CAPITULO 5

CHAPTER 5

SITE SELECTION

“It is my belief, Watson, founded upon my experience, that the lowest and vilest alleys in London do not present a more dreadful record of sin than does the smiling and beautiful countryside.”

- Sherlock Holmes, by Sir Arthur Conan Doyle

When housing a data center in an existing building, several design issues must be considered to choose the best location. Careful planning is essential to assure that a location will meet not only immediate needs, but future needs as well. In the event that a building or area must be built to house the data center, there are even more considerations. The build-to-suit option typically offers more flexibility than utilizing an existing area, but careful planning is still essential. Looking ahead and planning the site and layout with forethought can save tremendous amounts of time, money, and aggravation. Poor planning often means costly upgrading, retrofitting, or relocating.
This chapter contains the following sections:

• “Geographic Location”
• “Data Center Site Selection”
• “General Site Considerations”

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Geographic Location

Choosing a geographic location for the data center could mean many things. Will the data center be housed in an add-on structure to an existing building? Will a separate building be built? Must property in a remote location be purchased and a new building be built? Will the center be located in a pre-existing building?
Aside from budget, there are several factors, many of which are described below, that should be considered when determining the location of a building site. Consider all of the possible problems with the area. Then, decide which of the problems are necessary evils that must be tolerated, which can be remedied, and which will involve building or retrofitting in such a way as to factor them out.
Potential problems in the geographic location might not be obvious. Resource availability and potential problems, whether natural or man-made, are critical issues and uncovering them requires careful research.

Natural Hazards

The most obvious of potential natural hazards are flooding, tornados, hurricanes, and seismic disruptions such as earthquakes and volcanic activity. If you must locate the data center in an area with a history of these phenomena, make sure you retrofit or build with these hazards in mind. Obviously, a determination must be made whether or not it is financially worthwhile to locate the center in an area with potential hazards. If the site can be set up in such a way that nullifies the problem (for example, in the case of earthquakes, using seismic restraints on the equipment), then it might be worthwhile.

Flooding

Consider whether or not the site is at the bottom of a hill that would catch rain or snow melt. Is the site on a flood plain? Is it near a river that might overflow? Is the site in the basement area of an existing location? While you are at it, you might as well consider tsunamis.

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Seismic Activity

Anything that shakes the building is bad for equipment. Is the potential site in an area that has frequent earthquakes, volcanic activity, or gigantic prehistoric lizards stomping about? What is the seismic history of the area? How often and how severe is the activity? What precautions can be used against the vibration and possible structural damage that can be caused by tremors?

Tornados and Hurricanes

As with seismic activity, what is the history of these phenomenon in the area? What measures can be taken to prevent them from causing damage to the facilities? Is it worth the risk?

High Winds

This might be a concern if you are locating the data center in any of the higher floors of a tall building. If you intend to put the center on the 57th floor of a building in downtown Chicago, you might reconsider unless the building is built to resist moving in high winds.

Temperature Extremes

It is important that data center equipment stay within a specific operational temperature range. In areas with extreme levels of heat or cold, it might be necessary to have more HVAC and insulation. In these areas, humidification is also a problem, and larger humidification units might be necessary. Larger HVAC systems might be worth the cost.

Fire

Though arson is a concern, fires can also occur naturally or accidentally. Consider the history of local fire hazards. Is the site near a wooded or grassy area? Are there lightning storms? Is the building fireproof or fire resistant? Can the building be designed or retrofitted to be fireproof? Can the center be located well away from any facilities where chemicals might create a combustion problem?

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Man-Made Hazards

Nature isn’t the only culprit in compromising the integrity of data centers. There are also many hazards created by man to disrupt your hard work. Some of them are described in the following sections.

Industrial Pollution

If possible, avoid locating the facility near major sources of industrial pollution. Look carefully at neighboring facilities such as:

• Factories
• Manufacturing facilities
• Sewage treatment plants
• Farms

If chemicals associated with these facilities migrate into the controlled areas of the data center, they can seriously impact not only the hardware, but the health of personnel. The chemicals used in the field treatment of agricultural areas can also pose a threat to people and machines. Though a natural problem, also consider sand and dust that might be blown into the center.
If you must locate in an area with these potential problems, consider this in your design plans for the center. Make sure you use a filtration system robust enough to filter out any local contaminants.

Electromagnetic Interference

Be aware of any surrounding facilities that might be sources of electromagnetic interference (EMI) or radio frequency interference (RFI). Telecommunications signal facilities, airports, electrical railways, and other similar facilities often emit high levels of EMI or RFI that might interfere with your computer hardware and networks.
If you must locate in an area with sources of EMI or RFI, you might need to factor shielding of the center into your plans.

Vibration

Aside from natural vibration problems caused by the planet, there are man-made rumblings to consider. Airports, railways, highways, tunnels, mining operations, quarries, and certain types of industrial plants can generate constant or intermittent

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vibrations that could disrupt data center operations. Inside the center, such vibrations could cause disruption to data center hardware, and outside the center, they could cause disruption of utilities.
If constant vibration is a problem in the area, you should weigh the possibility of equipment damage over the long term. In the case of occasional tremors, you might consider seismic stabilizers or bracing kits which primarily keep the racks from tipping over.

Emergency Services and Vehicle Access

Are fire and police services in close proximity to the site? What is their response time to the site? Emergency services also include support services such as emergency power generation, air conditioning vehicles, and network service providers.
It is important, particularly in congested urban areas, that there be unobstructed access and parking for emergency vehicles. All possibilities should be examined in the planning stages because emergency situations can and will happen. The personnel of one major company in Chicago was kept out of the building for two days due to a chemical spill from an overturned truck. At another major company, the main access road was blocked by fallen trees. There was no chain saw readily available, so no one could get into the center for a long time. Such situations should be considered in disaster planning, but comprehensive lights-out management can help mitigate such problems. So can having a chainsaw.
Beyond emergency situations, there should also be easy access to loading areas for large delivery vehicles. There should be plenty of room for the trucks to get in and out, pass one another, and to turn around.

Utilities

Make sure the district provides adequate power, water, gas, and any other necessary utilities. Are there redundant feeds from the electrical supplier? Is there an adequate Internet infrastructure in the area? Extreme rural areas might be more problematic in supplying the necessary utilities or assuring consistent uptime.

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Data Center Site Selection

Whether the data center will be a dedicated facility or part of a multipurpose building, the physical location is very important. Knowing the scope of the center is essential in making this decision, because many factors come into play. Flexibility is also key to the decision. All of the data center systems must be coordinated with the building systems for the overall support of operations.
The location of the center must be based on numerous criteria, including those discussed in the following sections.
FIGURE 5-1 Data Center Before the Walls, Raised Floor, and Equipment Are Installed

Retrofitting an Existing Site

Building to suit is not always an option. Locating the data center in an existing site could be very different than building a data center site to suit your needs. With an existing area, you must decide whether or not it meets the requirements of the company. Certain factors might make the area unacceptable, such as clumsy size, difficult access for large equipment or vehicles, the inability to control access, or overhead water pipes.

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If you are faced with making a choice between locations or determining the viability of a site, you should consider the following questions:

• What is the general layout of the area?
• Is there enough room for required equipment?
• What is the proximity of the area to chillers and condenser units?
• Is there adequate access for moving in and rotating large equipment?
• Where will HVAC units be placed? Inside the area? Outside?
• What are the possibilities for controlling access?
• Is the area isolated from contaminants and liquid leaks?
• Is there room for future expansion?
• Can walls be removed without creating structural instability?
• Can walls be added?
• Can a raised floor be added?
• Is the floor-to-ceiling height adequate for a raised floor, ceiling plenum, and equipment height?
• Will the existing subfloor be able to handle the weight load?
• Is there space for a separate Command Center?

