If I were to go grab a compressor out of a fridge and solder it to a series of CPU radiators (@Low pressure end), could I stick the radiators in the hydro solution? I know its weird, but I am modding my room and want to keep individual tanks cooled off (rig em later with some arduino or something). If I can braze something like this maybe smaller, and have say ... three in series for different tanks, could this work? Maybe I need to grab some plastic finned radiators, but I don't think that would be wise for refrigerant. Maybe its better to run individual Peltier devices, and just use cooling blocks instead, but I'm not sure how many such devices I would need, and at 14% efficiency, I'm thinking a cheap compressor is better.
There's been a few threads over the years by people using various stuff to cool their reservoirs. One guy had two radiators and a water pump, one radiator went in the fridge and the other in his reservoir. Another guy modified a window air conditioner to cool his tank. I don't know why you couldn't rig up something. Here's one DIY thread by this guy who was quite resourceful. Let's Convert an A/C to a Chiller... He says you can't use just any evaporator, it's got to be made of a metal that doesn't corrode in a tank of nutrients.
There is a similar video where someone uses a dehumidifer, but this is for a large res, not just 6 gallons. I think 6 gallons you could use a smaller amount. Also, that system was for one unit only. I was thinking something for multiple small reservoirs like: but I don't think its wise to stick a radiator in the solution. They are made of copper and aluminum and at pH 5.5 that would probably start to breakdown, but maybe not, idk. That would be filled with refrigerant as well, so not a good thing if it busts open. But, in defense of this method, one could always spray an epoxy sealant over everything to waterproof the radiator. Now, given the smaller volumes that I am working with, I was thinking instead to combine a similar item to: along with a cooler block and a small pump. But I'm not familiar enough with Peltier elements to conclude. Also if @Henchman21 @Tbone Shuffle @Nobueno714 @Steakbomb and lets welcome @Nafiestion , if you guys have any insight on this topic, maybe we can help out the community (heh heh and me) with a cheapo rig. Btw, that peltier rig is 72W, no driver included, but its just 12v so can just use a powerpac.
You're mixing refrigeration and water cooling. Those water cooling rigs can't take the pressures needed for refrigerant. Your refrigeration system is missing the orifice after the condenser that causes a pressure drop to change the temp cold. Put one of these coils in a cooler full of ice water. Some of the new more advanced coolers will last a while. With the copper in contact with the ice water you'll get amazing heat transfer. Put a similar coil in each res but stretch them out. Fill the coils with food grade glycol or just water. Run a circ pump triggered by a cooling thermostat in the res. Running a dehumidifier will cost lots of electricity and add heat to the space.
Cool idea! I think if you ran your coolant in series that your last tub may not be very cold compared to the first 1, but idk? Radiators typically have to hold hot liquid which they force air across to cool and circulate back around, so they need to be made of a material to withstand the heat. But if you're reversing the process, maybe you don't need metal radiators? Maybe just some tubing taped/shaped into coils? Then you wouldn't have to worry about pH coroding metals or leak spots at the radiator tubing interface?
Heat pump (AC, freezer, ect) uses a special refrigerant and certain designed pressure changes (condensors, evaporators, compressors and expansion valves) within a system to create a temperature gradient. You'd have to figure the pressure in the cold side if you wanted to try to use coils of tubing as your evaporator, but it might work, the cold side will be the least pressurized side. Peltiers would work. Like cactus said maybe a mini fridge that you drill a few holes in the side of or something for tubing, and then just put a few of the circulation water blocks inside?? Even a suped up cooler like tbone is saying would work. I like not having to empty or refill but perhaps if you had a good enough cooler you could keep temps in the range desired by only having to add a few trays of ice in the morning or something?
Aluminum is pretty non corrosive, Idk about a constant pH of 5.5, they may last for years but I can't say. But what about just creating a box for the radiator to sit in? Like a Tupperware box or maybe a sectioned off portion of the res. The solution won't conduct heat to the radiator though, then it would only convect heat, but it still may be enough heat transfer depending on how you designed it? Or maybe instead of a box filled with air, you drop the radiator into a box filled with a non corrosive liquid (with a lid?) so that the res can conduct heat to the radiator (by way of non-corrosive conduction liquid) instead of convecting heat, you will probably get better results that way.
If your trying to individually control the temperature of your reservoirs then a thermostat controlled peltier cooling block would probably be your best bet rather then a mini fridge or anything else. Your average peltier cell can lower the temp by 65 degrees Fahrenheit or raise it based on the polarity. Now as for a material that wont corrode in the solution, graphite would be your best bet. It is on par with aluminum for heat transfer plus it can handle pretty insane environments and not break down. You could individually mount these to your reservoirs as well and have them independently controlled. Peltier cells will give you total control but it will take a bit to setup with all the different drives and everything. Cooling using a mini fridge with a oil cooler or several coils of copper will be cheaper and easier to assemble but your not going to have the control. How many watts of power do we need to transfer also dictates how much cooling your gonna need. The peltier cells mount inside are going to put heat back into the grow area. Where as a mini fridge can be located outside. If your grow area is 77 degrees and the temp outside is 65 or less you could get away with just a pump and radiator style setup I'd think but any warmer and id look towards the either the mini fridge idea or mounted peltier cells.
