Improved temerature with Antec P180B top fan off?!

where?wolf · Post by **where?wolf** » Mon Nov 06, 2006 6:10 am

Im a bit surpriced to find that if I shut down the top exhaust (orginal Tricool fan) I loose 3 -4 C, compaired to haveing the top fan on at "Low".

I decided to try this after reading in a forum, about some members discussing various fans and fan configurations for the P180.

One guy there at the forum, claimed, that he got better temps removing the top fan, but leaveing the vent / fan hole open.

And when I did shut down my top fan, it actually proved to be true. And the noise lowered a little bit too.

The case fans in my P180B is as follow:

Intake: ( Sitting on the upper hd chamber with the clips) Nexus 120mm (36CFM, black /white varity)

Exhaust: Sunbeam Anodized LED 120mm fan 45.21 CFM, 21.75 dB(A) I guess this is a true noise figure or at least very close to, on the Sunbeam. It's very quiet.

The orginal Tricool set to "low" in the lower wind tunnel.

The cpu, is a Clawhammer 3000+ s.754 oc'ed to 2.4 GHz with a Thermalright XP90 + Arctic Cooling AF12025 120mm fan. 56.3CFM / 24.5 dBA, 1500RPM.

This, sitting on a Epox 8NPA + SLI mobo.

Idle temps: case: 29C Load 35C ( with top fan off)
CPU: Idle, 32C. load 44C

This in 18C room temperature.

Also wanna add, that I have cut out all the stamped fan grilles on the P180B. And replaced them with rounded wire ones instead, for the top and rear exhaust fans. Front fan grilles cut out, with just the filters in front.

What I finally wonder about is how? It can be possible that shutting down the top fan will actually improve the temperatures? Should'nt it be the other way around?

zoatebix · Post by **zoatebix** » Mon Nov 06, 2006 7:46 am

That sounds reasonable, actually. I remember reading a theory that the top and rear exhaust fans are close enough to each other that they'll work against each other.

For an interesting experiment, try re-mounting the top fan as an intake.

where?wolf · Post by **where?wolf** » Mon Nov 06, 2006 11:47 am

Hi!

Hmm, that theory may prove to be very true. At least with the stuff I have inside the P180B

I did install the top fan as intake, after reading your ansver. And the temperatures dropped on the cpu to 29C idle and 40 load. This with the Tricool top fan at low. The top load temp where 42C when Running F.E.A.R. with all bells and whistles for 1 hour. There, I use to have 46 - 47C max with the Tricool as exhaust on "low". And as said 44 max with the top fan off

The case temp where'nt shifting more than 1C, compaired to the top fan shut down.

Neither did the temps improve or decrease with the top Tricool on "medium", as intake, wich is a bit amazing. Actually, this did'nt even make 1 degree difference. I mean, one could expect something to happend there. As you have 36 + 56CFM intake and 45.5 CFM exhaust in this case then.

I use the log in Epox Thunder Probe software to keep track of the temps while gaming for ex.

The only gripe I have, using the top as intake, is that the dust will probably build up faster inside the case.

But every degree lower temp is a gain. So I guess I have to clean the fans, heatsinks and case a little more often then lol.

fmriguy · Post by **fmriguy** » Mon Nov 06, 2006 12:57 pm

I've discovered the same thing when I removed the top fan. I've been meaning to just set up a duct to make it even more efficient.

Another thought though...what about using the rear as the intake and the top as the exhaust? It seems that it would have the same effect (e.g. the two wouldn't be working against each other) and it might reduce the amount of dust that results in having a top intake?

where?wolf · Post by **where?wolf** » Mon Nov 06, 2006 1:11 pm

[quote="fmriguy"]I've discovered the same thing when I removed the top fan. I've been meaning to just set up a duct to make it even more efficient.

Another thought though...what about using the rear as the intake and the top as the exhaust? It seems that it would have the same effect (e.g. the two wouldn't be working against each other) and it might reduce the amount of dust that results in having a top intake?[/quote]

Yeah, that could be interesting. But then I guess I have to remove the intake Nexus fan, sitting on the upper hd cage? The rear (Intake then) exhaust Sunbeam, 45CFM fan and the Nexus may eventually counter act eachother othervice I guess? They are practically facing eachother.

And It would be interesting to also see what impact this would have on the videocard temperature when gaming?

