DIY Non Fridge/Cooler Chiller

[StirCrayzy]

Well it starts like this... Im going to need a low budget (under $100) Chiller for the winter, because i am going to run my woodstove to heat my house. The room that the tank is in will be 85-90deg for 12-15 hours a day.

Details will follow, but the basic idea is that i run tubing through the floor into my crawlspace (dirt floor) bury a pipe, or just plastic tubing, 2 feet deep, and plumb it inline with the output of my magnum 350. I know plastic tubing is going to insulate, and i dont prefer this, but a 6' length of 1/2" nickel/chromium tubing costs $120 and im on a budget.

The concept is that Ground temp here in Michigan 18-30" below ground stays a consistent 65 deg. If i pump through that at a rate, yet to be determined, i will distribute the excess heat.
Forgot to add that when successful, this method will be used on both FW and SW setups.

This is not the only option i am exploring, but it is the most economical.

The second method would be to use a heat exchanger, and make a fan shroud to force air across plates or coiled tubing. This also will mount in my crawlspace where the air is much cooler. The flow would always be on, but the fans would be on an adjustable thermostatic switch, which already own.

The problem is:
Metal selection. I have lots of sources for tubing and heat exchangers, im getting mixed reviews on whether or not stainless is reef safe. It is by far, the most economical metal choice, and has the most abundant selection.
so if stainless is out, then titanium, or nickel will be my entire budget.

 

[Frankie]

Titanium is going to be the only metal you would be able to safely use.
Being your tank is only 40 gallons you might be able to cool it off some with this method. You can use other non insulated plastic tubing. Check out Plastic Tanks, Plastic Buckets, Plastic Bottles, Labware, Plastic Tubing, PVC Pipe, Plastic Sheet - United States Plastic Corporation ® for alternative materials.
This is going to be very experimental. The length of tubing and depth you bury it will play a huge roll in success. I would recommend searching out reef centrals diy data base for other threads on this topic. Many have tried it with varying results. Good luck!

 

[StirCrayzy]

Thanks for the link Frankie,
I checked out that site, and found some 1/16" wall tubing that will be the best if i bury plastic tubing. They have an excellent selection.

Im still drawing blanks when searching for a plastic heat exchanger.
I know they are terribly inefficient but for my purpose/budget, it would be ideal.
Im still pricing out replacement Ti heat exchangers for different size chillers, but apparently it is not common to replace these parts.

Im also looking for broken chillers as freebies or to buy for parts.

 

[BobBursek]

StirCrazy, you are overthinking this! You live in Detriot, cold in the winter, and sorry for the Lions, I bet if you just run the air line for your skimmer to the outside that cold air will keep your tank within normal temps, I ran some 1/4 tuping in my tank to pre warm my RO/DI water, my 2 300w heaters could not keep up, I was surprised how much 25' of that in sump/fuge at 56*water cooled it, plus the outside air will help keep your PH in line.

 

[StirCrayzy]

StirCrazy, you are overthinking this! You live in Detriot, cold in the winter, and sorry for the Lions, I bet if you just run the air line for your skimmer to the outside that cold air will keep your tank within normal temps, I ran some 1/4 tuping in my tank to pre warm my RO/DI water, my 2 300w heaters could not keep up, I was surprised how much 25' of that in sump/fuge at 56*water cooled it, plus the outside air will help keep your PH in line.

Bob, I too am sorry for the Lions,
I cant unhook the line on my skimmer or it runs like crap with staight air ,its HOB. I thought about outside air, and it wont be stable enough temp anyway, to get a consistent result.

 

[BobBursek]

SC, do you have a sump pump crock? My mentor has one, and has his DYI cooling coil in that water, but in the winter they usually not a turn over of the water, just a thought.

 

[BobBursek]

Water is so dense, even sitting in a "hot tub" below 98*F body temp, the water will pull your body temp down, that is why most hot tubs/spaws are about 102-105*F, so think about the sump pump crock if you have one.

 

[StirCrayzy]

No sump Pump.
But as an alternative, if the ground itself doesnt want to absorb the heat, i will bury a 5g bucket of water and run my coil through that.
That may be better surface area contact anyway.

