Power management system enhances emergency response

Case study: A super-tall building in the Middle East.

By Suzan X. Sun-Yuan, PE, LEED AP, CDT, and Mohsen Aghai, Environmental Systems March 20, 2014

A super-tall building in the Middle East contains three levels of enclosed underground parking, a hotel with multiple ballrooms and restaurants, several floors of offices, and multiple residential and observatory levels. Seven floors will host the building’s mechanical, electrical, plumbing (MEP), and fire protection equipment, which will use district-chilled water as a cooling source and feature three main chilled water pressure zones.

The building’s generator power systems will serve the following loads: fire pumps, fire transfer pumps, firefighter elevators, emergency evacuation elevators, emergency lighting system, safety and alarm systems, stair pressurization systems, lobby pressurization systems, public corridor exhaust systems, refuge floor pressurization systems, garage exhaust fans, partial building cooling load and associated equipment, and partial refuge floor cooling.

Three base building generators are located in each plant to support the life safety systems. Two plants are interconnected, providing reliable redundancy and backup for the building’s emergency power distribution system.

Like other super-tall buildings, there is a discrepancy between the code-required peak design demand and the building’s actual peak power usage. To take advantage of the additional power capacity already designed into the facility, the building’s power management system is programmed to accommodate a second and third tier of MEP systems that will enhance building response in the event of an emergency. This includes the building’s garage exhaust and corridor exhaust systems, life safety equipment supporting cooling devices, and refuge floor cooling.

During a power outage and after life safety Category 1 and legally required Category 2 systems were activated, then the third category is potentially energized. The power blocks in the third tier will be assessed based on each individual block’s power requirements and power availability. For example, the underground garage system was designed with 14 individual zones and allocated to the third tier. Upon receiving a signal simultaneously, all exhaust fans within this zone and adjacent zones will be activated. After necessary garage exhaust systems are online, the next power block in the third tier could also be activated if there is ample power capacity.


Suzan X. Sun-Yuan is a senior associate and lead mechanical engineer with Environmental Systems Design. She has experience with super-tall buildings, food labs, and central plant designs and upgrades. Mohsen Aghai is a senior associate and lead electrical engineer with Environmental Systems Design. He has experience with super-tall, mixed-used, commercial, and governmental buildings as well as hospitals and central plant designs and upgrades.