any condensation.

Also I would like to play around and possibly run another loop to another exchanger that would sit just outside the building, inline and up against my new intake vent that's for the lights closed loop ducting. I'm thinking in the dead of winter if running the fan at slow speed it would keep the freezing cold air (which sucks in and through the hoods and then blows right back to outside, through another exhaust vent that just above the new AC's cubby ) from causing condensation around the lights by actually pre-warming it some from the chiller res. Also, the chiller probably wouldn't be running at that time if at all but the air handler would be running in the room & warming up the chiller res, while the new exchanger would be sucking that heat away and chilling the res as well as the light. Not sure if that makes sense so I will make a diagram soon. Maybe even add a loop to help warm a pond or too another geothermal type coil outside!

I have more tools, materials laying around, patience, and time than money.. and a 1/2 ton of questions that I will add to the list.



1. Sound good? Crazy? Won't work? Not worth it?

2. Can someone tell me the best way to control and re wire this particular AC into a chiller?(diagram included below).

3. Best liquid solution or mix to run in the system?

4. Should I remove all the fins on the evaporator, add an aquarium current pump aiming at it in the res, dip it in plastic? What else can I do to help extend the life or make it work more efficiently?

5. Will this type of setup get me by for at least 1 year until I could afford a better chiller to install? How long has or did yours last?

6. Off topic, but could one also dunk the hot condenser coil into its own cooler just like the evaporator coil into a cooler for a res? Then remotely mount a radiator and water or oil cool the hot side? I know its possible with a coaxial exchanger like in the factory WC'd models..And that some people hook up misters. But would it simply work like that without too much effort?

Thanks!
-Drop

this is a bad idea, unless u have some hvac tools.

converting to a chiller is possible, but not without some real tools.

its unlikely that you could simply dunk the evaporator into a bath. in a dehumidifier? u probably could owing to how they are built... but an ac unit will simply not have the slack available to do this.

biggest problem is going to be your metering device. its probably a regular r134a cap tube affair which would mean any alterations to the evaporator performance would require altering the length and possibly the diameter of the cap tube...

u could throttle the flow of water to match the design subcooling though... u would need a thermostatic or pressure sensing water valve though. they are like 200 bucks, but u might find one on ebay or something.

they basically throttle a plug or valve according to condenser or evaporator temperatures or pressures.

I was prepared to cut or notch through the bottom front half of the AC units base plate that all the componets are bolted to, to make some slack for the bigger copper tube to bend down through. It would sit right on top the water tank res cut out hole, so Im sure it will reach, barely!

That valve your talking about.. If it the same kind Ive heard of guys are making there own out of an old drill with a cheap microchip that spins a regular valves handle, and saved 2-300$. It was to regulate flow into a washing machine converted to hydro generator to limit current to the charge controller. Like if the batteries are full it starts closing the water off to make it stop. Thats a whole other project im interested in..

So I also had another plan, somehow duct just the cold evaporator coils flow into the room without having to mount the whole thing through the wall. Basically the exact opposite of an AC box mod on the hot side, just duct the cold air in instead of the other way around. Then i was going to use a 25-30pint dehuey to chill the 3 systems as well.

Oh and ive noticed some refridgeration units they simply kink the copper to cap the flow to the evap instead of a smaller tube. Usually on fridges though. Also got me thinking about how when you just dunk the evap it does throw off the temp dif, and was thinkin maybe dunking the condensor in water too might balance it out again.

Now check this out, ive even thought about raising the evap coil and its sensor and fan straight up in the air, and submersing the entire unit (exept for the evap coil) down into a fish tank full of mineral oil. Like an oil cooled PC. The tank itself would be cooled with an outside radiator. it would run without shorting out in the oil, sounds crazy I know but might work great!

I can't help you, but I sure want to watch you make this happen. Please throw up a bunch of pics if you do this!

Cheers! Git r done!

no not a drill... idk wtf u are talking about there.

https://www.zoro.com/johnson-contro...PmGjwQyePlsVF09m9bL1EaAj1F8P8HAQ&gclsrc=aw.ds

queequeg152 said:

no not a drill... idk wtf u are talking about there.

https://www.zoro.com/johnson-contro...PmGjwQyePlsVF09m9bL1EaAj1F8P8HAQ&gclsrc=aw.ds

Click to expand...

https://www.youtube.com/watch?v=KSrSPDDnsn4 i was talking about this guys homemade flow controller that uses a drill to open or close a valve

def subbed lol

I've wondered the same thing about being able to convert an a/c into a chiller...or how hard would it be to turn a cold water dispenser into the same....

