2bm’s award-winning compressor-free cooling solution

Yorkshire Water is a water supply and treatment utility company that serves 5.5 million households and 140,000 businesses.

The company, which owns over 69,000 acres of land, is responsible for an area that includes North, South and West Yorkshire, the East Riding of Yorkshire plus parts of North Lincolnshire and Derbyshire.

Since this project was completed Yorkshire Water has benefited from lower operational costs, improved energy savings and the benefits that come with using the very latest technology. 2bm’s project was voted ‘Data Centre Cooling Innovation of the Year’ at the DCS Awards.

Requirement

This was a 10-year refresh of an existing system that involved the installation of a compressor-free cooling solution. The upgraded equipment had to be configured to the existing data centre monitoring software, to allow the IT team to be alerted day or night in the event there are any issues.

In addition to utilising maximum free cooling and maintaining the air quality in the IT facility, there was a requirement to retain a closed-loop sealed room environment. The solution was a replacement for a direct fresh air system, there were multiple vents and other areas of potential ingress which had to be closed.

Challenge

One of the major challenges was that the new solution had to be installed and completed within a live critical facility in a data centre, presenting zero risk or disruption to the site’s day-to-day operation or existing cooling infrastructure.

The backup system had to remain operational while the primary cooling system was being replaced. This meant the new solution required an automatic changeover control apparatus to be integrated into both the new and old systems.

Result

The replacement solution from a fresh air system is designed to:

• Provide a highly resilient cooling system within a controlled environment;
• Deliver a low PUE via an indirect free-cooling compressor-free and refrigerant-free solution;
• Provide increased energy efficiency and equipment reliability;
• Support an IT load of 150 kW for the current day-one requirement;
• Allow for modular expansion as the site load grows to a design maximum of 330 kW IT loading (+100% increase on their current loading in line with CEEDA principals);
• The new cooling solution consists of a separate cold water system utilising elevated water temperatures to provide maximum efficiency of the external heat rejection equipment together with increased free cooling through the use of adiabatic coolers;
• Within the facility, specifically designed down flow cooling units are provided to the perimeter of the data centre, where high-temperature coils and EC variable speed fans deliver efficient airflow and heat rejection;
• By providing conditioned air to the floor void, it enabled us to deliver cold air to the front of the racks and utilise hot and cold air flow separation, maximising the efficiency of the cooling system design;
• The rear of the racks is enclosed within a hot aisle containment system ducted to the room ceiling void and in-turn back to the perimeter cooling units, resulting in a complete hot and cold air separation within a room’s cold aisle topology;
• This allows the new cooling system to work with the existing downflow emergency standby mechanical cooling system for increased resiliency in the event the data centre supply temperature rises above its critical free cooling set point;
• The internal down flow cooling units are arranged within a N+1 one configuration, connected to external compressor-free cooling solution utilising adiabatic hybrid cooling units, providing N+1 redundancy, coupled to an N+1 pump expandable for the day two loading;
• Stainless steel pipework is used to ensure the highest specification of water distribution and minimising maintenance and risk of corrosion over time and performance drop associated with this;
• Using Uptime 20-year weather data, we have designed the cooling system so that during normal operation it will provide a cold aisle temperature of 24°C, allowing a 3°C temperature increase before the ASHRAE A1 recommended temperature is exceeded;
• The free cooling system maintains this operation for circa 98% of the year, leaving 2% of the year (non-concurrent) when the temperature will guild into the ASHRAE A1 allowable temperature ranges for short periods of time, with an upper limit of 30°C air temperature;
• The result, the data centre can operate on the new cooling system 100% of the year without the need for any compressor-based cooling.

Conclusion

By utilising a compressor-free design and working to ASHRAE guidelines for new and legacy equipment, means the organisation can now apply for CEEDA accreditation – keeping it in line with Yorkshire Water’s wider environmental strategy and policies.