Make your own Chiller

[Luniyn]

Posted this in another section of the forum and it was suggested I place this here in the DIY section. The only reason I didn't put it her first is because I've never tried this so I don't know how well it will work. However, this question has come up many times recently especially with the hotter months approaching, so I was toying around with this idea of an inexpensive chiller for your tank. Now, maybe if there is anyone out there with these parts I will mention below that is willing to try this, we could see if this is a viable option or maybe with some small modifications (some of which I mention below) it might be doable. In any event, here goes....

A chiller is really just the simple process of taking water from your tank, cooling it off, and then putting it back... except they want $250 for the cheapest one I've found. So the question is, can we do it cheaper.... maybe.

What you will need:
First you need a water pump and it would be nice if it didn't have to be a submerged pump so it doesn't have to be in the tank. Also it doesn't have to be really powerful, in fact the lower the power the slower the water will move through the pipe (you'll see why that's important in a second). I found one at the good Drs. website for $19.99 and it's the . The next thing you will need is a (have seen them for a few bucks at gas stations). Then the only other things you will need is some plastic tubing to fit the pump, a short piece of PVC pipe with a large diameter that can fit into the cooler easily, some salt, and a bag of ice.

How to assemble:
1. Place your water pump near your tank and hook up some of the tubing to the tank. If you have a hang on back filter then just place the intake tube into the tank and make sure to cover the end with a straining device of some sort so the fish don't get sucked in. If you have a inline filter then you could possibly take the outflow of that and put it into the pump.

2. Place your Styrofoam cooler right next to the pump.

3. Find a screwdriver or something that you can poke a hole with that is as close to the size of the tubing as possible if not a bit smaller.

4. Take the lid off the cooler and poke 2 holes into it on opposite corners of the lid. (See diagram below)
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5. Get your PVC pipe and spiral wrap your tubing around it as close as possible so the entire pipe is covered. Make sure to leave 2'-3' of tubing lose at one end and several feet of tubing lose at the other end. Also secure the tubing to the PVC pipe so it doesn't unravel (some silicon glue or you can tie it down with fishing line... anything water proof).

6. Place the PVC pipe into the water cooler and feed the 2'-3' line though one of the holes in the lid. Then take the longer end and feed it through the other hole in the lid. Make sure that you have some slack in the line so the lid can be removed but not have to lift the PVC pipe out to do it. Secure the tubing in the holes with some silicon glue.

7. With the PVC pipe in the cooler and the lid attached on top, connect the 2'-3' piece of tubing to the outflow of the water pump. Take the longer end and run it back up to your tank. If you have a hang on back filter then you could place it into the filter tank so that the water goes through filtration before going back into the tank, but if you took the outflow of your inline filter then just run it back like you always have.

8. Now that everything is hooked up, turn on the water pump and make sure that the flow of water is moving fine and that you don't have any leaks or other problems. And let it run for a little while to be certain.

9. Now open the lid of your Styrofoam cooler and pour in a little bit of ice. Just enough to cover the bottom of the cooler. Sprinkle some salt over all of the ice so it all gets a light dusting. Now add a little more ice and then more salt. Keep doing this until you have covered the PVC pipe with ice.

10. Secure the lid back on top of the cooler and wait. The ice will melt and the salt will mix with the water (salt water gets colder then regular water) and get nice and cold. The water that is flowing through the tubing will now spend a lot of time going around and around that pipe and the slower the water goes through the tubing the longer it is exposed to this cool down process. Now the water should come back out of the cooler at a lower temperature and once it gets back into your tank it should eventually lower the temp of your tank water.

Note: You will need to keep adding ice over the course of the day and as the cooler gets full of water it will need to be emptied. Don't empty all of the water though because it will help keep things cold while the new batch of ice is melting.

 

[lolagurl]

I REALLY LIKE THIS AND I THINK I COULD DO IT,,, BUT UNFORTUNETLY IM NOT THE HANDIEST PERSON.Maybe if you took some pictures of when you construct it and set your up i could have a chance

 

[timg]

It's a great idea and should work very well. I would suggest an old washing machine pump for this, as you can restrict the flow on the outlet of these pumps without causing any damage, and they are very low consumption. (I use these with great effect in lots of ways!)

One possible improvement that you could make to this is to use a piece of old cast iron drainpipe or a large bore copper pipe instead of the PVC. this will transmit the heat/cold better than the PVC and also once cold, will stay that way longer. Even a solid bar would work well.

