Arch Rock Energy Optimizer-Data Centre Edition (AREO-DC) is the first solution to measure both power and cooling system efficiency in the data centre using non-disruptive Internet Protocol (IP)-based wireless sensor networks. It lets data centre managers:

• "baseline" the data centre against American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) benchmarks for temperature/humidity/air quality, as well as for actual dollars spent on energy and its carbon equivalent;
• identify the factors that cause energy waste (e.g., short-cycling, missing blanking panels, sub-floor obstructions) or "hot spots" and other harmful conditions, and correct these problems to reduce existing power consumption or allow the facility to support more equipment;
• optimize available capacity for new servers based on the actual electrical/cooling consumption of equipment, rather than the overstated "nameplate" ratings.

AREO-DC works by deploying wireless sensors to measure electrical, thermal, flow and pressure conditions on power circuits, server racks, computer-room air conditioners (CRACs) or air handlers (CRAHs), chillers and underneath the raised computer-room floor. The sensed data is then transmitted via wireless sensor networks to a graphical, multi-window dashboard that shows the electricity load (and associated utility rate-adjusted spend rate) of various equipment, electricity usage by physical or functional area over user-selected time intervals; temperature and humidity data from CRACs, CRAHs, server racks and chillers over time; chiller water-flow rates; "heat maps" superimposed on a floor plan; and key performance indicators such as the Green Grid organisation's Power Usage Effectiveness (PUE) Level 3 standard.

From the AREO-DC dashboard, users can drill down to specific data centres and specific racks within a data centre, and bring up side-by-side views of various factors, such as energy usage vis-à-vis indoor and/or outdoor temperature. Alerts can be generated when heat- and energy-use thresholds or user-defined financial thresholds are exceeded.

"Conserving power is a major concern in today's data centres", stated Roland Acra, Arch Rock CEO. "In the past, data centre managers often overprovisioned CRACs, CRAHs and chillers to give themselves a 'safety zone'. Now they are being encouraged to raise set points to save energy. But they lack the data to answer key questions: How high can they raise temperatures without creating hot spots that will lead to server shutdowns? Are there plenum leaks or missing blanking panels that waste energy? Are air-conditioning units fighting each other, one humidifying and the other dehumidifying? What is the best new topology for server consolidation using the existing cooling and power-distribution system?

"These questions can only be answered by understanding the relationship between power consumption and the cooling infrastructure. For that you need continuous, precise measurements of both electricity usage and cooling-equipment performance - especially supply air temperature into the server racks. While many systems can give a Power Usage Effectiveness (PUE) figure, only AREO-DC provides the data to improve that PUE while conforming to ASHRAE recommendations. And because it's wireless, it's practical to deploy and redeploy tens or hundreds of sensors where needed."

AREO-DC can help data centre managers, for example:

• pinpoint improper mixing of hot and cold air: e.g., missing "blanking panels" in racks, open or misplaced floor tiles, under-floor obstructions - conditions that may lead to insufficient cold air pressure at rack inlets, top-of-rack hot spots, or cooling-plant overcompensation;
• verify the existence of short-cycling or conditions that cause sub-optimal CRAC/CRAH operation; users can then decide whether to add hot- or cold-aisle containment to maintain efficient server operation;
• obtain an accurate PUE figure in mixed-use environments by measuring the cooling load of the data centre relative to that of the entire facility, and combining this with measurement of the central cooling plant's electrical consumption;
• use continuous rack supply air temperature data to determine how high HVAC set points can be raised without creating hot spots;
• measure outside air temperature and humidity to identify air or water free-cooling opportunities through the use of HVAC economizers or cooling towers rather than costly use of compressors and refrigerants.

Components of Energy Optimizer-Data Center Edition include:

• IPthermal-XT Nodes (new), which provide up to seven temperature and one humidity measurements, are used in hot and cold aisles to measure input and output air temperatures at various heights from the raised floor and to generate heat maps.
• IPthermal-HT Nodes (new), which provide up to four combined temperature and humidity measurements, are used for sensing CRAH supply and return conditions.
• IPthermal-CF Nodes (new), which measure chiller water flow and temperature with up to two pipe surface temperature probes and one ultrasonic flow meter input, are used to measure air conditioning unit efficiency.
• IPpressure Nodes (new), placed at up to three points just above and below the data centre's raised floor to measure differential air pressure, reveal air-flow paths and indicate possible plenum leaks or sub-floor blockages.
• IPpower Nodes are mains-powered nodes mounted in or near electrical circuit-breaker panels to measure AC power and voltage on 3-18 circuits per node.
• Energy Portal (with new thermal data software) is a web-based application that displays detailed energy and thermal usage data in graphical and tabular formats.
• PhyNet Router is an IP router connecting users' WSNs to the PhyNet Server and the Energy Portal. The router connects to the portal over local- or wide-area network links (e.g., Wi-Fi, Ethernet) and to the sensor nodes over IEEE 802.15.4 low-power radio links using the IETF 6LoWPAN (IPv6 over low-power wireless personal area networks) standard.

All wireless nodes are battery-operated with an optional AC wall adapter, and support over-the-air (OTA) software upgrades.

Arch Rock Energy Optimizer-Data Center Edition is available now. The Energy Portal is offered as a hosted service or an on-site customer premise appliance. An example starter configuration including the Energy Portal (one-year subscription to hosted service), one PhyNet Router, three IPpower Nodes (monitoring up to nine circuits), four IPthermal-XT nodes (up to 28 temperature measurement points and four humidity points), one IPthermal-HT node (up to four combined thermal and humidity measurement points), two IPpressure nodes (up to six differential pressure measurement points), and two IPrelay (extender) nodes, is priced at $9995.