View Full Version : Advice Requested
Player0
08-07-2002, 09:39 AM
Okay, here's my problem. I have a dual loop water chilling system. My hot water loop has a pump/resevoir at the bottom of the case, flows through a large peltier heat exchanger block, and then up to four BIX radiators mounted at the top rear of my system. This works great when the pump is running, i get good flow, everything stays nice and cool.
But when I shut the pump off and go to bed, the next day I have to flush all this air out of my radiators. It doesnt affect the functionality of anything, and the air clears out quickly, but its still annoying to have to do every morning. This only started happening when I added the 3rd and 4th radiators.
The BIX rads have built in resevoirs, and they end up storing alot of water. Since the radiators are pretty much the highest point in the system, all that water weight presses backwards on the pump and resevoir. I dont have any water leaks anywhere, and I use clamps on all my water connections. Somehow air is getting up in there though, and im not sure from where. It probably is from the fittings, but I dont know how to seal it up. The pressure of all that water up above the resevoir when the pump is off must be causing the problem somewhere.
Anyway, Im looking for a solution to this problem. My idea was to mount a second 32oz resevoir deal at the top of the case above the radiators. This would store enough water so that the radiators wouldn't empty out every night, and It would self-prime the next morning. I have no idea where my water is going and where this air is coming from. But, anyway.
My only concern is that im putting more waterweight on the system, and that the resevoir is going to fill up with air and be useless.
i dont know...maybe it has to do with the water itself expanding or contracting with all that heat pumped in to it. Thoughts?
RichBa5tard
08-07-2002, 01:24 PM
I think you've got some tiny little holes in one of your BI rads. I've got a BI 2 myself, and I used to have a Swiftech rayden: both had little holes that were too small to exctually leak water, but large enough to let in some air. Then again, I only buy second hand stuff. :)
When you sniff your rads, can you smell a the waterwetter or anti-freeze?
Player0
08-07-2002, 01:36 PM
I pressure tested all the radiators before I put them in the system, because I wanted to check for leaks. I attatched a 1/2" barb fitting to my kitchen faucet, and primed the radiator. Then i sealed the water exit. This put the radiator under tremendous pressure, which should have showed me if I had any leaks. I did this test after I drilled the mouting holes larger, cause I wanted to make sure I didn't damage anything.
So as far as I know, all four radiators are leak free. How did you find your little holes?
Not to say it isnt possible that they are leaking air somewhere. I do smell antifreeze in the system, but I've had coolant leak all over on me while building/tweaking multiple times. I have no idea whether its smelling because of my previous screw ups, or if there is actually a hole present. All i know is that I've not seen any drips, and everything is a-okay with the pump running.
RichBa5tard
08-07-2002, 01:57 PM
Well, I haven't spilled any coolant nor had any leaks since my BI 2 setup, and I still smell it. I can see them too: little white places with coolant deposits. It leaks at such a slow rate it evaporates at the surface, leaving little, white powder behind.
Player0
08-07-2002, 03:02 PM
Hmm...i just looked, don't see any white deposits anywhere. None on any of the fittings either. I wonder what else it could be.
sjohnson
08-07-2002, 03:07 PM
When you shut the system down, you create a partial vacuum, and air finds a way into the system due to the partial pressure difference between the cooling system and atmospheric pressure?
Player0
08-07-2002, 03:21 PM
I think that might be whats happening, yeah. Because of the water cooling down and compressing, and also because the weight of all the water in the radiator squeezes down on the pump and resevoir, and i think this pressure might be enough to suck air in to fittings, no matter how tight my clamps are.
So I guess i need to find a way to keep the pressure balanced. I dunno. Its all guesswork here. :)
Id like to make a suggestion here if I may.
Now from reading all that you have posted here Im thinking its not that you have a leak anywhere in your system. Im honestly thinking you just dont have enough water in your system.
Now what I would do, is make another res attachment that can be taken off once you are finished with it.
Hmm... tryin to think how to explain here.....
Ok, take and add in a new res at the Top of your system, like you were thinking of doing.
Next, run the pumps, get the water flowing, then slowly add in water to the new res thats at the highest point in your system. It should force any air up and out of the system. Shut it down, see if you get more air to come out. If you do, keep filling. Keep filling it until it wil take no more.
Then, once its full, close off the connection to the res, and remove the res.
That should fill it to the brim, which I honestly think is the problem here. Just not full enough.
Player0
08-07-2002, 06:29 PM
Well, I spend alot of time chasing bubbles out of the system. The system is as bubble free as I can get it. Any air trapped in the radiators/waterblocks/resevoir isn't coming out any more easily with another resevoir at the top. Im pretty confident that the system is quite full to the brim.
The highest point in the system is actually the tubing that goes to the radiator. When I immediately turn off the pump, there are no air bubbles that flow backwards in to this tube. But after 10 hours or so, the tube will be empty. I dont think there is enough residual air left in the system to cause such a 'drain'.
But, anythig is possible i guess.
Hmm... odd... Well I would suggest that once it has that empty space, just open it up and filler to the brim!!
See what that does. It shouldnt be doing that unless you have a leak. Im sorry, but I dont buy the air will seep in but water wont leave. Unless the leak is in the very top of the system.
Player0
08-07-2002, 07:16 PM
Well, I guess when the hot water cools, it compresses, and can form a partial vacuum. This might suck air in, but when the pressure equalizes, the seal is tight enough for water to not escape. ?
sjohnson
08-07-2002, 07:42 PM
No matter what the reason, I'd still be checking for leaks. Even if the surface tension of the fluid is enough to "seal" a fitting when wet while allowing less "thick" air to pass when the system cools, it's still a leak that's letting air into the system.
Player0
08-07-2002, 07:47 PM
How can i find the leaks if water doesnt drip out?
sounds like a decent thought.
But keep in mind, if it does taht and draws air in, then when you start your system, the air would still have to go somewhere.
Where? My thoughts, into your res. Where else? Hopefully not into your rads or block.
Player0
08-07-2002, 08:11 PM
Well the air goes to the top of the system, which is where the radiators are.
When i turn the pump back on, the air goes back down in to the res, i just have to jiggle the tubes around to get all the air back out again.
crane
08-07-2002, 08:29 PM
Get a hand vacuum pump from an auto parts store....pull 10-15 lbs vacuum on it and watch the gauge. If you start losing vacuum,take a spray bottle with water and start spraying all your connections and radiators....watch the needle on the vacuum gauge,the water you are spraying will temporarily seal the leak and help pinpoint the leak.
sjohnson
08-07-2002, 10:35 PM
And pay particular attention to coat all joints (not the paper and herb kind :) ) and junctions with the water (I would apply it with a brush and hold a rag under the part to catch any drips). While you could have pinhole leak(s) in the tubing, a common place for leaks are at clamped and threaded connections.