Essential Electrical Systems and Resiliency in Hospital Cooling

For the healthcare industry, waiting out a power outage is not an option. When the power goes out, it is vital for hospitals and healthcare facilities to have an emergency power system in place to continue treating patients without a lapse. Unfortunately, many facilities do not have a means to condition the air during these power outages, and in a climate like Texas, it could be only a matter of hours without cooling that a facility’s operations are significantly impacted and the ability to care for patients is adversely affected.

Our team provided the engineering to add cooling ability to an existing emergency power system for an 840,000 square foot, full-service hospital. The project began with an emergency power feasibility study to include a percentage of the existing central plant cooling systems on emergency power in order to support the hospital needs for cooling during normal power outages. 

This fully operational, 24/7 hospital required a detailed investigation to determine existing sequences and capacities of the cooling and generator plant along with the potential to add components to the systems to achieve the desired outcome.

The emergency power assessment was the key component in determining the feasibility of the project. The facility did not have the budget to install additional emergency power capacity, therefore the scope was to work within the parameters of the existing systems. The available capacity was determined by installing multiple meters and logging the data of all the currently connected loads. Analyzing the data required engineering expertise to account for any load anomalies and appropriate demand and safety factors.   

Investigating and assessing the existing emergency power system of the hospital before going into design was a key component in determining the feasibility of the project.   

For the cooling plant to properly function, we had to assure that multiple large equipment loads would simultaneously work together including the chillers, cooling towers, pumps, and associated controls. Factoring in the required loads against the existing spare capacity revealed that only a portion of the cooling plant could be connected to the emergency power system. Because of this, the control sequences were complex and required interface between the emergency power system, the building automation system, and chiller plant controls to demand limit the plant so as not to overload the emergency power system.

The control sequences design not only required technical engineering expertise, but also an understating of the hospital’s business and clinical operations. Intricate control sequences and valving schemes were set in place to provide cooling to critical areas, which are different in short-term versus long-term outages. Upon the initial loss of normal power, diagnostic and treatment areas such as operating rooms have the greatest need for cooling. If the outage extends, surgeries will be canceled or diverted to other hospitals where possible, and the greatest need for cooling is for patient beds. The system was designed to allow the trained facility engineer to, via the building automation system, divert the available chilled water to the appropriate areas.

Throughout the course of the project, new challenges were encountered along the way. Since the cooling systems were not on emergency power when the hospital was originally built, many of the associated components were not either. It was important to locate all control circuits and other components such as valves and dampers throughout the entire facility (not just the central plant) and change them over to emergency power, as well as replace some actuators for the proper fail position for the new sequence.

The hospital leadership knew they could trust our team members as an innovative and nimble team to respond to the dynamic demands of the project and ensure any impact to the hospital operations was controlled and limited during the implementation phase. 

The facility has experienced normal power outages since the completion of the project. The ability to provide cooling on emergency power proved to enhance their ability to provide care to their patients and limit the number of cases canceled or patients that had to be transferred or diverted.