UK: Two Carrier AquaSnap 30RBP inverter-driven air-cooled chillers are said to be providing high performance, low noise cooling for wards and operating theatres at Royal United Hospitals Bath.

The chillers are running on lower GWP refrigerant R32 as part of a major upgrade of the hospital’s air conditioning system.

The chillers, mounted on a new roof-top platform, replace two older split-system chillers, significantly reducing servicing requirements and related costs due to their compact, fully packaged design.

The combination of Carrier’s proprietary Greenspeed Intelligence inverter-driven speed control, electronically commutated condenser fans, high-performance Novation heat exchangers and R32-optimised compressors, are said to give the chillers a very high seasonal energy efficiency rating of 5.18. 

The N+N system design ensures a second unit is available to take over full cooling duties in the event of a failure, providing the resilience required in this critical hospital application.

The installation wasn’t without problems. “There was an issue with the hospital’s electrical supply, which was limited and couldn’t be upgraded in time for the start-up of the new chillers,” said the project’s consultant, James Allard of Brunel Integrated Services. “Carrier responded quickly and programmed a load limit into the chiller control system to ensure they would not draw more than the maximum allowed, protecting the hospital’s electrical system while ensuring cooling needs were fully met.”

The chillers went into service while work continued to upgrade the electrical supply. The chillers were also equipped with soft-start electronics, which provided a further safeguard to peak electrical load.

Additional options specified included enhanced acoustic attenuation to further reduce noise given the sensitive hospital application, and Enviroshield condenser coil protection, with a three-year warranty.

Although the National Health Service was Carrier’s direct customer on the project, the company also provided support to the installer, Intoheat Ltd.

Based on the positive experience on the project, Brunel Integrated Services recommended a similar Carrier solution for a replacement project at another hospital located in the West of England.