Passive water cooling

[boucher91]

why not just very quiet? you did say expense wasnt an object..
about 4 to 5 biga$$ rads fesser, xspc rx series the great big fat ones like mine in sig..lo fin per inch made for low speed fans...
make urself a shroud for each rad so 1or2 fan used each there are some really quiet fans that when downvolted they are virtually silent...

 

[don256us]

My system was a full tower case. For my RAD, I used a heater core that I got from a junk yard. A heater core is the small radiator in your car that provides heat in the passenger compartment.

I cut a hole in the very top plate and put my radiator there. I did add a fan but as the components added heat to the air space inside the computer,the air would naturally rise through the radiator. This would cool the radiator and brin cool air in through the bottom of the case. I used a rather large water pump that provided for the only noise that the system made.

 

[Kasm]

I'll tell you the idea I had trouble with - wrapping my head around the fact that the open end of the T could be below the top of the loop!

Though this is true in certain circumstances, it is not always true. It the T-line is capped (sealed) then it is always true as the captured air will prevent fluid from entering the T-line.

But if the T-line is not capped, the placement of the T-Line relative to the other parts of the loop determines if the water will flow out of the T-Line until their isn't enough water to reach the pump, or gravity has pulled all the water to a level equal to the T-Line openning. Also, in the cases that the fluid doesn't leave the loop, as soon as the pump is turned off then the water will suddenly leave the loop, as the pump isn't drawing in anymore water.


Just wanted to say this to warn the inexperienced so they don't potentially damage their systems.

 

[QuietIce]

But if the T-line is not capped, the placement of the T-Line relative to the other parts of the loop determines if the water will flow out of the T-Line until their isn't enough water to reach the pump, or gravity has pulled all the water to a level equal to the T-Line openning. Also, in the cases that the fluid doesn't leave the loop, as soon as the pump is turned off then the water will suddenly leave the loop, as the pump isn't drawing in anymore water.

That is incorrect.

I've got rigs running right now with T-line ends well below the top point of the loop. There is no air in the lines above the T-line and water does NOT come bubbling out the top of the T-line. No, the T-line is not sealed well enough to hold water against gravity. No, the pump does not need to be turned on. In fact when I filled it and was bleeding the system it wasn't capped at all - and no water was coming out the top. Nor does water come out the top when I (very rarely) turn the system off for maintenance.* As I explained earlier a closed loop is essentially "flat" as far as relative height goes and as long as the open end of the T-line is pointed up it is "above" the rest of the loop regardless of the actual 3-D location of that loop.

From your apparent mis-understanding of how a single T-line in a closed loop works you now know why it might have been difficult for me to wrap my head around the idea that the T-line end does not have to be above the top point of the loop nor does it need to be sealed to stop water from coming out of it. I was told this by someone on these forums back in June '06 when I was putting together my first loop and I ran experiments to prove it to myself because I couldn't believe it either - now I'm a believer. (Cut to I'm A Believer written by Neil Diamond and performed by The Monkey's, 1966. )


The T-line should have some type of dust prevention on top to keep the loop from getting contaminated. It can be "sealed" if desired but it's not necessary. One of my loops is more or less "sealed" because I got fancy with it and bought a fill-port but the others aren't.


PS
*It should be noted that there is a very small rise in the water level when the pump is turned off. It's no more than maybe 1/4" (when the system was new) and is caused from contraction of thin-walled tubing when the pressure is decreased. If one were to "top off" the T while the pump is running there might be some spillage when the pump is turned off. The change in water level should be minimal when using thick-walled tubing but all I've ever used inside the case is thin-walled 1/2" Tygon with SmartCoils so I can't say what change there might be - only that it will be less or equal to ~1/4" ...

 

[Ben333]

A loop is a lot easier to fill when the T is the highest point. If it was not at the highest point I'd want it capped - actually I'd prefer it capped either way. It it were to point down at an angle, water would run out and air would work it's way in, above the water, allowing water out.

 

[Kasm]

I have two sources that I am drawing on to make my statements.

1) I have messed up a loop long ago when I has still in school and did have water come flying out of the T-Line. The T-Line was after the pump and the water flowed out of the T-Line. Gravity keep feeding the pump from the rest of the loop that was higher than the T-Line and pump. So placement of the T-Line is important, but I was young and didn't know any better. (No damage was done to the PC as the T-Line was pointing away from the system with the case panel off) This loop had 2 T-lines, one for filling, one for draining, hence the problem. The other T-Line was sealed, but the volume of air trapped was enough to cause problems.

2) I have since taken fluid mechanics class and become a mechanical engineer. My senior year project was based on fluid flows and I have worked in marine applications for the last several years.

I am not stating this to contradict you but just to let people know to be careful. Placement of objects in the loop can have consequences.

 

[QuietIce]

Heavily edited:
If you're looking at this from a marine perspective then you're looking at it all wrong. With a single T-line there is no gravity to consider and therefore no height differences. There is only one "height" inside the loop and as long as the end-point of the T is above the bottom of the T where the fitting is then the opening is always higher than the loop.

I hope your near mis-adventure didn't burn out your pump! But you would have had the same problem if the T had been above the rest of the loop unless you waited for the air to work it's way to the top (and that takes time - I tried that once but never again).

A loop is a lot easier to fill when the T is the highest point. If it was not at the highest point I'd want it capped - actually I'd prefer it capped either way. It it were to point down at an angle, water would run out and air would work it's way in, above the water, allowing water out.

I amended my post to reflect that. Yes, the 'T' must be pointing UP.


I haven't noticed any significant difference between the location of the 'T' (as far as height above the loop goes) and ease of filling/bleeding the loop. Air always gets trapped in the loop anyway and I guess I'm too impatient to wait for it to work it's way out. Jogging the pump seems quicker and easier - I little tougher on the pump though ...