CDCS Exam Dumps - EXIN EPI Certified Data Centre Specialist

SHR = Sensible Load / (Sensible + Latent Load); it describes the portion of the total cooling that is sensible (temperature change) versus latent (moisture removal).

A Power Usage Effectiveness (PUE) of 1.20 (achieved by Data Center B) indicates the highest facility efficiency among the three data centers. A lower PUE value signifies better energy efficiency, as it means that a greater proportion of the total energy consumed is used directly for IT equipment rather than for cooling, lighting, or other facility needs.

Detailed Explanation:

PUE is calculated as the ratio of total facility energy to IT equipment energy. A PUE close to 1.0 suggests that almost all the energy is dedicated to computing processes, with minimal overhead. With PUE values of 2.45, 1.20, and 1.90, Data Center B (1.20) operates most efficiently by devoting a higher percentage of its total energy to IT equipment.

EPI Data Center Specialist References:

The EPI curriculum emphasizes PUE as a key metric for data center efficiency, with lower values representing better performance. Achieving a PUE near 1.0 aligns with industry best practices for energy-efficient data center design and operation.

The amount of FM200 gas required can be calculated using the formula:

Weight of Gas=Net Volume×Design Concentration×S-Factor\text{Weight of Gas} = \text{Net Volume} \times \text{Design Concentration} \times \text{S-Factor}Weight of Gas=Net Volume×Design Concentration×S-Factor

Using metric units:

Net Volume: 2,500 m³

Design Concentration: 7% (or 0.07)

S-Factor: 0.1359

Calculation:

2,500 m3×0.07×0.1359=821.325 kg2,500 \, \text{m}^3 \times 0.07 \times 0.1359 = 821.325 \, \text{kg}2,500m3×0.07×0.1359=821.325kg

Rounded to the closest answer: 820 kg

In imperial units:

Net Volume: 88,287 ft³

S-Factor: 1.885

Calculation:

88,287 ft3×0.07×1.885=1,165.27 lbs88,287 \, \text{ft}^3 \times 0.07 \times 1.885 = 1,165.27 \, \text{lbs}88,287ft3×0.07×1.885=1,165.27lbs

Rounded, this is approximately 1,800 lbs.

EPI Data Center Specialist References:

EPI instructs on using specific formulas and S-factors provided by manufacturers for each gas type, ensuring that calculations reflect the correct concentration for the given room volume.

EMF shielding is most effective when installed close to the source of the EMF, which in this case is the transformer room. Shielding at the source contains the magnetic fields before they spread, minimizing exposure throughout the facility, including the computer room.

Detailed Explanation:

Placing shielding close to the EMF source minimizes the area impacted by electromagnetic interference, as it reduces the distance over which the EMF can spread. Shielding materials near the source can absorb or redirect EMF, providing the most effective reduction of EMF levels in adjacent spaces, like the data center.

EPI Data Center Specialist References:

EPI data center training advises positioning shielding close to the EMF source to contain fields more effectively and reduce interference in critical areas. This method is more efficient and cost-effective, as it limits the spread of EMF from the point of origin.

To determine the charging current for a battery bank, a general rule of thumb is that the charging current should be 5% of the total battery capacity. For a battery rated at 600 Ah, this calculation would be:

600 Ah×0.05=30 Amperes600 \, \text{Ah} \times 0.05 = 30 \, \text{Amperes}600Ah×0.05=30Amperes

This ensures the battery is charged efficiently without overloading the rectifier or risking battery damage.

Detailed Explanation:

Battery charging current is typically set as a percentage of the battery's capacity to balance effective charging with longevity and safety. A 5% charging rate is standard for lead-acid batteries, which would be 30 Amperes for a 600 Ah battery bank.

EPI Data Center Specialist References:

EPI standards recommend calculating charging currents based on a percentage of the battery capacity to ensure safety and efficiency, aligning with best practices for battery management in data centers.

When the window area exceeds the maximum exposed area specified for fire-rated glass, it is necessary to split the window into sections that comply with the fire rating requirements. This means creating smaller sections that are each within the 3 sqm/32 sqft limit and using fire-rated frames to ensure that the entire assembly meets fire safety standards. This approach maintains the fire-rated integrity of the glass, while allowing for larger window areas.

Detailed Explanation:

Fire-rated glass is designed to contain fire and prevent it from spreading. If the window exceeds the maximum exposed area defined by the supplier, the integrity of the fire-rated glass could be compromised. By dividing the window into compliant sections with fire-rated frames, you ensure that each pane performs as intended in the event of a fire. Fire-rated frames help maintain the fire resistance across the entire assembly, making this option the best for safety and compliance.

EPI Data Center Specialist References:

EPI recommends adhering strictly to fire safety standards, especially when using materials like fire-rated glass. The guidelines emphasize that modifications should always respect the manufacturer’s specifications to ensure the system remains effective in containing and preventing the spread of fire.

The wet bulb and dry bulb temperatures become identical when the relative humidity reaches 100%. At this point, the air is fully saturated with moisture, meaning it can no longer absorb additional water vapor. As a result, the rate of evaporation decreases, and there is no difference between the dry bulb and wet bulb temperatures.

Detailed Explanation:

The dry bulb temperature measures the air temperature, while the wet bulb temperature takes into account the cooling effect of evaporation. When relative humidity is at 100%, the air has reached its saturation point, and no further evaporation occurs. This causes both the wet bulb and dry bulb thermometers to display the same temperature reading. This condition is critical in understanding environmental conditions, particularly in HVAC and data center environments, where humidity control is essential to avoid equipment overheating or corrosion.

EPI Data Center Specialist References:

The EPI Data Center Specialist training includes understanding humidity levels and their impact on data center environments. Knowing when wet bulb and dry bulb temperatures align helps data center operators manage moisture levels effectively, which is essential for preventing issues related to high humidity, such as condensation on IT equipment.

The Top-of-Rack (ToR) cabling layout places an access switch directly inside each rack. Each server in that rack only requires a short patch cable to connect to the switch, and only one or two uplinks per rack connect to aggregation switches. This greatly reduces the number of long horizontal cables across the data hall.

In contrast, an End-of-Row (EoR) design centralizes switches at the row end, requiring long horizontal cables from each server to the row cabinet. This can lead to thousands of extra copper or fiber runs in large deployments.

ANSI/TIA-942 and Cisco Design Guides emphasize that ToR is the best solution for minimizing cable bulk, improving airflow, and reducing cost in hyperscale or dense rack environments.

Thus, if the explicit design goal is to minimize cable quantity, ToR design is superior.