Noctua NH-D15 fan orientation question

[Stellarisk]

Hi I was watching some videos on installing the Noctua NH-D15 and was wondering which way the fans should point. The guide I was watching pointed the fans directly to the exhaust fan. I was told that it's better for the fan to point away from the blower so the airflow would bounce back towards the exhaust fan. Which is the correct way?

[WoodenMarker]

All of the fans in the system should optimally face the same way.

One example is front intake to rear exhaust. 

[Pixel5]

the best way it to get uninterrupted airflow so through the cooler to the exhaust fan and out of the case.

 

though as long as you got a good airflow you will probably not notice any difference at all but be aware there is no such thing as bouncing back when it comes to air movement it always means there are turbulences which usually slow down the air flow

[Stellarisk]

8 minutes ago, Pixel5 said:

the best way it to get uninterrupted airflow so through the cooler to the exhaust fan and out of the case.

 

though as long as you got a good airflow you will probably not notice any difference at all but be aware there is no such thing as bouncing back when it comes to air movement it always means there are turbulences which usually slow down the air flow

Huh. Weird. I had never noticed it because of my current cooler; the fan is pointed towards the front of the case. (which doesnt have room for air) So with the new cooler; I should  make sure the blowing side of the fan is pointing directly at the heatsink, towards the exhaust?

[Pixel5]

1 minute ago, Stellarisk said:

Huh. Weird. I had never noticed it because of my current cooler; the fan is pointed towards the front of the case. (which doesnt have room for air) So with the new cooler; I should  make sure the blowing side of the fan is pointing directly at the heatsink, towards the exhaust?

yes that is the prefered orientation unless all your fans are blowing out the front which is very rare.

[Stellarisk]

5 minutes ago, Pixel5 said:

yes that is the prefered orientation unless all your fans are blowing out the front which is very rare.

Ah man. So my current heat sink has been installed wrong lmao? weird. I made it look the way it's supposed to on the box.

[Alex Atkin UK]

25 minutes ago, WoodenMarker said:

All of the fans in the system should optimally face the same way.

One example is front intake to rear exhaust. 

I actually found in my case that ditching the top fans entirely runs cooler, as the top fans disrupt the air from flowing smoothly from the front, through the D15 and out the back.

I also don't think its wise to have two fans next to each other one blowing out and one in, as it just sucks the hot air back in again.

[Stellarisk]

Isn’t one of the selling points of the d-15 that it has two fans?

[Stellarisk]

7 minutes ago, Alex Atkin UK said:

I actually found in my case that ditching the top fans entirely runs cooler, as the top fans disrupt the air from flowing smoothly from front to back, through the D15 and out the back.

I also don't think its wise to have two fans next to each other one blowing out and one in, as it just sucks the hot air back in again.

Sorry I thought I replied directly to you lol. Isn’t one of the selling points of the d15 having those two fans for cooling?

[Alex Atkin UK]

5 minutes ago, Stellarisk said:

Isn’t one of the selling points of the d-15 that it has two fans?

Yes, but the one above the RAM often wont fit due to case width and clearly there is no space at the back.  I'd probably have replaced read fan with it.  I found the D15 makes a horrible noise if you have the fans in pull configuration so wouldn't do that.

 

In a case with TOP fans, the one at the top back would be sucking against the side of the D15 second fan so completely counter productive.  Airflow always works best (and quieter) in as straight a line as possible.

[Stellarisk]

2 minutes ago, Alex Atkin UK said:

Yes but there's clearly not the space in that photo.  Although personally I'd have either ditched the rear fan and kept the two fans on the cooler, or replaced the rear fan with the one from the D15.

 

In a case with TOP fans, the one at the top back would be sucking against the side of the D15 second fan so completely counter productive.

Oh yeah I see that’s why I was going to avoid top fans completely. I was going to do 3x 140mm front intake. 1 140mm rear exhaust and now that I realized my current cooler is installed wrong. I guess the two noctua fans pointed directly towards the exhaust. I think I’ll still have room. The case I got is a p500a and the cooler is still coming in the mail so I’m trying to learn as much as I can about it before doing so. 

