DIY Chiller or am I crazy?

[BCWolfen]

Ok this may just a completely crazy idea that would never work but I wanted to run it past the pros and see what everyone thinks.

Would it be possible to build a DIY chiller out of a bar fridge?!?!?
They are cheaper than a chiller especially if you get one used in teh buy and sell.

My thought is.
Drill 2 1" (well slightly larger) holes into the side near the bottom. Feed some 1" flex tubing through it so you have a stack of say 3-4 coils lying in the bottom. Connect this to 2 valves (so you can completely exclude it form the system) and 2 couplings. Then run a smaller pump or Aqua Clear 5000 powerhead or even branch it off the skimmer.

The fridge can also be used to keep your Phyto and the freezer portion for all the frozen foods. The top makes a great stand for flake foods, equpiment etc etc.

Would it cool the water enough?? Or am I sniffing too much glue tonight??

LMK

[Stasher]

I have read this done elsewhere but the only worry is the automation of something like this. You are always cooling the water, what if your heater were to quit?

[Tarolisol]

You could always connect it to one of those neptune systems, just plug it into the chiller part and it will only turn on when needed, might not be good for keeping frozen food in thought after. Also i would be carful about where you drill into.

[Jaws]

Do a search on Reef Central regarding this. There has been many discussions about this on there. I think overall, they decided it was a bad idea but I haven't looked into it myself, just heard. Hope you find something.

[Delphinus]

I think the basic problem is that the duty cycle of the compressor is nowhere near what it needs to be, for a tank chiller. Typically your fridge compressor runs for a little while, then the inside is cool, and the motor "rests" while the fridge stays cool until the temperature rises just a wee little bit, and the cycle begins again.

In the case of the tank, the temperature is always warmer than the temperature setpoint of the fridge. So the motor is always running, it never gets that "off" part of that cycle.

So in the end, it works, but only until the motor burns out.

[golden69_ca]

if u were going to use a frigde u would have to run it full time never turning it off and puting the pump on a temp control that would put less stress on the fridge .as for the compressor i have seen some of the maufactured chiller units by companies and they use the same ones , the heavy industrial units is when they get into diferent syles of compressors .

[Delphinus]

Is it more of a myth then, that they tend to burn out (if it's the same compressor model)? Or do I just have the basic concept wrong?

[Nemo]

First you would need to run a large section of coils probable more like 40-50 feet of 1/2" tube. This would alow you to have a fair amount of water in the fridge being cooled.
Second I would run a dual solinoid valve one on the outlet from the fridge and the other from your return line (this would elliminate the need of a pump and maintain no pruser in the line so no risk of blowing a line) off of a temp controler to turn on when cooling is needed.
Third I would probable run a timer on the solinoid so that you would only have it open for about 1-2 minutes, any more time than that and the fridge would not be able to keep up. If you run a large coil in the fridge there should be plenty of cooling water in the coils to do the job.

This should solve the problem of having the fridge cycling all the time and give you a cheap chiller.


JMO


Robert

[BCWolfen]

Hmmm all good ideas. Aside from being an interesting topic its great fun to see all the gears turning in everyones heads. We all turn into Tim the Toolman and want to run to Home Depot with a no limit credit card, buy 20 fridges and try different variations. :biggrin:

[Rikko]

I think the main problem with cooling our tanks is just that chilling technology isn't very good. Even a full size kitchen fridge can't do as much as you'd think. It kicks into the duty cycle by cooling the air inside the fridge, but before long everything in there is cold. No cold air is really being lost because it's so heavily insulated. Like has been said before: temp drops a bit, compressor goes back into action, then off again.

But now run some warm aquarium water through it and ask it to constantly be cooling that water down.. How much, really, can a fridge be expected to cool when there's a neverending supply of water heated by the pumps, lights, even the surrounding room?

Lots of guys have good luck using bar fridges to keep their tanks cooler during the hot summer months, but I think for any serious temperature control (ie. try running a 90 gallon Pacific Northwest biotope system), we just can't do it.