That idea of a duct is probably a good idea. What material will you use? And shape?

cmthomson · Post by **cmthomson** » Mon Nov 06, 2006 5:48 pm

Based on your first post, this temperature drop is entirely expected.

You inlet fan moves fewer CFM than even one of you outlet fans, and much less than both of them combined. So when you removed one of the outlet fans, its opening became a second inlet very close to the CPU fan, thus providing lower ambient air to the CPU.

In quiet systems, it is increasingly important to balance inlet and outlet air flow. The base P180 is not particularly good for that; in my system, I added a Scythe Kama Bay to increase the inlet cross section to better match the outlet cross section.

where?wolf · Post by **where?wolf** » Mon Nov 06, 2006 7:07 pm

[quote="cmthomson"]Based on your first post, this temperature drop is entirely expected.

You inlet fan moves fewer CFM than even one of you outlet fans, and much less than both of them combined. So when you removed one of the outlet fans, its opening became a second inlet very close to the CPU fan, thus providing lower ambient air to the CPU.

In quiet systems, it is increasingly important to balance inlet and outlet air flow. The base P180 is not particularly good for that; in my system, I added a Scythe Kama Bay to increase the inlet cross section to better match the outlet cross section.[/quote]

Thanks for your input.

O.k. I see.

In order to hopefully improve the balance.
Could this be a better way?

Move the Nexus to the top fan mount as an exhaust fan.
And then mount another 120mm Sunbeam fan as intake ?

Would that give a better configuration?

Or should i get a Kama Bay also? Mounting this in the cd drive apartment.

I have only used up the lowest sitting 5.25 bay. So I hope in that case, the Kama Bay will fit?

And then use the orginal Tricool as exhaust on top.

snapshooter · Post by **snapshooter** » Tue Nov 07, 2006 12:32 am

I have a very similar fan setup as yours and I also discovered that removing top exhaust fan improves CPU temp. I've been planning to mount it as an intake but never actually tried it. Now your result encourages me even more.

BTW, do you see any improvement in terms of noise and temp by removing fan grills ? And what did you use to do it ? I'm thinking about doing it myself, mainly to reduce noise from the back fan.

where?wolf · Post by **where?wolf** » Tue Nov 07, 2006 6:49 am

[quote="snapshooter"]I have a very similar fan setup as yours and I also discovered that removing top exhaust fan improves CPU temp. I've been planning to mount it as an intake but never actually tried it. Now your result encourages me even more.

BTW, do you see any improvement in terms of noise and temp by removing fan grills ? And what did you use to do it ? I'm thinking about doing it myself, mainly to reduce noise from the back fan.[/quote]

Hi!

Yes, by all means. Use the top Tricool as intake instead. It probably will do more good as such.

As for cutting out the stamped grills. Yes defenite. you will certainly notice, that the noise will be lower. And the temperature did drop 4C for me when removing the grilles in the P180B. I did the same thing to my old Chieftech full tower before with good results.

Just be careful when cutting the front grilles, so you dont cut away the holes holding the filters by accident.

But take steps to prevent metal shards / dust getting inside the case when cutting. Tapeing a small plastic bag securely around the inside of the fan hole will catch any metal debris flying around.

And if you wanna make the edges looking nicer after the cutting. Get some "U" shaped rubber, door or window isolation an glue it to the edge of the fan hole.

Also , if you are going to use the upper hd cage as fan duct for the intake fan, using those spring clips? Tape up every hole in the cage you can find.

I found that some of those small holes in the cage generates a low whisteling noise when air under pressure passes thru them. Taping those holes also stops any eventual air leakage.

Also tape up all unused holes in the back of the case with duct tape for ex.
This will enhance the air pressure inside the cage.

Another thing that is good to keep the noise down. Is to get some 10 - 15mm sprongue rubber or noise damping mat and isolate the front door on the inside. Just make sure you dont pick any such sound damping that will obstruct the air intakes due to beeing to thick.

snapshooter · Post by **snapshooter** » Tue Nov 07, 2006 10:44 am

You gave some very nice tips where?wolf, especially the one about taping holes in the upper HD cage. I notices that whisteling noise but I could not figure out the cause. Will try them out soon. Thanks alot for it

where?wolf · Post by **where?wolf** » Tue Nov 07, 2006 11:08 am

[quote="snapshooter"]You gave some very nice tips where?wolf, especially the one about taping holes in the upper HD cage. I notices that whisteling noise but I could not figure out the cause. Will try them out soon. Thanks alot for it[/quote]

You're welcome.

