- Data center environmental control
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Data center environmental control is the methodology of maintaining temperature, humidity, and other physical quantities of air in a limited range to allow the IT equipment housed in a data center to perform optimally throughout its lifespan.
Contents
Air flow
Typically a concept discussed in regard to data centers, air flow management is a strategy that addresses the need to improve data center equipment cooling efficiency by preventing the recirculation of hot air exhausted from IT equipment and reducing bypass airflow.
Background
Data centers house IT equipment recommended (by IT vendors) to operate within certain temperature ranges (70-75 degrees Fahrenheit). Also the American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) sets recommended temperatures (68-77 degrees Fahrenheit) and allowable (59-90 degrees Fahrenheit) temperature ranges guidelines for IT equipment.
Often today, with the ever growing information processing densities, data center servers continually run the risk of producing heat that goes well beyond these guidelines, even when using (the now commoditized) precision cooling units.
Overheating of data center equipment can result in:
- Reduced server performance or total non-functionality due to re-circulated, hot exhaust air from IT equipment finding its way into an IT inlet.
- Precision cooling equipment being set at temperatures lower than recommended due to air stratification or the layering of different temperature air masses in the data center.
- Minimization of, rather than precision cooling efficiencies due to by-pass air (the remixing of the cool supply air and exhausted air that becomes part of the return air stream)
Air flow management strategies can best be applied through rack hygiene and hot aisle containment measures. That is, creating stop gap fittings that plug air leaks around the wires protruding from server rack levels and designing equipment that attaches to the back and top of each server rack. The attached equipment re-directs as much of the hot air exhausted from the server as possible up and away from the IT equipment.
Rack Hygiene
Blanking plates and other fittings around the edge, top and floor or the rack are used to manage air intake so that only air from the cold aisle reaches equipment intakes, and to prevent leakage of exhaust air back into the intake area within the cabinet. Fans on the top or rear doors of the cabinet ensure a negative pressure for exhaust air coming out of equipment. Effective airflow management prevents hot spots, especially common in the top spaces of a rack, and allows the temperature of cold aisles to be raised.
Hot/Cold Aisle Containment
Containment of hot or cold aisles or ducting hot air from cabinets is intended to prevent air temperatures being mixed within server rooms. Generally rows of cabinets will be placed facing each other so that cooling air going to equipment cabinets can reach the equipment air intakes at the temperature set point for the room.
When cold intake air is separated from hot exhaust air, cooling equipment can operate more efficiently and can be safely set to use higher temperatures with less dehumidification than if cold and hot air was being mixed within a server room. This is because chillers, computer room air handlers, heat transfer devices, and air-side economizers work most efficiently with a high differential between outside temperatures and the hot air being cooled.
See also
- Server Room Environment Monitoring System
References
Further reading
Categories:- Data centers
- Heating, ventilating, and air conditioning
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