• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

External Reservoirs / Techniques. Looking to go sub-ambient.

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.


Babysitter for OCF Lounge Day Care, Still a bad-as
Apr 3, 2015
Planet Earth
What's Chillin' in Extreme Cooling?
(har, I kill myself)

So, have been working with water for a bit now on The Bianch and still have Father Time to finish...
(see links in sig)
My original idea was to equip Father Time with external ports for a chiller, which will eventually happen.
But as I "practice" on The Bianch, I noticed something that should let me experiment with an external cooling approach.

So I am looking for feedback/advice on approaches for using an external res/et. al to achieve sub-ambient temps.
From the fishtank to a submersible solution.

Here is what I am working with on The Bianch...

This gives a good idea of the current loop set-up

This shows the two expansion ports. I use the one on the left to fill and is the out. The in is the one down by the pump. Right?

EDIT: OK, durr. Its a radiator I need to submerse, not a res! silly dunderhead!

So my idea is to get something like:

Something that you can submerse in whatever medium I choose: ice water, etc. In whatever tub/tank, bucket.
Is this the standard approach, kinda?
Or when I hear people talk about floating something in their tank are we doing an active cooling of the actual coolant and the tank/loop is open?
Or are we doing a passive, conductive process, where we keep our loops closed and use the said before-mentioned approach?

Cause I did see a submersible pump specific to computer water cooling??

I also realize I will need to introduce another pump in the loop.
The shown res has a mount for pump on back, but can you submerse the entire thing with pump?
Or just put pump in-line somewhere on external res out?

Also I had some question involving coolant.
Up to this point I am using the manufacture's coolant, the good stuff, and its spendy as we all know.
I haven't really looked yet into DIY coolants, yet I know many people use them.
Any pointers here. I kinda looked for a thread on DIY coolant, but it eluded me.

So that's about it for now. I know what I want to accomplish,
but not necessarily all the wisdom to do it.

That were you all come in:D Thanks,

Last edited:
I have taken my loop cold in 2 different ways, other than putting it outside.

I have submerged the entire rad in an ice bath and changed out ice/vegetables as needed.

The second method I employ its I run the loop without a radiator. I have a 3 gallon bucket with a submersible pump that runs to my blocks and then back to the res. I then float either frozen bottles of water or DICE in the fluid to chill it down. I run a water methanol mix to avoid freezing.

Either route you go you will want to be prepared for condensation on the tubing and blocks.
So, yeah, see EDIT. I realized afterwards I wanted a rad, not res if I wanted to keep loop closed.

Lochekey said:
Either route you go you will want to be prepared for condensation on the tubing and blocks.
Thanks, I was gonna hit you up as I heard you mention floating things. I get it now, kinda.

SO, yeah condensation, I was gonna look into that next. I assume it corresponds to local conditions as well, like dew point? As well as ventilation.
And how it applies to an open bench vrs closed case?!
Am I going to need to go full treatment to the mobos like I have seen, where everything gets covered with something, like clear nail-polish?
I have actually seen/read a number of discussions/Posts on that.

So basically either active or passive submersion is possible then.
Sounds like the submersible pump/active approach is possibly a little messier, but more effective?

And coolant. You got a recipe to share?
Just plain old water (or distilled) and methanol? You don't use any anti-whatever additives, like those silver spiral deals I have seen? to avoid whatever reactions between whatever?

Thanks for any info.

Well here is a link too a thread about my first time ambient, it is also how I got started with the benching team(which can be blamed on Mandrake, Blaylock, and Caddi)


As for coolant. In my normal closed loop I just use distilled water with a silver kill coil ( strip of 99% silver plate I bought from a local jeweler). When I submerge the rad from this loop in an ice bath I have never gotten it cold enough to need an anti freeze type agent as the water has never reached the freezing point.

In my newer loop I built it with a submersible pump (Like this) that I have in a 3 gallon bucket. I run a 35%methanol/65% water mixture in this mainly because I have been experimenting with throwing DICE in the reservoir. I also used this loop outdoors in the winter and saw water temps in the -20s. I have tried floating bottles of frozen water in it a few times but have not had great success because I did not have enough frozen bottles to keep the loop cold. I do not run a dioxide in this loop as I figure the methanol will kill most things. I had tried running a 50/50 mix of antifreeze but the viscosity when it got cold was hard on the pump thus I switched to methanol.

As for condensation it will have a lot to do with the dew point as you mentioned. I have a piece of shammy cloth cut to fit around the cpu ihs and this has dealt with the condensation on the block well for me to this point. I also wrap the tubing in paper towels anywhere were they may have the possibility of dropping on my board. I have seen some people use pipe insulation on their tubing add well. I tend to not run my gpu's on a cold loop unless the whole rig is outside as I do not feel like dealing with condensation under full cover blocks.

Just for fun here is a picture of my rig outside this past winter.

Locheky said:
here is a picture of my rig outside this past winter.
That is one nice bug zapper there. Looks fun.

I can't wait to experiment this winter, this last winter was huge/cold here and my unheated garage is gonna be perfect.
At least I won't put my rad in the sun outside, like @Blaylock! hardy, har.

That's a bunch of great info Lochekey. Thanks a ton!
Looks pretty easy to have your set-up go both ways, with minimal change over.
Think I got a good idea where I am going, eventually...

A farcking kitty litter box! You are a bumble farck most definitely!
I love it, truly in the Hackineering spirit:clap:

A farcking kitty litter box! You are a bumble farck most definitely!
I love it, truly in the Hackineering spirit

If I remember correctly Mandrake have me that idea, as my wife always tells me I'm a cheap *******.

I found that by putting the whole system outside I did not have to worry about condensation until I was finished and brought it back in. One word of advice if you pot the whole rig outside be careful out any parts that have heatpipes, I had one burst on me when it froze. I also use Ssd vs hdd as the hdd do not like the cold temperatures and the temperature swings.
Yes, yes, yes. Preparing for the winter freeze in the early summer months. We're all missing those cold hard nights. Like many of us you can for sure hang the rad out a window or put your whole rig out there when the cold wind bites. For the hot summer days I've discovered another devious method of torturing the little beasts.

Warning: This can be very dangerous to your system. Only do this if you are truly willing to torture to the point of failure. Hehehehehe.

Fill teh loop with a nice 50/50 mix of Ethylene Glycol and water. (Prestone is my flavor) Place your rad in a nice large cooler. Be sure to keep all fans off. It's actually better to remove the fans from the rad but you don't need to. Make sure your pump is on a separate PSU as you never want the coolant to stop moving. (Something about flowing water never freezes-not true but certainly helps) The 50/50 mix I use is good til around -36c standing still. Put Dice pellets directly on top of the rad. I kept my non-spinning fans between the rad and DICE just as a safety measure but could have had better results without the fans there. I kept my k-type temp sensor in my reservoir to monitor coolant temps. Bench away. If you notice the coolant not flowing pull the rad from the DICE. and allow it to warm so you can restore the flow rate. In extreme cases (like when I shut my pump off) and you need to thaw quickly keep a hair dryer near by. :D

Best of luck and happy clocking.