Solved CPU

[YTBOY83]

Is my cpu fan better as intake or exhaust???????

 

[Product FRED]

Is my cpu fan better as intake or exhaust???????

I'm not sure I understand your question, but from the looks of it your CPU is running fine.

 

[YTBOY83]

I have a cooling fan attached to my cpu heatsink and it is set up as an intake. I am wondering whether it is better off as an intake or exhaust?????

 

[Product FRED]

The CPU fan should blow away from the heatsink to pull off excess heat. This also helps draw air across the cooling fins. If you have a rear fan, then the heat that the cooler is blowing away gets exhausted from the case.

 

[seekermeister]

Hmm, I have always installed the fan blowing toward the heatsink, rather than away. In fact, that is the way that the heatsink/fan originally came from AMD. What is the basis of your conclusion?

 

[Product FRED]

As I've stated, the heatsink draws heat from the CPU. The fan needs to transfer the heat away from the heatsink, towards the back fan, which transfers the warm air out of the case. Having the fan blow towards the heatsink will cool the system, but it will also be inefficient since it'll be pushing the heat back towards the heatsink and CPU.

That's why a vacuum is better for putting out fires than blowing air (small scale).

 

[cloud8521]

.... unless you learn that fire feeds off of oxygen, and you also learn that moving cold air toward a heat source is better. that is why ALL fans blow towards the heatsink when you buy them, if the opposite was true then they would do it themselves.

 

[seekermeister]

The only thing that I can think of that might be an improvement with directing airflow away from the HS, is that blowing toward it would split the stream, rather than keeping it together. Split or not, I believe that it would still carry as much heat away, but I'm not so certain about how this would effect the air circulation pattern within the case?

That's why a vacuum is better for putting out fires than blowing air (small scale).

Not particularly relevant, but this made me think about the fact that a procedure in flying is that in case of an engine fire, the plane is put into a dive in hopes of extinguishing the fire. Of course, a vacuum is not an option.

 

[Product FRED]

.... unless you learn that fire feeds off of oxygen, and you also learn that moving cold air toward a heat source is better. that is why ALL fans blow towards the heatsink when you buy them, if the opposite was true then they would do it themselves.

You contradicted yourself. Fire feeds off of oxygen. Draw the oxygen away, suck the air away.

 

[seekermeister]

.... unless you learn that fire feeds off of oxygen, and you also learn that moving cold air toward a heat source is better. that is why ALL fans blow towards the heatsink when you buy them, if the opposite was true then they would do it themselves.

You contradicted yourself. Fire feeds off of oxygen. Draw the oxygen away, suck the air away.

You are not actually sucking the air away, because the air that is exhausted is replaced by fresh air coming from between the fins. Also, the heat in question is not a fire, and oxygen does not feed it.

 

[Product FRED]

.... unless you learn that fire feeds off of oxygen, and you also learn that moving cold air toward a heat source is better. that is why ALL fans blow towards the heatsink when you buy them, if the opposite was true then they would do it themselves.

You contradicted yourself. Fire feeds off of oxygen. Draw the oxygen away, suck the air away.

You are not actually sucking the air away, because the air that is exhausted is replaced by fresh air coming from between the fins.

Exactly. Cool air. By sucking the air away from the heatsink, you're creating suction, drawing in cool air as you push the hot air out of the case through the rear fan.

 

[seekermeister]

You contradicted yourself. Fire feeds off of oxygen. Draw the oxygen away, suck the air away.

You are not actually sucking the air away, because the air that is exhausted is replaced by fresh air coming from between the fins.

Exactly. Cool air. By sucking the air away from the heatsink, you're creating suction, drawing in cool air as you push the hot air out of the case through the rear fan.

We are going in circles here. Regardless of the direction of flow, the air is cooler when entering and warmer when leaving. Either way, the air is not being forced out of the case by this fan, it is directed by the main intake and exhaust fans, which creat a circulation across the CPU.

When I asked about how you came to this conclusion, I did not mean to simply explain your reasoning. I wanted to know if you had read something about this, that you could link to, or if you had made a hands on experiment and measured a temperature differential yourself.

 

[Product FRED]

You are not actually sucking the air away, because the air that is exhausted is replaced by fresh air coming from between the fins.

