Almost finished- last questions

[Raxxath]

I'm almost finished with my first liquid cooled build, and now I just have a few last questions.

1. Just how important is it to get cool air going through a radiator, as opposed to warmer air? I'm specifically speaking about top-mounted radiators(like mine). I see lots of people pulling air from inside of the case, but wouldn't that raise temperatures, regardless of how full your radiator's cooling capacity is? Or would it simply lower your radiator's cooling capacity, so that if you had a small heat load on the radiator, you would see no difference? It seems to me that it would be the former, but I'm not certain.

2. Is having two radiator's in a row viable? Its said that air doesn't heat up very much when passing through a radiator, so wouldn't you still get plenty of performance out of the second in line? This picture is from FrozenCPU, its something I've been considering...

http://i38.photobucket.com/albums/e119/LordBrona/99d932db.png


3. Will a DDC 3.2 be okay heat-wise if its mounted on Petra's gel with direct airflow over it? Or will the bottom still get dangerously hot?

4. Will I be okay having 5 intakes and only 2 exhausts(one of which is the PSU) if the back of the case has plenty of vent holes? The case is a Lian Li PC-A70B, the black version of the picture above.

5. Lastly, are these fan filters (http://www.petrastechshop.com/12alfanfibl.html) from Petra's effective at keeping dust out? The holes look a little large to catch finer dust.

I'll be posting lots of pictures when its all finished. :)

[kohlersc]

1. You can not cool the water below the ambient temperature...now if you are pulling cooler air from outside of the case you will be able to cool the water more than if you are using warmer air from inside the case. As the ambient temp of the air outside the case should be cooler than the air inside it is definitely better to use the cooler air if possible as it will give you your maximum heat dissipation with your radiator.

2. From experience I can't tell you. However there have been a couple of times this question has been asked and the general consensus is that it would not be a very good alternative. A couple people have put up more exact formulae as to what it would do to your overall cooling capacity, but suffice to say that it is not a good alternative and you would not be getting that much more cooling by running radiators in that manner.

3. Not sure

4. I have always been a fan of having a negative pressure in my case. With more fans exhausting than pulling air in you have a better shot of getting all the hot air out and not having it pool in specific areas. I am sure it will be ok as the air will find a way to get out, but generally speaking I have seen better temperatures if I had an equalized air flow or negative pressure air flow through the case.

5. Not sure

[Xilikon]

1. You are correct, it's better to draw cold air throught the radiator and not the warm case air. however, the impact is marginal so it's up to you to pick whichever works best.

2.Not sure about that but I guess the second radiator will get less airflow so you may need stronger fans to reach thru both radiators.

3. Never ever put the DDC on the petra's gel since the hottest area is indeed the bottom. It's easier to use rubber mounts and lift it 10-15mm to get air thru it.

4. Yes, it's ok and this will give you positive pressure (more air blowing off the case, keeping the dust at a minimum).

5.No filter is perfect but this one is great. It will not filter all but will leave most dust out.

[Raxxath]

Thank you both for the quick responses.


1. You are correct, it's better to draw cold air throught the radiator and not the warm case air. however, the impact is marginal so it's up to you to pick whichever works best.

If that's the case, I think I'll keep it intaking cooler air for now, but maybe I'll switch it in the future to see the difference.



2. From experience I can't tell you. However there have been a couple of times this question has been asked and the general consensus is that it would not be a very good alternative. A couple people have put up more exact formulae as to what it would do to your overall cooling capacity, but suffice to say that it is not a good alternative and you would not be getting that much more cooling by running radiators in that manner.

I guess I won't bother with it then. I don't really need that much cooling capacity at the moment anyway, I was going for a little overkill.



3. Never ever put the DDC on the petra's gel since the hottest area is indeed the bottom. It's easier to use rubber mounts and lift it 10-15mm to get air thru it.

What if I cut the gel pad in half and spaced them apart, so that there was a channel for air to flow through beneath the pump? I'm all about silence, so I need the pump to be as quiet as possible. And is the DDC the only pump like this? I may be getting D-Tek dB-1s in the future, I could put them on the gel without worry, correct?



4. I have always been a fan of having a negative pressure in my case. With more fans exhausting than pulling air in you have a better shot of getting all the hot air out and not having it pool in specific areas. I am sure it will be ok as the air will find a way to get out, but generally speaking I have seen better temperatures if I had an equalized air flow or negative pressure air flow through the case.



4. Yes, it's ok and this will give you positive pressure (more air blowing off the case, keeping the dust at a minimum).

Good to hear that it can work well both ways. I'll be trying positive pressure first I think, but hopefully I can test both eventually.



5.No filter is perfect but this one is great. It will not filter all but will leave most dust out.

That's good to hear, too, as they match the anodized aluminum of my case pretty well. I already have one, so I'll buy a few more to put on the top radiator intakes.

One more thing, do you think the fan bracket in the PC-A70 is too restrictive to airflow? I've taken off the white plastic slot holders, and I could probably cut off some of the metal, too... would it be worth it?

http://i38.photobucket.com/albums/e119/LordBrona/9d1d6e05.png

[Waterlogged]

What if I cut the gel pad in half and spaced them apart, so that there was a channel for air to flow through beneath the pump? I'm all about silence, so I need the pump to be as quiet as possible. And is the DDC the only pump like this? I may be getting D-Tek dB-1s in the future, I could put them on the gel without worry, correct?
I would cut the gel into small squares (maybe 1/4" or 1/2") and put one on each corner. Not sure a fan would be needed in that case, anything else, IMO, is risky. Also, the DB-1 is a tall step down when compared to the DDC or D5.


http://i38.photobucket.com/albums/e119/LordBrona/99d932db.png
http://i38.photobucket.com/albums/e119/LordBrona/9d1d6e05.png

:rofl: :ROTF:

I really like the guys at FCPU (I visit them in person somewhat often) but sometimes I just have to wonder what the hell their (mostly Bucky) thinking when they come up with some of these ideas.