How To: Choose A Server Rack


To the casual observer, server racks are their components are often indistinguishable from others rack. However, if you are considering investing in new racks, it is important to understand the distinctive differences between the variations of data center racks. If you need a synopsis on servers and server racks, read our Beginners Guide to Sever Racks

Open Frame VS Closed Frame

In your hunt for server racks, one of the first questions you should ask yourself, is whether or not you need an open framed rack or a closed frame rack (also referred to as server cabinet.) One of the most notable differences in the many rack types is whether or not the server rack is open framed or closed framed. Open frame is as the name implies, open. Open frame racks come in both 2-post and 4-post options. You can read more about the differences between 2 post and 4 post racks here

Open Frame Rack:


  • Cost Efficient- typically, open frame racks cost about one third as its equivalent counterpart in a closed frame option.
  • Air Flow- being, open frame-d, there is nothing to obstruct airflow from circulating through the rack. Keeping a constant access of ambient air flowing through your equipment.
  • Accessibility- again, being open, means easier accessibility to the equipment inside.


  • Security- being open framed (see a pattern here?) means all your equipment is exposed making it susceptible to theft. Not only that, buttons or wires might accidentally get pulled or pushed if somebody were to brush up against them
  • Dirt and Dust- dust is not conducive to the high-heat and high-functioning operation of server equipment. Having an open frame option will not protect your equipment from this type of debris
  • Organization- the open frame option has everything out in the open, including all cables, shelves, rails, and whatever other server rack accessories you choose to employ. If you value order and organization, the closed frame option might be a better fit for you.

Closed Frame Rack:


  • racksolutions data center rack cabinet enclosureSecurity- The closed frame option allows for your equipment to be locked up. Prohibiting unauthorized tampering and reducing accidental device damage
  • Organization– With this option, you can store all of your cables and accessories neatly inside your rack and have the appearance of a neat and organized box. This also reduces the risk of cables being accidentally pulled.
  • Air Flow Flexibility– the closed frame isolated heat sensitive equipment inside the frame. You have more control over where that air flows with the addition of fans and cooling accessories designed for closed frame racks.


  • Cost– typically, closed frame racks cost more than open frames due- in part -to the additional materials required to build the product.
  • Accessibility– the process of installing or maintaining equipment is trickier due to the obstructed nature of a closed frame rack. If you choose to use this type of rack, sliding rails and shelves for severs and other equipment is highly recommended.
  • Weight– with the additional materials, comes additional weight.

Size and Capacity

These differences are fundamentally rather minor, except that racks are open and cabinets are closed.  One of the main points of focus when you are choosing your server racks however, should be size and capacity. Server racks are sized in units classified as “U” space.  Each U represents 1.75″. So, a server rack that is 58U is 101.5″ tall. The rack height is significant for how much equipment that can be held inside, as well as how much power can be transmitted to equipment in the server storage device.


Mike Kendall, group manager of options and infrastructure for industry standard servers and software at Hewlett-Packard, told the news source the 19″ rack is widely considered a standard size for equipment storage.“There [are] a variety of racks available on the market, but the most common type you see in data centers is the 42U-high 600mm-wide rack, which is anywhere from 1,000 to 1,100 mm deep. These all support mounting of standard 19” IT products. Another common rack you’ll find in a data center is a 36U rack, but the trend is definitely moving towards 42U,” Kendall told a Data Center Journal.

RackSolutions Colocation Cabinet

While a 19″ rack with a 42U height may be the most common in the market, many companies will deploy larger server racks when they need to store equipment at higher densities. Furthermore, shorter racks are beneficial for organizations that require more space between the server rack and the ceiling.Server rack sales could be on the rise as a growing number of companies are investing in data center services. According to a recent RealPoints report, businesses are increasingly depending on mission-critical IT systems, leading to more investments in data center outsourcing services for everything from colocation to disaster recovery.

Taller racks also attribute to less data center space being used, equating to more money in investor/owner pockets. Check out our projections for the demand for taller data center racks in coming years

How To: Choose A Server Rack
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How To: Choose A Server Rack
If you are considering investing in new racks, it is important to understand the distinctive differences between the variations of data center racks.
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Open frame, wall mount, enclosed server racks