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Hoot can I get some help please?

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New Member
Jun 19, 2001
I decided to do the case cooling that you wrote about. I bought the 12v blower today. I have a few questions though. Were did you get the device to down the voltageto 7v and name and model number would help to. Also how do you wire this thing. Do i connect the blower to a molex from like an old fan then plug it into my PSU? Also is a 300 watt PSU enough for this and 2HD 2CD and a duron 750 or do i need a bigger one?
If it's a 12v dc device then it should run ok from a molex conector. To get 7v you can either use a resistor on the 12v line which wastes power and gets warm or run the ground wire to the 5v line which creates a 7v potential differance.
I designed a high current 3 terminal regulator circuit. It should have been mentioned in the article. I am currently working on a followup article describing how to construct it, for the non-technician. Should be done and up this coming week.

Do Not wire it between the +12 and +5 to get 7volts. Unlike brushless axial fans, that blower looks like a dead short, for a short amount of time, after power is applied. If you wire it to the 12 & 5, the PSU will crowbar upon power up, thinking there is a short between the 12 & 5 outputs. If this happens, you have to unplug the AC going to the PSU for 30 seconds or so, to let it reset. It will run off of 5V just fine, but it will not deliver peak performance. A 300W PSU will handle the motor just fine.

Watch for the article this coming week.

Hoot, quick question. I am intrigued by the cohesive cooling, but I have to be able to move my rig around which will not allow me to have the protruding out. I could use a duct from the output of the fan to empty out over the CPU without loosing the airquality right? I don't see why not but I had an interesting idea. If you used say the Yeong Yang case you could mount the blower internally, which would be great!
I have pondered all kinds of variations on this theme. One problem with putting the blower inside the case is the fact that, at higher RPMs, the motor gets quite warm. That heat would be added to the existing heat removal task inside the case. On the outside, it is no big deal. The other approach is to try a bent duct and mount the blower on the rear of the case. I'm looking at my mid-tower as I write this and it would have to bee quite a sharp bend if you wanted to use the 80mm case fan knockout right next to the CPU. From what I've seen at the local hardware store, in the form of pipe and gutter elbows, nothing turns adequately, in that short of a radius to be an off-the-shelf solution. You would have to fabricate something from stock. You definitely want to avoid using corrugated materials as the corrugation imparts a lot of resistance and also deteriorates the cohesive quality factor of the airflow. For the modder with a reasonable tool compliment and raw materials, it could be done, all the same. As a solution to having the blower mounted on the side, it would reduce the width issue, but add to the depth issue. Almost like "Jumping out of the frying pan and into the fire".

Keep Pondering

Hoot, I have a few more questions. The molex that plugs into the HD, CD and CDRW is that the 12v lead that you used to plug your fan in? Is the 5v the plug that plugs into a Floppy drive? Or is the 5v the connector that is on the MB its self? I know these are stupid questions but I am new to all this hardware stuff. One last thing does putting the blower over the HSF disrupt the Fan on the HSF from operating properly? Thank you for the help
On a 4-pin molex connector ( yes, the ones that go to the drives), you have access to both +12V (Yellow), Its Return (Black), +5V (Red) Its Return (Also Black). Having those two voltages on the same connector is one of the reasons why the +7V trick is so popular. The two voltages are right there for you.

Besides improved case cooling, the blower doubles as the CPU HS fan. You do not use it in conjunction with the HS fan. That's the beauty of this whole design. Get rid of all your case fans and the
CPU fan. "One PC, One Airsource". By the way, when you implement it, you cover up the case fan hole on the rear of the case, so the air travels towards the lower front opening. The bigger that lower front opening, the better.

The whole point of the Cohesive Air aka "Hoot Chute" approach was that having lots of bad air sources is not as good as having one good one. Hence the title, Good Air, Bad Air, Good Fans, Bad Fans...

Here's the link, yet again, in case this has tweaked anyone elses curiousity.

Hoot, Thanks for you help and patience. Thanks for pointing out that the blower takes the place of the fan on the HSF. I will try it both ways and see which works best for me. Another thing is how close is your chute to the HS? The whole Hoot Chute is got to be the best air cooling system I have seen!