I remember one guy in Cali dug a huge hole in his back yard and ran several dozen feet of tubing underground to the water table and then back up.. It was sufficiently cool down there to keep his tank well under control,

[Chin_Lee]

I've had this idea but never had the chance to test it out so I'll post it to see what you DIY guys think.
Since the seawater starts to freeze around -2C, i figured why not use a small chest freezer instead of a bar fridge. I believe that freezers have a more power compressor than a bar fridge so if thats true, then the plan is as follows:

1) Get a small (or whatever size you can accomodate) chest freezer off the buy&sell
2) find a BIGGEST container that can fit inside the freezer to occupy the most space inside the freezer
3) throw in 50 feet or so of 3/8 or 1/2 inch plastic tubing and space them out as much as possible inside the container
4) drill through the freezer wall and plumb plastic tubing through
5) plumb the other ends of the tubing into your sump
6) attach two pumps to one end of the tubing
6a) pump A will be a small pump to keep the water in the tubes moving and will be on constantly to provide a very slow flow through
6b) pump B will be a bigger gph pump on a thermostat to turn on when you want to start cooling
7) fill the container inside the freezer with water
8) add auto antifreeze into the water
9) put a small powerhead into container of water to keep water moving
10) set your freezer to around -5C or so

You will probably have to play around with the freezer settings, temp of antifreeze and the small pump setting until you get the desired effects.
The antifreeze will stop the container of water from turning into block of ice and the powerhead in the container will keep maximize heat transfer from the tubing
During the day when the heat rises, it will transfer the heat into the container of antifreeze through the tubing and the freezer may or may not have to run as much as a bar fridge.
Overnight, the freezer will bring the antifreeze back to -5C.
The small pump will keep the water inside the tubing from reaching below -2C
I have no idea if antifreeze will ever leak through plastic tubing - but I'm sure somebody out there will know. Considering antifreeze is stored in plastic containers thats thinner and softer than the tubing that we normally use, i believe it will be safe.
You can probably even store your frozen fish food in the freezer if its strong enough.

This is just an idea that I've been throwing around for a while so give it a try if you think it will work for you.

CWLee

[StirCrazy]

I believe that freezers have a more power compressor than a bar fridge so if thats true, then the plan is as follows:


nope not really, they are designed to operate at a different temperature but still have a low duty cycle.

Bar fridges, full size fridges, freezers ect all have motors with very low duty cycles as they are not designed to run much. to get something with a decent duty cycle you are looking at more than it would be to buy a chiller in the first place.

now if you want to look into a home made chiller, start looking at window ACs hooked to a heat exchanger. you will need some one who is certified to do refrigeration work to plumb it and in the end it might save you 100.00 on a chiller (unless you already have a AC you can use)

Steve

[Chin_Lee]

I guess that puts my idea down the drain :redface: ...... thanks a lot steve :mrgreen:

[Willow]

when your talking about a freezer surely it would be cheaper to think about a chiller?

[cc_bruno]

Here's a link to a DIY article that you might find helpful:

http://www.aloha.net/~hqf/indexjrosechiller2.htm

Seems like it would work just fine, but, not having built one myself, I can't speak from experience. Hope it helps, though.

Robert

[Chin_Lee]

when your talking about a freezer surely it would be cheaper to think about a chiller?
you can buy used ones for cheap in the buy and sell. i've seen them for 50-100 bucks! But if the compressors are not any different, probably won't work anyways.

[snaggle]

Here in Alberta it might work better then other places because it gets colder at night I think if you tank is in the basement it would help. I would use the whole fridge including the freezer part turned all the way down on a timer that has a random setting so it will turn on and off and not burn out the compressor. That is just my two cents I am going to run an apartment sized AC in my room this summer to keep the heat down. Also remember that chillers and bar fridges kick out a lot of heat so that will bleed in to the room and in the end might just kill all the effects of having it in the first place.

Brad

[StirCrazy]

Here's a link to a DIY article that you might find helpful:

http://www.aloha.net/~hqf/indexjrosechiller2.htm

Seems like it would work just fine, but, not having built one myself, I can't speak from experience. Hope it helps, though.

Robert

they will work good for minor temp drops (usaly about 1 to 3 degree drop in a smaller tank) concider I am droping my temp 16 degrees in the summer with a small chiller.
the part that they are not good for is the fridge motors will have to run more than there made for and burn out. how long 1 year maybe 2 maybe more. but you won't much more than that.

Steve

[cc_bruno]

Good to know. I thought about building one as well, but, didn't notice any temp spikes in the summer, (the tank is in the coolest room in the house), BUT, I was not running MH bulbs either, (will be running 3 - 4, 400 watt ones this summer... but, the tank will be much bigger, so, we'll see if I'm going to have to buy a chiller this summer :eek: ).

Robert