Air conditioning units in a purpose-built external plant enclosure designed and installed by Salvis

Southfield plant replacement

NHS Healthcare

3 Mitsubishi ASHPs Installed
1000L AO Smith Buffer Vessel
17.59% Increase in kW Capacity
100% Electric Heating Transition

Plant Replacement Plan.

Southfield Hospital required a reliable, energy-efficient replacement for their ageing gas-fired boilers. We installed a complete Mitsubishi air source heat pump system, supported by a 1000L AO Smith buffer tank, new pipework, controls, and electrical integration.

The Challenge:

The existing gas-fired boilers (2x Hamworthy Warmwell, 54 kW each, installed 2004) had suffered recent failures, showed corrosion, lacked proper safety relief valves, and the secondary pump was suspected to be oversized.

A reliable, modern heating solution was urgently needed to restore system integrity, improve efficiency, and ensure uninterrupted comfort for the hospital.

The Solution:

We replaced the outdated gas boiler heating plant with a fully electric air-source heat pump system using Mitsubishi units and a 1000 litre AO Smith buffer. The project was successfully delivered within a 5-week programme and included:

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A full plant room strip-out of the legacy 2004 equipment.
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Installation of three high-efficiency Mitsubishi air source heat pumps.
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Integration of a 1000L AO Smith buffer vessel.
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Fitting of entirely new LTHW (Low Temperature Hot Water) pipework.
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Upgraded system controls and complete electrical integration.
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Minor building modifications to accommodate the modernized plant infrastructure.

Results & Impact:

By transitioning from failing gas infrastructure to a modern, fully electric air source heat pump system, Southfield Hospital has future-proofed its heating capabilities while achieving a 17.59% increase in overall system capacity. The upgraded plant room now operates with vastly improved reliability, lower carbon emissions, and advanced control systems, ensuring a safer, warmer, and more sustainable environment for both staff and patients for decades to come.

2x 54kW Old Boilers Replaced
5 Weeks Delivery Programme
2004 Legacy Plant Retired

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