19” IT Server Rack Width May Be ‘Standard,’ but There Are Variables to Consider

Most data center equipment is 19 inches (482.66mm) wide, including the “ears” that allow for mounting inside a server rack. Although there are some variations, this standard provides consistency in the data center infrastructure design and greater operational efficiency.

The “standard” IT server rack width is designated as “19 inches” in relation to the IT equipment. However, that doesn’t correspond to the physical width of the rack — it refers to the measurement from edge to edge of the equipment mounting flange. 

The minimum inside opening of the mounting flange is 17-3/4 inches (450mm), and the distance between the center of the mounting holes is 18-15/16 inches (465mm). The Electronic Industry Alliance (EIA) established all of these standards and are maintained by the International Electrotechnical Commission in document IEC 60297-3-100.

Most server racks are about 24 inches (600mm) from edge to edge, leaving space between the cabinet frame and equipment for airflow and cables. Some racks are 29-1/2 inches (750mm) or 31-1/2 inches (800mm) wide, leaving more room for cable management, wider IT equipment, and equipment that uses side-to-side rather than front-to-back cooling.

These variances make it difficult to maintain that all-important consistency in the data center environment. Data center managers must carefully consider current and future requirements when selecting the width of server racks. IT server rack depth is also a consideration, discussed in a recent blog post. 

Types of IT Server Racks

The term “rack” is often used to refer to both open server racks and enclosed cabinets. Traditionally, open server racks are used for networking gear, while cabinets are used for servers, storage, networking, and other equipment.

Network Racks

Open racks consist of vertical mounting rails without sides or doors. They provide airflow and easy access to equipment, but they aren’t secure and do not protect against dust and other contaminants. There are two basic types: two-post and four-post. Two-post racks require less depth than four-post racks but cannot support heavy equipment. They should be bolted to the floor for stability. Generally, networking racks should be at least 29-1/2 inches (750mm) wide to accommodate network cabling trunks.

Cabinets

Enclosed server rack cabinets have front and rear doors and side panels attached to the four vertical mounting rails. Because the doors and side panels can be locked, cabinets are suitable for colocation facilities and areas without physical security. However, cabinets require ventilation to ensure adequate airflow and cooling. Server racks should be 24 inches (600mm) wide but have sufficient depth to accommodate deeper equipment and provide room for power distribution and cable management in the back of the cabinet.

Other Considerations

When selecting a wide rack, it’s essential to ensure that the open space between the side and rails is sealed to prevent cold air leakage and hot air recirculation. Adjustable, tool-less mounting rails save time when installing equipment.

Server Racks from Enconnex

Enconnex offers server racks and cabinets in 24-inch (600mm) and 31-1/2-inch (800mm) widths. Both widths are available in heights ranging from 24U to 52U and depths ranging from 39 inches (1000mm) to 47 inches (1200mm). Every server rack is manufactured to our exacting specifications to ensure the highest levels of quality and durability. Enconnex cabinets are UL-listed and tested to have a static load capacity of 1500 kg and a dynamic load capacity of 1200 kg. 

Our stocked warehouse and quick shipping allow us to get quality racks in your data center faster. Contact one of our server rack specialists for help in selecting the right solution for your use case.