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Standard cubic feet per minute (SCFM) - The volumetric flow rate of a gas corrected to standardized conditions of temperature, pressure and relative humidity.
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Sensible Cooling Capacity - Cooling capacity related to dry bulb temperature and objects that do not produce condensation.
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Sensitivity - An equipment setting that binds the set point range and triggers a change in device function when exceeded. Most commonly referring to CRAC/CRAH temperature and humidity set points. Also known as Band or Range.
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Set Point - Typically used in reference to air conditioning equipment thermostat temperature and humidity settings.
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Short Cycling - Chilled airflow returning to cooling units without passing through IT equipment, also referred to as recirculation.
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Static Transfer Switch (STS) - Also known as Transfer Switches allow switching from a primary power source to a secondary or tertiary power source and are employed in some electrical power distribution systems. Most often transfer switches can be seen where emergency power generators are used to back up power from the utility source. The transfer switch allows safely switching from utility power to emergency generator power while maintaining isolation of each source from the other. The switch may be either a manual switch, an automatic switch, or a combination of manual and automatic. In a home during a power outage, for example, the transfer switch allows isolation of the owner's critical circuits (e.g. cooling, refrigerator, lighting) from the utility service, allowing for operation of the generator without backfeeding to the utility, which can damage utility equipment and hurt (or kill) utility workers.
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Sub-floor - The open area underneath a raised computer floor, also called a sub-floor plenum.
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Supply Air - The cooled airflow emitted from air conditioning equipment
