Top Considerations When Buying A Server Rack

Understand your cooling strategy for server racks.

With the heat produced by today’s denser technologies, such as Blade Servers, it’s critical to understand the function of server racks in your overall data center cooling plan. The cooling techniques utilized in your environment will determine the kind of rack you choose. The baseline kW of heat output per rack varies significantly depending on the kind and density of equipment, and may range from 4 kW to 12 kW or more per rack, with some experts predicting that the development of high-density settings and future equipment designs will result in a 30-50 kW per rack output.

Fully Perforated Server Racks: If ambient air cooling (fans, air handlers, blowers, and/or Computer Room Air Conditioning (CRAC) units with a raised floor) will be the main means of cooling in your data center or server room, choose a fully perforated rack for optimum air flow.

Fully-Sealed Server Racks: If a liquid cooling unit or rack air conditioner will be utilized in your environment, choose a fully-sealed rack.

Liquid Cooling & Rack Air Conditioning

As power-intensive applications and server densities have grown, Liquid Cooling Units (modular, temperature-neutral high-density cooling systems that use air/water heat exchangers to deliver uniform, effective cooling) are increasingly being utilized. The fact that self-contained liquid cooling systems have little or no effect on the current HVAC system is one of its major advantages. Liquid cooling units are installed at the rack base in a rack “side car,” with up to three cooling modules per equipment rack and a total cooling capacity of 30kW.

In conventional data center settings with appropriate CRAC systems, rack air conditioners are seldom utilized. Rack air conditioners are utilized when IT equipment is located outside of a regulated data center environment, such as in a warehouse or factory. Remember that rack air conditioners are designed for use in industrial and big areas, that they produce condensation and noise, and that they vent hot air into the room where the enclosure is placed.

The heat will disperse in a big space. The hot air from the AC unit may cause the area to overheat in a smaller room or confined place like a closet. If an air conditioner is utilized in a small space, special steps must be taken to exhaust the hot air. The level of cooling output provided by air conditioner types varies, so choose one that meets your requirements.

Here are some formulae to assist you estimate a rack’s heat load and choose the right size air conditioner:

Add up each device’s wattage and convert it to BTUs (the wattage is typically listed in the device’s handbook). Wattage may alternatively be calculated using the formula (Watts=Volts X Amps), where 1,000 Watts equals 1kW. (5)

Consider that every 1 kW used generates about 3,400 BTU when using a rack air conditioner. Because air conditioners have various BTU ratings, choose one that will offer sufficient cooling for the anticipated BTUs produced.

Rack Airflow Suggestions

Using blanking panels to control air flow efficiency, choosing a rack with built-in channels for better cable management and increased air flow, and eliminating any outdated or unneeded equipment from the rack are also other methods to enhance cooling. Consider that 3-phase power may substantially boost available amperage in the server rack, decreasing the total number of PDUs required to power equipment and allowing for greater ventilation.

Placement of Server Racks in a Data Center / Server Room

Rising energy prices are forcing many businesses to reassess their IT strategies and adopt energy efficiency best practices to minimize power usage. Increase existing cooling capacity with proper design, including hot/cold isle containment techniques, controlling present and prospective hot spots, and continuous monitoring of heat dissipation in your data center. Grommets are also essential for sealing cable holes on the elevated floor.

Take into account the most recent power technologies

PDUs (Electricity Distribution Units) provide power to servers equally throughout the whole power strip. Rack mount power strips are designed especially for server racks and may be mounted vertically or behind mounting posts in the cabinet’s rear. There are two types of power strips: regular and intelligent.

Standard power strips offer several useful features, such as fuse replacement indications and current output monitors, but they must be handled in person and on-site. Intelligent power strips, on the other hand, offer remote power control, allowing administrators to conduct a cold reboot of servers and devices as well as diagnose issues from any place with an internet connection, minimizing server downtime and restoring critical business operations fast. Remote power solutions not only offer intelligent management of connected equipment, but they also enable administrators to take advantage of cutting-edge power distribution technologies like 3-phase power.

Although three-phase power technology is not exclusive to remote power management devices, it may be accommodated or incorporated into various systems. 3-phase power utilizes fewer circuits, offers a better balanced power load, lowers the total number of PDUs required to power equipment, and substantially boosts available amperage into the server rack when compared to single-phase power. In a typical rack setup, for example, four 20-amp circuits are needed for 64 amps of available power (assuming a maximum 80 percent load).

A 3-phase circuit, on the other hand, may provide up to 51.6 amps per circuit, or more than 82 amps of usable power, with just two circuits required (assuming a maximum 80 percent load). The cost reductions of 3-phase power are advantageous, particularly because experts predict that energy prices will increase from their present levels of 10% or less of IT expenditures to 20-30% in the future. The amount of outlets you’ll need, plug/receptacle needs, and redundancy requirements are all things to consider when it comes to electricity.

Choose a Rack That Is Appropriately Sized

Choose a server rack with enough interior capacity to fit your existing equipment, as well as enough room to support planned future growth and any unexpected equipment acquisitions. The Electronic Industries Alliance (EIA) standard “Rack Units” or Rack “U” is used to measure rack mount devices. The height of one “Rack Unit” is 1.75″. Keep in mind that additional space may be required for peripherals such as environmental monitoring devices, remote power control devices, rack mount LCD displays, and battery backup. If you need to handle 20 2U servers, for example, you’ll probably want to go with a 44U rack to include peripherals like a 1U patch panel and a 2U UPS backup battery.

The interior height of a rack is measured from the highest point of any side rail to the bottom chassis; the internal depth is measured from the insides of both front and rear doors; and the internal width is measured from one side panel to the next. Make that the rack’s exterior dimensions fit in the available floor space, that it can be safely moved through all doors, and that its placement complies with any applicable clearance or safety requirements.

Always use proper rack-loading techniques, such as placing heavy items at the bottom of the rack to keep it from becoming too top-heavy, having a plan for what you want to put in the front and back of the rack (based on how much you will need to access or remove equipment), and having someone assist you with equipment that is heavy and/or above your head height. (1)

Physical Safety Begins Here

Security is critical to your business’s general well-being and operation. It’s just as essential to understand how your server rack fits into your entire security plan. There are many steps you can take to enhance the security of your data center’s racks and equipment. To begin with, consider purchasing server racks that have locking front and rear doors, as many models offer this option. Smart Card – CAC access control may be available on certain modern racks.

Second, utilize environmental monitoring equipment to keep an eye on your racks on a regular basis. Several environmental monitoring devices have door sensors that support “normally open” or “normally closed” conditions and can alert administrators when a cabinet dries out.

In addition to allowing administrators to continuously monitor amperage draw per circuit, water leaks, temperature, and other variables, and sending alerts automatically via SMTP/SMS/SNMP when conditions exceed established thresholds, several environmental monitoring devices have door sensors that support “normally open” or “normally closed” conditions and can alert administrators when a cabinet (The gadget communicates a “error” condition when its status changes in relation to its specified threshold.)

There are other gadgets that operate with connected camera pods and sensor pods to enable administrators to keep an eye on server racks and rooms while also recording audio snippets. If you’re constructing a new data center, you should think about adding physical security features like building it away from a busy road, reducing the number of windows, and providing secure entrances and exits.

Customize Your Rack Design to Fit Your Needs

Most manufacturers will let you choose from a variety of choices to ensure that your server rack fits your environment’s particular needs. You should be able to choose from a variety of choices in many common areas.