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CPU Fan too close to exhaust fan?

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reap3r

Member
Joined
Jun 18, 2009
Location
BC, Canada
I finally got sick of my Cooler Master V8's cooling performance... So I decided to go for a replacement. I don't use my computer for daily use, it's only used for gaming, so I don't care about noise.. So what I've gone and done is bought myself a Prolimatech Megahalems and 2x Panaflo Ultra High 120mmx38mm fans for a push/pull set up... Now the only concern I have is that in my case the 2nd CPU fan is VERY close to my rear exhaust, probably a little under a centimeter.. and with both CPU fans producing around 114 CFM, and the rear exhaust only pulling 90 cfm, will that cause significant damage to the rear fan? Note I also have a top fan pulling air out at the same 90cfm if that makes a difference.. What do you guys think? Is there any problem of burning out my rear exhaust fan with that setup?
 

muddocktor

Retired
Joined
Nov 1, 2001
Location
New Iberia, LA
I don't think it will burn the fan out, but it's probably not the best setup for airflow. Have you access to either a Dremel tool or case nibbler? If so, thn you might think about cutting the fan grill off of the back side of the case and then mounting your fan externally on the back. If you look in my third post in this thread, you can see how I did this for 2 92mm fans and how much more room it gives me inside the case on the back side of the heatsink.
 
OP
reap3r

reap3r

Member
Joined
Jun 18, 2009
Location
BC, Canada
I don't think it will burn the fan out, but it's probably not the best setup for airflow. Have you access to either a Dremel tool or case nibbler? If so, thn you might think about cutting the fan grill off of the back side of the case and then mounting your fan externally on the back. If you look in my third post in this thread, you can see how I did this for 2 92mm fans and how much more room it gives me inside the case on the back side of the heatsink.

Great, this is exactly what I was looking for. Thanks! :attn:
 
OP
reap3r

reap3r

Member
Joined
Jun 18, 2009
Location
BC, Canada
I don't think it will burn the fan out, but it's probably not the best setup for airflow. Have you access to either a Dremel tool or case nibbler? If so, thn you might think about cutting the fan grill off of the back side of the case and then mounting your fan externally on the back. If you look in my third post in this thread, you can see how I did this for 2 92mm fans and how much more room it gives me inside the case on the back side of the heatsink.

Hmm.. so I've read over the post and I see that it is a possibility.. How much do you think mounting my rear exhaust fan on the outside of the case will affect case temps? I mean will keeping it inside not allow it to draw heat from the rest of the case, raising temperatures? I'm not all that keen on mounting the fan on the outside of the case unless there would be noticeable changes in overall temperature (say more than 3-4C difference).. What are your thoughts on this?
 

Bobnova

Senior Member
Joined
May 10, 2009
What i would do is take that exhaust fan out and simply duct the CPU fan to the back of the case.
Now all that hot air is removed.

As it is, the majority of the cpu HSF's hot air is dragged out. Case temps will go down if you duct that air out.
Then you can put that exhaust fan somewhere else for even more exhaust, or put it as an intake to get some positive pressure. Now that the cpu HSF is ducted to the outside, any positive pressure in the case forces more air through the HSF.
 
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reap3r

reap3r

Member
Joined
Jun 18, 2009
Location
BC, Canada
What i would do is take that exhaust fan out and simply duct the CPU fan to the back of the case.
Now all that hot air is removed.

As it is, the majority of the cpu HSF's hot air is dragged out. Case temps will go down if you duct that air out.
Then you can put that exhaust fan somewhere else for even more exhaust, or put it as an intake to get some positive pressure. Now that the cpu HSF is ducted to the outside, any positive pressure in the case forces more air through the HSF.

Wow, good thinking.. I think that's exactly what I'm going to do!! I'll have to go old school on the fan duct though, probably going to pick up some thick a$$ pvc piping and spray it black hehe
 

Bobnova

Senior Member
Joined
May 10, 2009
That works :D

I generally use cereal box cardboard and masking tape :p


If you have a 120mm fan that has annoyed you too much you could rip the hub and fan blades out of it it and install it at the rear and then simply tape over the 1cm gap between fans. Easier then cutting and painting PVC, though it does require murdering a fan.
 

muddocktor

Retired
Joined
Nov 1, 2001
Location
New Iberia, LA
I personally like having the fans mounted externally as it gives you a good handhold on the back for moving the case around. ;) Seriously, it doesn't bother much of anything mounting the fan on the back side like that. Just be sure to get some wire fan guards to keep your fingers out.
 
OP
reap3r

reap3r

Member
Joined
Jun 18, 2009
Location
BC, Canada
That works :D

If you have a 120mm fan that has annoyed you too much you could rip the hub and fan blades out of it it and install it at the rear and then simply tape over the 1cm gap between fans. Easier then cutting and painting PVC, though it does require murdering a fan.

Oh do I ever! 2x failed Ultra Performance fans 0, plastic cutter 1

Looks like i've got myself a fan duct!
 
OP
reap3r

reap3r

Member
Joined
Jun 18, 2009
Location
BC, Canada
I personally like having the fans mounted externally as it gives you a good handhold on the back for moving the case around. ;) Seriously, it doesn't bother much of anything mounting the fan on the back side like that. Just be sure to get some wire fan guards to keep your fingers out.

This is a fair point, however I have decided to go with removing the rear exhaust and ducting the cpu fans.. Plus I have the Cooler Master Storm Scout case which has a pretty good handle for carrying already ;)

Thanks for the suggestions though, at least you guided me in the right direction! :thup: