Rack Cooling Index (RCI) ® Return Temperature Index (RTI)TM
ANCIS has introduced two highly effective performance metrics for thermal and energy management of data and telecom centers. In addition to being referenced by a number of industry authorities, including ASHRAE Datacom Series, ANSI/BICSI ® Data Center Standard, and The Green Grid ® Data Center Maturity Model, they have been incorporated into the U.S. Department of Energy (DOE) DC Pro software tools for data center energy assessments and the Data Center Energy Practitioner (DCEP) program.
The metrics have also been utilized for work with/by a number of industry leaders, including Amazon, Eaton, Hewlett Packard (HP), Intel, J. R. Simplot, Lawrence Berkeley National Laboratory (LBNL), Liebert, Network Appliance, Pacific Gas and Electric (PG&E), Verizon Wireless, Wick Fisher White, and Yahoo. Finally, the metrics are incorporated into comprehensive data center analysis tools and monitoring systems from vendors such as Applied Math Modeling (CoolSim), ATEN International, Delta Electronics, FieldView Solutions/Nlyte Software), Future Facilities (6SigmaDC), MAYA HTT, RF Code, Schneider Electric, Siemens (DC Clarity LC), Subzero Engineering (PolarXpress), and SynapSense/Panduit.
For RCI and/or RTI license inquiries, please contact RCI@ancis.us
Rack Cooling Index (RCI)®
The most important aspect of a data center or telecom central office facility is to provide a physical environment that ensures reliable operation of the data processing equipment. The equipment intake temperatures characterize the thermal environment. A number of data center standards provide recommended and allowable intake temperatures to protect the equipment and cap cooling costs.
The Rack Cooling Index (RCI) is a best practice performance metric for quantifying the conformance with thermal data center standards such as ASHRAE and NEBS. The RCI metric compresses the intake temperatures (measured or modeled) into two numbers: RCI(HI)=100% mean no intake temperatures above the maximum recommended and RCI(LO)=100% mean no temperatures below the minimum recommended. Both numbers equal to 100% signify absolute compliance, i.e., all intake temperatures are within the recommended range. There are many applications of the RCI; the following are some important examples.
Assess Equipment Environments. Temporary or permanent monitoring of the environment is feasible by using intake temperature sensor arrays.
Design Equipment Environments. The RCI combined with CFD modeling provides a standardized way of evaluating and reporting the effectiveness of cooling solutions.
Provide Design Specifications. Data center owners/operators can now specify a certain level of thermal quality in a standardized way, e.g., RCI > 95%.
Help Product Development/Marketing: The RCI demonstrates the benefit of a cooling solution. A product with an RCI near 100% could be marketed as such.
The link to the right allows free down loads of an ASHRAE paper discussing the Index in some detail. It describes the RCI for analyzing, reporting, and specifying the thermal environment in data centers, telecom central offices, and other mission critical facilities. The paper was published in ASHRAE Transactions (Volume 111, Part 2). This posting is by permission of ASHRAE; see our Publications page for details.
RF Code uses the Rack Cooling Index (RCI) in their DCIM software Webinar >>
Applied Math Modeling uses the Rack Cooling Index (RCI) in the CoolSim CFD software. Webinar >>
Using the Rack Cooling Index (RCI) Calculator is the easy way to show conformance with ASHRAE Thermal Guidelines. The software automates the task of calculating the RCI metric for IT equipment intake temperatures stored in Excel ®. It also plots the temperature distribution and calculates key temperature statistics. This information provides additional data for analyzing and optimizing the thermal equipment environment. The latest version 2.3 of the Calculator has a full implementation of the RCI and ASHRAE specifications.
The Rack Cooling Index (RCI) Calculator v 2.3 (Excel®) is available as single-user ($399) and three-user ($699) licenses. To purchase the software, please write to RCI@ancis.us
The link to the right allows down loads of a product flyer.
While the Rack Cooling Index (RCI) ® is a measure of how effectively the equipment racks are cooled within industry thermal guidelines and standards, the Return Temperature Index (RTI) is a measure of the energy performance of the equipment room air-management system. Combined, these metrics provide an opportunity to objectively establish the overall performance of the building's air-conditioning system.
Specifically, the RTI is a measure of net by-pass air (RTI < 100%) or net recirculation air (RTI > 100%) in the equipment room; both effects are detrimental to the thermal and energy performance. By-pass air does not participate in cooling the electronic equipment and depresses the return air temperature. Recirculation, on the other hand, is one of the main reasons for hot spots or areas significantly hotter than the average space temperature.
The link to the right allows free down loads of an ASHRAE paper discussing the Index in some detail. It also demonstrates the usage of the RCI combined with the RTI. The paper was published in ASHRAE Transactions (Volume 114, Part 2). This posting is by permission of ASHRAE; see our Publications page for details.
