Will this work? Separating Rads.

[iB CoMpL3XiTy]

Hey all,

So I'm messing about in sketchup, designing a PC case.

The case will hold 2 x 480 Rads at a minimum, these two Rads are located in a separate compartment to the rest of the PC.

I've done some research and found that sandwiched rads don't perform very well and in some cases can actually be worse than a single rad, I believe this is because of two reasons.

1) Warm air from the first rad isn't very effective at cooling the second.
2) You need high static pressure fans/high RPM to move the air through both rads.

I thought the best solution would be to have the two rads separate from each other, both having their own supply of cool air and their own set of fans.
I want to expel the warm air from both rads out of the rear of the case using a 120mm high airflow fan.

Pics.

Hopefully you can see what's going on, there's two rads in the bottom compartment separated by a dividing "wall" and then a rear fan exhausting air out the back.

My concern is that the 120mm fan at the rear won't be able to remove the warm air fast enough and so the rads will gradually heat up and so become inefficient.

Any thoughts? Is this a better design than just have cold air coming through one side of the case and warm air coming out the other?

Thanks for your feedback.

 

[dfour]

might it be better to use the rads in push (in to out) so they themselves expell the hot air and not overwhelm the single 120 fan. Maybe use 2 120mm fans, one front and 1 rear to help supply the rads??

I assume you going to have fans on the rad??

 

[iB CoMpL3XiTy]

might it be better to use the rads in push (in to out) so they themselves expell the hot air and not overwhelm the single 120 fan. Maybe use 2 120mm fans, one front and 1 rear to help supply the rads??

I assume you going to have fans on the rad??

Yep both rads will have a full set of fans (4 per 480 rad).

If I can help it I'd rather not have another fan at the front as space would be really tight (though I could make the case longer if I had too).

With your concept would the two middle fans of both rads get much airflow? I'm just thinking that the two outer fans would expel the air before it reaches the middle fans.

 

[dfour]

I would also be assuming you would be using lower power fans on the rads as they are 140's and you dont want the case to sound like a jump jet taking off.

Im also thinking with 2*480 rads you could cool the earth down so a little less airflow to the middle fans is going to make little or no difference.

 

[JeffyB]

I have run 2x420 rads (3x140mm) in the bottom section of my lian li v2000 before, was a tight fit but i got them both in with fans on both rads. I found the warm exhaust air from the front rad was still cooler than the water in the rear rad. Having ventilation in the base of the case also helps this sort of setup (my v2000 has a nice cutout in the bottom to suply cool air), I used a 120 fan at the front of the case feeding cool air to both rads but mostly the rear rad, similar to how you have it sketched but intake instead of exhaust.

I did consider separating the rads with a wall but the cut-out and front fan provided plenty of cool air.

 

[iB CoMpL3XiTy]

I have run 2x420 rads (3x140mm) in the bottom section of my lian li v2000 before, was a tight fit but i got them both in with fans on both rads. I found the warm exhaust air from the front rad was still cooler than the water in the rear rad. Having ventilation in the base of the case also helps this sort of setup (my v2000 has a nice cutout in the bottom to suply cool air), I used a 120 fan at the front of the case feeding cool air to both rads but mostly the rear rad, similar to how you have it sketched but intake instead of exhaust.

Spoiler

I did consider separating the rads with a wall but the cut-out and front fan provided plenty of cool air.

That is a damn good idea! Draw cool air from the bottom of the case!

I'll have to come up with a way of attaching a dust filter that's easily removable though, and I'll switch the exhaust fan around so it's an intake.

Now we're cooking with gas.

 

[shadowscotland]

If you keep the dividing wall you can do without the single fan completely.
Two full length slots (one to each rad chamber) will be amble if the rads have a full set of fans attached.
Forming two separate back to back rad boxes with their own air flows.

Another option using 4 fans instead of the current 9 is to have a Plenum chamber
4 floor mounded intake fans supply air to the central void - the rads can then be used semi-passive as extract vents.
The 50mm+ gained by removing both banks of fans should give you more space in the central voids floor for 120 or 140 fans.
Your construction of the rad box will need to be more air tight and a few millimetres higher but it removes the losses of fan deadspots, and will make it massively quieter.
Taller case legs (30mm+) and a hard surface to stand the case on are a must.
But thats true with any case floor intake setup (note the casters on JeffyB's v2000)

 

[iB CoMpL3XiTy]

If you keep the dividing wall you can do without the single fan completely.
Two full length slots (one to each rad chamber) will be amble if the rads have a full set of fans attached.
Forming two separate back to back rad boxes with their own air flows.

Another option using 4 fans instead of the current 9 is to have a Plenum chamber
4 floor mounded intake fans supply air to the central void - the rads can then be used semi-passive as extract vents.
The 50mm+ gained by removing both banks of fans should give you more space in the central voids floor for 120 or 140 fans.
Your construction of the rad box will need to be more air tight and a few millimetres higher but it removes the losses of fan deadspots, and will make it massively quieter.
Taller case legs (30mm+) and a hard surface to stand the case on are a must.
But thats true with any case floor intake setup (note the casters on JeffyB's v2000)

Thanks for your suggestions

I'm probably going to go with keeping the dividing wall and using separate holes in the bottom of the case for each rad, don't know if I'll keep the rear 120mm fan or not.

Never heard of a plenum chamber before, had to google it Seems ideal for near silent builds, however there would be some headaches, the main one being making the chamber air tight enough whilst keeping the "look" clean, also even if I didn't have any fans on the rads there wouldn't be enough space on the floor for 120mm fans, I'd have to elevate the rads by atleast 25mm and slide the fans underneath...

EDIT: Oh and the case will be on Feet and will be sat on my desk

 

[Five.Stars]

It would work, but ideally you want air blowing through the fins, which if I am understanding your plans correctly would not be the case. You look to, in effect be cooling the rads passively, and then exhausting the warm air out the back. I would think that will be quite inefficient.

EDIT: I appear to have misread your plans on 2nd viewing lol.

 

[iB CoMpL3XiTy]

It would work, but ideally you want air blowing through the fins, which if I am understanding your plans correctly would not be the case. You look to, in effect be cooling the rads passively, and then exhausting the warm air out the back. I would think that will be quite inefficient.

EDIT: I appear to have misread your plans on 2nd viewing lol.

I should have really added fans to the rads before taking screenshots to save confusion lol, but yes I will have fans on the rads, unless I opt for the Plenum Chamber route.