How many rads for passive watercooling?

[T.Vengeance]

How many radiators and the size of them would I need to watercool a GTX 780 and a FX-8350 without fans (all at stock clock speeds and voltages)?

 

Hmmm...I think I set the standards too high. Let me reask:

 

How many radiators and the size of them would I need to watercool a GTX 760 Ti and a i7-4770 without fans (all at stock clock speeds and voltages)?

 

Reason behind this? I'm planning to make some sort of custom radiator for an upcoming project and I'm wondering how much surface area I need for convection cooling through this radiator I'm making. I figured that a safe starting point would be from rads that already work.

[Samdb]

What case do you have? Or are you planning a build? I would recommend getting some low RPM Noiseblocker eloops and running a waterbox, it's as passive as you can get without actually being passive.

[Cacao]

Well you would need a minimum of a 360, the more you add the slower fans you can get, which means less noise. Why are you watercooling if you don't want to overclock?

[Ghost]

Probably 8-12 120 fans worth of rad space. More to be safe.

 

Unless you have money to burn, don't bother. Plus you would need some airflow in your case for things like VRM. Convection currents probably wouldn't cut it.

[Gaming_Addiction]

240/280 should be fine although if you have the room you should get a 360/420

[sk8ermanblue]

I wouldn't recommend trying to do passive water cooling. the pump puts out heat and all components put out heat. you need to have atleast some sort of air flowing across the fins of your rad(s). you will run the risk no matter how many rads you have of overheating and burning up your pump or hardware. you can get mostly silent fans and with more rad space you can have them at even lower rpm. but your still going to want fans on a watercooled system

[Ghost]

Well you would need a minimum of a 360, the more you add the slower fans you can get, which means less noise. Why are you watercooling if you don't want to overclock?

 

 

240/280 should be fine although if you have the room you should get a 360/420

Have you guys read the question before posting?

[SSOB]

Three 480 Rads should do it , though dont do it ...

[T.Vengeance]

What case do you have? Or are you planning a build? I would recommend getting some low RPM Noiseblocker eloops and running a waterbox, it's as passive as you can get without actually being passive.

Just planning a build

[sabot]

Would you be interested in water cooling the motherboard? Then airflow would not be a problem.

[T.Vengeance]

Reasked the question...this time with less heat output components. 

[everything count to life]

Reasked the question...this time with less heat output components.

At least 2 to 3, quad rads (480) but it would be a waste especially for the parts your cooling you could spend that money on a better graphics card,

[Cacao]

Have you guys read the question before posting?

He edited his post.

[João Severino]

How many radiators and the size of them would I need to watercool a GTX 780 and a FX-8350 without fans (all at stock clock speeds and voltages)?

 

Hmmm...I think I set the standards too high. Let me reask:

 

How many radiators and the size of them would I need to watercool a GTX 760 Ti and a i5-4770 without fans (all at stock clock speeds and voltages)?

 

Reason behind this? I'm planning to make some sort of custom radiator for an upcoming project and I'm wondering how much surface area I need for convection cooling through this radiator I'm making.

 

 

Reasked the question...this time with less heat output components. 

 

 

Even with this less heat output you would need an immense amount of surface area to achieve any decent cooling without fans blowing some ir throw the rads

You would need at least 8*120mm worth of rads but even then it would probably run very hot

This is not a good idea because you need some airflow passing throw the rad in order to cool the liquid inside by transferring the heat from the hot component (the rad) to the colder component (the air around your system)

[T.Vengeance]

He edited his post.

No that was before I edited it. Thanks though

[Cacao]

No that was before I edited it. Thanks though

Oh I just reread it, my bad I completely misread it!

[techswede]

get two Phobya Xtreme nova 1080s and mount them outdoors...

Nah but seriously the surface area needed to dissipate the heat generated by your components would be quite large if you don't have any fans blowing air through the radiators. 

that's why i brought up the novas. that's about 12 fans worth of space on one side of both of em.

There is also the possibility of stacking a couple of 4x140 quad rads

but in the end the cost to performance would probably not make it worth it.

