DIY Chiller Beer Fridge

[bh750]

Ok, so I've done a little research here and sounds like this idea never works? For reference I have a 220g display tank. Right outside my fish tank room I have a fridge that runs a Kegerator (maybe 5 cubic feet of space). It's always running whether or not I have a keg or just storing beer bottles in there. So figured why not use it? I would run some small tubing about 10 feet through my sump room wall into the fridge, through as much coiled tubing inside, then back to tank. I wouldnt be over-driving or stressing the compressor, just using the cool air (35 degrees) thats already there.

Worth it? Would the cool water even make a difference?

Appreciate any and all feedback!

 

[NowGlazeIT]

I think your tank might be too big for this diy hack. I struggled trying this on a mini fridge with my 29g biocube. Trick is matching the flow rate with the amount of coiled line inside the fridge to get cold water. If the flow is too fast the coil won’t cool down enough, too slow and it won’t change the temp in the display. A bit of a juggle there but if I were to try again it would be on a mini freezer with moderate to fast flow.

 

[Irregardless]

All I read was beer fridge.

 

[neonreef3d]

Ok, so I've done a little research here and sounds like this idea never works? For reference I have a 220g display tank. Right outside my fish tank room I have a fridge that runs a Kegerator (maybe 5 cubic feet of space). It's always running whether or not I have a keg or just storing beer bottles in there. So figured why not use it? I would run some small tubing about 10 feet through my sump room wall into the fridge, through as much coiled tubing inside, then back to tank. I wouldnt be over-driving or stressing the compressor, just using the cool air (35 degrees) thats already there.

Worth it? Would the cool water even make a difference?

Appreciate any and all feedback!

 

[neonreef3d]

It may work, but how are you going to run the hose inside? drilling a hole is an option, but only through the top cover, because the fridge coils that carry the r22 gas may be lined on the interior of the fridge walls.

 

[bh750]

Thanks for the feedback. I've been doing some more reading. Great article by Bean animal that pretty much seals it for me -- even though I can only follow 75% of it. https://beananimal.com/articles/dorm-fridge-aquarium-chiller/

I guess my thought was, since I have this thing running all the time why not take advantage of the cool air in it. I still may try it just to see but more and more I'm feeling like Kramer and Newman and the Michigan Deposit Bottle Scam...

 

[gbru316]

Sounds like a fun DIY project, but not effective in any way. You'll just end up with a higher electricity bill, hot tank, and warm beer.

An average fridge uses 488 BTU/hr. Each BTU/hr = 0.293 watts. If you're putting in more than 143 watts into your tank, the fridge will never be able to keep up. (488*0.293=142.9)

For reference, an 800 GPH return pump and 1 MP40 (running at 100%) is about 87 watts.

 

[SlugSnorter]

Ok, so I've done a little research here and sounds like this idea never works? For reference I have a 220g display tank. Right outside my fish tank room I have a fridge that runs a Kegerator (maybe 5 cubic feet of space). It's always running whether or not I have a keg or just storing beer bottles in there. So figured why not use it? I would run some small tubing about 10 feet through my sump room wall into the fridge, through as much coiled tubing inside, then back to tank. I wouldnt be over-driving or stressing the compressor, just using the cool air (35 degrees) thats already there.

Worth it? Would the cool water even make a difference?

Appreciate any and all feedback!

sorry to say but I don't think it would do much good.

 

[NowGlazeIT]

Fun DIY project, but not cost effective.

An average fridge uses 488 BTU/hr. Each BTU/hr = 0.293 watts. If you're putting in more than 142 watts into your tank, the fridge will never be able to keep up.

For reference, an 800 GPH return pump and 1 MP40 (running at 100%) is about 110 watts.

Whaaa??

 

[bh750]

Yea I guess I wouldnt be looking to cool my whole tank in the summer (I get great cooling just from a fan blowing across the sump or display tank surface.

Sounds like a fun DIY project, but not effective in any way. You'll just end up with a higher electricity bill, hot tank, and warm beer.

An average fridge uses 488 BTU/hr. Each BTU/hr = 0.293 watts. If you're putting in more than 142 watts into your tank, the fridge will never be able to keep up.

For reference, an 800 GPH return pump and 1 MP40 (running at 100%) is about 110 watts.

So, I think, from your point above and what I've been reading, part of the problem is: the heat from the warm tank water running through the fridge would cause the temp in the fridge to rise, which would then cause the compressor on the fridge to run more to keep the beer cold? Is that correct? I kept reading that the fridge compressor wouldnt be able to keep up, but now I think I get it.

 

[Duncan62]

Ok, so I've done a little research here and sounds like this idea never works? For reference I have a 220g display tank. Right outside my fish tank room I have a fridge that runs a Kegerator (maybe 5 cubic feet of space). It's always running whether or not I have a keg or just storing beer bottles in there. So figured why not use it? I would run some small tubing about 10 feet through my sump room wall into the fridge, through as much coiled tubing inside, then back to tank. I wouldnt be over-driving or stressing the compressor, just using the cool air (35 degrees) thats already there.

Worth it? Would the cool water even make a difference?

Appreciate any and all feedback!

