I bought a server rack. A proper one, 24U, steel, the kind with the square-hole rails and the little cage nuts that ping off into corners of the room you didn't know existed. It came off a company refresh for less than the cost of a meal out, and the man who sold it to me helped me load it into the car with the expression of someone watching a problem leave on someone else's insurance. I should have read that expression more carefully.
It lives in the garage. This is the first thing I'd tell anyone considering it: think very hard about where the noise and the heat go, because they go somewhere, and that somewhere is now a room you have to share with a lawnmower and your own decisions.
the noise
1U servers are loud in a way that does not come across in the listings. The fans are 40mm and they spin at the speed of a small jet because that is the only way to move air through a chassis that thin. One of them, idling, is a hairdryer. Three of them is a conversation you have to shout over. The garage is detached, which is the only reason I am still married, and even so I swapped the worst offender's fans for Noctua equivalents and accepted the slightly higher temperatures as the price of being able to think.
If your rack is going anywhere near a living space, buy quiet kit from the start or buy tower servers and stack them. The fan noise is not a quirk you get used to. It is a constant, and it is the thing that turns "I have a homelab" into "I have a room I avoid".
the heat and the damp
A part-full rack puts out a surprising amount of heat. In summer the garage became a sauna; in winter it became the only warm corner of the property, which sounds nice until you remember the other half of a cold garage in a British winter, which is damp. Warm electronics plus cold humid air plus the temperature swings of a space that isn't climate-controlled is a recipe for condensation, and condensation is a recipe for the kind of fault that turns up at 2am and clears itself by morning, leaving you nothing to debug.
I run a cheap dehumidifier in there now, on a smart plug, triggered off a humidity sensor. It is genuinely the most important thing in the rack and it cost the least. The lesson, if there is one: the environment is part of the system. You can have immaculate kit and immaculate cabling and still lose a disk to the weather.
the power
I had not thought properly about power, which in hindsight is embarrassing. A handful of older servers idling draw more than you'd guess, and the bill arrived to remind me that "spare hardware" is not free to run. I measured everything with a plug-in meter and was unpleasantly surprised: the rack was costing me a noticeable amount a month just to sit there being a rack.
So I did the unglamorous work. Decommissioned the two power-hungriest boxes and folded their workloads onto one newer, more efficient machine. Put the whole rack behind a UPS, not for uptime heroics but because the garage circuit is shared and the lawnmower's neighbour, the freezer, occasionally trips things. And I set up monitoring of actual draw so the number is on a graph and not a surprise on a bill.
# the boring measurement that changed my mind
# average draw before consolidation: ~310W
# after retiring two boxes: ~140W
Cutting it roughly in half made the whole project defensible again. Before that, I was paying a quiet monthly tax for the privilege of nostalgia about hardware.
The UPS taught me its own small lesson, incidentally. I bought it imagining dramatic power cuts and rode-out outages, and what it actually does, ninety-nine times out of a hundred, is absorb the brief brownouts and switching transients that a shared domestic circuit throws off when a big motor starts. The freezer kicking in used to be invisible; on the monitoring it turns out to be a real dip. The servers never noticed because the UPS ate it. That's the unglamorous truth of a lot of homelab kit: the value isn't the disaster you pictured, it's the steady stream of small ones you never see.
what made it worth keeping
Despite all of the above, I have not got rid of it, and I'm not going to. A real rack with real rails means everything has a place and slides out for service without unplugging the whole stack. The cabling, once I'd committed to doing it properly with a horizontal manager and labelled patch leads, is a genuine pleasure to work in compared to the nest of cables it replaced. And there is a real, unhuffy satisfaction in having a small, well-ordered system that you fully understand, top to bottom, because you assembled every layer of it yourself.
The honest summary is that the hardware was the cheap part and the easy part. The cost was heat, noise, damp and power, none of which the listing mentioned, all of which I had to solve before the rack was an asset rather than a liability. If you go for one, solve those four things first, on paper, before the car boot ever opens. The man who sold it to me knew all this. I just had to learn it the way I learn most things, which is the long way, in a cold garage, on a Sunday.