Security

Not all businesses have a need for high-level security, but most businesses must make sure their data centers are secure from vandalism, industrial espionage, and sabotage. Make sure the potential area is situated so that access can be controlled. In a pre-existing building, check for problem areas like ventilators, windows, and doorways that lead directly outside or into an uncontrolled area. Could these openings be a breach to security? Can they be blocked or can access be controlled in another way? Can motion detectors and alarm systems be placed to increase security?
Some siting considerations might include:

• A separate control room and remote access to the systems to minimize the traffic through the data center.
• Locate the data center inside the existing building so there are no exterior windows or doors.
• Avoid sites with windows leading to uncontrolled areas.
• Design the area to limit and control access.
• Make sure the design includes surveillance cameras, motion detectors, and alarms.
• In situations where you must share data center space with other companies, an effective means of segregating the space should be considered.
• Make sure the design includes fast-acting fire control such as FM200.

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Also consider the possibility of vandalism by disgruntled employees and accidents that could be caused by the actions of untrained personnel.

Access

Aside from security access considerations, the potential site for the data center should be set up for the loading and unloading of large items such as HVAC units and computer racks. In the case where the data center is not in direct proximity to a loading dock, there must be a way to get bulky equipment to the site. It might also be necessary for small vehicles like forklifts and pallet jacks to have access.
Access considerations might include:

• Area for a loading dock
• Freight elevators
• Wide doorways
• Wide aisles
• Wide hallways
• Ramps at floor-level height changes
• Adequate turning radius space for racks and vehicles
• Adequate space at corner and column areas
• RLU design to ensure open pathways within the data center

Problem areas might include:

• Stairways
• Tight corners
• Low ceilings and overhangs
• Floors with poor load capacities
• Numerous changes in floor height
• Oddly shaped spaces
• No way to make the existing area secure

Raised Flooring

If the data center will have a raised floor, look at the space with some idea of what will be placed beneath it. Consider the following:

• How high can the floor be raised?
• Consider the amount of open plenum necessary to channel air for cooling. Too little space will cool inadequately, too much space will cool inefficiently.
• Are there structural items in place that might obstruct the free flow of air below the floor?
• How will wiring, cabling, and outlets be run?

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• Is a raised floor a viable option for the available space?
• With the reduced space between floor and ceiling, is there enough space to get heated air from equipment back to the returns of the HVAC units?

Isolation From Contaminants

Isolate the data center from contaminants or contaminant-producing activities. Avoid locating the center near print rooms, machine shops, wood shops, loading docks, and areas that involve the use of chemicals or generate toxic vapors or dust. Make sure the exhaust from generators or other sources of exhaust do not enter the intakes of air handlers serving the data center. If the data center must be located near these hazardous locations, adequate filtering systems must be added to the design. Also, maintenance schedules for the filtering system should be more frequent.

Risk of Leaks

Liquids pose another serious hazard to data center equipment. Despite precautions, water pipes and water mains can leak or burst. If you plan to locate the data center at a pre-existing site, make sure you know where all water pipes, valves, pumps, and containments are located. If pipes with flowing liquids are running through the ceiling, you might want to consider a different site. Also, will the data center be under floors occupied by other tenants who might have facilities with the potential of creating leaks?
If you must locate the center where there is a risk of leaks, make sure you design in a way to move water out of the room. Consider troughs under the pipes that are adequate to handle the water from a pipe failure and will carry the water out of the room without overflowing. Also make sure there is an emergency water shut-off valve readily accessible in the event of a pipe failure.

Environmental Controls

The type of air conditioning system chosen for the data center, and the location of the units, might determine the viability of a location. Chilled water units must be connected to chillers located in the building or an adjoining support facility, and might require cooling towers. Due to noise and structural issues, chillers are usually located in a basement, separate wing of the building, on the roof, in a parking lot, or in a separate fenced-in area. Direct expansion air conditioners require condenser units located outside the building. Also, the roof or outside pads should be structurally adequate to support the condensers.

