DIY Chiller

[rldavisou]

My dad's tank is running about 82 degrees. He has a fan on the canopy, and that helps a little. I'm thinking about making a DIY chiller by taking a mini cube fridge and running some piping through one side, winding it around in there, and then out the other side. Has anyone tried this? Would like to know if anyone has any advice, or better yet, a schematic for something like this. Metal tubing inside would transmit the heat better, but I'm worried about corrosion and leaching of copper into the water.

 

[scsinet]

It won't work. I usually launch into a huge long post on exactly why it won't work, but trust me, it won't. The cooling capacity of a fridge (any fridge) is simply not enough to do the job.
If you were going to DIY a chiller, a better route to go is to start with a window AC unit or maybe a dehumidifier.
If you do want to read up on all the gritty details, go to my website (click my username), then go to articles and help.

 

[rldavisou]

Thanks. I liked your scientific explanation. I just saw my old dorm fridge sitting there, unused, and began to wonder. I don't think I'll try it now.

 

[jovial]

Or try a geothermal cooler by running a series of coils underground.

 

[scsinet]

Originally Posted by rldavisou
Thanks. I liked your scientific explanation. I just saw my old dorm fridge sitting there, unused, and began to wonder. I don't think I'll try it now.
Dorm fridges sitting around should be a felony. They should be full of beer.

 

[scsinet]

Originally Posted by Jovial
Or try a geothermal cooler by running a series of coils underground.
Always thought this idea was neat. Unfortunately it's not cost effective unless you have free access to some of the materials and/or means, like a billion feet of tubing or a backhoe to bury it... but I'm really hoping one day someone that has access to some of the stuff will try it.

 

[jovial]

Originally Posted by SCSInet
Always thought this idea was neat. Unfortunately it's not cost effective unless you have free access to some of the materials and/or means, like a billion feet of tubing or a backhoe to bury it... but I'm really hoping one day someone that has access to some of the stuff will try it.

Me too. Craigslist, materials section, PEX tubing (used for snowmelt systems), services, Bobcat.
Im thinking the ideal time to install it would be when the trench is dug for a sprinkler system, you could run the PEX alongside the sprinkler tubing. The trench would have to be a little deeper than normal though to provide enough cooling. The basement is normally about 10 degrees cooler, its about 10ft below grade though.

 

[scsinet]

I've always thought that you'd need a huge amount of buried tubing... hundreds and hundreds of feet as it's a heck of a lot of heat you're dumping into that ground... I know that geothermal HVAC systems still use a compressor to achieve a high enough delta, so I'd imagine you'd have to do the same with this type of setup, of course killing any money you'd save...
What I've always wanted to see is someone with a lake or pond on their property, or even a swimming pool, and using that. The water would certainly make for an easy transfer of heat... A pool would certainly work in the winter, and maybe even spring or fall, but obviously once it warms past 80 degrees...
but then again my chiller hardly even runs in the winter ...
Another way would be to lay tubes in a grid pattern under a basement floor before it is poured in a new house???
Dang now I'm getting all DIY crazy again... someone please try this so I don't have to put in a pool or build a new house!!!

 

[thangbom]

geothermal is kinda cool but i dont know how much worth it, it is... i know Stockton College in Galloway/Pomona NJ uses geothermal and they say they save tons $$$$.. but thats a really big scale.. i mean there piping runs under there parking lot.. and thats a lot!!!! heck.. im certified for fusing polyethalene pipe welding used for geothermal... i dont know too much about it other that they bury it underground about 4' because at that depth the earth keeps a relativly steady temp around 65 deg... which would be cooler then the hot summer days and warmer then the cold winter... so you only heat/cool from 65 to in our case.. 79-80 deg... and the savings is the $$ that you dont spend heating up from 0-65... you would want the most suface area as possible to contact the pipe cuz the more water touch the pipe the more the pipe can transfer.. thats why they melt/weld the pipe together and that 'nub' is no concern cuzz that becomes more surface area.... again i dont really think it's worth it on a small scale but on a big one it can be... i guess it's kinda on the same term as buying a $1000 mother size skimmer for a 55 or 75 gal tank.. sure the skimmer works good but how long will the skimmer efficency take to get your $$ worth... or even in the feild of tunze or vortec pumps.. you save $$ monthly on electric but they cost you a arm and a leg...
YzGyz

 

[al mc]

Going back to your dad's tank......Does he have a sump or fuge? What size is the tank? If a sump or fuge you can reduce the water temp by 1-4 degrees with a fan running on the fuge or placing a plastic bottle with frozen water in the sump. Low tech ideas, but they can/do work.

 

[thangbom]

to tell you the truth i dont think 82 is too big of a problem... any more and it could be... my tank runs 82 and everything seems fine... take it that i dont have a bunch of sps but i have a handfull that is growing quit well... fans blowing across your water surface is the easiest way to lower your temp... those clip on fans work great and are cheap to boot... 2 over the tank and one on the sump could drop the temp some... it will increase evap rate though... and will make the house AC work a little harder due to it having to take out more humidity...
YzGyz

 

[jovial]

Unless of course your pump was solar or wind/mill powered. Might be intermittent but still enough to provide some benefit?
Grids in a basement floor are a good idea and could also serve a dual purpose as to provide hydrothermic radiant heating as well.

This may be the break you need to take the plunge and build it.

Im thinking, depending on location the line may be subjected to freezing as well, meaning it would need to be buried below the frost line. I believe it's 3FT where I live and deeper in the higher elevations.
Eventually temp equilibrium will be reached with the surrounding earth but many factors determine this. The length of the line, the time the water spends in the line and the soil. An experiment is necessary.