Cooling fan for electronics cabinet
I want to install a small fan for cooling the cabinet that holds the satellite receiver, dvd player and control box. Can someone please point me in the right direction. TIA.
Forum Discussion
Kiwi_too wrote:
I took a 12v fan out of an old PC I had. I wired it to a USB cable and plugged that into a 120v to 12v adapter. Pulls quite a bit of air through the cabinet.
:h
Not sure as to why you would use a USB cable in between a 12V fan and 12V power supply.
Bad things will happen if someone decided to plug a USB device in using a 12V power supply.
USB ports (and USB wall charger/power supplies) provide FIVE VOLTS, not 12V.
You can power a 12V fan from 5V but it is going to run considerably slower than designed. While that is a good thing noise wise, it does a bad thing for actual air movement. These fans get very inefficient when run at a lower speed than designed so a fan rated at 50CFM at 12V running at 5V will result in at the best 20CFM. Same happens when you take a fan that is designed for 240V and run it on 120V, you will get CONSIDERABLY LESS than half the rated CFM.
A funny story, my company builds some industrial products, we had some of the customers complaining about noise from the cooling fans.
The fans cooled a PC built into the device along with power supplies and other electronic parts. The fix for the noise was to buy a 220V fan to replace the 120V. Problem was our engineers discarded the fact that the 220V fans was rated the same CFM as the 120 fan but when running the 220V fan on 120V it barely moved any air.. Items inside the case soon didn't like the heat and failed more often..
Another point to consider, typical USB ports or USB chargers supply 500 ma per port or there are high power ones which supply 1A per port.
Please make sure the fan you select DOES NOT draw more than the USB port or charger can supply.
