Fan pull air through rad, will it heat up the inside of my case?

[stratuh]

My motherboard has a sensor that I think is tied to ambient temperature inside the case as it spikes in relation to GPU and/or CPU temp and slowly rises over time. I find even at idle, the inside of my case hovers around 35c, and after gaming for just 30min, it rises to 42c. Opening the case and removing any front choking (fan grille and filter) sees it quickly decline to low 30s. It's a 400c so my cooling options are somewhat limited (rear can only take 120mm, no bottom airflow to reach GPU).

 

I was humoring a Kraken G12 as well as an AIO cooler to affix to my 2080. My 2080 temps aren't bad, but synthetic benchmarks do show in the high 60s with ingame performance, I quickly shoot up to 70c. I think the case temp at least partially attributes to this, as I've seen high 50s on a cold day with no heat on (where case temp was 27c). The only place I could realistically put a radiator is on one (or both) of my front intake fans and I wonder how how these rads get?

 

I know my GPU temp will lessen with an AIO attached, but it might be introducing heat by way of the radiator. Instead of hot air pouring out the rear, the heat accumulates in the rad. Are my fears unfounded?

 

tl;dr: I'm looking at an AIO with 140mm rad. How do radiators work when air pass through them? Will my case heat up as air passes through the hot rad?

[Windows7ge]

As air passes through the radiator it'll increase but only by 1~2°C. It's very negligible.

[stratuh]

1 minute ago, Windows7ge said:

As air passes through the radiator it'll increase but only by 1~2°C. It's very negligible.

Interesting, I didn't know it was only 1~2c. I know my GPU backplate is a real scorcher after even 10min of use. I wish I had an IR thermometer but I can just barely touch it before it hurts too much. I wonder if a rad would emit less ambient heat versus a backplate.

[JammyCreedog]

Bitwit Kyle, Jayz2cents and Luke when he still worked for LTT all did experiments on airflow configurations and radiator placement.  I think the consensus is that it really doesn't matter that much but if you wanted to drop the temp inside your rig by 2-3 degrees C, mount your rad at the top of your case and exhaust thru it out the top.

[Windows7ge]

2 hours ago, stratuh said:

Interesting, I didn't know it was only 1~2c. I know my GPU backplate is a real scorcher after even 10min of use. I wish I had an IR thermometer but I can just barely touch it before it hurts too much. I wonder if a rad would emit less ambient heat versus a backplate.

The amount of heat produced would be the same. The difference would be how effectively that heat can be transferred from one body to the next.

[Mick Naughty]

I know the heat goes up quite a bit after coming out of my rads. Like the back of a blower style gpu. So I never use them as intake anymore. Wouldn’t make any sense to. 

 

But if your hardware isnt doing much it should be fine either way. 

[Daniel644]

On 2/7/2019 at 10:01 PM, Windows7ge said:

As air passes through the radiator it'll increase but only by 1~2°C. It's very negligible.

I have to disagree with this, long story short, I sold my 2 1080ti's and so I split my 2 Titan Xp's between my 2 systems (I converted the Titan's to Hybrids using the EVGA SC 1080ti Hybrid kit), when I pulled one of the Titans from my gaming PC to put in my Work PC I screwed up and had that rad sucking air into the case (mounted in the top) instead of exhausting out and the whole case was noticeably hotter (this was after a sustained mining load on the GPU for an hour or 2), the CPU was running 10c hotter and removing the sidepanel resulted in a wave of heat escaping the computer, maybe under general usage it wouldn't be to bad, but any kind of sustained loads is gonna dump a metric ton of heat into the case, configuring rads to blow out of the case is the best practice.

[Windows7ge]

3 hours ago, Daniel644 said:

I have to disagree with this, long story short, I sold my 2 1080ti's and so I split my 2 Titan Xp's between my 2 systems (I converted the Titan's to Hybrids using the EVGA SC 1080ti Hybrid kit), when I pulled one of the Titans from my gaming PC to put in my Work PC I screwed up and had that rad sucking air into the case (mounted in the top) instead of exhausting out and the whole case was noticeably hotter (this was after a sustained mining load on the GPU for an hour or 2), the CPU was running 10c hotter and removing the sidepanel resulted in a wave of heat escaping the computer, maybe under general usage it wouldn't be to bad, but any kind of sustained loads is gonna dump a metric ton of heat into the case, configuring rads to blow out of the case is the best practice.