Exactly. Cool air. By sucking the air away from the heatsink, you're creating suction, drawing in cool air as you push the hot air out of the case through the rear fan.

We are going in circles here. Regardless of the direction of flow, the air is cooler when entering and warmer when leaving. Either way, the air is not being forced out of the case by this fan, it is directed by the main intake and exhaust fans, which creat a circulation across the CPU.

When I asked about how you came to this conclusion, I did not mean to simply explain your reasoning. I wanted to know if you had read something about this, that you could link to, or if you had made a hands on experiment and measured a temperature differential yourself.

Yes, actually I did. I've read mixed responses, but the ones that agree with my statement make more sense. The air flows like you said: Cool in, Hot out. By blowing the air, you're not cooling it, you're just moving it back towards the fan. So the air is still hot, still in the heat sink, and not circulating, or at least not efficiently.

 

[seekermeister]

Exactly. Cool air. By sucking the air away from the heatsink, you're creating suction, drawing in cool air as you push the hot air out of the case through the rear fan.

We are going in circles here. Regardless of the direction of flow, the air is cooler when entering and warmer when leaving. Either way, the air is not being forced out of the case by this fan, it is directed by the main intake and exhaust fans, which creat a circulation across the CPU.

When I asked about how you came to this conclusion, I did not mean to simply explain your reasoning. I wanted to know if you had read something about this, that you could link to, or if you had made a hands on experiment and measured a temperature differential yourself.

Yes, actually I did. I've read mixed responses, but the ones that agree with my statement make more sense. The air flows like you said: Cool in, Hot out. By blowing the air, you're not cooling it, you're just moving it back towards the fan. So the air is still hot, still in the heat sink, and not circulating, or at least not efficiently.

You have read mixed responses...that sounds as though what you read was other forum threads on the subject, rather than some kind of expert analysis. Despite the fact that I find flaws in your reasoning, I shall not debate them, because it would serve no purpose.

 

[Product FRED]

Yes, I did browse forums for an answer. Just like someone posted here, and we responded. But like you said, we're not experts and we're going by what we know. Everyone's entitled to their opinions.

 

[YTBOY83]

I have thought about this in depth, if my cpu fan is set as exhaust then there is not any cool air helping the cpu stay cool. If i have it set to intake then air is helping keep the cpu cool whilst still blowing heat back. Answer this, shall there be more cool air getting blown back than there is hot air.

I think the cpu need cool air.

What do you think??????????

 

[seekermeister]

I agree, everyone is entitled to their opinions, and they are entitled to express them, but I prefer to know and understand the nature of what a person says, whether it is simply opinion, or something more substantial.

Along the lines of personal opinion or perspective, I have been thinking about your vacuum fan arrangement. Obviously, what counts is the amount of heat that is imparted to the airstream, and since the majority of the heat is going to be at the base of the fins, nearest the CPU, it would seem that the amount of air that comes in cantact at that point would be a critical factor in cooling. Since the vacuum fan would be pulling air laterally along the full length of the fins, some of the airflow would never have contacted the base area. Plus there would be a point between these lateral flows, near the base, that would be either a dead zone or an eddy, which would not conduct heat as well as a fan blasting directly and evenly on it.

 

[Product FRED]

I have thought about this in depth, if my cpu fan is set as exhaust then there is not any cool air helping the cpu stay cool. If i have it set to intake then air is helping keep the cpu cool whilst still blowing heat back. Answer this, shall there be more cool air getting blown back than there is hot air.

I think the cpu need cool air.

What do you think??????????

Like I said, if you set it as exhaust, the hot air will be drawn out of the heatsink while cool air will replace it. The air comes in cool, passes through the heatsink and CPU, and leaves hot. Get it?

PS: I just called a friend for professional advice, and he agrees with me. He's been working with servers, among other things for about 20 years and he 100% agrees with me. It just makes sense. Think about it.

 

[YTBOY83]

Good points, i suppose it also depends on how you have your intake fans set up.

I shall try it when i wake up and take temp readings. Thanks.

 

[seekermeister]

Either way, the air is cooler coming in, than going out. The crux is which direction is permitting the air to absorb more heat? The question is somewhat rhetorical, unless you have something to add that you haven't already said.