*done* Considering adding passive rad to setup

[sjong1]

EDIT: Based on input and consideration, I'll just leave loop as is.

OP:

I've currently got an i5 2500k and two GTX 570's on a single loop with two 240mm rads and an MCP35X pump.

res->pump->rad1->gpu1->gpu2->rad2->cpu->res

I've yet to fill the loop (just drained and added a second 570) and was wondering if adding a passive 120 rad into the loop would help at all. I've got space for one but no space for a fan.

Let me know if you think:

1)2x240s are enough
2)a fanless 120 will help

Thanks.

 

[EarthwormJim]

If anything it could be detrimental to performance since you're adding even more restriction to your loop, with next to no cooling capacity gained.

 

[sjong1]

I was afraid of that, too. The rad would be mounted vertically in the bottom front of the case and there would be a 240 rad with 2 120x38 Panaflos at the bottom only a few cm away.
I've also got two San Aces at the top exhausting and one in the back drawing in air. Would the amount of air being circulated in the case help dissipate enough heat through the passive rad to turn it into a positive?

 

[billyb0b]

what case are you using? have pics of the h2o setup?

 

[EarthwormJim]

I was afraid of that, too. The rad would be mounted vertically in the bottom front of the case and there would be a 240 rad with 2 120x38 Panaflos at the bottom only a few cm away.
I've also got two San Aces at the top exhausting and one in the back drawing in air. Would the amount of air being circulated in the case help dissipate enough heat through the passive rad to turn it into a positive?

I really doubt it. Radiator fins are pretty densely packed, so not a whole lot of air will flow through them without a fan directly blowing.

 

[dawp]

I suppose it might be possible with a rad like the SR1 series from hardware labs. They have a fin spacing of 9 per inch and are meant for slow speed fans. I have a sr1 120 and it works fairly well for my needs. If your fans aren't too far from the rad you should still get decent airflow.

would the rad be mounted directly to the front of the case or some distance away? would you cut the face panel to mount the rad or mount on the face panel?

you may also want to add a second pump in series in the loop.

 

[sjong1]

what case are you using? have pics of the h2o setup?

Using a CM 692. I don't have pics, but basically one 240 in the top, one on bottom, and the proposed location for the 120 is in the front.

I really doubt it. Radiator fins are pretty densely packed, so not a whole lot of air will flow through them without a fan directly blowing.

Good point.

I suppose it might be possible with a rad like the SR1 series from hardware labs. They have a fin spacing of 9 per inch and are meant for slow speed fans. I have a sr1 120 and it works fairly well for my needs. If your fans aren't too far from the rad you should still get decent airflow.

would the rad be mounted directly to the front of the case or some distance away? would you cut the face panel to mount the rad or mount on the face panel?

you may also want to add a second pump in series in the loop.

I think I'll just stick with the setup I have now and exclude the passive radiator. I chose blocks/rads with low restriction, so the mcp35x should be able to handle things fairly well on its own.

Thanks for your input!