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Room for Expansion

Anticipating future expansion needs can be a challenge since it is difficult to predict future trends in equipment. As technology advances, it tends to make hardware more space-efficient (though more power and cooling consumptive). Over time, you might fit more equipment into less space, avoiding the need for more floor space (though it might necessitate more power and HVAC capacity which would need floor space). Also, networking allows for expansion in a different place inside the building or in a nearby building. Another separate data center can be built, can be connected logically to the other networks, and therefore to machines in the original data center.
If the need for more space is anticipated, consider this in your plans. Try not to land- lock the center. If building an addition to the existing structure will eventually be necessary, consider how the new area might share the existing support equipment, like chilled water loops, security, etc. If expansion is likely and budget allows, consider putting in the addition with raised floors and using the space for temporary offices or storage.

General Site Considerations

As with any aspect of data center design, the number of questions you can ask yourself about site selection can be almost endless. As food for thought, the following sections list a few questions and ideas you might consider for both geographic (district) and specific (room) locations.

Geographic and District Criteria

Where in the world will the data center be located? Many geographic factors must be considered in the placement and design of the data center. Will the system be installed on the 56th floor of a high-rise in earthquake country? Are there enough skilled people in the local hiring pool? Is there adequate power, or will it be necessary to build a power generator? Consider the following:

• What is the local hiring pool like?
• Does the district offer adequate technical employee resources?
• Is the area conducive to employee relocation? Will employees want to live there for a while?
• What is the local power situation?
• Is there adequate power? Are there redundant grids?
• Historically, how often does the power fail? For how long?
• Is there adequate connectivity to the Internet or intranet? Does such an infrastructure exist?
• How many lines of the type needed (for example, T1 or DS3) are available? How soon will they be available?
• What types of local services are available? Is there access to adequate bandwidth?
• Is there a history of natural disasters in the area?
• Are there earthquakes?
• Are there tornados or hurricanes?
• Is there runoff from rain and/or snow melt?
• Will flooding be a problem?
• Are there lightning storms?
• How cold does it get? How hot?

Data Center Area Criteria

The area is the specific location, the room or rooms, possibly even multiple floors, that will become the data center. Consider the following:

• Is the data center area protected from weather and seismic problems?
• Is the area safe from flooding (not near a river that overflows, in a flood plain, at the bottom of a hill)?
• How will the data center be used?
• Will it be used for production, testing, information access?
• Will equipment or racks be rotated?
• How available must the equipment be (how often online)?
• What security level must there be for data center access?
• Will there be a separate Command Center? Will it be in a separate location than the data center? Where?
• What area is available? What is its shape (round, rectangular, square, L-shaped, T-shaped)?
• How will the area be divided? Consider walls, storage, a Command Center, offices, other rooms, loading docks, etc.
• If built within a multi-level building, what floor or floors will be included and what parts of them are available?

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• Is there enough width in the corridors, aisles, doorways, etc. to move large equipment and vehicles?
• Are floors, ramps, etc. strong enough to support heavy equipment and vehicles?
• Is there a nearby loading dock? Is it on the same floor?
• Is a separate site needed for loading, unloading, and storage?
• How much room is left for data center equipment?
• Are there freight elevators? How many?
• Are there passenger elevators? How many?
• Is the area safe from seismic activity (earthquakes, hurricanes, high winds)?
• Are there any water system (bathrooms, kitchens) or pipes above the area?
• Are there necessary facilities such as restrooms and break rooms available?
• Is food available, even if from a vending machine? This is important for people working late or in emergency situations where leaving the area for long periods of time is not possible. Consider a small kitchen in a Command Center.

BIBLIOGRAFIA:

Enterprise Data Center Design and Methodology, Snevely Rob (2001).