The demand for reliable power systems in critical facilities continues to increase, putting pressure on engineers to design reliable systems within project budgets that are often decreasing. This article discusses some of the factors to be considered when designing systems for critical facilities and provides examples from a recent hospital design. The case study used throughout this article is for a new hospital that is approximately 1 million square feet in area.
The code requirements for essential power are focused on providing the minimum amount of emergency power to allow people to safely egress a facility. While this amount of emergency power meets the requirements for life safety, it’s often not sufficient for critical facilities that also need to maintain business continuity during an interruption of power. Power systems that cannot be interrupted during utility outages are important to maintaining safe operation of critical facilities and can also support ongoing maintenance activities. When designing normal and essential power systems for a new facility or upgrades to an existing facility, close attention must be given to resiliency, redundancy, and maintainability.