Also for your Radiator I would suggest getting a heater core. Their just mini Radiators but are generally way cheaper to purchase. I've seen brand new ones for 20 bucks.
OK I wasn't sure, I didn't think it could and kinda doubted it. So it'll be back to copperhead road if I go this route. It was just a simple schematic; I realize some parts were missing; could even add a reversible flow valve to create a heat pump. Thanks also @Henchman21 for listing the parts, and thank you as well Tbone. I think we are all one the same page regarding convection and refrigeration, etc. Now we discuss the feasibility and expense of all methods, as we have started. yes, either a cpu or heater core... small and cheap. Wouldn't a cooling block (shown above) in the reservoirs be better? I like your answer too. I like everyone's answers. I've browsed some more and would like to share some results (I like to browse the Asian markets from time to time, I discover a lot of innovative and inexpensive devices). This looks like a better device than the first one I showed, although double the power. Naf, you mentioned to place one Peltier per res, so maybe the earlier Peltier example is better, but wouldn't this unit connected to a pump that splits off (manifold) into nth amount of lines to nth res work? The reservoirs should all be the same temp, so just monitoring one would suffice. I suppose I'm asking how much cold could a Peltier make is a Peltier could make cold? Maybe a larger unit is needed? *side note, a lot of people think China when they hear AliBaba, but this unit comes from Turkey. Still Chinese parts though lol. anyhow. As Nafi mentioned, these generate heat (which isn't always a bad thing), cost power, and still cost a bit considering you need a supply capable of delivering (up to?) 6A. money/efficiency...again, peltier elements are only 1/4 as efficient as contemporary compression refrigeration. Another thing I noticed, which isn't bad considering is a one package, everything included deal, are aquarium chillers like I'm just showing this one for example. They seem to range about ~$100 a piece (including ship). But I just don't trust what is in the white box; not when I see what it costs to piece a decent unit out. atm I'm not worried. My rt has been lowered to ~70F since the plants are in veg. I will ice pack the res' if the temps raise higher, but when the 96s come back and temps are raised, I will need to choose from the options you've all listed. So far, I'm thinking a combination of @Cactus Ed and @Tbone Shuffle suggestions. Little impro; get a (used) beer fridge; mod it to contain a reservoir (like a DIY keginator) (contains antifreeze whatever) -> pump/controller/sensor -> manifold/separate lines -> cooler blocks-> recirculating. dig it?
Here's an idea, get an old refrigerator that works in any position, lay it down, put your reservoir inside and it's Miller time.
I've thought about doing this with a mini deep freezer for some seriously high powered lights. People will also fill these with mineral oil and submerge their pcs in them to keep them ice cold when over clocking since mineral oil doesnt conduct electricity.
Using a chest freezer instead of a fridge laying on it's back is a better idea. You can get plug in freezer thermostats that convert a freezer into a fridge and the temps can be set from like 20-80F. A used chest freezer can be found for not that much and the temperature controller costs about $60-$70. The reservoir, depending on size, can be set in the chest freezer and as lazy as I am I think that's the way I'd go about cooling a reservoir.
Very good suggestion Cactus and Nafi. But I'm thinking to just get another fridge and double down to make a keginator with it too. My wife likes beer, and is asking me to brew some, but I don't like bottling and cleaning all that, so addy a keg, some CO2 and it would work. ...but now its going to cost more than everything else put together!? smh
Instead of running the coils in the 3 tanks in series you could create a manifold so it flows through each of the 3 tanks at the same time instead of one then the next. The savings using just ice over a refrigeration system running all day would be huge. It would remove heat from the space instead of adding it. It would only cost the electricity from the pump usage, almost nothing. Unless whatever refrigeration system you use has a remote condensing section you're looking at significant electricity usage and heat generation with one. You would have to locate the condenser outside at least if not the compressor as well. Peltier coolers can be good for a specific purpose but they have horrible efficiency numbers. I used to be into gaming computer building and they always sounded like a great idea for adding to a CPU cooler but they create so much heat they're not worth running or they weren't 10 years ago when I was building pc's. One side of the peltier cooler gets cold but the other side gets hot to radiate the heat. What will you do to eliminate the additional heat that would be right on the outside of your res? Also electricity usage with each cooler would add up. I do have a degree in HVAC/R and worked as a tech for several years. It was in the late 90's but I still have a foundation.
I knew a guy that had a water source heat pump he used and he set up the condenser in his pool. Had to use a stainless steel condenser so it wouldn't corrode.
To better automate it you could place the cooling coil in a freezer but the cooling effect in ice water would be much better. Possibly it could be in a container of water in the freezer.
just the logistics and the power savings of your suggestion makes a lot of sense. One cooler will rule them all!. I need to revamp a bunch a stuff, so saving money is a necessary. BUT if I decide to build the keganator thing for my wife, I would probably just use the fridge. Right now, ice packs. Rebuilds coming soon.
You can find cheap sources of ice as well if you work in a food industry. When I went to refrigeration school they would let any of the students come in a fill up anything with ice from the many ice machines we had to work on for free.