Rack knowledge
Server rack questions, answered properly
These are the questions we hear from installers, IT contractors and end clients before they order a rack: what U sizes mean, how to choose between wall and floor cabinets, how cooling and cable management actually work, and what ships in the box with every AV RACKS cabinet. Short answers, no sales voice.
01 / Sizing
Rack sizes and U heights
What does the U in 6U or 42U mean?
U stands for rack unit, the standard vertical measurement for 19 inch rack equipment. One U is 44.45 mm, or 1.75 inches. A cabinet described as 42U offers 42 units of mounting space, and equipment is sized in the same units, so a 2U amplifier occupies two of them.
What size server rack do I need?
Add up the U heights of every piece of equipment you plan to mount, then add spare units for ventilation gaps, cable management and future additions. A common rule is to leave 20 to 30 percent of the rack free on day one. AV RACKS cabinets come in 6U, 18U, 27U and 42U, so there is a sensible step at each project size.
What sizes do AV RACKS cabinets come in?
The range has four sizes: a 6U at 350 mm tall, an 18U at 1000 mm, a 27U at 1400 mm and a full height 42U at 2000 mm. All four share the same 600 mm wide by 600 mm deep external footprint in the 19 inch format.
Should I choose a wall mounted or floor standing rack?
Small racks are often wall mounted in risers and service cupboards to free floor space, while anything tall or heavily loaded should stand on the floor. The deciding factors are total equipment weight, wall construction and how much service access you need. If in doubt, put it on the floor: a floor standing cabinet never worries about its fixings.
02 / Build and cooling
Inside the cabinet
How do rack cabinets stay cool?
Electronics shed heat into the cabinet, and that heat has to leave. Fans move air through the enclosure and out, while spacing between hot equipment helps air circulate. Every AV RACKS cabinet includes cooling from the start: one fan in the 6U and two in the 18U, 27U and 42U. In hot climates such as the UAE, also think about the temperature of the room the rack lives in.
What is included with an AV RACKS cabinet?
Every cabinet ships with a UK standard aluminium shell PDU for power distribution, plus one cooling fan on the 6U or two on the 18U, 27U and 42U. Threaded mounting rails are standard across the range.
Why threaded rails instead of cage nuts?
Cage nuts are small sprung steel squares that have to be clipped into every mounting hole before a screw can bite, and they are fiddly, slow and easy to drop inside a loaded rack. Threaded rails have the thread cut into the rail itself, so equipment bolts straight in. AV RACKS cabinets use threaded rail holes as standard for exactly that reason.
Will my equipment fit in a 600 mm deep rack?
AV RACKS cabinets are 600 mm deep externally. Most AV and network equipment sits comfortably within that, but always check the depth of your longest unit and allow extra room behind it for connectors, power leads and cable bend radius before ordering.
How should I plan cable management in a rack?
Decide the routes before mounting anything: power on one side, signal and network on the other, with slack loops dressed at the rear so units can slide out for service. Label both ends of every cable. Ten minutes of labelling during the build saves hours of tracing later.
What is the difference between an AV rack and a server rack?
Structurally they are the same thing: a cabinet built to the 19 inch standard. The difference is what goes inside. An AV rack typically carries amplifiers, matrix switchers and control processors, while a server rack carries IT and network equipment. AV RACKS cabinets are used for both, and often for both at once.
03 / Buying
Ordering and delivery
Where can I buy AV RACKS cabinets?
AV RACKS cabinets are sold through Cache, the official distributor for the UAE and GCC, with stock held in Dubai. Order online at cache.ae, or message the team on WhatsApp at +971 58 541 2806 to have a rack sized for your project.
Do you deliver outside the UAE?
Yes. Cache distributes AV RACKS cabinets from Dubai across the GCC, including Saudi Arabia, Qatar, Kuwait, Bahrain and Oman, alongside delivery within the UAE.
Question not covered?
Send the Cache team your equipment schedule or a photo of the plant room, and they will size the rack with you. Or compare the four cabinets side by side, starting from the compact 6U up to the full height 42U.