[Alex Atkin UK]

5 minutes ago, Stellarisk said:

Oh yeah I see that’s why I was going to avoid top fans completely. I was going to do 3x 140mm front intake. 1 140mm rear exhaust and now that I realized my current cooler is installed wrong. I guess the two noctua fans pointed directly towards the exhaust. I think I’ll still have room. The case I got is a p500a and the cooler is still coming in the mail so I’m trying to learn as much as I can about it before doing so. 

I'm actually finding the D15 a bit counter-productive on my 9900K machine.  I recently built a Ryzen 5950X and went with a Deepcool AS500 Plus instead which leaves a lot more space in the case for moving air around.

My GPU however does have a blower cooler (as it was in an ITX build before) so its not blowing hot air back into the case.  Will probably have a re-think if I can ever get a new GPU as wont get another blower as they're so darn noisy.

[Stellarisk]

2 minutes ago, Alex Atkin UK said:

I'm actually finding the D15 a bit counter-productive on my 9900K machine.  I recently built a Ryzen 5950X and went with a Deepcool AS500 Plus instead which leaves a lot more space in the case for moving air around.

My GPU however does have a blower cooler (as it was in an ITX build before) so its not blowing hot air back into the case.  Will probably have a re-think if I can ever get a new GPU as wont get another blower as they're so darn noisy.

See that’s where I’m confused on what to do with my gpu. I have a 1660 ti. Not sure about cooling there. I know for a fact that the d15 is overkill for my i7-8700 but I’d rather temps just be the lowest it can be especially with erratic temp spikes. 

[Alex Atkin UK]

5 minutes ago, Stellarisk said:

See that’s where I’m confused on what to do with my gpu. I have a 1660 ti. Not sure about cooling there. I know for a fact that the d15 is overkill for my i7-8700 but I’d rather temps just be the lowest it can be especially with erratic temp spikes. 

I can see why people go with AIO water coolers, so much simpler when you can move the heat exchanger right to the edge of the case.  However their life span is also much shorter and I have very sensitive ears, I'm sure I'd hear the pump.  I had to remove a HDD recently because I could hear to humm of it spinning and it drove me insane.

I actually have the same fans as the D15 as intakes for my case and having an issue with harmonics from those when they spin up/down.  They make a kind of whine that again is driving me nuts.  Hopefully I can find what speed they do it at and tweak the fan profile accordingly.

[Stellarisk]

2 minutes ago, Alex Atkin UK said:

I can see why people go with AIO water coolers, so much simpler when you can move the heat exchanger right to the edge of the case.  However their life span is also much shorter and I have very sensitive ears, I'm sure I'd hear the pump.  I had to remove a HDD recently because I could hear to humm of it spinning and it drove me insane.

I actually have the same fans as the D15 as intakes for my case and having an issue with harmonics from those when they spin up/down.  They make a kind of whine that again is driving me nuts.  Hopefully I can find what speed they do it at and tweak the fan profile accordingly.

Have you tried using rubber pads? I got a similar issue with Arctic fans. See once I looked at an aio and how it was installed. Some of the budget ones; i kinda regretted buying the noctua. From what I read it’s the best air cooler on the market.  But it’s always a pain for me to get them set up because I have poor eye hand coordination. And I dislike the fan brackets. I didn’t know they had a shorter lifespan though. Kind of a dealbreaker for me. I completely relate on the humming noise and from what I guess it’s either the motor or just vibrations. But I don’t want to use rubber screws. 

[Alex Atkin UK]

3 hours ago, Stellarisk said:

Have you tried using rubber pads? I got a similar issue with Arctic fans. See once I looked at an aio and how it was installed. Some of the budget ones; i kinda regretted buying the noctua. From what I read it’s the best air cooler on the market.  But it’s always a pain for me to get them set up because I have poor eye hand coordination. And I dislike the fan brackets. I didn’t know they had a shorter lifespan though. Kind of a dealbreaker for me. I completely relate on the humming noise and from what I guess it’s either the motor or just vibrations. But I don’t want to use rubber screws. 

I very nearly went with an AIO, it was having to remove the HDD that reminded me it was probably a bad idea to get something else that causes a low hum.

The thing is with air coolers is if the fans fail, or you don't like the noise they make, you just replace them.  If the pump fails on an AIO or makes an annoying noise, you have to replace the whole thing.

I still have air coolers from well over a decade, I can't imagine an AIO being usable for that long.