 

[Luniyn]

One possible improvement that you could make to this is to use a piece of old cast iron drainpipe or a large bore copper pipe instead of the PVC. this will transmit the heat/cold better than the PVC and also once cold, will stay that way longer. Even a solid bar would work well.

My original design was actually to use a metal pipe of some sort, but I was worried about the corrosive effect of the salt water on the metal over time. Although it wouldn't effect the water from the tank because that is completely contained in the plastic tubing, it would still make for a messy cleanout of the cooler each day before adding more ice and salt. The PVC was edited into the project temporally until I can come up with a better solution. I actually have a birthday party for my son this weekend after which I should have a lot of leftover ice to deal with. The perfect time to run some experiments ;D.

 

[not4you]

I read this a few days ago and although I don't have a need for a chiller this is an interesting idea. An idea I had is probably a little more pricey than the cooler/ice idea but could still be cheaper than a chiller and definitely less maintenance than the cooler.

My idea was to replace your cooler and ice with a mini-fridge or wine chiller. Drill two small holes for tubing to enter/exit and then stuff as much tubing as you can in the fridge. Set the fridge to the coldest setting and pump the water through the tubing and assuming you could cram enough tubing in the fridge it should be nice and cool by the time it leaves the fridge and is returned to the tank.

Just my .02

 

[Luniyn]

I read this a few days ago and although I don't have a need for a chiller this is an interesting idea. An idea I had is probably a little more pricey than the cooler/ice idea but could still be cheaper than a chiller and definitely less maintenance than the cooler.

My idea was to replace your cooler and ice with a mini-fridge or wine chiller. Drill two small holes for tubing to enter/exit and then stuff as much tubing as you can in the fridge. Set the fridge to the coldest setting and pump the water through the tubing and assuming you could cram enough tubing in the fridge it should be nice and cool by the time it leaves the fridge and is returned to the tank.

Just my .02

I had that thought as well, then you could even adjust the level of cold via the temp of the fridge. Plus if you keep live frozen food, you could keep it in that mini-fridge instead of leaving it in your regular fridge. The down side is that the cheapest I've seen is still over $50. The one's cheaper then that usually don't do what they say they do on the front of the box (i.e. when you read the fine print they say "Can't cool more then 20o from room temperature" or something silly like that). But still for under $100 compared to the $250+ they want for even the cheapest cooler, it's still a good bargain.

 

[Wizzbone]

I live in the tropics and could really do with a chiller.

I also thought of fixing a fridge to make a chiller. Putting a garden hose through the fridge seem to work.... however, when I thought about it, I decided against it. let me explain before you guys start on it.

If you have a tank say for arguments sake that has water in it of 30 degrees Celsius, (sorry if you use Fahrenheit). The room itself is also 30 degrees for simplicity. The ideal temperature is about 25 right? So you want to lower the temp by 5 degrees.

you have a 300 litre tank, and this water goes through your filter - fridge every 15 minutes (Fluval 404 1200L/hr).

Ok, say your fridge is the ideal temp of 3 degrees. To exchange the temperature, - that is to lower the temperature to 5 degrees, the water needs to stay a certain time in the fridge.

1 litre of water is equal to 10 metres so garden hose (about 1cm inside diameter). So if you have 10 meters of hose in your fridge you have 1 liter in your fridge. the pump of the fluval pumps 1200 liters in 1 hour = 20 litres a minute = 3 seconds one litre.

so your 10 meters hose in your fridge will give 1 litre of water 3 seconds to cool down. Which is clearly not enough to make any significant difference, considering that this litre of water will be another 14min, 57sec to stay in a fishtank, that is in a 30 degrees room!

I hope this makes sense?

Wizz

 

[COBettaCouple]

That's an interesting idea and i bet timg might have a few good thoughts on that, being as good at DIY as he is.

 

[timg]

With temperatures in the low 60's this week, a chiller isn't something that I need, but you're right, I do have a couple of ideas that might help here:

If you wanted to use a fridge to chill the water, as stated, the problem is the length of time the water dwells in the cold before going back to the tank. Two thoughts come to mind here:

The size of the pipe. Using garden hose with a large bore creates two problems, firstly, the surface area of the pipe is small in comparison to the volume of water and secondly it allows too much water through too quickly;

The working temperature of the fridge itself. Fridges are highly efficient tools, but only if they are given time to work.