The way I see it, I can totally run with just the coil dunked into the tank of glycol, same with a cold water dispenser or dehumidifier.. but only for so long before someday it corrodes or leaks?.

Most the guys try chilling the lights and eventually give up or something.. but I think its a waste to do so and will just air cool them. For the room itself and the 2 control reservoirs I will complete the loops and air handler, which is the real heart of my system. 1/2 ton cooling should be plenty, correct?

In the mean time keep an eye out for a nice coaxial and line up an hvac guy and re-do the AC right or even have another one ready to pop right in. The whole cooling system besides that will already be complete and won't really cost much, i'm in the process of salvaging most everything.. + the AC was a gift

I will make the seperate loop going outside so that its hybrid and can be adapted to different coils for different circumstances, like down into the nearby creek when its raining from fall-spring, in front of the intake for the lights in the winter, maybe out again to another large res, pond, or holding tank someday, etc. I want to eventually rely on the geothermal aspects more than the AC to be honest.

It's like the only thing holding me back from the ultimate system is like two 100 bills, 1 for hvac guy 1 for new coil, some freon, a bunch of old scrap RV AC exchangers and car heater cores\radiators, some hoses and fittings, scrap metal panels, a couple fans & pumps,cheap temp controllers, and about 40 gallons of glycol solution!

lol... i've definitely strapped in for this one.

Drop That Sound said:

The way I see it, I can totally run with just the coil dunked into the tank of glycol, same with a cold water dispenser or dehumidifier.. but only for so long before someday it corrodes or leaks?.

Most the guys try chilling the lights and eventually give up or something.. but I think its a waste to do so and will just air cool them. For the room itself and the 2 control reservoirs I will complete the loops and air handler, which is the real heart of my system. 1/2 ton cooling should be plenty, correct?

In the mean time keep an eye out for a nice coaxial and line up an hvac guy and re-do the AC right or even have another one ready to pop right in. The whole cooling system besides that will already be complete and won't really cost much, i'm in the process of salvaging most everything.. + the AC was a gift

I will make the seperate loop going outside so that its hybrid and can be adapted to different coils for different circumstances, like down into the nearby creek when its raining from fall-spring, in front of the intake for the lights in the winter, maybe out again to another large res, pond, or holding tank someday, etc. I want to eventually rely on the geothermal aspects more than the AC to be honest.

It's like the only thing holding me back from the ultimate system is like two 100 bills, 1 for hvac guy 1 for new coil, some freon, a bunch of old scrap RV AC exchangers and car heater cores\radiators, some hoses and fittings, scrap metal panels, a couple fans & pumps,cheap temp controllers, and about 40 gallons of glycol solution!

Click to expand...

im sorry but i think you will find that 200 bucks is a bit low for the services of an hvac tech... unless you really know someone who will do it for parts and a get a coil for cheap.

more realistically u are looking at 500 bucks for a decent job here.

u need to recover the refrigerant in all likelyhood... braze in some service valves, ideally u would add a a piston oriface so you can fine tune it better/easier.

the above would be like 60 bucks in parts?

then u want a good valve to handle the head pressure changes... 100-200 new.

a brazed plate could be found for like 50 bucks... a coaxial coil for like 75-100.

then u will want to fine tune the refrigerant charge to close in on target specs for the origional condensing unit.

it might actually be cheaper to just buy an old water cooled condensing unit from like... a commercial freezer, and swap out the compressor for a single phase 120 unit.

I am willing to throw about $500 total. I have alot of materials, parts and pumps already. 30-40 gallons of glycol will cost a few. Fittings are unlimited and cheap at the reclaimed and unused building stores around here.

For the air handler I want to buy 2 of these http://www.sears.com/brent-industri...clid=CJyn7bq-v84CFVKEfgodH4sIVg&gclsrc=aw.ds#

or maybe 1 of these http://www.sears.com/brent-industri...Furance Supply&prdNo=1&blockNo=1&blockType=G1.

Was thinking I could put the two 8x8s in a triangle shaped config with the fan blowing in through the unused side. Just like a real system. From what I've seen just one 8x8 or 12x12 is possibly enough though?

I also was thinking I could use scrap evap coils from RV roof top ACs but they wouldn't have the same flow. All seems kinda bulky to me though..

So my other idea is to run a long skinny coil or bunch of connected 1/2 copper pipes through the caps from one end of a 8-10 inch diameter tube to the other. Use a large sweep tee on each end to also duct the air through, and make a bunch of half circle dams to stagger the air flow through it. Just like a water to water exchanger but for air. This could contain all the moisture to be drained from the lowest point on the tube, and be hung up on the ceiling, and help to flow air from one side of the room to the other! Seem like a better idea?

