GLUMAC - Engineers for a sustainable future

David Summers, P.E., LEED^® AP,
Los Angeles Associate

Earthlink was growing and their Pasadena Data Center needed to expand. They required 7,000 sf of additional data center space, and they were searching for an engineering firm that could make it happen. With no time to waste, Earthlink was asking one important question, "Can you complete the design in two months?" Glumac said, "Yes!"

Staubach from Atlanta served as project manager for Earthlink. Glumac led the design team and provided mechanical, electrical, and plumbing design services through the Irvine and Los Angeles offices, and technology design services from the Portland office. The design team also included architects from Wirt Design Group. Turelk was brought on board early in the design to provide construction management and general contracting services under a guaranteed maximum price contract.

The project consisted of two parts: the data center and the central plant. The 7,000 sf data center is designed for a capacity of approximately 100 watts/sf. When fully occupied, the data center will be served by twelve power distribution units and eight air conditioning units. The central plant expansion involved a 50% increase in electrical and cooling capacity over the existing central plant. Additional equipment included a 1,500 kW emergency generator, 1,000 kW of UPS capacity, a 320-ton centrifugal chiller and matching closed circuit fluid cooler. The existing central plant was surveyed, and cost-effective improvements were made to increase system reliability.

Given the fast track schedule, one might expect that the design was complete without consideration of any options. However, the project team worked together to consider many different mechanical and electrical alternatives. Turelk provided timely cost information and constructability reviews to allow quick decision-making and progress towards the deadline. Through this team collaboration process, value engineering was performed that allowed the project to stay on budget and provide a quality installation to Earthlink. Having the contractor on board during the design phase allowed the project to move quickly into construction.

Working Within Limits

The data center is housed in a converted office building. Limited floor-to-floor height did not allow space for a typical 30-36" underfloor air plenum. The proposed central air handling unit scheme was discarded in favor of a distributed downflow air conditioning unit scheme, which resulted in better air distribution with the 18" raised floor, as well as lower installation cost.

Routing the electrical conduit and chilled water pipes from the central plant to the data center proved to be a challenge. The data center is located on the ground floor, and the new services were originally planned to be routed across the building above the ground floor ceiling. However, during Glumac's survey work, the ceiling space was found to be too congested. The design had to be quickly modified to route the services up to the roof, across the building, and then back down to the data center.

Creating a trench in the existing floor slab for the underfloor chilled water pipes was not possible because the building is located on a reclaimed landfill site. The underslab methane barrier and methane exhaust tubing could not be disturbed. The chilled water pipes could not be routed overhead due to limited clearance above the ceiling. So an extensive leak detection system is employed underfloor, and the pipe routing is arranged to minimize obstructions to airflow.

In all cases, the project team collaborated to determine the most effective solution to maintain Earthlink's goal of a first-class data center within the constraints of the existing building.