Here's my mostly finished Lanboy, P4 2.66, Alpha heatsink, Aopen AX4GE Max, SilentTec cooling running, with complete ducting for everything.

Ducted Lanboy

Pict #1 Shows the Alpha with the enlarged case fan hole...92mm.

Pict #2 Shows the front case fan setup. The fan opening was enlarged and relocated more to the center to accomodate the hard drive duct. More pictures of the fan holder... De-Coupled Fan Holder

Pict #3 Shows the rear with foam insulation for the intake duct. More pictures of the intake duct......Intake filter/exhaust duct combo

Pict #4 Shows the ducted Alpha. More pictures of the setup......Alpha duct

Pict #5 Shows a secondary shroud over the Alpha duct. This forces the exhaust flow from the PSU and front exhaust fan to flow more directly over the mother-board components.

Pict #6 Shows the hard drive duct setup. The front case fan blows out, drawing air directly over the two drives.

Pict #7 Side view showing all the ducts.

Pict #8 Rear view of the filter duct...the PSU blows on an upward angle.

Pict #9 Front of Lanboy. The door is foam insulated and the louvers on the front are covered. The exhaust of the front fan blows downward toward the floor.


This computer runs cooler than any computer I ever built, probably because of the Alpha duct. If you want almost complete silence, using the SilentTec utility you can turn off the alpha duct fan completely.....for normal activity the cpu stays under 36c, with the PSU and the hard drive fans blowing out....which in turn draws air through the Alpha duct, keeping the CPU cool.

With the Lanboy's stock PSU fan and the hard drive fan slowed way down by SilentTec...the whole setup is plenty quiet for me.

Whoa!
I'm impressed!

OK, to clarify, some questions:
1. The PSU fan exhausts air out like normal?
2. The front intake fan is now an exhaust?
3. The Alpha duct is now an intake (blow mode)?
4. What are your temps? Ambient, CPU, Case, etc?

Thanks.

I just got the whole thing completed, so my temp readings are not final. Also, depending on how quiet you're running, using SilentTec to control the fan speeds, the readings can vary. I also have a DigitalDoc5 measuring temps at eight places, and these readings vary from the SpeedFan temps because of the differing location of the DD5 sensors.

Yes to all your questions. Because I want all the incoming air to be filtered, the front fan is now an exhaust. All the air goes through that one filter (an in-cabin filter off a Nissan Xterra). Also, with the PSU fan and the front case fan only running, there is enough air being drawn through the duct, that the duct fan can usually remain off. At higher CPU usage the duct fan turns on.

Here's some idle temps....

PSU fan turning slowly.
Front case/HD fan @2000rpm
Duct/CPU fan off.

DigitalDoc5 measured temps....

CPU.........28.3
Ram.........31.5
Chipset.....34.6
Ambient.....25.0
PSU...........32.2
Case..........27.2
Slave hd.....31.7
Mast hd.......31.6

SpeedFan measured temps.

CPU...........32
Mother-Board.....36
Smart temps.......slave 41
Smart temps.......master39

At very high CPU usage, the Alpha duct fan turns on, the HD fan speeds up slightly, the PSU fan should be turning faster (can't tell). The highest temp SpeedFan ever showed was CPU 40c. The other temps went up slightly......

There are several ways to set the SilentTec cooling utility, so I'm still trying it out.

Edit: I modified the HD mount for better cooling....cut almost 5c off the measured smart temps. More pics

OK...here's a set of temps running Cpuburn (100% cpu usage) for 1/2 hour. The temps stabilized at about 5 minutes and remained the same after that.

DigitalDoc5 measured temps

cpu.....35.5
ram....34.7
chipset....37.0
ambient....24.6
psu.......32.8
case.....29.0
hd1......34.6
hd2......34.9


Speedfan temps

cpu....45
case...36
hd1....38
hd2.....38

The 92mm alpha duct fan running 100%......2500rpm
The front case fan running 2058rpm
The output temp of the PSU was only .5c higher than at idle. The rest of the temps were up only slightly. As I said in the first post, the temps can vary depending how SilentTek is set. But this gives an idea of the cpu cooling potential of the duct. Should you need more cooling(?), you would only need a more powerful duct fan. But as it stands, it's ok for me.

I would be really interested to know how this setup would work if you closed the front exhaust and let the PSU do all the exhaust duties. Granted the PSU fan would spin faster, but, since you're using a ducted intake straight at the CPU there would be some flow through the PSU without the PSU fan operating at all.

Furthermore, with positive case pressure the PSU fan would be much quieter at all speeds.

Your setup looks not unlike the HP pavilion setup, a pretty quiet setup for a stock machine.

Can't help but think that a front mounted exhaust fan would be audible even at pretty low flow rates.

I wonder how much the CPU raises the ambient air temp. If you're blowing cool room air directly on the CPU I bet it isn't coming off the CPU HS more than a few degrees above ambient, which shouldn't be a problem for the PSU.

Just my two cents worth. I could be wrong, but I doubt it

Roger....I have made a few changes to this setup this past week-end. The Lanboy is now sitting on this little wooden drawer thing.I used to have hard drives in it, as in the pictures. Now it's functioning as a large muffled fan exhaust duct...for the front case fan. I'm not using the rear fan shown in the pictures. It's working only as an exhaust duct. Exhaust enters the front end through a hole right under the front bottom of the Lanboy and exits at the rear. The bottom holes are covered. I can't hear this exhaust at all...I can only feel a slight flow of warm air.


