Exhaust fan

Sc00by · 20 Dec 2020 at 10:52

Hi

Looking at upgrading my current 140mm exhaust fan on the rear of my case, is their a type of fan that is designed specially for exhausting air?

Also whould having one of them Pcie exhaust fans be a good shout as an extra or are they pointless?

robj20 · 20 Dec 2020 at 11:05

Upgrade for what reason. Quieter, more air flow?
To do either you'd need to know what your current fan is capable of.

Sc00by · 20 Dec 2020 at 11:27

robj20 said:
Upgrade for what reason. Quieter, more air flow?
To do either you'd need to know what your current fan is capable of.

The current fan, came with the case it's a corsair one about 3 years old but not sure on the model.
Looking for more air flow extraction noise factor isn't a issue really.

robj20 · 20 Dec 2020 at 11:32

Be aware it's not the best idea to just pull air out of a case as this will pull dust in from everywhere.

It's better to pull air in through filtered fans and exhaust slightly less than is going in. This will keep your case cleaner.
For instance I have 2x 140 filtered fans on the front and 2x 120 fans exhausting. Something to think about.
Without delving into the specs of fans generally if you want high airflow you want fast fans and as big as possible.

pp111 · 23 Dec 2020 at 08:05

The disadvantage of three wire fans is they tend to require a fairly high voltage to get them started which means there isn't much room for control. They can also "stall" or fail to start when commanded on. PWM on the other hand are easier to start rotating so they are very unlikely to stall and have a wider control range. Three wire fans are usually used for case fans because that level of fine control is just not needed and usually the problem of stalling is avoided by setting them fairly high all the time. PWM are preferred for things like CPU coolers where a wider range of fan speed is used and NOT stalling is very important. So, you can use non-pwm for cases! PWM fans are typically higher pressure fans, aimed at cooling heat-sinks, whereas non-pwm are lower pressure aimed at getting the highest possible airflow in a case. Some cases though benefit from using PWM fans because air flow is a bit restricted. Many fans these days are hybrid which means they are good for every situation. What case are your trying to cool?