Emerson Network Power Obtains Seismic Certification for Liebert CW Precision Cooling System
The Liebert CW is a chilled water-based computer room AHU available in upflow and down flow configurations with cooling capacities up to 400 kW. The system, which uses the building’s chilled water supply as the cooling source, offers precision cooling and humidity control matched to the needs of data center equipment. The Liebert CW is available with energy efficient EC plug fans, which achieve the highest level of energy efficiency.
All upflow and downflow configurations of the Liebert CW are seismically certified in accordance with IBC 2006 and 2009, CBC 2007, and American Society of Civil Engineers (ASCE) Minimum Design Loads for Buildings and Other Structures, ASCE 7-05. The certification also is in accordance with OSHPD CAN 2-1708A.5. California’s OSHPD is a state agency that approves health care construction in the state.
“While seismic building codes were established to ensure new buildings be resistant to earthquakes and allow for safe evacuation, recent codes have addressed nonstructural components that require operation after the event,” said Fred Stack, vice president of marketing, Emerson Network Power’s Liebert precision cooling business in North America. “As the first precision cooling system of its kind to be seismically certified by IBC and OSHPD, the Liebert CW can help data center managers ensure availability and avoid costly downtime during seismic activity. This is especially good news for healthcare facilities in California, which are mandated to follow the seismic design requirements of the OSHPD.”
To qualify for the certification, the Liebert CW was subjected to shake table testing by an independent lab, in accordance with Acceptance Criteria (AC) 156 (2007). The certification covers all sites and events up to a seismic value of Sda = 2.0 at v/h of 1.0 and an Importance value of 1.5. Higher Sda values are available at lower v/h conditions. This requires the unit to be operational after the event.
The Liebert CW utilizes the Liebert iCOM control system that enables multiple control algorithms depending upon the type of sensors connected. Intelligent control capabilities give data center managers the ability to tune their cooling systems to dynamically adjust airflow patterns by controlling the speed of the EC plug fans to allow cooling unit capacities to adapt quickly to changing room conditions.