How Are Server Racks Measured? Explaining Server Rack Sizes

A server rack has long been a must of any modern telecommunication network. It stands as a guard of expensive equipment, which provides the required level of security. It can even be vandal-proof. Furniture pieces also successfully do not allow moisture, dirt, and dust to pass inside. Racks prevent expensive computing hardware from damage and malfunction caused by temperature changes.

Correctly selected telecommunication furniture is one of the guarantees of uninterrupted operation. Open-frame server racks are designed to provide an excellent opportunity to house the required equipment. They help make the SCS maintenance process comfortable and orderly. To achieve maximum efficiency and ensure convenient access to all operating parts, take a responsible choice of the model. Server racks come in a huge range of sizes, and there are a few general requirements that should be met by server furniture manufacturers. Thus, below, let’s find out the answer to the issue of “how are server racks measured?” and consider dimensions used in server equipment measurement.

What is the Width of Server Racks?

Firstly, let’s consider the answer to the question of “how wide are server racks?” Mostly the widths are 19 inches (600 mm) and 24 inches (800 mm), where 19-inch models are of the basic type and 24-inch products are extended ones. In 24-inch wide cabinets, it is easier to handle large wire bundles, the extra width can be used to install cable management systems inside furniture. Note that this width works well for data centers because their floor panels are usually 48 inches.

600-mm furniture is the most common and popular option due to its compactness. It perfectly fits both small rooms and large centers. However, in 800 mm cabinets, a large number of network cables can easily be placed between the side panels and the rails due to their internal capacity.

What is the Height of Furniture?

Height is the second important dimension. So, let’s proceed to answer the question of “how tall are server racks?”

The heights of network devices are measured in units. This avoids overlapping when determining the optimal height for the equipment you are planning to place inside. Pay attention to the calculation of the height in the units. Heights of all devices to be accommodated inside the product are added. Pay attention that this will give you the minimum height. In practice, you’ll need to add a headroom of several units. You will not be able to predict with certainty whether it will be necessary to expand your SCS in the future. In addition, such “useful voids” have a beneficial effect on the quality and efficiency of passive and active ventilation since they maintain the required climate conditions and improve air circulation inside the construction.

One unit is equal to 1,75 inches (44.45 mm). Thus, if you see “22U” or “12U” in the names of rack models, it means that the actual height of the furniture is 19* 22 or 12.

The most popular height terms include “42U server racks” or “seven-foot models”. These products are rather specific since the height of such models exceeds 2 meters, and not all premises can house them. They are capable of accommodating a lot of hardware. In such cases, 22U or 27U products are more suitable. They are spacious enough but are not so tall. Bigger models provide more flexibility since there have more opportunities for expansion.

An Example of Choosing an Optimal Height

In a 9U wall-mounted cabinet, you can place only 9 patch panels, each of them is 1-unit high. The model can freely house these devices since this passive hardware is classified as small. If you do

not plan to expand the data center in the near future, with the correct and high-quality organization of cables and equipment, you will get that very ideal option.

A completely different situation for your future SCS will arise if the apparatus suffers from quick heating during operation. Server enclosures often face overheating problems. For example, if you need to place 6 2U or 12 single-unit items, then a 19` 12U server furniture will never be the best solution.

Why? The answer lies on the surface. Free space between equipment and cables is required to efficiently exhaust hot air to the outside. Overheating can not only destabilize the entire system, but also completely render it inoperative. A 19` 15U network rack is more suitable here. If necessary, it will allow installing additional ventilation shelves, and free space will help passive cooling work for you.

Unfortunately, no one has yet managed to come up with an effective algorithm for choosing an “ideal server rack”. Thus, it is better to consult with an experienced system administrator.

What is the Depth of Server Models?

Depth is the third important criterion, so let’s answer the issue of “how deep are server racks?” As a rule, a depth ranges between 1000-1200 mm. Here, the thing is that complete and actual depths exist. You should take into consideration the actual indicator. It is measured from inner posts and usually a few centimetres less than a complete depth.

When calculating an optimal depth of the required model, note that about 2 cm from the front and rear sides of the mounted equipment should be left for cable routing and ventilation. Devices should not tightly fit the rack.

To conclude, note that you should have at least an approximate layout (and better a precise one) of hardware allocation inside the rack to calculate all three above-mentioned dimensions, pick the best model, and organize the system setup correctly.

To make the right decision and achieve an excellent result from the procedure for choosing the optimal server rack for your telecommunication network, we recommend that you first consult with specialists. They will help you not miss even the most insignificant, at first glance, trifles, so that you are satisfied with the result obtained for solving your problems.