Just glad if I could be of any assistance in any small way.

Would be really interesting to hear what you think after finishing those mods?

cmthomson · Post by **cmthomson** » Tue Nov 07, 2006 4:43 pm

where?wolf wrote:In order to hopefully improve the balance.
Could this be a better way?

Move the Nexus to the top fan mount as an exhaust fan.
And then mount another 120mm Sunbeam fan as intake ?

Would that give a better configuration?

Or should i get a Kama Bay also? Mounting this in the cd drive apartment.

I have only used up the lowest sitting 5.25 bay. So I hope in that case, the Kama Bay will fit?

And then use the orginal Tricool as exhaust on top.

A Kama Bay occupies three 5.25" bays, so yes, you can mount it in your case. Since you were willing to hack up the case inlets, you would probably also want to drill larger holes in the Kama Bay face plate for lower resistance. You can install the P180 clips to the Kama Bay (not easy) or just duct tape it in place. You could use the Scythe fan that comes with it to replace one of the other louder fans in your system.

I've documented how I managed airflow in my system (including using a Kama Bay) here: http://www.silentpcreview.com/article672-page1.html

But overall, I'd say you have a lot more fans and noise than you need. I think your CPU and MB need only one exhaust fan, and unless your graphics card is dependent on that inlet fan, you don't need it at all. You certainly won't need to install a fan in the Kama Bay. The TriCool fans are loud even at low.

where?wolf · Post by **where?wolf** » Tue Nov 07, 2006 5:48 pm

[quote="cmthomson"][quote="where?wolf"]In order to hopefully improve the balance.
Could this be a better way?

Move the Nexus to the top fan mount as an exhaust fan.
And then mount another 120mm Sunbeam fan as intake ?

Would that give a better configuration?

Or should i get a Kama Bay also? Mounting this in the cd drive apartment.

I have only used up the lowest sitting 5.25 bay. So I hope in that case, the Kama Bay will fit?

And then use the orginal Tricool as exhaust on top.[/quote]
A Kama Bay occupies three 5.25" bays, so yes, you can mount it in your case. Since you were willing to hack up the case inlets, you would probably also want to drill larger holes in the Kama Bay face plate for lower resistance. You can install the P180 clips to the Kama Bay (not easy) or just duct tape it in place. You could use the Scythe fan that comes with it to replace one of the other louder fans in your system.

I've documented how I managed airflow in my system (including using a Kama Bay) here: [url]http://www.silentpcreview.com/article672-page1.html[/url]

But overall, I'd say you have a lot more fans and noise than you need. I think your CPU and MB need only one exhaust fan, and unless your graphics card is dependent on that inlet fan, you don't need it at all. You certainly won't need to install a fan in the Kama Bay. The TriCool fans are loud even at low.[/quote]

Thanks for your ansver.
And also thanks for the link. It whas interesting reading. I really liked the Scythe heatsink + the duct idea.

Well, I have to agree to, that the Tricool fans is'nt the most quiet fan there is to choose from.

When I get the second Sunbeam Anodized 120mm fan. I probably will have it as intake. And then move the Nexus to the top mount. But I guess I will have to start to experiment with the fan configuration again when that time comes.

The Kama Bay in the cd compartment, is probably something I might add as additional intake. It wont add any noticable noise anyway.

I may also get an 140mm Aerocool Streamliner as exhaust + the 2 Sunbeams, alternative Stremliner, exhaust. And Nexus + Kama Bay as intake and see what that gives in the way of airflow?

Unfortunatly, My videocard is intake fan dependent.

I did shut down the intake fan once. But then the videocard load temp went up 5C.

cmthomson · Post by **cmthomson** » Wed Nov 08, 2006 4:56 pm

Don't bother with a 140mm Aerocool Streamliner.

I bought one, and it was louder than a Nexus and moved less air. Double whammy.

where?wolf · Post by **where?wolf** » Wed Nov 08, 2006 5:26 pm

[quote="cmthomson"]Don't bother with a 140mm Aerocool Streamliner.

I bought one, and it was louder than a Nexus and moved less air. Double whammy.[/quote]

Thanks for the warning!

It's hard to buy fans without having people like you to ask. Just trusting the manufacturers specs can be a mine field.

I will go for the Kama Bay instead. Scythes stuff is reliable.

P.s One fan that I'm a bit curious about is the SilenX fans. Do you know anything about them?