How to select a cabinet
Choosing the right housing for your IT infrastructure is more than just a storage decision – it is a critical factor in hardware longevity, network performance, and physical security. Whether you are setting up a small office network or a high-density data centre, this guide provides the expert advice you need to select the perfect cabinet.
Understanding the Core Differences: Server vs. Data Cabinets
Before diving into dimensions, it is essential to understand which category of cabinet your project requires. While they look similar, their engineering serves different purposes.
- Server Cabinets: Built for active hardware. These are typically deeper (1000mm+) and feature mesh doors to facilitate front-to-back airflow, preventing high-performance servers from overheating.
- Data Cabinets: Designed for networking equipment like patch panels and switches. They are usually shallower (600mm–800mm) and often feature glass doors for noise reduction and aesthetic appeal in office environments.
Key Specifications: U Height, Width, and Depth
To ensure your equipment fits and remains accessible, you must calculate three primary dimensions.
1. Rack Height (U Space)
Equipment height is measured in Rack Units (U), where 1U = 44.45mm.
- Small Installations: Wall Mounted Cabinets (2U to 21U) are ideal for limited floor space.
- Enterprise Setups: Floor-standing units (usually 24U to 47U) provide room for growth.
- Search Intent Tip: Always allow 20% “growth space” for future hardware to avoid the cost of a full rack migration later.
2. Cabinet Width (600mm vs 800mm)
- 600mm Wide: The standard for most server applications where space is at a premium.
- 800mm Wide: Highly recommended for Data Centre Racks. The extra 200mm provides vertical “alleys” for intensive cable management, ensuring cables don’t block airflow.
3. Cabinet Depth
Measure your deepest piece of equipment (usually a server) and add at least 100mm–150mm for cable bend radius and power connectors.
- Standard Server Depth: 1000mm or 1200mm.
- Networking Depth: 600mm or 800mm.
Quick Comparison: Selecting Your Cabinet
| Feature | Data Cabinet | Server Cabinet |
| Primary Use | Patching & Switches | Active Servers & UPS |
| Typical Depth | 600mm – 800mm | 1000mm – 1200mm |
| Door Type | Glass or Solid Steel | Perforated Mesh (Airflow) |
| Load Capacity | Medium | Heavy Duty |
| Cable Management | Side & Rear | Extensive Vertical Alleys |
Essential Accessories for a Professional Rack Build
A cabinet is only the foundation. To complete your installation, consider these essential add-ons:
- Cabinet Shelves: For non-rackmount equipment like routers or monitors.
- Power Distribution Units (PDUs): Ensure stable power delivery to all devices.
- Fan Units: For active heat extraction in enclosed data cabinets.
- Cage Nuts & Bolts: Never forget to stock up on the hardware required to mount your gear.
Side Panels and Physical Security
While side panels are often optional in secure, climate-controlled data centers, they are essential for managing ventilation and restricted access.
Without doors or sides, a cabinet functions similarly to an Open Frame Rack. However, a key advantage of choosing a cabinet is flexibility; you can add lockable doors or side panels later to enhance security, a feature typically unavailable on standard racks. Additionally, high-quality cabinets feature adjustable mounting rails, allowing you to customize the internal depth for specific hardware—a level of versatility usually not found in a four-post rack.
Environment Protection: Moisture and Dust Resistance
If you are deploying IT hardware outside of a pristine data center such as on a factory floor or in a warehouse—environmental protection is non-negotiable. You should prioritize cabinets with a NEMA rating.
Understanding NEMA Ratings for Data Cabinets
The National Electrical Manufacturer’s Association (NEMA) defines the standards for enclosure protection. Common ratings include:
- NEMA 12: Built for indoor use. These protect against falling dirt, circulating dust, lint, and dripping non-corrosive liquids (including oil or coolant seepage).
- NEMA 4X: These are heavy-duty, weatherproof enclosures. They protect against windblown dust, rain, and hose-directed water, and offer superior corrosion resistance for indoor or outdoor use.
Logistics: Pre-Assembled vs. Flat-Pack Cabinets
When ordering, consider the physical journey the rack must take to its final location.