Solutions:

Let's look at the possibilities of reducing the size of the piping used. My mind leads to the idea of air piping, which is readily available and the reducers are also easy to obtain to reduce from 12mm to 6mm in the form of teeing off to 6mm. I have a very similar arrangement on my air pumps, where I am using large bore supply pipe to the tank outlets, and 12 outlets off the pumps all of 6mm. I have used three tees to join the pumps to the large bore pipe and it works brilliantly. So, if I were to reduce the bore to 6mm inside the fridge, I would run large bore from the filter/pump to the fridge, tee off into 3 to 6 lengths of 6mm inside, depending on the flow rate, then tee back to the large bore to return to the tank. This would increase the available surface area without slowing the flow of water and would give you the dwell time in the fridge to allow for cooling to take place.

The tubing inside the fridge would need to be wound round metal pipes to help with the transfer of the cold to the water, but this wouldn't pose a problem since it wouldn't be submerged in water like the original idea states. 3 to 6 coils of 6mm tubing, each around 10m in length should start to make a difference. The longer the tubing, the more time it takes for the water to travel through, and the better the effect. If you really wanted to make a difference, then you would need to go to something in the region of 25m each. My head can't do the calculations of flow like Wizzbone, but I don't think it would be far off.

Now let's take the second concern and look at it: The working temperature of the fridge. Refrigerators are very efficient so long as they have time to work. When you put food into a fridge it takes some time for the temperature of the food to drop, and during this time, the fridge is working overtime. With freezers, it's not difficult to get the warning light on, just by putting a lot of warm food into it all at once. The same happens with a fridge, you just don't have the warning light to tell you!

So, let's take Wizzbone's calculations and run the numbers:

1200L per hour and run it instead through 4 x 6mm coils at 10m each. The dwell time in the fridge has just gone up from 3 seconds to around 12 seconds in effect, with the same volume being moved at the same rate. Still not long enough, IMO to have a dramatic effect on the temperature, but much better, though the fridge would find it hard to cope with the heat transfer at that rate.

To have a real effect using this method, you would really need a decent chest freezer where you can extend the length of tubing per line, (which would increase the dwell time), and maintain a much lower temperature inside. You could also use the freezer for food simply by running the tubing in the bottom and using baskets for the food. A few small holes drilled through the casing each end will allow access for the tubing without disturbing the seal on the lid, and the food will help to maintain a lower temperature as well.

You would need to adjust the length of the runs to regulate the temperature, rather than adjust the temperature in the freezer, the longer the tube, the lower the outflow temperature. Most people already have freezers at home, so costs are minimized, though you might need to re-arrange the location!

In conclusion, the Ice box idea that started this topic is great, but very limited by the availability of the ice and the continual maintenance issues. The idea of fridges can work, but is limited in it's effectiveness due to the operating temperature and ability of the fridge to cool. The freezer is by far the most effective and efficient idea of the three, and will IMO obtain the desired results, so long as you can get enough tubing and the reducers. There you go folks. That's my penny worth!

 

[darkwolf29a]

THe only successful models of these I have seen are made from those bar-type fridges. And then their turned into freezers really. But...what about a small chest freezer. Sears has this 5.0 cubic foot model for 170 online.

If you are looking for max cooling capacity...a freezer is your best bet. Anything else is almost.

The other thought for doing it would be to use 1/2in MIP tubing, which can offset higher pressures. Remember that as water gets colder, it gets wider diameter-wise. MIP tubing is readily available from Menard's and such places. Personally, I use it a lot more than airline tubing, because it's cheaper and better quality.

 

[timg]

Thank you for that Darkwolf, I guess my thoughts were pretty well on track. The only reason I thought of air pipe is because it expands easily to absorb the increased volume, rather than speeding up the flow. 1/2" piping is really too big though, if you want to increase the surface area substantially. It may be possible to get 10mm or 8mm instead, but whatever you use will effect the final result. The smaller the tubing, the better the effect. As the concern is to reduce the temperature by a minimum of 5 degrees, dwell time is important. MIP tubing is available in sizes from 6mm anyway (See )

As for pressure, if you are running from a HOB or such, there isn't a great deal of pressure to concern yourself about. They run at maybe 1/4 bar, with a lift capacity of perhaps 12", so any pressure is minimal and easily within the capacity of air pipe. The freezer you have there is exactly the type I had in mind when thinking this through, and anything that size or bigger will work fine. The tubing will only take perhaps 1/4 of the capacity of that particular model, leaving loads of spare room for storage of foodstuffs, frozen brine shrimp, etc!

