• We’re currently investigating an issue related to the forum theme and styling that is impacting page layout and visual formatting. The problem has been identified, and we are actively working on a resolution. There is no impact to user data or functionality, this is strictly a front-end display issue. We’ll post an update once the fix has been deployed. Thanks for your patience while we get this sorted.

H70: pull fan doesn't spin as much

Eureka

Eureka

Diamond Member
I just got my H70 core in, and I put a Yate Loon as my push fan and used the stock cosair exhaust fan as my pull fan. I originally tried 2 Yate loons but I found out very quickly that one of them had a bad bearing.

Now, I can free wheel the corsair fan (which is in the pull position) with my finger. I do notice that while its running, with both fans on automatic voltage control from the motherboard, that the push fan is always spinning. The pull fan does not spin at low temps, but when the temps is high, both fans spin.

I'm wondering if this has to do with air pressure from the push fan? I have yet to flip the fans the other way around but I'll try that when I get home. Until then, I'm wondering why it would do this.
 
The fans are powered by the motherboard but I assume that they are on separate headers, push with CPU_FAN and pull with SYS_FAN. Both are regulated differently and the CPU_FAN will be of higher priority than SYS_FAN. SYS_FAN headers are usually used for rear exhausts but the motherboard has no way of knowing that they have identical priorities. One way of getting both of them to spin simultaneously is to use a Y splitter from CPU_FAN but that would make both fans spin at all times.
 
They are both on a Y-splitter from the CPU_FAn header.. it's included with the H70. I'm more inclined to think it's an air pressure issue since it only happens on low RPMS, when the motor isn't getting much voltage/current.
 
If that's the case, it could be due to non identical fans connected to the same header. With a Y splitter, your max voltage would be 12V which is what you would get at full load, both fans will spin. But at idle or low load, the voltage is turned down and fans of different make will have different start up voltage(minimum voltage required before it starts spinning).

It is possible that the Corsair fans have a much higher start up voltage than the Yate Loons due to it being much faster. Since it is only splitted, the voltage that both fans receive at idle is the same. At the voltage that the motherboard gives, it is sufficient to make the Yate Loons idle but the higher idle voltage Corsair will stop spinning.
 
You must log in or register to reply here.

TRENDING THREADS

Back
Top