In many data centers, water-cooled chillers are paired with an open- or closed-circuit cooling tower for heat rejection. Other options include dry coolers, hybrid fluid coolers, and adiabatic fluid coolers. Due to the numerous choices, it’s beneficial to evaluate all heat rejection options to optimize energy and water consumption.
Project details
BAC was approached by a high-performance computing customer with 160 MW of operating power to provide a more sustainable cooling solution. They had previously used open cooling towers with water-cooled chillers. BAC worked with the customer to understand the major challenges and needs. The following were identified as critical priorities:
- Minimize water usage while balancing energy consumption to support customer sustainability efforts.
- Provide cooling for an increasing heat load in a smaller footprint.
- Meet system water temperature requirements without chillers at high loads and varying outside conditions.
The solution
BAC analyzed the IT capacity, space requirements, operating power, and location weather data, and then evaluated fully evaporative, hybrid, and adiabatic solutions. Based on the analysis, BAC recommended a chiller-less system utilizing the HXV Hybrid Cooler. The HXV’s packaged evaporative and dry cooling features offered the water saving and energy-efficient solution the customer desired.
The factory assembled unit also allowed for easier maintenance and serviceability for the operations team. They were able to easily access the cold-water basin, prime surface coil, and drive system due to the crossflow design, large doors, and internal access platforms. Additionally, the customer could perform faster inspections of the spray distribution system while the unit was in operation.
The HXV Hybrid Cooler not only addressed all the customer’s challenges and needs, but it also reduced annual energy costs and improved system efficiency, helping to achieve an estimated power usage effectiveness (PUE) of 1.136.
HXV Hybrid Cooler
The HXV incorporates three modes of operation. It has the benefits of evaporative, adiabatic, and dry cooling in a water-saving and energy-efficient solution. It maintains peak system performance for a variety of applications where water is scarce, water costs are high, uptime is critical, or plume is a concern. The HXV hybrid cooler offers the following benefits:
- Up to 70% water savings compared to an open cooling tower due to a high dry switch point and more dry operating hours.
- Year-round sensible cooling with the dry coil to maximize water savings.
- On average, 25% water savings even on a design day through sensible cooling.
- Up to 60% lower energy costs compared to air cooled systems due to evaporative cooling and combined flow design.
- Increased operational and layout flexibility with balanced water and energy savings.
- Highest reliability, and water saver mode eliminates plume abatement.
- Up to 25% less maintenance than traditional fluid coolers due to dry operation and crossflow design.
- Up to 70% chemical savings due to dry operation
Conclusion
In this installation, the HXV Hybrid Cooler met the customer’s need for a reasonable first cost while significantly reducing both water consumption and operating costs.