There's a couple things at play here. The hotter the radiator of course the hotter the air will be once it passes through it.

 

However you admitted that you made a mistake when you installed it. And worst of that it was on the top. Heat rises, with the radiator blowing down it was compiling more heat ontop of itself. Probably the only fan exhausting was the rear fan. Once the loop equalized under full load your situation may be 2~3°C or 3~4°C hotter air but what you don't understand is that the heat was building up because of that top mount. You had an instance of positive pressure inside your case with the intakes acting like heaters. This isn't the fault of how hot the radiator gets its just a bad fan configuration.

 

If you want to favor the GPU temp over the rest of the system you can mount it on the front or back as an intake it's just that the top exhaust has to be able to compensate for the rate of flow coming in. Setup correctly it doesn't matter if your GPU mining the system won't increase by 10°C like you experienced. It WILL increase but not by that much.

 

The size of the case will also have an effect. The smaller the chassis the faster that heat will build up. Exhausting it is important.

[SolarNova]

Really depends on how much heat ur dumping in to the rad, how big, thick, and higher the FPI is, and speed of fans.

 

I found with my rig that having my front 240 x 80mm Monsta rad as intake seriosly increased case temps, which was no good for my other rads exhausting that air. I ended up turning all my rads to exhaust. I have to dust more regularly but al lthe rads use cool air now and loop temps improved.

 

if u have positive pressure via the rad, then it will heat up as ur not exhausting the warmed air fast enough. But if u have say a single 240 at the front then 3 120 mm Airflow fans as exhasut, u should be fine.

[Daniel644]

9 hours ago, Windows7ge said:

There's a couple things at play here. The hotter the radiator of course the hotter the air will be once it passes through it.

 

However you admitted that you made a mistake when you installed it. And worst of that it was on the top. Heat rises, with the radiator blowing down it was compiling more heat ontop of itself. Probably the only fan exhausting was the rear fan. Once the loop equalized under full load your situation may be 2~3°C or 3~4°C hotter air but what you don't understand is that the heat was building up because of that top mount. You had an instance of positive pressure inside your case with the intakes acting like heaters. This isn't the fault of how hot the radiator gets its just a bad fan configuration.

 

If you want to favor the GPU temp over the rest of the system you can mount it on the front or back as an intake it's just that the top exhaust has to be able to compensate for the rate of flow coming in. Setup correctly it doesn't matter if your GPU mining the system won't increase by 10°C like you experienced. It WILL increase but not by that much.

 

The size of the case will also have an effect. The smaller the chassis the faster that heat will build up. Exhausting it is important.

actually the case had an exhaust fan in the other spot at the top (and maybe one in the rear, I've reconfigured this case a few times now) and positive pressure should only work to push the air out through any crevice available and my point was that I was dumping the heat from the rad into the case resulting in the same kinds of temps you would see from a traditional multi fan GPU that dumps it's heat into the case, so you are better off having the rad exhaust out because a sufficiently powerful GPU can dump a ton of heat into a case very quickly and being that the OP is specifically concerned about  dumping the heat from an AIO cooled GPU into the tower my scenario is an example of the kind of heat build up that can occur as a result of that.

[Windows7ge]

3 hours ago, Daniel644 said:

actually the case had an exhaust fan in the other spot at the top (and maybe one in the rear, I've reconfigured this case a few times now) and positive pressure should only work to push the air out through any crevice available and my point was that I was dumping the heat from the rad into the case resulting in the same kinds of temps you would see from a traditional multi fan GPU that dumps it's heat into the case, so you are better off having the rad exhaust out because a sufficiently powerful GPU can dump a ton of heat into a case very quickly and being that the OP is specifically concerned about  dumping the heat from an AIO cooled GPU into the tower my scenario is an example of the kind of heat build up that can occur as a result of that.

Fair enough. My primary argument was to explain that the air only increases by a couple degrees as it passes though a radiator (at least for how hot your typical computer radiator will get). He's going to be mounting it on the top or back so configuring it as an exhaust would be recommended.

[DerKaizerII]

I would recommend not putting the rad above because bitwit shower it can make the CPU 10c or so hotter. And if mounting it on the first makes the inside only a deglegable 1-2 or 3-4 C than I would recommend that.