 

[MrPex]

Just get a 5 gallon bucket, one 10 foot section of 1/2" PVC- about 5 bucks. Get about 20 90 degree PVC fittings. Cut the PVC into 6" sections or so, and create a square shaped coil with the fittings and sections of pipe. Put the bucket in the cold air and place the coil in the bucket of water (you may want to put anti-freeze in the bucket of water for two reasons- one is so it won't freeze and destroy your plumbing, but also water with anti-freeze has better heat transfer than just plain water.) Plumb the coil to your pump and just keep checking the 5 gallon bucket for top off every other day or so. 30 bucks total, probably.

I wouldn't even bother burying the bucket. Just make sure it's covered with egg crate to allow evap to assist cooling (top off with plain water) but also so no little critters that may get under your house try to drink it. Anti-freeze is sweet. And poisonous.

One last thought - If you put a ball valve in line with your coil, you can also adjust the amount of "cold" water coming back into your system as the weather changes. Add 5 bucks.

 

[DaveK]

... Get about 20 90 degree PVC fittings. Cut the PVC into 6" sections or so, and create a square shaped coil with the fittings and sections of pipe. ...

Why not just use flexible PVC pipe also known as spa-flex? You can easily coil it, and you wouldn't have all the fittings, and having to glue all of them perfectly.

Here is an example of the product (offsite link) - Savko Plastic Pipe & Fittings

BTW, if you are going to glue pvc pipe, and you want a much nicer looking job, a clear PVC primer is available. This way you will not get the purple runs from the purple primer.

 

[Reef Wall]

You could also do what MrPex suggested but instead of using a bucket and putting it outside. You can get an old used mini fridge. Plumb the hose through this fridge. Instant DIY chiller. The fridge will even have a thermostat to regulate temp. This will even give you somewhere to store your live or prepared fish food. I would use some sort of flex tubing like Davek suggests to get rid of all the fittings needed. Here is a link that might help.

DIY Do It Yourself Aquarium Chiller - DIY Do It Yourself Aquarium Chiller

GOOD LUCK.

 

[StirCrayzy]

Re: DIY Non Fridge - Chiller

You can get an old used mini fridge. Plumb the hose through this fridge. Instant DIY chiller. .......
GOOD LUCK.

Ya ive read many threads about fridges, but i dont want the electrical draw, it's very inefficient, and dont have room for even a small one within 30 feet of the tank.
I understand they have a place in the DIY hall of fame...
I just dont want to settle for that, when i have more unique options that will use FAR less power.

How many people do you know can say they run a Geothermal chiller on their tank? Ya know ! It just sounded like a grand idea.


BTW Im striking out on replacement Ti heat exchangers. It seems the chiller manufacturers offer these at a greater cost than an actual chiller.
ie. $800 for a replacement for a 1/2 hp chiller !
So that option is out unless by chance i come across an electrically broken chiller that i can strip down. :fingerx: :fingerx: :fingerx:

 

[MrPex]

Why not just use flexible PVC pipe also known as spa-flex?

Didn't even think of that... !

Or you could use PEX tubing. (No relation to this MrPex.)

 

[StirCrayzy]

those both insulate more than standard polyethylene 1/16" wall

 

[MCU Research]

This may be a dumb question- but we're talking about a small 40 gallon tank here. Can't you just relocate it to another room?

 

[StirCrayzy]

This may be a dumb question- but we're talking about a small 40 gallon tank here. Can't you just relocate it to another room?

Thats not an option at the moment.

I will clarify this situation, as some things have been learned. First I am installing the chiller to keep the temp down in a 65g cichlid tank that will become a paludarium this winter.

IF the chiller is successful, my 40g reef will move into that room also, to make room for a 90g . I have a friend who may possibly be giving up his reef til he moves to a house, and i would like to have a system in place in case that happens and i get to tank-sit for a year.

SO if geothermal heat transfer is enough, Im good to go.
If not and i need forced air then i can do nothing with SW tank situation,
I should reword this poll to specify FW ONLY for stainless, because that is the immediate need.
I polled 10 LFS yesterday to get opinions, and
6 said ok to SS for FW only
2 said dont use on either
2 said ok for both FW and SW

I have sourced some SS tubing 3/8" ID with Hose barbs 15' for $35.
so im still looking for a broken chiller to swipe the Ti heat exchanger, but im ordering 1/16" wall Poly hose anyway, because i need it no matter what option, for plumbing. So i'll order 30' and probably bury 20' of it to see if that works then move on to forced air if necessary.