[SOLVED] Cooling question about fans

Apr 17, 2021
6
0
10
HI,

The problem is this i live in Thailand and the ambient temperature is a bit higher then back in Europe. Now i do turn on the aircon to 27. Its enough for me.

Now I got an I8700 with nzt watercooling 360mm fan. This is put at the front of the case so sucking in air but it passes the radiator. So basically im sucking in warm air.

The processor is ok with this as the temperature stays within limits.

I got one fan in the back of the case pulling air out. Now I am thinking of adding 2 fans at the top of my case. Now the question is should the be pulling cool air in or blowing hot air out. Or could I even have one pull in and the next push out.

Reason I want extra cooling is my 2 m2SSD's they get hot during the day 50 and higher. Even without too much load. I worry about those. One has a heatsink on it the other has not. Strange thing is the one with heatsink gets hotter.

My VGA card is a nvidia 3080.

So what is best for the top case fans both sucking in cool air
Both pulling hot air out
One pulling out and one sucking in

Or making my back fan suck in cool air while the two top fans blow it out.

I cant change the NZT liquid cooling radiator its place.
 
Solution
I'll post based on assuming you do NOT want to make huge changes and spend a lot. First thing: if you mount two fans at top, do NOT make them blow in opposite directions. That only creates a very small circulation loop at the top of the case and does NOT improve cooling.

Secondly, you report that your system - or, at least the CPU - is running at entirely acceptable temperatures. Adding more fans to increase air flow will help, but maybe not what you expect. The automatic cooling control system is focused on the TEMPERATURE measured inside the CPU chip, and it alters the speed of the rad fans in the front according to that. Similarly, the rear fan is probably connected to a mobo SYS_FAN header that is changing its speed according the...
You are experiencing the catch 22 of aio coolers.
Not much you can do about it.

What is the make/model of your case?

The objective of cooling is to get component heat our of the case.
To that end the front intakes from the 360 aio is where all of the relatively cool air is coming from.
27c. is relatively cool compared to the 50c. you might find inside the case.
All the cooling air that comes in the front will eventually exit somewhere, taking component heat with it.

What to do?
A i7-8700 does not require excessive cooling.
I suggest that you would be better served by replacing the aio with some strong intake fans and cool with a decent tower type air cooler.
 

Paperdoc

Polypheme
Ambassador
I'll post based on assuming you do NOT want to make huge changes and spend a lot. First thing: if you mount two fans at top, do NOT make them blow in opposite directions. That only creates a very small circulation loop at the top of the case and does NOT improve cooling.

Secondly, you report that your system - or, at least the CPU - is running at entirely acceptable temperatures. Adding more fans to increase air flow will help, but maybe not what you expect. The automatic cooling control system is focused on the TEMPERATURE measured inside the CPU chip, and it alters the speed of the rad fans in the front according to that. Similarly, the rear fan is probably connected to a mobo SYS_FAN header that is changing its speed according the temperature measured by a different sensor on the mobo. Currently they are managing to keep temperatures under control. If you add fans and air flow POTENTIAL, what will happen is that all those fans will slow down slightly to achieve exactly the SAME temperatures. So the impact is more subtle. IF your workload (and heat generation) is increased a lot, you might get to a point WITHOUT those added fans that full speed fans still is not enough. BUT with the extra fans, you WOULD have the capacity to meet high-level cooling needs for very high workloads.

Adding two exhaust fans to the top in addition to the rear exhaust fan may produce a condition of more exhaust capacity than intake capacity. This is because the three front intake fans are pulling though the rad which impedes air flow, whereas the exhaust fans have no interference. This is OK for cooling, but it MAY mean that unfiltered air can be sucked into the case at small openings and cracks, leading to dust accumulation. IF you are concerned about that, you could install only one added top fan. This would avoid that unfiltered air entry, but not add as much cooling capacity as two fans would.

Your main concern appears to be the SSD's. First, they MAY be quite OK as they are - depends on what operating temperatures they were designed for. But could you manage to mount a fan that blows directly on them - either with fresh outside air, or even with air already inside the case? This would not impact overall cooling, but would enhance cooling of the items that concern you. This fan could be plugged into any SYS_FAN header.
 
