Building A Sound Proof Server Cabinet - Electrics, Cabling and Networking

Now that the cabinet was complete structurally, it was time to outfit the interior with all of my networking hardware. Since I had now built a full blown server cabinet, it made sense to add some additional hardware alongside the sever to increase functionality and enable easy scalability whenever I wish to add more devices to the network (more future servers!). Specifically, I added a 24 port patch panel at the top, to make wiring and routing easier, and a 24 port network switch below that to enable many more devices to link to the network (such as the router, Raspberry Pi's and Ethernet compatible Arduino's).

Since I wanted plenty of flexibility with my network and allow hardware to be added and removed as easily as possible, I opted to design my system in a slightly unusual way. The ports on the patch panel run to cables that come out the back of the cabinet and rest at the side. Whenever I want to add a new device, I simply plug it up to one of these spare cables using an Ethernet coupler. Labels on the cables match up with the patch panel and switch numbers preventing cable mix up. This also means devices can quickly be disconnected from the cabinet so that it can be rolled out for maintenance. I got together some assorted Cat 5e cables and cut them down to size. Using spare RJ-45 jacks and my trusty Ethernet repair kit, I whipped up some cables ready to be punched down into the patch panel.

Then came the tedious task of punching down all the Cat 5e tails to the patch panel according to the standard colour guide. Luckily my punch down tool and RJ-45 tester kit made the job a lot easier and flagged up any errors I accidently induced along the way.

You can see the cable ends, labels and couplers that stick out the back where devices can be linked to the network.

The next job was to make a bunch of small patch cables to link the ports on the patch panel to the Ethernet switch. Once again, my Ethernet repair kit was indispensable.

The cabinet was really starting to take shape. Before putting the server in, I decided to clean the dust from the inside of it using a can of compressed air. The rack was then loaded in, bolted to the rails using cage nuts and wired up to the switch.

And there we have it, a fully functioning sound proof home made server cabinet!

At the side you can see the Ethernet coupler cables that pass device connection to the patch panel. There is also plenty of space at the back when the door is off for cable maintenance. Additionally, there is ample space below the cabinet for cool air to enter and ample space at the top for hot air to escape.

But the real test was to quantitatively measure how much quieter the server was now that it was inside the cabinet. This was done by placing the server where the cabinet was planning to go and measuring the noise level at the desk with a decibel meter. This was measured to be 69 dBa. The server was then put back in the cabinet and the noise level was read again in the same position. This was measured to be around 53 dBa. This was a 16 dBa improvement, and remembering that decibels is a log scale, this meant a hug reduction in noise. Finally, I also measured the temperatures and verified that the CPU cores inside the server did not heat up as a result of being inside the cabinet. This evaluation proves the project was a total success!

With that, the server cabinet project that started in 2019 was finally finished at the end of summer 2020. It took much longer than expected, but I'm very happy with the result as I can now work in the lab without having to listen to the deafening sound of fans. There's still plenty of room for future projects now that I have the cabinet. I am planning on adding more hardware, more servers, firewalls, multiple networks, perhaps even speed control of the PSU fans, lighting and maybe even a lick of paint. There is also a whole new realm of software exploration to dig into now that I have CentOS installed. I plan on setting up media, file and web servers, and even make the server hub for a custom written lab IoT project that I have been planning for years. Either way, the cabinet is just the beginning for my networking and software plans I have for the lab.

I strongly recommend you watch the construction video log I have made showcasing this project. It show a lot more on how I put this together and provides a more detail on the projects justification and evaluation.

That's all for now. Sorry again for not getting around to posting project blog posts after I complete them, it's been a very busy past few years at uni. Keep a look out for more project blog posts and videos soon.

 Building A Sound Proof Server Cabinet - Mechanical Construction

During the Christmas of 2018, I finally acquired a rack server to go in the lab. The purpose of this was to facilitate software projects and to acts as a general purpose PC for the lab (before I was just using my laptop). Despite the server doing everything I wanted to and more, it had one major drawback...

