Posted by UNS News on July 9, 2012
The main objectives of any ventilation system are management of environmental air temperature, humidity and air quality. In a data center, or any facility in which electrical equipment and battery systems are installed, the ventilation system must address:
- Health safety – the air must be free of pollutants that could be toxic, corrosive,poisonous, or carcinogenic
- Fire safety – the system must prevent and safely remove the accumulation of gasses or aerosols that could be flammable or explosive.
- Equipment reliability and safety – the system must provide an environment that optimizes the performance of equipment (including both batteries and electronic equipment) and maximizes their life expectancy
- Human comfort
Stationary lead-acid batteries are the most widely used method of energy reserve for information technology rooms (data centers, network rooms). Selecting and sizing ventilation for battery systems must balance and trade off many variables. These could include different battery technologies, installation methods, operating modes, and failure modes.
Lead-acid batteries are the most widely used method of energy reserve. Ventilation systems must address health and safety as well as performance of the battery and other equipment in a room. Valve regulated lead acid (VRLA) batteries and modular battery cartridges (MBC) do not require special battery rooms and are suitable for use in an office environment. Air changes designed for human occupancy normally exceed the requirements for VRLA and MBC ventilation. Vented (flooded) batteries, which release hydrogen gas continuously, require a dedicated battery room with ventilation separate from the rest of the building. This paper summarizes some of the factors and codes to consider when selecting and sizing a ventilation system for a facility in which stationary batteries are installed.
- Environmental design considerations
Ventilation systems for stationary batteries must address human health and safety, fire safety, equipment reliability/ safety, and human comfort. Vented (flooded) batteries should be installed in dedicated battery rooms, but may share the same room as the equipment they support (such as a UPS system). VRLA batteries and modular battery cartridges can be used in an office environment. The amount of heat generated by a battery system is insignificant compared to the total IT system. However, batteries need cool, clean air for optimum performance and long life. Vented batteries must have a dedicated ventilation system that exhausts to the outside and prevents circulation of air in other parts of the building. For VRLA and MBC systems, the ventilation required for human occupancy is normally sufficient to remove heat and gases that might be generated. A minimum of two room air changes per hour and a temperature in the range of 20 – 24° C (68 – 75° F) are recommended. The ventilation system must prevent the accumulation of hydrogen pockets in greater than 1 – 2% concentration.
For vented batteries, it is recommended to enlist the services of an engineering firm experienced in battery room design, including ventilation, fire protection, hazardous material reporting and disposal, and spill control.
For VLRA and MBC battery systems, the ventilation requirements for human occupancy and electronic equipment operation in a data center or network room well exceed the requirements for the batteries. No additional engineering should be necessary for VRLA battery ventilation.
White Paper Written By:
Stephen McCluer is a Senior Manager for external codes and standards at Schneider Electric. He has 30 years of experience in the power protection industry, and is a member of NFPA, ICC, IAEI, ASHRAE, The Green Grid, BICSI, and the IEEE Standards Council. He serves on a number of committees within those organizations, is a frequent speaker at industry conferences, and authors technical papers and articles on power quality topics. He served on a task group to rewrite the requirements for information technology equipment in the 2011 National Electrical Code.
Universal Networking Services’s partnership with Universal Power Group, Inc. has enabled us to build a strong distribution network of battery and related power components that meet consumer needs for accessibility, portability, security and mobility, coupled with value added offerings such as battery pack assembly and battery replacement/recycling programs.
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