Recently I shutdown my 1U servers and decided to move them into the spare bedroom. To my surprise they were making less noise than I originally thought. A lot of the noise was coming from the pfSense firewall I recently replaced my ASA with. The server is an atom board with passive cooling mounted in an older Supermicro case. All of the noise was being generated by the 200 watt power supply.
I did some bad calculations to determine how many watts the system was currently using then started researching some ways to quite down the power supply. There were a couple people online that swapped the power supply out with a similar unit but I did not think that would be enough. I knew there were fanless power supplies but did not know much about them. They are called PicoPSU and come in various wattage outputs but most of them are designed for larger cases and need at least 1.5U.
The lower wattage PicoPSU is supposed to fit a 1U case. They make these power supplies so small by moving the AC to DC conversion to a power brick like a laptop. I ordered the PicoPSU-120 + 102W Adapter Power Kit for $52 online and hoped it would be enough. It was difficult to find how much power would be used by the POE Gigabyte ethernet adapter that I installed to power my access points but I was able to borrow a Kill A Watt from a friend and got a good reading… although I will admit this was a day or two after I placed my order.
When I was planning the project I originally planned on removing the old power supply and fabricating a bracket to hold the power adapter. Once I got the server apart again and was looking at the back I decided that was a lot more trouble then it was worth. I also thought it might be nice to leave the old power supply in place for a manual fail over backup. I plugged the PicoPSU in and wired everything then decided to drill a 5/16th hole into the PCI bracket. This held the power adapter very nicely and looked cleaned.
The new setup works great. It is now impossible to tell if the firewall is running or not without taking a look or hoping online.