I'm impressed with this $25 submersible pond/fountain pump from Harbor Freight. :thumbsup:

Great thread ny_driver! Made for a very interesting and informative read. I myself am experimenting with a "chiller" of sorts. Sub ambient for now ;) Running into a lot of issues at -25 and below. I'll start my own thread here soon.....

OCM :thumbsup:

Thank you!

I'm feeling like quite the expert now. I documented most of the trials and tribulations.

The keys are the coolant mix and the ability to pump that coolant. 70% antifreeze seems to be the best mix so far, but it is thicker than water. So when designing your loop keep in mind the added viscosity of the coolant. :cool3:

Today I tried 75% anti-freeze/25% DI Water and got slush at -25C. Looks like I need a better pump and coolant mix.

Another one tippy toes into the sub-zero realm. :good:

You must have bought really cheap RV antifreeze or something, because a mix of 70% automotive antifreeze won't ever slush up at all even at -45 C (the coldest I have tested)....it's good to ~-60C according to the manufacturer at 70%.

Maybe you are way below -25 actually...what are you using to determine the temperature? And what are you using to cool the coolant? How many BTUs?

We will get this slush problem solved.

No need for distilled water when using antifreeze...you are not going to get any algae or anything.

Hmmmmmm:blink: slush problem huh? I only had that when I used RV-water system antifreeze, or with too much water.

Ohh and do not try the -50 ice breaker washer fluid either. The evaporator gets all gel covered at ~ -30 C.

Are you positive you have a slush problem or is the problem that the coolant isn't pumping (viscosity/restriction problem) and you are assuming slush? Just want to be sure. I modded my block so there was no unnecessary restriction.

This is the pump that did all my chiller work, viscous and all:
http://www.xtremesystems.org/forums/...d.php?t=170509

Yeah, tell me about it, lol.
Ok, here is the thread: http://www.overclockaholics.com/foru...4866#post54866

OK finally with some concrete numbers........:thumbsup:

I started today(4.5GHz of course) ~8 AM with the chiller @ -40 C and the block @ ~ -25 C, now @ 1:45 PM the chiller is @ -30 C and the block @ -17 C.

Good thing electric is cheap where I live. I've had the chiller running for the better part of a couple weeks now. :D

Nice numbers! I still have a ways to go........

OCM :thumbsup: