Latest News
Newsome Completes Major Chiller Replacement at York Hospital
We have recently completed the replacement of two ageing rooftop chillers serving the main air handling unit cooling circuit at a hospital in York.
The project followed an energy and performance review of the existing system, which identified a clear opportunity to improve efficiency, resilience and long-term reliability. The original installation used two York YAES 0415 air-cooled chillers. One unit had already failed, while the remaining chiller was continuing to support the site. Because the system served a critical hospital environment, the replacement programme had to be carefully planned around live operations and completed with minimal disruption.
Before recommending replacement equipment, we carried out a detailed comparison between the existing chillers and current high-efficiency alternatives. The analysis showed that the new system could reduce annual power consumption by approximately 28% across the two units, with the detailed single-unit comparison indicating an estimated efficiency improvement of around 33% under the assessed operating profile.
This gave the client a strong technical and operational case for replacing the ageing plant rather than continuing to invest in older equipment. We also assessed the potential benefits of adiabatic spray systems, allowing the site team to compare the performance of upgraded existing equipment against a full chiller replacement.
Selecting the New Chillers
We selected two CGAF 105 HE LN air-cooled chillers, each capable of providing approximately 395kW of nominal cooling.
The new units comfortably met the required duty for the main AHU circuit and were chosen for their improved efficiency, wide operating range and suitability for external installation. Each chiller also incorporated two independent refrigeration circuits, providing additional resilience and helping reduce the impact of any future maintenance requirement.
Lower-GWP Refrigerant
The new chillers use R454B refrigerant, which has a significantly lower Global Warming Potential than older refrigerants such as R410A. For the hospital, this provided a more future-focused solution as environmental legislation continues to move the industry towards lower-GWP refrigerants. The change supported the wider aim of improving the environmental performance of the cooling system while maintaining the cooling capacity required by the site.
Planning Around a Live Hospital Environment
Replacing large rooftop chillers at an operational hospital required careful coordination.
Before work began, our Contracts Manager reviewed the complete programme with the site team and agreed on the sequence of works, access requirements and lifting arrangements. The failed chiller was disconnected first. The main lifting operation was then scheduled for a weekend to reduce disruption to normal hospital activity.
During the lift, the remaining chiller was isolated and disconnected before both existing units were removed from the roof and the new chillers positioned. The work was phased so that the first replacement chiller could be connected and commissioned before the second unit was completed.
The location of the chillers meant the project required a full contract lift from the hospital car park. Local restrictions on mobile crane weights also had to be taken into account. The crane was therefore transported without ballast, with the ballast delivered separately under the appropriate movement arrangements. Careful planning allowed both existing chillers to be removed and the new equipment positioned during the scheduled lift.
Once the replacement chillers were in position, our pipework engineers installed new DN100 stainless steel pipework between the existing system and the new equipment. The pipework incorporated the necessary valves and fittings for flow control, filtration and isolation. After installation, the circuit was filled, vented and pressure tested before the chillers were brought into operation. All new pipework was also insulated and weatherproofed to protect the system during external operation.
Electrical Installation and Commissioning
Our electrical engineers disconnected the original equipment and adapted the existing supplies and control cabling for the new chillers. Once the electrical works were complete, the systems were tested and energised, with NICEIC certification provided.
Each chiller was then commissioned by a Newsome Service Engineer against the available heat load. This staged commissioning process allowed the hospital to regain cooling capacity progressively while the remainder of the installation was completed.
Protecting the New Equipment
Connecting new chillers to an existing chilled water circuit also made water quality an important consideration. We took samples of the circulating fluid for independent laboratory analysis before and after the installation. This allowed the condition of the system water to be assessed and helped confirm that the completed circuit met the manufacturer’s recommendations. Good water quality is essential for protecting heat exchangers, pipework and other system components against corrosion, scale and fouling.
Delivering a More Efficient and Resilient Cooling System
The completed project replaced two ageing chillers with modern, efficient equipment using lower-GWP refrigerant. The result is a more resilient chilled water system with significantly lower estimated energy consumption and improved long-term maintainability. From the original energy assessment through to crane lifting, pipework, electrical installation, water quality checks and final commissioning, the complete project was managed by the Newsome team.
Projects like this demonstrate the value of combining technical analysis with practical installation expertise, particularly in live environments where continuity of service is essential.