Still.. Good luck if you're still going to attempt it

 

edit;

The phobya supernova 1260 could work

that thing is huuuuuuuge. and might have enough surface area to dissipate a bit of heat

[TheMuskr]

This would not work with standard radiators, they are designed for forced air. cooling computer components solely by convection is very difficult. water cooling is not ideal at all for convection cooling look into systems designed for this kind of cooling. This is a very expensive and difficult road to take so be prepared for that. There are a lot of resources online that can help you do the fluid dynamics calculations to compute the needed amount of heat dissipation (as in rad area).

here is one option for a fanless heatsink. http://quietpc.co.uk/nof-set-a43

[warmmilk]

for passive cooling look into this

 

 

edit:

i'd still have a silent fan or 2 in the case for some airflow, a noctua with an ultra low noise adapter will be silent at more than 3-4" away...

 

Also, Ice Dragon claims that their fluid is better in conditions with low heat dissipation (idk if its true or not), so maybe look into using that with whatever you decide to go with.

[T.Vengeance]

for passive cooling look into this

 

 

edit:

i'd still have a silent fan or 2 in the case for some airflow, a noctua with an ultra low noise adapter will be silent at more than 3-4" away...

 

Also, Ice Dragon claims that their fluid is better in conditions with low heat dissipation (idk if its true or not), so maybe look into using that with whatever you decide to go with.

Oh wow, thanks for linking the video. I'll definitely watch it.

[warmmilk]

Oh wow, thanks for linking the video. I'll definitely watch it.

 

if you decide to go with these, make sure to post up this system (pm me about it if you remember to).  I'd be very interested to see how it turns out.

[T.Vengeance]

if you decide to go with these, make sure to post up this system (pm me about it if you remember to).  I'd be very interested to see how it turns out.

Yup. I'm currently in the process of finding a job. Once I get hired, I'll be making a new system with this custom rad and I'll be making a build log. Hopefully everything goes well...

[Relttem]

Hi all - I lurk around, but I thought I'd chime in on this.  What you are after is "natural convection".  And, since you know the CPU/GPU etc you are going to use you can look online and find out how many watts they disspate at whatever speed.  Then, assuming you lose a little bit of heat thru the tubes you can then do an energy balance and figure out how much surface area you are going to need.  You said you were going to make a custom radiator, which is probably the only way this will work.  That is because you need to the fins to run north-south and not east-west.  You need that because you'll want the temperature at the bottom of the radiator to be the hottest which will drive the air up, since hot air rises.  If the fins are east-west the hot air can rise along the fin.  You might want to look into a series of pins instead of fins.

 

good project.

 

Energy Balance:

 

h*A*dT = mdot*Cp*dT

 

you know everything but A*dT, so you can pick some reasonable dTs and get an A.

 

Ice Dragon Cooling works by changing some of the parameters used in forced convection flow. 

 

I use Ice Dragon cooling an I7 and an old GT640 with an 80mm rad and a northbridge fan on it..

[T.Vengeance]

Hi all - I lurk around, but I thought I'd chime in on this.  What you are after is "natural convection".  And, since you know the CPU/GPU etc you are going to use you can look online and find out how many watts they disspate at whatever speed.  Then, assuming you lose a little bit of heat thru the tubes you can then do an energy balance and figure out how much surface area you are going to need.  You said you were going to make a custom radiator, which is probably the only way this will work.  That is because you need to the fins to run north-south and not east-west.  You need that because you'll want the temperature at the bottom of the radiator to be the hottest which will drive the air up, since hot air rises.  If the fins are east-west the hot air can rise along the fin.  You might want to look into a series of pins instead of fins.

 

good project.

 

Energy Balance:

 

h*A*dT = mdot*Cp*dT

 

you know everything but A*dT, so you can pick some reasonable dTs and get an A.

 

Ice Dragon Cooling works by changing some of the parameters used in forced convection flow. 

 

I use Ice Dragon cooling an I7 and an old GT640 with an 80mm rad and a northbridge fan on it..

Yup that's what I was going for in this project. Using science and what not. 

 

h*A*dT = mdot*Cp*dT

m dot Cp*dT? Is that the q=mc delta T equation?

Whats h*A*dT

[Relttem]

Liquid Side

 

Mdot = mass flow rate (you know your pumps gpm.  from that you can get mass flow rate)

Cp = specific heat (look up online or get from tables - temperature dependant)

dT = Temp difference (T2-T1) (measure)

 

Air Side

 

h = convective coefficient (estimate/look up online)

A = area

dT = Temp difference

 

with natural convection you have a few other variables too, but you can look them all up online if you know temperatures.

 

rock on