Folks, love to hear what the collected wisdom is on this:
I was thinking of building a CPU duct onto a Zalman 7000Al-Cu. Browsing around this site:
Option 1) some have gone for the fan on the HS and built a duct to it (ie. ?pulling air over the HS)
Option 2) while others have taken the fan off the HS and installed an intake fan at the entrance to the duct (?pushing configuration)
I'm wondering what's the better option, and your reasoning?
- for cooling
- for noise (I'm presuming, all being equal, that the fan buried deep inside a PC should make less noise than one at the case)
cheers
ducting theory
Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee
I've exhaust-ducted a Zalman7000 in my Mobile Pentium 4-M System, the details of which you will find in the General Gallery. I completely removed the fan from the HS, and ducted it to an exhaust fan on the rear of the case, as this is the easiest way to do it. I prefer to get the CPU heat out of the case immediately so that it is not blowing around and heating up the rest of the system. Also, you can usually design a system with one less fan if you use an exhaust duct. Most of the noise is caused by the air being drawn through the heatsink's fins, so the actual position of the fan in this case is largely irrelevant.
An intake duct bringing cool air directly from outside the case onto the HS can be used in cases where the lowest possible CPU temperature is required (however the heated air will then be circulating inside the case, heating other components). I haven't tried this, but I think that a fan on the HS may be quieter in this situation due to it being further inside the case. The difference is probably quite subtle, however. The fan that comes with the Zalman7000 isn't that quiet compared to a decent case fan.
An intake duct bringing cool air directly from outside the case onto the HS can be used in cases where the lowest possible CPU temperature is required (however the heated air will then be circulating inside the case, heating other components). I haven't tried this, but I think that a fan on the HS may be quieter in this situation due to it being further inside the case. The difference is probably quite subtle, however. The fan that comes with the Zalman7000 isn't that quiet compared to a decent case fan.
sorry - just to clarify, my post wasn't so much about re-igniting the debate between sucking/blowing air over the HS.
tay - thanks for the tip, joseph's mods are very interesting and giving me food for thought if I want to change the original fan on the z7000
alleycat - stumbled upon your rig some time ago and decided to experiment with the P4-M myself! Got the chip and mobo finally (after some angst), and now thinking through the other bits. I take your point that the zalman fan itself is not as good as others.
As a follow-up, what would be people's thoughts on this:
bluefront has this setup of intake manifold where fresh air flows through his HD before entering the rest of the case, driven by a fan blowing in. What are the consequences of extending a duct from this fan onto the HS on cooling and noise (longer duct, resonance?, less cooling for other components)
tay - thanks for the tip, joseph's mods are very interesting and giving me food for thought if I want to change the original fan on the z7000
alleycat - stumbled upon your rig some time ago and decided to experiment with the P4-M myself! Got the chip and mobo finally (after some angst), and now thinking through the other bits. I take your point that the zalman fan itself is not as good as others.
As a follow-up, what would be people's thoughts on this:
bluefront has this setup of intake manifold where fresh air flows through his HD before entering the rest of the case, driven by a fan blowing in. What are the consequences of extending a duct from this fan onto the HS on cooling and noise (longer duct, resonance?, less cooling for other components)