Right now the Alpha duct fan hardly ever turns on, since the psu fan and the front case fan are pulling air through the alpha duct. If I turned off the front fan, and covered the hole, the psu fan would be the only exhaust. It would probably handle the heat ok, but I don't think it would provide enough suction to keep the cpu cool...the alpha duct fan would probably have to run all the time.

Also airflow over the rest of the board would be way down, plus the hard drive temps would go up. I think this setup would run just fine on reduced airflow and/or quieter fans. The temps would go up somewhat and I could do that using SilentTek.....But it's running so quiet as is, I'm satisfied.

Really this Alpha Duct continues to amaze me. I'm running a P4 2.66, most of the time, with passive cooling . Airflow being pulled into the case by the PSU and a low output front case fan is providing all the cooling necessary. I've got an AIW 7500....using it as a PVR. Yesterday I captured 1.5gigs of some TV show without the Alpha duct fan turning on...the measured cpu temp never got over 36c. Hard to believe.

Look....there's a reason, not very obvious, why the CPU runs so cool... it's in the pictures.

The duct is solid aluminum and it's a snug fit on the Alpha end. Heat from the Alpha is transferred into the aluminum of the duct by conduction....and by convection also. If you feel the duct on the Alpha end, it gets warm. This actually makes the duct itself, an extension of the Alpha heatsink. Now look at the power supply in the pictures...it has a 92mm fan drawing air over the hot end of the duct. Also when the duct fan is not running, this same fan is sucking air through the Alpha duct. Remember...the Alpha duct with it's filter is the only way air enters the case. The hard drive fan does the same thing...blows out and sucks it's air through the Alpha duct. Another thing, the air entering the duct and hitting the Alpha is ambient temperature. This computer can be run for hours with normal usage, without the duct fan even running. The CPU never exceeds 36c.

More mods....The wooden roll-around box the Lanboy is sitting on has been turned into a muffler/ with a fan in the box. The front case fan has been completely eliminated, with the exhaust coming out a tailpipe....

interesting ideas!

How much Intake filter/exhaust duct combo reduces noise?

That doesn't look that difficult to build, maybe I'll make one

Hmmm... I like that ducted intake setup. I've got an old dual processor Pentium Pro system that I'm gonna mess with. Only one CPU in it right now, but surprising how hot the heatsink gets, even at idle. Wish I had a way of measuring CPU temps on it.

But doing some duct work on that will make for good practice before I move on to my main systems.


Zyzzyx

tonalt.....the intake/exhaust box helps reduce noise a little bit. It's main purpose was to hold a large filter and to make certain the intake and the exhaust streams had no chance to merge.

What is the sound foam you are using there?

It's an adhesive-backed 4mm acoustic foam from CompUSA. I've used it on a number of projects....works well.

FWIW....I've made a few changes since I first posted the Lanboy project. MikeC has been running a few articles on the whole setup. Part three should be up soon.

Wow thats a very nice project youve got there! Nice writeup too.

Very very innovative Bluefront. Great work!

Whoa - electrical boxes, stair flashing, PVC pipe, a chrome exhaust tip and excuse me , but isn't that a water closet (aka toilet) gasket? Has anyone every told you that you are a flippin' genius? Or perhaps that you are just a tiny bit crazy? Cause it seems obvious to me that you are both - and I am T-totally envious !

Heh....thanks. Too bad the Lanboy project is now history. It was a good learning project for several ideas. I'm now finishing up another project using the guts of the Lanboy.

I had a few problems with the Lanboy, mostly with it's overall size, and with the external intake box on the back. I wanted to make the outside look more normal, and the roll-around wooden stand/duct shorter.

Some of my new ideas would have been a difficult build with the Lanboy, so I'm using a different case. I like the quieting ability of a front door, but I haven't found another suitable case with a door setup. I may try my hand at making an add-on door for this case. I could do it....I'm considering a tight-fitting cabinet-like door with a glass front so I can see the front LCD display.....

Oh yeah...that is a toilet part in the photos.

Where did the pics go?

That particular setup was the subject of a three-part SPCR article. You can see most of the photos there. I have modified my construction technique quite a bit since I first made the Lanboy mod. Most of my mods are now internal, with the computer looking mostly normal from the outside. That particular setup was pretty quiet......but later hotter-running CPUs, required different construction.

Wouldn't that intake duct fan on the CPU be drawing the hot air that the PSU exhausts back into the case?

That filtered intake box separate the CPU-intake and the PSU-exhaust it seems.

There was no exhaust recirculation. The problem with the Lanboy was it's small size. Trying to fit a decent sized filter in the rear intake was difficult, and required me to build that rear intake/exhaust box as a one-piece unit.

The thing was hard to photograph.....but the PSU exhaust was forced upward by a solid channel of foam-covered aluminum. The intake was below this exhaust channel, and completely separate from the exhaust flow. It worked well, but looked rather clunky. It's history now.

Do you know of anywhere i could get a good filter like that?

It's a cabin filter from a 2002 Nissan Xterra....comes 2 per box for about $35. There were some plastic channels I cut off the edges. Those things work well.....I still use them.

one more thing sorry i ment to ask before, what are the dimensions of them?

No pictures for me...

Likewise

Old technoogy.....heh. SPCR ran a three-part article on this project 2 1/2 years ago. The various things in this computer all worked great.....some are still in use. I learned a lot with this project....notably how effective ducting could be with CPU cooling. This thing ran with passive CPU cooling most of the time. The duct fan only turned on with high temps.

I'll find one of those filters and measure it.....