- Pre-Assembled Cabinets: Best for rapid deployment. Your equipment can be loaded as soon as the unit arrives.
- Flat-Pack Cabinets: Ideal for locations with narrow doorways, tight stairwells, or limited elevator space. While they require on-site assembly, they solve the logistical headaches of restricted access.
Power Provisioning and UPS Integration
Modern cabinets require robust power solutions to prevent downtime.
- Rackmount PDUs: Choose between horizontal strips or vertical (0U) Power Distribution Units. Vertical PDUs save valuable rack space but require a cabinet with compatible mounting brackets.
- Uninterruptible Power Supplies (UPS): Always account for the weight and “U” space of a Rackmount UPS. Because of their significant weight, UPS units should always be mounted at the very bottom of the cabinet to maintain a low center of gravity and prevent tipping.
Advanced Cable Management
Effective Cable Management is the difference between a high-performing network and a maintenance nightmare. To avoid “spaghetti cabling,” plan your horizontal and vertical pathways in advance. Knowing the exact location of your equipment connectors allows you to place organizers and raceways where they are most effective, ensuring clear airflow and easier troubleshooting.
Data & Server Cabinet Selection: Frequently Asked Questions
1. What is the standard depth for a server cabinet vs. a data cabinet?
A standard Server Cabinet typically requires a depth of 1000mm or 1200mm to accommodate deep rail-mounted servers and cable management. In contrast, a Data Cabinet used for patching and switches is usually shallower, ranging from 600mm to 800mm. Always measure your deepest device and add 100mm for cable clearance.
2. Should I choose a glass or mesh door for my rack?
If you are housing active, heat-generating equipment like servers, perforated mesh doors are essential for front-to-back airflow. If you are installing noise-sensitive networking gear or patch panels in an office environment, a glass door provides a sleeker look and reduces acoustic noise, provided there is adequate side or fan cooling.
3. How do I calculate how many Rack Units (U) I need?
One Rack Unit (1U) is 44.45mm (1.75 inches) high. To find your requirement, total the “U” height of all your equipment (servers, switches, UPS, and patch panels) and add at least 20-30% extra space for future expansion and cooling gaps.
4. Can a 42U floor-standing cabinet fit through a standard doorway?
Most 42U cabinets stand roughly 2000mm high. Since a standard UK office door is often 1981mm, height can be an issue. If your access is restricted, we recommend a Flat-Pack Cabinet which can be assembled in situ, or choosing a shorter 39U unit.
5. What is the difference between 600mm and 800mm wide cabinets?
Both widths use the standard 19-inch mounting rails. However, an 800mm wide cabinet provides an extra 100mm on each side of the rails. This space is critical for high-density Cable Management, allowing you to run large bundles of Cat6a or fibre vertically without blocking equipment airflow.
6. Do I need a NEMA-rated or IP-rated cabinet?
If your cabinet is located in a warehouse, factory, or damp environment, you need an enclosure that protects against dust and moisture. A NEMA 12 or IP54 rating ensures your delicate electronics are shielded from falling dirt, dust, and light liquid splashes that would bypass a standard ventilated office rack.
7. Why should I install my UPS at the bottom of the rack?
Safety and stability. An Uninterruptible Power Supply (UPS) is usually the heaviest component in the rack. Placing it at the bottom keeps the centre of gravity low, preventing the cabinet from becoming top-heavy and potentially tipping over when a server is extended on its sliding rails.
8. What is the benefit of a 0U PDU over a horizontal PDU?
A 0U PDU (Power Distribution Unit) mounts vertically at the back of the cabinet, meaning it occupies zero rack units of mounting space. This allows you to use every available “U” for your servers and switches while providing easy power access to every level of the rack.
Summary:
This guide covers the essential keywords for IT infrastructure, including Server Cabinets, Data Racks, U height, rack depth, mesh doors, and cable management. Whether you need a wall-mounted cabinet for a small office or a floor-standing server rack for a data centre, we provide the expert advice and delivery options to get your project moving.