Remember when Racks had glass front doors? They are now replaced with perforated doors which have as much as 83% open area for maximum airflow. Imagine how much air flow was allowed with a glass door. Thank goodness for technology. Today, some racks have no doors or even side panels. Some companies are doing this to allow for total airflow, their data center rooms are very cool though to start with.

SharkRack Rear Door Fans

Remember when the fans were only located on the top panel? Today, it is popular to to push the air from the back with cooling coils integrated on rear doors to promote "front to back" airflow. Also, the amount of cables used and the amount of power being used in a rack has also increased resulting in cables and clutter everywhere, which leads to a greater potential for airflow blockages within the data center rack. Because of this, rack depths have increased to 42" and even more than 48" in some instances to provide a deep server form factor to allow for all of those pdu's, cable management items and also increasing the airflow.

If we assume that all items relating to air blockage within the rack are constant, increasing the rack depth has a neutral effect on airflow. If we stretch the rack a little deeper to 42" or more we can then provide more room to exhaust air upward, as opposed to pushing it through the rear of the rack.

Although a rack that is 30" wide is common for networking applications with "side to a side" cooled switches, we have seen a trend for server rack width to stay at 24". However, it is still not uncommon today for 30" wide racks to be deployed in many server applications. The wider the rack the less airflow obstructions the customer will have, in most cases, by locating power distribution and data cables further away from a hot air stream.

Rack height is usually dictated by the size and shape of a room. The most common server rack height is around seven feet, which provides 42U of internal mounting available for rack-mounted equipment (1U=1.75"). Recently, we have seen a need for the marriage of networking equipment with servers in the same rack. This has pushed the rack to grow to a height of almost eight feet tall. This would be a 51U rack. When a rack is above 42U's we have seen it populated with networking switches, routers and patch panels. Higher racks can usually accommodate more IT devices. The SharkRack Great White Rack is a 51U rack and is in-stock and ready to ship.

SharkRack Great White Rack (51U)

By Carrie Schmelkin, TMC

As the cost of data center power continues to go up and the demand for more power increases exponentially, data center managers all over are looking for ways to make their data centers more efficient and enjoy cost savings. "Their interest in efficiency is really about saving money and cost," Server Technology's Senior Director of Software and Firmware Engineering Calvin Nicholson told TMCnet in a recent interview. "We like to believe that they want to save the earth and that they are green, and I think some of the California companies take that seriously, but in general it's because they see that it's really affecting their bottom line. "Because of that, there's a bunch of different areas where things have changed," Nicholson said. "They are looking at efficiencies of the devices that are in the data center. The UPSs that are on the data center floor have gotten a lot more efficient, and the power supplies and the servers and the devices have gotten a lot more efficient." Server Technology, a company that works to design, develop and provide the world's best power management products and system, has been a leader in the industry for the past 25 years. During that time, the data center industry has seen some definite changes including the fact that data center managers are overseeing more facets of the data center than ever before and the fact that virtualization projects have begun to gain momentum, Nicholson said. A few years ago, a manager may have been focused on just monitoring data center power consumption but managers have added other facets to what they monitor, particularly since managers are looking for ways to curb spending. For example, data centers are more concerned with environmental factors such as cooling. "In the data center, they use a huge amount of cooling through crack units and they are really starting to up the temperature that is allowed to go into those servers," Nicholson said. "They are actually not cooling the data centers as cold as they used to and that's to save money." "The drawback to that is with the densities going up and the temperatures going up if you do have a failure it can become much more critical much faster, so you do need to monitor," he added. The reason data center personnel are monitoring lots of different things more closely than ever is that they want to better understand where they are using power and where they could be more efficient. Companies like Server Technology, for example, rely on its Sentry Power Manager to measure, monitor and trend data center power usage. "We are monitoring power usage, we are monitoring the environmentals and we are rolling all that information into the Sentry Power Manger," Nicholson said. "Once the information is rolled up into that tool then there's a lot of different ways that the user can use that information. They can schedule reports so they can see what their power usage is, they can identify devices that are comatose or not doing any useful work and they can check those devices and/or turn those devices off." Companies like Server Technology have been increasing the scope of what they monitor and have also been considering the advantage of implementing virtualization projects.

The process of virtualization, another change to the data center industry, is designed to increase the efficiency of a data center by consolidating different servers. According to Nicholson, the majority of servers in a lot of the data centers today are running at 15 to 25 percent of their capacity but if one looks at a server and the amount of power it uses, roughly 40 to 50 percent of that power is used to just keep it on. "You have a cost just for that server sitting there and not doing the most efficient amount of work," Nicholson said.

Once a virtualization project is completed a manger can go from having 100 servers to 25, according to Nicholson. So are data centers more efficient then they were 10 years ago? Nicholson thinks they are. "Overall, the power usage has gone up but they are doing a lot more work, they are getting a lot more done and they are providing a lot more services with the power that is being used," he said. "I think they have gotten more efficient but the demand has gone up radically."