Data Center Glossary Terms Flashcards
2N
A redundancy model that ensures that every component has a backup such that the data center has no single point of failure.
ACAE
Air Conditioning Airflow Efficiency, the amount of heat removed per standard cubic foot of airflow per minute.
AHU
Air Handling Unit.
ASHRAE
American Society of Heating, Refrigerating and Air-Conditioning Engineers is an international technical society organized to advance the arts and sciences of air management.
BACnet
A data communication protocol for building automation and control networks.
CAC
Cold Aisle Containment system that directs cooled air from air conditioning equipment to the inlet side of racks in a highly efficient manner.
CFM
Cubic Feet per Minute, a unit of flow rate, commonly used to specify airflow.
Heat Exchanger
A device used to transfer heat energy from one medium to another. Common uses of heat exchangers are water to air heat exchangers in air handling units, plate and frame heat exchangers in economizers, etc.
HAC
Hot Aisle Containment, system that directs heated air from the outlet side of racks to air conditioning equipment return ducts in a highly efficient manner.
Harmonic Distortion
Distortion in the line voltage waveform. Any cyclical waveform can be described as the sum of sine waves of various magnitudes which are integer multiples of the root frequency (60 Hz, 120 Hz, 180 Hz, etc.). Harmonics are often the result of the non-linear loading of the power distribution system due to the nature of solid state power supplies. Harmonics are detrimental to the efficiency and capacity of power delivery equipment and rotating equipment due to increased eddy current losses and non-fundamental frequency torques.
HDG
Hot Dipped Galvanized.
Hot Aisle
An aisle where rack backs face into the aisle. Heated exhaust air from the equipment in the racks enters this aisle and is then directed to the CRAC return vents.
HPDC
High-Performance Data Center, a data center with above average kW loading, typically greater than 10kW/rack.
Hot Spot
An area, typically related to a rack or set of racks, where ambient air temperature is above acceptable levels. Typically caused by poor airflow management (insufficient cool air supply or an excess of re-circulation).
HVAC
Heating, Ventilation and Air Conditioning system, the set of components used to condition interior air including heating and cooling equipment as well as ducting and related airflow devices.
N+1
Need plus one, a redundancy concept where capacity is configured to include used capacity plus one additional device to enable continued operations with the failure of one system in the configuration.