 

[Luniyn]

The problem with a $170 fridge is that by the time you get the pump, tubing, etc. you will have almost spent the $250 is costs for a basic chiller thats made to do the work in the first place. The point of the DYI is to be cheap. With the original setup I was proposing, it was designed based on how a Slurpee machine works (Slurpee = a somewhat frozen flavored drink that is kind of like slightly melted, slushy snow in a cup). My original setup said to use a metal pipe which is the best method of cold transfer (and what is used in a Slurpee machine) but I took it out because I was worried about the metal rusting. The trick is to get an easily found, cheap metal cylinder that the tube would be wrapped around. In the Slurpee machine, the cylinder is actually a thin piece of aluminum that is filled with the coolant (in our case ice and salt water) and then is sealed and put into a dispenser. Then the actual flavored liquid is poured in around the cylinder and the cylinder is rotated in one direction while a coil wrapped around the cylinder rotates in the opposite direction. What happens is that the aluminum cylinder gets so cold that the flavored liquid actually freezes to the outside of the cylinder in a matter of seconds and then the rotating coil scrapes off the now flavored ice off the cylinder making a shaved ice that is mixed back into the liquid. Over time this becomes the slushy flavored drink. I was inverting the system a bit and taking out the mechanical parts to the system but the theory is the same. Unfortunately I don't actually need a chiller as my house is kept at the perfect temp for the tank (i.e. the water is the same temp as the house) so I keep putting off my testing of this setup for other things (family always gets in the way). I do have to make a trip to the hardware store though, so maybe I will just wander though and see if I can find anything that might make for a good "metal pipe" in the system.

 

[VertigoXLR8R222]

okay here is my two cents worth. everyone has heard of heater mats to go under your tank so why not make a chiller mat. it is a little complicated but it is also a separate water source that doesn't interact with the tanks conditioned water my idea comes from radiant floor heating its where they serpentine 1/4 or 3/8 inch pipe across a floor and then fill over it with a type of self leveling concrete then when its warm you pump cool water thru and when its cold you pump warm water thru the temperature of the floor has a lot to do with the temp of the room simple thermal transfer most of us understand it the overlay on the residential and commercial floors is only two inches ( sorry bout this metric guys) so i think you could use rigid air tube and elbows and make the serpentine easily keep them about an inch apart and let them run the length of your tank one in and one out on the same end of the the serpentine on opposite sides (front and back) now heres the tricky part make a form outline that is a little bigger than the base of your tank and about an inch and a half thick lay the serpentine in it with the in and out hoses hanging past the form (ideally thru holes drilled in the side for cosmetic purposes) lift the serpentine up and fill the form HALF full of concrete lay the serpentine back in so that it rest halfway thru the form cover with the rest of the concrete up to the top of the form once this cures take the form off and hook it up to your pump and return from the fridge now the water is almost in continuous circuit with the cold from the fridge and the concrete the concrete cools and so does the tank above it and if you put a thermostat on the water pump then when it gets hot enough to turn on it will and chill your tank and i think you could still use the fridge for a fridge if you looped the line inside thru a catch basin like a water heater but in reverse then the water stays in the fridge longer than in the concrete sound doable? hit me back with any questions Lee

 

[darkwolf29a]

timg - you can get smaller tubing, that's fore sure. I just bought some 1/4in for my CO2 project, which is on hold until I figure out if my fish will still be alive in a few days. Honestly, I have been having some issues with my Petco and fish that keep dying. So, I changed to WalMart, so we'll see. At least my Oscar seems happy and healthy. So, I'm keeping my fingers crossed, since I broke my own rule number 1.

Luniyn - I completely agree. I'm just thinking about effeciency. Honestly, as good as diy can be, if it isn't cost effective...what's the point? Maybe find one on ebay or something? I'm just trying to get the most bang for your buck. I've actually heard of people using computer fans, run by old computer power supplies and such things to cool stuff down a bit.  Maybe, between all of us we can come up with something useful and cost effective.

 

[timg]

Hi Luniyn, I did have diy in mind when I suggested the freezer option, in as much as most of us have freezers in our homes that can be used for cooling as well as storage. I think that darkwolf29a was just showing an option which most would not need!

I have no need for a chiller either, unless it's to chill us, since our room stays at a constant 24 degrees with all the water I have in here, but the idea is aimed at those who are not as fortunate as us and have to contend with excessive temperatures for long periods. The gauntlet was rather thrown down too, by Flbettacouple! (I never miss the opportunity of a challenge!)

