Reservoir size and heatercore painting

Hi guys,
I've got two questions for you. 1) Does painting a heatercore or radiator affect its heat dissipation? 2) I am planning to put together a WC setup to cool my 3.2E CPU (Dtek whitewater block) and VGA (Swiftech MCW50) with 1/2" tubing. What size reservoir should I get? In general, how much does the size affect results and is there a rule of thumb I should go by? I would be grateful for any help. Thanks!

If you paint a radiator correctly, so it is only the very edge of the core that is covered, there should be no noticable increase in temperature, but if you cover the whole thing in thick paint, then it will be worse. You don't actually need a reservoir, but if you want one, the size is up to you.

well, i was using a 5.25" bay resivoir, and i switched to a dual 5.25" bay resivoir, and with the side panel off on both tests, the single had my CPU idle at about 32C, and with the dual bay resivoir it idled all the way down to 29C, it was a 3.4p4 which my system including my water cooling parts are being parted out. i still have the single bay resivoir and the dual 120mm heater core still available painted in black. PM if you want more info on it.

The water temperature in all water cooling systems will eventually reach equilibrium no matter how large of a reservoir you use. So, if you run your system 24/7 it won't make any difference at all how large the reservoir is or if you even have one--a t-line would work equally well. But, if you only run your computer for short periods of time and then turn in off, a larger reservoir may help because it will take the system longer to reach equilibrium.

In general, reservoirs mostly used to help bleed the system of air--they're better at trapping air that is flowing through the lines than is a t-line--and as an aid in filling the system. And, for these purposes, the size of the reservoir doesn't really make a lot of difference. In fact, reservoir design and placement can have a much larger impact than size in how well they work.

MVC said:

The water temperature in all water cooling systems will eventually reach equilibrium no matter how large of a reservoir you use. So, if you run your system 24/7 it won't make any difference at all how large the reservoir is or if you even have one

Click to expand...

That makes a heck of a lot of sense. Thanks! As for the design and placement of the reservoir do you have anything in mind?

Placing the reservoir as the highest part of the loop will make bleeding air faster.

Avoid 90 degree bends anywhere in the tubing or fittings (this is not always possible, but a goal to strive for nonetheless).

Make the loop as short as practical.

Obviously, in the real world, these guidelines can ( and probably will) be contradictory.
Every waterloop will be a comprimise, just do the best that you can.

You'll probably change and redo the system multiple times anyway, so just start and see what happens.

clocker2 said:

Placing the reservoir as the highest part of the loop will make bleeding air faster.

Click to expand...

Here's the first question I wish I didn't need to ask, but I can't find myself an answer. I understand you don't want air in your system, but how exactly does the reservoir work? Do you fill it all the way or do you leave some air inside so any air bubble circulating through would rise to the top in the reservoir?

P.S. "Cake or death?" It's nice to come across another Eddie Izzard fan

"Cake, please".

Unless you assemble and bleed the loop entirely underwater (it has been done), there will always be some air in the system.
A reservoir is more accurately just a glorified air trap, so yes, there needs to be space for the air to reside.
DON'T fill it all the way or the bubbles will continue to circulate.

Even so, the bleeding process is critical.
Air can and will be trapped in the worst places and you need to get it out.

The reservoir traps air because the water traveling through it is going a lot "slower" than it does through the tubing. This decrease in the water's velocity is what allows the air bubbles time to rise to the top of the reservoir, and the air will rise regardless of whether or not the reservoir is "full" when you start the bleeding process. (This is why it generally takes longer for a system with a t-line to bleed, the velocity of the water is never reduced and air bubbles have less time to rise up the t-line as the water circulates.) Note: reducing the velocity of the water in the reservoir does not decrease the flow of water through the loop. The same amount of water is flowing, it just isn't going as fast while it's in the reservoir.

One thing to keep in mind, if the reservoir isn't kept full you're much more likely to get the "swishing" sound of water circulating through the loop. Reservoirs make more, or less, noise depending on their design, but bay-reservoirs are "famous" for making lots of noise if they aren't kept completely full so if you don't want to constantly hear the water moving through the loop, you'll need to keep the reservoir full. Also if the reservoir isn't kept full, you're more likely to be continuously reintroducing air bubbles into the loop, though some reservoir designs are better than others in this respect. If the water rushing into a bay-reservoir is bouncing off the walls and creating bubbles, those bubbles will remain in the water and get sucked back into the loop. But, if the reservoir is full the water will enter and not create any new air bubbles so the entire bleeding process will go much quicker.