As customers’ appetite for data increases, data centers’ reliability, throughput, and complexity are scaling to match it. While this is not a new development, the rapid growth of data consumption means organizations must constantly evaluate their systems’ efficiency and performance. Central to that are the service racks that house servers and switches while keeping cables organized and airflow unimpeded. While organizations have many off-the-shelf options, custom server racks ensure optimal application and facility usage.
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The Basics of Server Racks
A rack is an essential and often overlooked element of system integration. While it’s the inside that counts when it comes to actual networking, racks play a vital role in thermal management, organization, and routing. Like the systems they support, racks are not one size fits all. However, there are some standards governing their design that ensure applicable rack equipment is viable across many different off-the-shelf and custom server rack models:
- Horizontal and vertical spacing of mounting holes.
- Size of the equipment cabinets.
- Rack width is 19 inches (except for some telecom equipment).
Manufacturers typically describe rack height by rack units. For example., a 28U rack supports any arrangement of 28 standard switches or servers. A rack unit is 1.75 inches tall, but note that the measured height of the rack is greater than the rack unit height multiplied by the number of units, as there’s space between each rack for ventilation and routing.
There are three general models of racks available:
- Open frame racks – Mounting rails without sides or doors. Open frame racks are highly accessible, which makes them beneficial for applications with especially dense cable routing. However, they provide no security or physical protection, and while the lack of a frame maximizes ventilation, it does not support active cooling solutions. Models can have two or four posts for support; note that two-post racks may not support the weight/depth of equipment designed for four-post racks.
- Enclosure racks – Enclosure racks have removable sides and doors, allowing easy access while providing greater protection than open-frame racks. The front and back doors typically contain ventilation to improve airflow, making them ideal for higher-power server applications. Locking doors and panels also offer security at the rack level (rather than just the room). Finally, enclosure racks are configurable as an analogous open frame by removing all sides and doors while supporting greater equipment weight.
- Wall-mount racks – The most space-conscious choice, wall-mount racks are suitable where floor space is at a premium. They cannot support as much weight as either open-frame or enclosure racks, but they are versatile (especially with added casters for a rolling rack configuration).
Determining Custom Server Racks’ Requirements
With numerous options available, technicians and managers may be unsure which rack best meets their needs. Start with these basic dimensions:
- Height – As mentioned, manufacturers express rack heights in rack units. Common rack heights range from 42U to 48U, but custom heights are available. Some operations may want to reserve some height for cable breakout/management or future expansions. Lastly, don’t forget that the rack height is often not the same as the measured height; ensure that there’s enough space in the room/doors of the facility to transport and install the server rack.
- Width – Since racks have fixed rail widths to comply with industry standards, most racks measure 24 inches (intentionally, this matches the width of removable floor tiles in a data center). However, extra-wide racks of 30 inches are available for managing cables side-by-side with the switches or servers. Extra-wide racks may even support higher-density switch/server integration with side-by-side placement.
- Depth – Racks must be deep enough to support equipment (including cable breakout); the standard depth is 42 inches, but deeper and shallower rack options are available. Note that equipment has to fit within the adjustable depth — most racks limit the shallowness of installed equipment. Conversely, shallower racks are available that save on space, with wall-mount racks able to achieve depths less than a third of some floor-standing units.
The weight of the fully furnished rack is also a critical concern. Load ratings indicate the maximum weight a rack can support, but the floor (or wall/fasteners for wall-mounted racks) must also exceed this load rating to prevent damage or failure. Along these lines, the facility should serve as the first and final consideration for server rack applications. The following questions can help guide rack selection or customization that harmonizes application to surroundings:
- Can the room support all the racks necessary (now and in near future expansions)? Is it easily accessible (no stairs, wide doors, etc.) for installation? Are heat sources nearby (including outside but near the room)? Does the room’s power capabilities (voltage and current) meet the needs of the servers during a theoretical maximum draw? Is it easy to route cables into and out of the room? What options does the room have for eliminating heat?
- Where will power circuits and cooling be in the room? To minimize recirculation, is it possible to arrange the racks side-by-side and alternate front-front/back-back facing?
- Is the server rack placement easily accessible for maintenance? Is the heaviest equipment placed toward the bottom of the rack to encourage stability and prevent tipping? Does the placement of equipment within the server rack impede heat dissipation?
Your Contract Manufacturer Builds Better Infrastructure
Custom server racks help bridge the gap between optimal facility/system design and standard networking equipment. For IT and similar roles, off-the-shelf racks may require significant concessions or changes to the system that incur downtime. Instead, let VSE handle your custom server rack requests. Our engineers are committed to building electronics for our customers, including many enclosures that comply with industry standards. We’ve been realizing life-saving and life-changing electronic devices for over forty years with our manufacturing partners.
