Water cooling

[The Borg]

Hi all,

As a mech eng, I suppose I should know this, but things seem to work slightly differently around PC's.

I have a slightly modified water colling system in my PC. I use a bucket as my resivour and a normal fish pind pump to pump the water to the CPU cooler, then via two radiators (1 x 120mm and 1x 240mm all with double 120mm flans).

When I connected the second radiator, the flow rate dropped quite a bit but o significant drop in cooling.

My reasoning is that a slow flow means more residence time to pick up heat which is then moved away. So heat is taken away form the CPU and the water may be warmer which is then good for the radiator as there is a higher delta T for heat disipations. High flow rate means less residence time and less heat pick up per unit of water. But that is also OK.

Looking at the equations for heat transfer, velocity does seem to be a factor but maybe I am already past the velocity where it matters. I have noticed that stopping the flow to swap out the bucket to clean the water for a few seconds has very little effect on temperatures.

So would installing a bigger pump help? Should I even reduce the flow?

 

[aigomorla]

yes flow rate can play a big eq in h2o.

its more head pressure tho and not flow rate.

Can you list your setup?

 

[SparkyJJO]

To a point, yeah. You can reach a point where more flow rate doesn't really give any noticeable benefits, but I have yet to see a case where lower flow rate is better.

 

[aigomorla]

Originally posted by: SparkyJJO
To a point, yeah. You can reach a point where more flow rate doesn't really give any noticeable benefits, but I have yet to see a case where lower flow rate is better.

well there usually related.

less flow rate, would yield greater head pressure and vice versa, however the block design needs to be looked at.

He's using a fish hobby pump which has high flow, but crappy head. I need to see what block he has to see if he even has the right pump.

 

[Gillbot]

A high rated flow pump usually has poor head pressure so if he is using a restrictive block, his flow rate will be very poor since the pump cannot make flow with pressure.

 

[The Borg]

Guys,

Thanks for the comments. I have a Thermaltake bigwater cooling system - minus of course the little tank and pump.

I hear you about the usual flow rate versus head - that is the characterisitc of a centrifugal pump and it's pump curve. High head low flow to low head high flow.

The pump is a 1.8m (no flow) to 1000 l/hour pump. So not so crappy compared to the kit pump.

Question remians, do I up the pump size or what?

 

[aigomorla]

Originally posted by: The Borg
Guys,

Thanks for the comments. I have a Thermaltake bigwater cooling system - minus of course the little tank and pump.

I hear you about the usual flow rate versus head - that is the characterisitc of a centrifugal pump and it's pump curve. High head low flow to low head high flow.

The pump is a 1.8m (no flow) to 1000 l/hour pump. So not so crappy compared to the kit pump.

Question remians, do I up the pump size or what?

you can, however i dont think the rest of your parts would benifit from the increased head output.

The bigwater isnt a very high performing kit in the h2o world. :T

If you want to replace it, i could point you to a couple of good pumps that would swap it right out.

 

[The Borg]

What make the kit not so good? What is it about other components that makes them better? Design, materials of constuction, layout?

 

[Cheezeit]

Originally posted by: The Borg
What make the kit not so good? What is it about other components that makes them better? Design, materials of constuction, layout?

All of those that you mentioned, actually. Thermaltake does not really put much thought into the design of their waterblocks compared to the innovative ones by Swiftech and D-tek, etc. You'll get much better blocks with better performance and design from companies like the above mentioned and DD, EK etc.

 

[The Borg]

But what are the differences that make these others so good? Mine is made of copper, got a good contact with the CPU, has good warter flow over the surface. What makes it so bad?

 

[Gillbot]

design

 

[The Borg]

What about the design?

 

[aigomorla]

Originally posted by: The Borg
What about the design?

lack of one, is what gillbot is trying to say.

if your happy with your setup, dont change it.

if your want more, upgrade the entire thing.

thermaltake is like cancer to the other h2o parts, by adding it on a good brand name, you only poison your entire system.

 

[Gillbot]

Originally posted by: The Borg
But what are the differences that make these others so good? Mine is made of copper, got a good contact with the CPU, has good warter flow over the surface. What makes it so bad?

There is a lot of design put into the internals of MOST waterblocks to increase the efficiency of them. The better design, the more heat that can shed into the water. The lack of design means a poor performing waterblock.

 

[The Borg]

So what is this substance you call design? I must get me some.

 

[Gillbot]

Originally posted by: The Borg
So what is this substance you call design? I must get me some.

With comments like this posted at people trying to HELP you, I would suggest you looking for something called a clue first.