  • Like
Reactions: robthai
Solution

Windows22

Prominent
Dec 30, 2020
173
17
585
You are experiencing the catch 22 of aio coolers.
Not much you can do about it.

What is the make/model of your case?

The objective of cooling is to get component heat our of the case.
To that end the front intakes from the 360 aio is where all of the relatively cool air is coming from.
27c. is relatively cool compared to the 50c. you might find inside the case.
All the cooling air that comes in the front will eventually exit somewhere, taking component heat with it.

What to do?
A i7-8700 does not require excessive cooling.
I suggest that you would be better served by replacing the aio with some strong intake fans and cool with a decent tower type air cooler.
I agree here, we can get a better idea if we know the other specifications.
 
Apr 17, 2021
6
0
10
Thanks guys, sorry I don't have more info on the case. I know its not a cheap case. But the problem is it has a glass plate on the side. So i cant put a fan there. It is an atx tower with a perforated top and back. I might have room for a samller fan next to my grapical card (but not sure if there are fans that are smaller then the standards 120 MM.

I might change my case.

The remark about the liquid cooling being a problem as it sucks in less air is noted I thought about hat myself too. The case has no opening / perforation on the side. Just top front and back.

Also the SSD's do take some time to get warm so it is an over time thing. I might look into setting the fan speed higher some way. Never thought that they would not be running at full speed. First time really looking into cooling.

I had an SSD fail a while back, not sure if it was heat related. But after that i watched it more closely.
 

Phaaze88

Titan
Ambassador
You don't know the make and model of the chassis? Then take some pictures of the side(glass panel removed please), top, and front so others will have a better idea of the cooling situation.
You can use the following to post the pics:
imgur.com
postimages.org
imgbb.com
 
Apr 17, 2021
6
0
10
I just found a setting in my mother board that allows me to control the case fan. It is now 1200 RPM (and silent) instead of 900rpm. My 360mm fan is doing 2000rpm
 
HI,

The problem is this i live in Thailand and the ambient temperature is a bit higher then back in Europe. Now i do turn on the aircon to 27. Its enough for me.

Now I got an I8700 with nzt watercooling 360mm fan. This is put at the front of the case so sucking in air but it passes the radiator. So basically im sucking in warm air.

The processor is ok with this as the temperature stays within limits.

I got one fan in the back of the case pulling air out. Now I am thinking of adding 2 fans at the top of my case. Now the question is should the be pulling cool air in or blowing hot air out. Or could I even have one pull in and the next push out.

Reason I want extra cooling is my 2 m2SSD's they get hot during the day 50 and higher. Even without too much load. I worry about those. One has a heatsink on it the other has not. Strange thing is the one with heatsink gets hotter.

My VGA card is a nvidia 3080.

So what is best for the top case fans both sucking in cool air
Both pulling hot air out
One pulling out and one sucking in

Or making my back fan suck in cool air while the two top fans blow it out.

I cant change the NZT liquid cooling radiator its place.

I too have Air conditioning (set to 24C) and it makes considerable difference. My AIO is top mounted drawing Ambient air from outside the case.
Remember that the air in your case is never cooler than Ambient temps especially if the GPU is none reference.
To improve throughput you should fit a rear 140mm fan to exhaust hot air more efficiently. If you can ofc.
 
Apr 17, 2021
6
0
10
I know but 27 is a nice temperature for me, at night in the bedroom it goes much lower think 20 or so.

Yes i know that case temperature cant be lower then ambient temperature. I am going to fix an extra small fan lower closer to the ssd. But so far the increaing of the fan speed has worked. But have to see the computer has only be on for 3 hours now. It usually is on more then 12 hours.
 
Apr 17, 2021
6
0
10
Ok been al long time now and the temperature has dropped around 5 degrees by just letting one fan run top speed (set this in the motherboard).

The new fans will arrive in a few days will see what it does. Thanks for letting me know that the mainboard controls it based on the CPU. Did not think i had to set it manually.