Remove Air From CPU Block
Remove Air From CPU Block
I've just completed a water cooled build but found air trapped in the CPU block. Anyone have suggestions or techniques to remove the air? I can't just shift the CPU block since I'm using rigid tubing, making movement difficult.
I would connect the filling hose to the res and blow; however, you’d need a significant amount of air to move the loop excessively. The effort you apply will indicate the pressure drop at the CPU block. I use a 3/4 inch hose directly to the block, but it includes 10mm couplers which cause an 80% pressure loss, making it difficult to push through when emptying. In contrast, my radiator experiences almost no pressure drop and is much easier to blow through. What this means is that your pump must exert more force to push the fluid through the loop; there are two possible solutions if you’re concerned about this issue.
Andreas_Day shared that they recently completed a water cooled build but encountered air trapped in the CPU block. They are seeking advice on how to remove the air. The person cannot simply relocate the CPU due to the use of rigid tubing, so they are looking for alternative methods. They suggest gently shaking the computer while the cooling loop is active to release any remaining bubbles, noting that some may dissipate within a day or two.
The most effective method is to gently move your computer while the loop runs to release the last bubbles. Some may come out after a day or two. Thanks.
I've attempted shaking the device thoroughly, but they remain unresponsive.
I've also tried rotating the entire PC and adjusting pump speeds.
I think I'll just give it another try and rotate it again unless someone else suggests an alternative.
Andreas_Day shared some tips on how to shake your computer effectively. It helps to move it slightly during the looping process to release any remaining bubbles, which may come out after a day or two. Some users have found success by shaking the entire PC and rotating it, or by changing the pump speeds up and down. They suggest trying again and turning it around if needed. For best results, place the PC on its side so the CPU block is horizontal and run the pump at full speed for a while.
Those bubbles are typical and should disappear within the next few days as startups and shutdowns continue. They stem from cavitation around the block, and once most air is removed, their occurrence will decrease. For now, they won’t significantly affect the system. If they become larger, it suggests air is being drawn into the loop through your pump or a leak.
FrankenDesign asked about the coolant type, whether the system uses open or closed loop, and how it’s filled. He explained he positioned his reservoir above the CPU block, allowing water to naturally flow in without activating the pump. He also mentioned that air bubbles might indicate pressure loss in the system, noting his CPU block contributes about 80% of the drop. By lifting the hoses slightly, he could remove the bubbles easily. He described using an open loop, where water simply returns to the reservoir through the return feed, and suggested using a pump to push water back up if needed, given its maximum height. He asked about tubing size—whether it’s 8/10mm ID/OD—and mentioned using deionised water and Mayhem Pastel Dye. His return feed goes into the bottom of his pump/res assembly, and he fills from the top of the reservoir. He noted his tubing is 13/10mm and emphasized that the issue might be related to air entering the loop rather than a leak.
I would connect the filling hose to the res and blow; however, you’d need a significant amount of air to move the loop excessively. The effort you apply will indicate the pressure drop at the CPU block. I use a 3/4 inch hose directly to the block; though it includes 10mm couplers, it causes an 80% pressure loss and makes it difficult to push through when emptying. In contrast, my radiator shows almost no pressure drop and is much easier to blow through. What this means is your pump must work harder to push the fluid through the loop; there are two possible solutions if you’re concerned: a higher flow CPU block with wider openings or a more powerful pump with increased pressure. This will help move the water and reduce air bubbles, lowering the pressure drop somewhat.
FrankenDesign:
I was thinking about attaching the filling hose to the res and blowing; however, you'd need a lot of effort to cycle the loop excessively. The amount of air you push will indicate the pressure drop at the CPU block. I use a 3/4 inch hose directly to the block, but it has 10mm couplers which cause an 80% pressure drop and make it difficult to blow through when I need to empty it. In contrast, my radiator shows almost no pressure drop and is much easier to blow through.
What this means is that your pump is working harder to push the fluid through the loop; there are two possible solutions if you're really concerned. One is a higher flow CPU block with wider openings or a flow channel, and the other is a more powerful pump with increased operational pressure. That should move the water and reduce the air bubbles, lowering the pressure drop somewhat.
That makes sense. Thanks a lot for your assistance.
But I've just completed the build, and I won't replace the CPU block or my pump (especially since I already have a pump res combo) just to eliminate one air bubble. I'll just keep shaking it and turning it, hoping the bubble gets out.
This build will be wall-mounted, so hopefully the air escapes before it rises, as I won't be able to easily shake or turn it afterward.