FM Issue: Airing It All Out
By Joseph DuTemple, RCDD, and Charles DuTemple
Published in the February 2010 issue of Today's Facility Manager
The relentless demands of technology have created workplace conditions that can literally be sweating for employees. Filled with monitors, servers, and other heat producing technology, these cluster computing environments—particularly in manned situations like trading floors, emergency command and control centers, broadcast studios, and industrial control terminals—must comply with design requirements and ASHRAE standards that govern both human comfort and equipment cooling.
Removing heat generating components is at the core of the solution, and employing blade PC workstations is one of the most viable ways to accomplish this goal. (Facility professionals who are unfamiliar with this terminology can refer to Wikipedia definitions for “Blade PC,” “Blade Server,” and “Thin Client” to get a better sense of the energy saving aspects of these technologies.) By taking away the majority of the processing power from the user’s desk and transferring it into blade workstations located in the telecommunications room or data center, facility managers (fms) can reduce processing power and cooling requirements by up to 80%.
While the use of blade workstations does not entirely eliminate power and cooling requirements, it does shift these demands into the data center, where they can be more readily and efficiently handled. [For more information on equipment closet cooling strategies for small and medium sized organizations, see the accompanying sidebar.] Remaining at the user’s desk is a thin client device which communicates with the blade workstations and the desktop equipment, requiring less power and cooling.
Blade workstations are gaining popularity because of their ability not only to remove a significant heat source from the user’s desk, but also to fulfill a number of additional functions within the critical computing environment. The benefits can include the following:
- Less disruption. PC or monitor repairs can be disruptive to any worker. But in a critical location where downtime is not an option, there can be significant repercussions.
- When the processing power is relocated to the data center, blade workstations can be used remotely, without requiring the user to stop work and relocate. As a result, maintenance response times can be significantly reduced. Furthermore, blade workstation solutions can allow employees to access information from their blade from any thin client location.
Increasingly, small to moderate sized companies are housing their electronics equipment in converted closets. Such equipment is susceptible to malfunctioning or damage due to overheating, so keeping it cool is essential.
If the building is still in the design stage, a server room’s cooling requirements can be taken into account and a dedicated air conditioning system specified. However, this is often overlooked.
Since IT equipment is heat generating, and typically, the allocated space for it is very small, temperatures can rise quickly. Without air conditioning, there is a high risk of heat caused equipment failure, costly damage, and—even more costly—system downtime.
In some cases, precision cooling systems can help resolve this issue. Originally developed for large server rooms, these systems can be inefficient when used for smaller spaces such as server closets. They have other drawbacks as well, including their large size, the cost of installation, and their placement inflexibility.
There are two basic options: air cooled and water cooled. Since water cooled air conditioners are typically considered unsuitable for use with electronic equipment, air cooled systems will be the focus of the remainder of this article.
Most conventional air conditioners consist of two separate units, one containing a compressor and the other an evaporator coil. Air cooled spot air conditioners, on the other hand, are self contained, combining both a compressor and evaporator coil in a single unit. Within the unit, cold refrigerant flows through copper tubing from the compressor to the evaporator coil. A fan blows over the coil, pushing cold air out. A second fan pushes hot exhaust air out through the system’s built-in flexible ducting, which is usually directed into the crawl space above a drop ceiling. Excess moisture removed from the air collects in a small condensation tank, which can be emptied manually or, with most models, automatically via a pump.
Spot air conditioners are portable or ceiling mounted, but most server closets won’t fit spot air coolers. In these instances, a ceiling mounted model is typically the most practical choice.
Most importantly, ceiling mounted spot air conditioners are quick and easy to install. A typical installation usually takes two installers working together only about four hours.
Since spot air coolers are self-contained, precharged units, they do not require sweating and brazing of copper connecting tubes or refrigerant charging. And whereas precision cooling systems tend to be offered only in 230-volt configurations, some ceiling mounted spot air coolers come in 115-volt models.
Another advantage of spot air coolers is flexibility. With precision cooling systems, the supply register and return grill are fixed on the evaporator cabinet. As a result, the cabinet must be installed directly above the location where cool air is needed. In some crawl spaces, obstructions can make this difficult.
Ceiling mounted spot units have flexible air ducts for both supply and return, so they can be placed anywhere in the crawl space. Also, the location of the supply and return can be changed whenever necessary to eliminate any new hot spots that may result from equipment reconfiguration.
When critical electronics or telecom equipment is involved, air conditioning must be reliable. Fms need high quality systems to protect this essential aspect of operations.
Doran is senior manager, commercial and industrial systems, for Long Beach, CA-based MovinCool.
- Aid disaster recovery efforts. Thin client devices can access the blade workstations from any location regardless of proximity to the blade that serves it. Therefore, during an emergency, employees can access their blade workstations from an offsite location, reducing the time to recovery.
Thin client technology also allows critical computing environments to install their blade workstations in more robust facilities that may be remotely located, such as a corporate data center or co-location facility.
- Electrical redundancy and energy savings. Unlike standard PCs (which only have a single power supply), blade workstations have the ability to connect to redundant power supplies. This allows each blade workstation to be powered from separate electrical sources, providing increased reliability.
While it is not very significant in comparison to the amount of energy expended in the overall electronic environment, moving to a blade workstation can result in a slight reduction in power usage, due to the use of high efficiency power supplies employed in the blade workstations.
- Improved acoustics. The combined noise from multiple PCs, desk-mounted exhaust fans, and associated room air conditioning units can result in an undesirable working environment in critical computing environments. By removing these noise generating elements, blade workstations can improve local acoustics for employees. While the thin client remains, it generates minimal noise and doesn’t require significant cooling.
- Reduced infrastructure requirements. In critical environments, a typical desk setup requires a minimum of one cable between each PC and the telecommunications room. Most thin client devices can support two or more blade workstations using a single cable between the user’s desk and the telecommunications room. When employing blade workstations, the structural cabling requirements for PCs are cut in half, at the very least.
- Greater space efficiency. Removing PCs from critical environments allows more effective use of real estate. Desks no longer need to house multiple PCs, so the size can be reduced up to 40%. Additionally, the power distribution is simplified, requiring less space for electrical distribution equipment. This allows most, if not all, of the supplemental cooling to be removed from the environment.
When used at the desktop, blade servers can decrease supply loads and cut air conditioning requirements. Meanwhile, in the data center, these efficient devices can also cut expenses, since they consume significantly less power than more traditional equipment. Add this all up, and fms are left with efficient, quiet spaces that require less infrastructure. Meanwhile, users benefit from a cool climate, where the only things that can make them sweat are the demands of he day.
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