 

[The Borg]

Well, if you look back, I have been asking all along for details. All I get it design. I get the feeling that those that are trying to help don't actually know what they are talking about and are only regurgitating sales hype and other's comments.

I have alsked for help expecting to get it form such experienced and well know forum posters and have revieved nothing concrete. I have posted 7 times (including this one). From post 3 onwards I have asked tha same question - what about the design. No answer.

I may not have a clue, but do you guys?

 

[Gillbot]

If you compare the internals across all the current top performing waterblocks, you will see the effort those companies have placed into their designs. Conversely, if you look at those waterblocks who do not perform well, you'll also see their deisgn (or lack of) and you would understand what we are trying to tell you. Instead of asking us to spell everything out for you, just do some research, compare and you'll understand what we are telling you.

EDIT: Here, i'll make it easy.

Look at this image of the thermaltake block: http://www.virtual-hideout.net.../ThermalTake_W3/04.jpg

There is not much turbulent surface area for the water to pick up CPU heat, it just has a simple flow channel.

Now look at the Swiftech Apogee GT internal section: http://www.legitreviews.com/im...ws/457/apogee_gt_1.jpg

Many pins that allow the water to pick up heat. That's the difference in design.

There is a lot more that goes into it, such as entry and exit points, flow rates, etc.

 

[The Borg]

Gillbot. Thanks. Now I am starting to understand. But tell me, is a forum like this not a place to start research? Looking at pictures all over the net is not going to help much in the undestanding that would come from the likes of you or 'aigomorla'. It is secrets that the fanufacturers will probably hold close to heart.

My block is exactly like you first pic. Anyway I can get it better?

 

[Gillbot]

Originally posted by: The Borg
Gillbot. Thanks. Now I am starting to understand. But tell me, is a forum like this not a place to start research? Looking at pictures all over the net is not going to help much in the undestanding that would come from the likes of you or 'aigomorla'. It is secrets that the fanufacturers will probably hold close to heart.

My block is exactly like you first pic. Anyway I can get it better?

It is a great place to start research, but many of us are very passionate about this hobby. Some people (such as myself) try to help but we don't have the time to walk everyone through each and every aspect. This is where we expect you to take our suggestions and look further on your own.

As for getting your block better, I'm afraid it is just not that simple. Replacement is an option but adding a better block to an already "weak" kit is asking for trouble. You should either start from scratch or just accept the limitations of your setup and work within it's limits.

Aigo stated it best:

Originally posted by: aigomorla
if your happy with your setup, dont change it.
if your want more, upgrade the entire thing.

 

[aigomorla]

okey...

lemme teach you block design 101 for newbies.

Water is not like air. Meaning massive does not mean better. Also water tho likes to have sufrace area. Each dip or ding on the block surface creates more surface area. Think crater vs flat land.

Now the TT block is VERY simple at best and has VERY limited surface area.

Now take a simple block like the ApogeeGT:
http://i125.photobucket.com/al...aigomorla/IMG_0559.jpg

Do you see the difference in quality? Do you see how the ApogeeGT easily has probably 4x the surface area to exchange heat with vs your TT block?

Now we can get even more complicated and introduce Injectors. What is an injector?
For this we look at the EK Supreme:

http://i125.photobucket.com/al...aigomorla/IMG_0841.jpg

Simple package until you open one up:
http://i125.photobucket.com/al...aigomorla/IMG_0842.jpg

http://i125.photobucket.com/al...aigomorla/IMG_0847.jpg

see that steel plate? Thats called an injector. Water can work on 2 principles. Low restriction, or impact/injector.

The low restriction would be like you pouring water over something to cool it down. Injectors would be you Sand Blasting the heat away. Injectors is by far superior then low restrictions, however planning a loop for injector can get very expensive.


Back to bases, the TT base is very poor in quality. :X Heres some more for you to compare:
http://i125.photobucket.com/al...aigomorla/IMG_0844.jpg

http://i125.photobucket.com/al...aigomorla/IMG_1105.jpg

dayam i lost my fusion base pic. :\

But i think you see the point. This is why i told you, if your happy with what you have, just keep it. You trying to upgrade a TT setup is asking for trouble, and would give you very little gain.

Also to mention the DDC-3.2 series is not 1/4ID friendly.

 

[Zebo]

Need decent flow for impingement on block so water pulls heat away faster. The German systems use low flow and 6mm tube and that's ok but they never have results like high flow US systems. But overall in grand scheme of things it only makes 2-5C difference assuming rad and fans don't change. They are the critical element of any water system.

 

[The Borg]

Cool pictures. Makes the understanding of the mechanism much easier. Thanks.