Advanced Hybrid Cooling Implementation for High-Density Data Center - Houston, TX
Category: Data Centers
Overall Area: 40,000 ft² white space; 12,000 ft² outdoor chiller bank and pumping skid
Services Provided: HVAC & Plumbing
Completion Date: 2024
Owner: Undisclosed
Contractor(s): Megawatt Construction
Project Description
To support next-generation computing, this high-density data center was designed in two phases, each accommodating server racks with heat loads exceeding 130 kW per rack. With high-density computing comes a critical need for precision—thermal management, energy monitoring, and equipment protection were at the forefront of this design. Pragmatic Professional Engineers (PPE) developed a hybrid cooling system utilizing a combination of In-Rack Coolant Distribution Units (CDUs) and Liquid-to-Liquid CDUs to maintain stringent temperature and humidity requirements. Liquid cooling was designed to handle 80% of the load, while an airside cooling system accounted for the remaining 20%.
Thermal Management: A 4,500-ton air-cooled chiller plant was designed with a primary-secondary pumping configuration to optimize efficiency and redundancy. The system operated with a 30% propylene glycol mixture to prevent freezing, particularly during colder months. The chiller sequencing was managed through a lead-lag control strategy, ensuring optimal energy use and equipment longevity. Specific attention was paid to the selection of bypass valves. Both linear and equal percentage bypass valves were evaluated for different applications. Chiller platform for this massive plant was coordinated well in advance for a feasible, economic, clash free and stress-free installation.
Energy Monitoring: Energy monitoring was integral to optimizing cooling performance. The system incorporated energy valves at each rack for dynamic flow control, solenoid valves for isolation, and circuit setters to regulate flow. BTU meters at each CRAH unit and chiller provided real-time performance tracking, ensuring operational efficiency and proactive maintenance.
Equipment Protection: Protecting the racks and cooling equipment from potential water damage was another critical aspect of the design. A well-coordinated leak containment system was implemented throughout the facility. Leak containment trays were strategically placed under piping within the server room, with rope-style leak detection sensors tied into the Building Management System (BMS). In the event of a leak, the BMS would automatically command solenoid valves to shut off, isolating the affected area and preventing further damage.
The design process remained highly dynamic, as the facility's infrastructure was developed in parallel with ongoing equipment specifications. PPE responded to multiple mid-stream changes while ensuring coordination across electrical, structural, and architectural disciplines. Despite an aggressive timeline and evolving requirements, PPE delivered a high-performance, scalable HVAC and plumbing system. The project's success reinforced PPE’s expertise in high-density data center cooling, leading to continued collaboration on future mission-critical facilities.