I would suggest that if the diy'er already has their own freezer, the cost of the chiller would not be any more than the ice/salt water chiller that you suggested to start with. They may need to move the freezer to a more convenient location in the house, but otherwise, there is minimal cost involved.

I hope that I haven't offended you by moving to the next level on the evolution stage. There was and is no insult intended and the original idea is still well worth consideration for those who just need a small amount of chilling for short periods of time.

 

[darkwolf29a]

okay here is my two cents worth.  everyone has heard of heater mats to go under your tank     so why not make a chiller mat.    it is a little complicated but it is also a separate water source that doesn't interact with the tanks conditioned water       my idea comes from radiant floor heating      its where they serpentine 1/4 or 3/8 inch pipe across a floor and then fill over it with a type of self leveling concrete       then when its warm you pump cool water thru and when its cold you pump warm water thru       the temperature of the floor has a lot to do with the temp of the room       simple thermal transfer      most of us understand it         the overlay on the residential and commercial floors is only two inches   ( sorry bout this metric guys)      so i think you could use rigid air tube and elbows and make the serpentine easily       keep them about an inch apart and let them run the length of your tank      one in and one out on the same end of the the serpentine on opposite sides (front and back)        now heres the tricky part       make a form outline that is a little bigger than the base of your tank and about an inch and a half thick          lay the serpentine in it with the in and out hoses hanging past the form (ideally thru holes drilled in the side for cosmetic purposes)     lift the serpentine up and fill the form HALF full of concrete       lay the serpentine back in so that it rest halfway thru the form       cover with the rest of the concrete up to the top of the form     once this cures take the form off and hook it up to your pump and return from the fridge         now the water is almost in continuous circuit with the cold from the fridge and the concrete        the concrete cools and so does the tank above it         and if you put a thermostat on the water pump then when it gets hot enough to turn on it will and chill your tank    and i think you could still use the fridge for a fridge if you looped the line inside thru a catch basin     like a water heater but in reverse      then the water stays in the fridge longer than in the concrete       sound doable?     hit me back with any questions     Lee

It's doable, and might work very well for a basement type layout. What worries me would be putting a stand underneath that. In my situation, I live in an upstairs apartment, for now, so anything I can do to keep weight down on the floor is a good thing.

 

[timg]

The problem with this setup is the double heat transfer, as well as the in-efficiency of a block of concrete sat under the tank. By this I mean that taken in it's proper place, it works well, mainly because of the insulation beneath the concrete floor and the fact that all the edges are surrounded by masonry. In this situation though, there would be little or no insulation, all edges left exposed and the block stands to lose too much of the coldness before having any effect on the tank. Coupled with the additional heat exchange through the concrete itself from the outside environment, the fridge would be unable to cope with the additional heat transfer requirements IMO.

Coupled with the weight that it would create, this would, in my opinion, be un-viable.

 

[Luniyn]

I hope that I haven't offended you by moving to the next level on the evolution stage. There was and is no insult intended and the original idea is still well worth consideration for those who just need a small amount of chilling for short periods of time.

No not offended at all. Please do take it a step or 7 farther! I usually get my best ideas from other people tossing a few options my way and it sparks some inspiration. So please keep the ideas coming.

I've actually played with some water/liquid cooling devices for computers. It was years ago when I worked for a manufacturer and could pretty much request anything I wanted from various companies under the premise of "testing" it for use in the factory. So my original idea was to see about retrofitting some of those to work in the tank, but in the end it came up to be close to $200 needed to be sure it was safe for the tank. Now I could probably get it down to about $125 if you didn't mind the risk of the coolant (not water) having a chance of leaking into the tank if something went wrong... which of course is not an acceptable option so I didn't even give it a second thought. But it's still an idea I'm kicking around... and the under the tank idea retrofitted with the system I was thinking of might be a good option. But still we are talking over $100 investment compared to a $15-$20 one, so it needs some polishing

 

[darkwolf29a]

Ok, taking the cancrete idea abit lighter....What about using foam insulation under the tank, instead of concrete. I'm thinking out loud, or in this case..out fingers. LOL

I like where this could go, and my 55 would appreciate it, as the tank is about 79 to 80 degrees, and the heaters are off most of the time during this time of year. And that's running with egg crate cvers instead of glass.

 

[timg]

I think that would be self-defeating, since the insulation would hold in the cold instead of transferring it to the tank. You would need another substance between the tank and the cooler that would transfer the cold to the tank. Maybe a metal sheet would do the trick, and give enough support for the tank as well.

You could also use copper pipe for the under-tank cooler, since it's not part of the aquarium system.