Kinda like this, about 4-5 ft long


or even a straight coil,something like this way..


I'm going to start collecting all the parts, any info on the wiring for the AC or where to get the best kind of stuff I'll need would be awesome, thanks guys.

For now I am cool with dunking the evap directly in, there's plenty of other people doing it..for years without a problem. Worst comes to worst ill have a high temp safety shut off going to the lights. If I break the line or it leaks somehow.. well off to grab another AC for like 50-100 bucks lol. Then I will be looking for the guy to do it right for sure. In the mean time it should work!

Oh ya 1 more thing. I have like 3-4 Roof top ACs sitting around on older 80's trailers and RVs. I was thinking maybe setup the AC as is and duct through the wall, the fool proof way to go! Then instead just play around with the roof tops and mount one outside on top a 50gal rain barrel and bury it or insulate it real good. The units are free to use, and weatherproof, keep the heat outside..where they belong! Then run the lines into the room outside.

Seems I would have the best of both worlds, a reliable working setup in a few days(minus the small amount of c02 lost from a window unit), and the ability to experiment and get a feel for water cooling. I could build the unit on a small utility trailer and have a portable standby water chiller on wheels. Have a quick connect ports ready to hook up next to my garden when and if need it.

I've done just that with a dehumidifier. It wasn't that difficult. Just be careful when bending the coil. Just took the front panel off, slowly bent the front coil(there are two in dehumidifiers) then dropped it in my main res' . The man res' has a manifold running 4 valves. 2 for heat exchangers and 2 for 2 reservoir's with stainless steel coils. Works great.

Nice job dwiz! Simple and effective, what size dehuey. running straight water?

I ended up getting lost on designing my system, and just been sitting on a bunch of different units and parts.

Sometime it will all come together in my head.. I would like to utilize the system to chill as well as a heat pump for other rooms.

I have decided that my garden would benefit mostly from an HRV at the moment, but plan to incorporate that and AC\Geo water cooling together somehow later. Right now my plants would die without aquarium heaters... Im looking more into saving heat energy as I cant pump it back into a house.

Where it gets real tricky is when you have constant nasty weather, multiple rooms in a super compact slightly extra insulated converted grow trailer , start throwing in multiple sensors, controllers, motorized dampers, raspberry pi/arduino chips, HRVs.. and try to make them all work together all at once in a fully automated setup.

What I really need to do is stop trying to design the whole thing first and build the individual components so I can experiment and begin to implement them together. The ultimate goal being a fully auto scale-able climate control system that i can replicate easily, sometime in the future. All on wheels, that can adapt to virtually any climate.

Lately I have been studying numerous different types of heat exchangers and the rotary wheel HRV (air to air)exchanger coupled with a nice DIY icebox like yours could make for a good air handler.








BTW, check out how easy it is to split an AC or dehumidifier if you have the right hvac tools in this video tutorial: https://www.youtube.com/watch?v=AXgHIrFqm9o.

Sounds like you got your hands full with designing hahaha. I started with a 50 pint then switched to a 70. The 70 pint works as a 1 hp chiller. Keeps a 30 gallon res' (only water) cooled to 57 degrees. That's 57 degrees while cooling two heat exchangers and 2 reservoirs. Its awesome!

I'd definitely start with a dehu and a res just to test things out. Diy the hole thing. The 12 by 14 exchanger on Amazon cost 65$. The air coming out is approximately 70 - 72 degree. The hydro innovations ice box on the same res stays at 74 degree and cost more.

Right now I could actually fill up a barrel outside with some water and glycol. 50/50 sound good? Hook up a pump and the exchanger and should be good to go until spring! Maybe even cheap out and use a spare radiator or heater core laying around...

I eventually wanted to get a few 8 or 10x10s, one for possibly heating and one for cooling, or both hot or cold when needed.

I just had a brilliant idea actually!! I could try to utilize the grey water tank (black water no thanks) that is strapped down below the floor, I already cut all the lines and gutted everything going to it from inside. I will have to check the size and location, but whoa that solves a big piece to my puzzle.

The floor is always cold and even if I managed to warm the tank up.. I would have radiant heated floors lol! This idea could make excellent use of the equipment on board my trailer that is otherwise useless right now.

Better yet..depending on location i might be able to punch a hole right down through the floor and into the tank, big enough to drop the exchanger of a dehuey or AC sitting above.

I do have a spot inside my trailer selected already for a short\long 30 gallon RV fresh water tank to sit as the res, and be insulated in 1-2 inch foam, but will involve a lot of work to make it work. One of the reasons I haven't started yet. The side vent from the old frig directly above actually matched the back of my 6300 btu AC perfectly, whith the res in a cabinet down below.