Chillers keep MRI scanner cool

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Published: 19 February 2020


The chillers have variable-speed water pumps and condenser fans to precisely match cooling output to current load conditions to maximise energy performance The chillers have variable-speed water pumps and condenser fans to precisely match cooling output to current load conditions to maximise energy performance

A new multi-million pound MRI scanner facility at NHS University Hospital of Wales, Cardiff, is being cooled by high-efficiency chillers from Carrier. 

Three AquaSnap 30 RBP air-cooled liquid chillers have been installed by mechanical and electrical contractor Whitehead Building Services for the project’s main contractor Kier, under the Designed for Life construction procurement and delivery frameworks set by the Welsh National Health Service.

The facility is at University Hospital of Wales, Cardiff

The chillers deliver a combined capacity of 900kW, and provide the cooling required to maintain the high-tech diagnostic equipment in peak condition. Chilled water is supplied to the scanners at 6°C and returned at 12°C, to begin the cooling cycle again. 

Equipped with Carrier’s Greenspeed intelligence, the chillers have variable-speed water pumps and condenser fans to precisely match cooling output to current load conditions. This enables the system to operate with outstanding part-load efficiency, ensuring low carbon emissions and reduced running costs over the life-time of the plant.

“These units offer exceptional resilience as they have three separate refrigerant circuits, and are therefore ideal for use in such critical applications,” said Russ Tyrrell, senior sales engineer for Carrier. “In the unlikely event of one circuit going out of operation, the chiller can continue to operate and deliver up to 66% of cooling capacity, maintaining a high level of cooling.” 

Variable speed fans also deliver low noise, an important consideration given the hospital application, plus extended operational life due to reduced wear and tear on compressors, fan motors and other moving mechanical parts. The chiller located closest to the hospital building has been specified with an acoustic attenuation pack to further reduce operational noise levels.

An acoustic attenuation pack further reduces noise levels

“The new scanning facility provides an important diagnostic and therapeutic service to the hospital, and it is vital the machines are kept operational,” said Martyn Brown, who led the project for Whitehead Building Services. “We selected Carrier chillers because of their reliability and the fact it is proven technology. There are three existing Carrier chillers in use at the hospital, and they have an established track-record.”

To safeguard the units from corrosion in the challenging coastal environment, condensing coils are protected by Carrier’s Enviroshield coil coating.

www.carrieraircon.co.uk