Enterprise grade hardware is always located in separate server rooms so they are designed without having to worry about noise level. To say the server fans are noisy is a grave understatement.

Without diving into the details, I tried a few different methods to quiet them down from software fan control to physically replacing the fans, but nothing I did worked. Instead I decided to design and build a custom server cabinet. The cabinet would not only be covered with soundproofing material, but it would also store the server properly (for the past year it just sat on the work surface) and provide rack space for more server hardware down the line.

I started by drawing up a design, looking at what wood I had, the size of the server and the size of the space I wanted the cabinet to go. I also did a fair bit of research and worked out the most practical way to sound proof the cabinet was to layer it with mass loaded vinyl. The design process was tricky, the cabinet had to keep all the sound inside while still letting plenty of cool air in and hot air out to stop the equipment from overheating. My design achieves this by taking in air through filters at the bottom back of the cabinet (tucked in the corner to reduce noise), pull it through an air corridor at the bottom, have it sucked up through the front of the servers where it will finally exit them and vent out the top back (also tucked in the corner to reduce noise).

I started construction during the summer of 2019, after I purchased my new belt sander. The first task was cutting and prepping the supporting wooden beams.

The main component that will make it a server cabinet and not simply a wooden box with a server in it was the front and back server server strip rails. You will find these rails in all server cabinets as they provide a common mounting point for all server cabinet hardware. Once those were screwed to the wood and spaced correctly, theoretically any server rack hardware should be compatible to mount in my cabinet.

I then started assembling the frame of the cabinet.

I then mounted a network switch to the strip rails, and used this to ensure the whole structure was spaced correctly before screwing it all together.

Time for the side panels. Unfortunately, none of my second hand recycled wood would do. I instead bought a huge new piece of MDF, which I still have a lot left over for other projects.

To make the cabinet mobile, castors were added to the bottom. This will allow the cabinet to be rolled out for hardware maintenance and upgrade with relative ease.

The next task was to make it sound proof. I cut a the big roll of mass loaded vinyl into sheets and screwed + glued them onto the inside of each side panel, floor and roof of the cabinet.

You can see in the last image that the sides of the bottom are raised up with wooden beams. When a flat piece of hardboard is placed across the top, it forms an air corridor with the inlet to the cabinet being at the bottom back causing the air to be delivered to the bottom front where the server intake fans are. This can be seen in the following images; the air exhaust holes can also be viewed at the back top of the cabinet. 

Filters were made using plastic tubs with screw on lids. Holes were cut in the lids and nylon fabric stretched over them to create a dust filters that can be replaced by unscrewing them.

Blank spacers were made to fill in the remaining rack slots such that the hot air from the back of the servers didn't mix with the cool air entering the front. These blanks will be removed as more hardware is added to the cabinet.

The back door was made using a simple wooden frame and an MDF panel. The front door utilized two layers of Perspex sheets such that the inside of the cabinet could be viewed but sound insulation was still maintained. Originally the doors stayed in place via a friction fit using protruding bolts. But this wasn't enough to create a good seal, so I instead embedded nuts into the cabinet frame, and essentially turned the bolts into large thumb screws that allowed the door to be screwed shut by hand.

After testing the server in the cabinet with the doors shut, I was confident that the noise was substantially reduced. The only problem was that heat built up faster than expected, which in turn caused the server to increase its fan speed leading to more noise. It was clear that I needed to increase air flow, so I repurposed the air outlets (white plactic tubs) as cable pass throughs, and cut out 3 new outlets holes behind them where I attached 3 PSU fans. Since these fans are quiet anyway, they enable heat to be vented faster without adding much noise.

It was at this point that construction stopped for 2019 (for various reasons). It would be the summer of 2020 before I resumed work on this. The next post will detail the cabling and networking side of the project.