IndustrialPPC NF-F12 and NF-A14 24V PWM Fans Review
 

The new IndustrialPPC NF-F12 and NF-A14 fans are 24V DC operated though they can operate at 12v which PC systems typically provide. The tradeoff is that it will operate at reduced RPMs. How could you get a 24v power on a desktop system when typical power supplies don't supply anything more than 12v? One of the better options is to use a 12/24v fan and pump controller, like a Koolance CTR-SPD1224M 12v/24v Pump/ Fan controller. After researching in multiple tech forums, one of the common suggestion is either to use +12v and -5v together thus providing 17v or +12v and -12v together for 24v.

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