I did a chilled freshwater water with a dorm fridge. In principle it works. I just drill 2 holes in the fridge put a coil of tubing and there it was. I'd spend 50 buck on the dorm fridge. It will cause your compressor to work harder than normal.

 

[gbru316]

the problem is: the heat from the warm tank water running through the fridge would cause the temp in the fridge to rise, which would then cause the compressor on the fridge to run more

In order to cool something, you need to remove more heat than is being added. A refrigerator is only capable of removing 143 watts/hr. If the wattage of your equipment (pumps, powerheads, etc) is more than 143 watts/hr, then your tank will never cool. It'll just warm up more slowly.

The warm beer part might be a bit of an overstatement. That's going to depend on heat transfer efficiency. And if you're using rubber/vinyl tubing, it's very inefficient (which is why copper is used in air conditioners, fridges, etc). So that 143 watts/hr is going to be further reduced by the inefficiency of heat transfer through the vinyl tubing to the water. So you might still have cold beer, but your tank will not be much cooler than without the fridge.

 

[bh750]

In order to cool something, you need to remove more heat than is being added. A refrigerator is only capable of removing 143 watts/hr. If the wattage of your equipment (pumps, powerheads, etc) is more than 143 watts/hr, then your tank will never cool. It'll just warm up more slowly.

The warm beer part might be a bit of an overstatement. That's going to depend on heat transfer efficiency. And if you're using rubber/vinyl tubing, it's very inefficient (which is why copper is used in air conditioners, fridges, etc). So that 143 watts/hr is going to be further reduced by the inefficiency of heat transfer through the vinyl tubing to the water. So you might still have cold beer, but your tank will not be much cooler than without the fridge.

Wow. This is great stuff and why I love this forum. So interesting. So what if the pump I'm using is already running in my tank. I tee it off one of my existing pumps, for example. So I'm not adding new watts/heat to my system. And I read if the tubing is in a bucket of water in the fridge it does a better job with transfer. But in my case the plan was to coiil tubing around the inside walls of the fridge. Keg and or beers wouldnt be impacted. I can think the tubing sitting around the innner walls of the fridge might be cooler there versus the center. Then the tubing will have to run approx 8 feet back to the tank, losing efficient there.

again

 

[gbru316]

I did a chilled freshwater water with a dorm fridge. In principle it works. I just drill 2 holes in the fridge put a coil of tubing and there it was. I'd spend 50 buck on the dorm fridge. It will cause your compressor to work harder than normal.

Sure. If you've only got a power filter hanging off the back you're looking at maybe 10 watts total, and the dorm fridge can handle 29.3 watts or so. Watts out >= watts in, so it's more-or-less effective.

 

[redfishbluefish]

OK, I'll be the one to say it point blank...it won't work.

Plastic tubing, air interface, heat transfer, flow rate. You couldn't pack enough plastic tubing in that frig to make a difference.

It's been tried with chilled water and efficiency is so poor, it won't work.

Throw an inexpensive window air conditioner in your fish room and sit back and have a cold beer!

 

[gbru316]

Wow. This is great stuff and why I love this forum. So interesting. So what if the pump I'm using is already running in my tank. I tee it off one of my existing pumps, for example. So I'm not adding new watts/heat to my system.

Every pump/powerhead/piece of electrical equipment in your tank is constantly adding energy (watts, heat) to the system while it's operating. That's just a result of equipment doing work -- converting electrical energy to mechanical energy (which is what pumps do). It has nothing to do with adding new equipment to your tank.


In order for this to work, you'd have to make sure that the energy transferred by all your equipment is less than the energy transferred by the fridge.

In other words, add all of your equipment ratings together. If it's significantly less than 143 watts, you have a small chance of it working. If it's equal to or greater than 143 watts, it's quite literally impossible for this to work.

 

[Mschmidt]

You could do it with some length of copper coil in the fridge, 25 feet may be good. It's what I use to cool my home brew. I run tap water, usually from the hose through it to pull heat out of the brew. Works well. Another option could be a plate chiller. Have a reservoir of cold water in the fridge hooked up to one end in a closed loop and the other run in a separate closed loop to your tank. The cold water loop could be something like a 3 or 5 gallon corner keg with tubing and pump attached. If you want to look it up try "diy reverse flow wort chiller".

I have more thoughts and some design ideas; let me know if you want them.

 

[Mschmidt]

After hitting send I realized you probably don't want to use copper. Something less reactive and deadly to the tank may be better.

 

[Tonycass12]

It may work, but how are you going to run the hose inside? drilling a hole is an option, but only through the top cover, because the fridge coils that carry the r22 gas may be lined on the interior of the fridge walls.

If its like any standard kegerator they are only in the back. Its rare to ever find coils running in the side walls.

 

[bh750]

Amazing learnings here. Well, looks like I just saved a few bucks on a dedicated pump, plumbing, and lots of frustration here. BTW - reminds me of a few years ago when I tried to build a DIY pool heater using a manifold out of copper tubing pipe through an old propane grill. Technically it heated the water that passes through it to super hot. And the pool did warm up (small 2000 gallon pool) But the amount of propane I burned through resulted in a big FAIL. Fun and informative but I'll never get that time back!