HVAC SYSTEMS


Net Zero: Transforming NHS’s energy efficiency


For the NHS to achieve Net Zero by 2040, hospitals must re-think their approach to heating and cooling. By adopting integrated, data-driven energy solutions, NHS estates can significantly cut carbon emissions while improving patient comfort and operational efficiency. Here, Graham Smith, Commercial director UK&I at Carrier Commercial HVAC, explores the role of heat pumps and heat networks in decarbonising NHS facilities, addressing both the technical challenges, and the opportunities they present.


The NHS is on a mission to become the world’s first Net Zero national health service. As one of the UK’s largest energy consumers, its vast estate – including hospitals, clinics, and healthcare facilities – accounts for around 15 per cent of total public sector emissions.1 Due to the need to maintain safe and comfortable


environments for patients, staff, and sensitive medical equipment, heating and cooling account for the biggest energy demands in the NHS, and are among the biggest contributors to the NHS’s carbon footprint. Heating alone accounts for a significant proportion of the NHS’s 5% share of total UK emissions, making it a major area for intervention in the transition to Net Zero.2


Heat pumps’ emergence Traditionally reliant on gas-fired boilers and steam heating systems, the NHS now faces a major challenge: transitioning to low-carbon heating solutions that can deliver the efficiency, reliability, and resilience, required for 24/7 healthcare operations. Heat pumps are emerging as a key technology in this transition. By extracting heat from the air, ground, or water, heat pumps can provide hospitals with efficient, low-carbon heating and cooling while significantly reducing energy consumption. Unlike the most efficient gas boilers (A-rated), which operate at around 90% efficiency (1:0.9 energy-to-heat ratio), heat pumps can achieve efficiencies of up to 300% or more (1:3 or higher energy-to-heat ratio). This efficiency gain makes heat pumps an essential part of the NHS decarbonisation strategy, helping to achieve the ambitious target of an 80% reduction in emissions between 2028 and 2032, on the path to full Net Zero by 2040.1 However, heat pumps alone are not the solution. Heat


networks – which distribute heat from a centralised source across multiple buildings – are playing an increasingly vital role in NHS decarbonisation. By integrating heat pumps within district heating networks, hospitals can achieve even greater energy savings, cut carbon, reduce reliance on fossil fuels, and enhance the resilience of their heating infrastructure. Recognising the scale of the challenge, the UK government has launched a £500 m framework to help decarbonise NHS buildings.3


This investment covers a


range of interventions, including air-source and ground- source heat pumps, electric heating solutions, ventilation upgrades, and photovoltaic systems. However, while financial support is increasing, implementing these solutions effectively requires a strategic and technical shift in how NHS estates approach heating and cooling. As a result of their exceptional efficiency, heat pumps


October 2025 Health Estate Journal 67


are central to the NHS’s heating decarbonisation strategy. Their ability to harness low-grade heat from the environment, and upgrade it into a useful form for heating buildings and producing hot water, is crucial for NHS hospitals looking to lower their energy consumption while maintaining the heating demands of complex healthcare environments.


De-steaming of heating systems Traditionally, hospitals have relied on high-temperature gas-fired heating systems, often running at 85°C or more, to support sterilisation, heating, and hot water production. A key challenge for decarbonisation is that air-source heat pumps alone cannot always reach these high temperatures, leading many NHS Trusts to de-steam their heating systems as part of the transition. This means redesigning heating infrastructure, not just replacing one technology with another. Cooling has traditionally been seen as separate


from heating in NHS buildings, but integration offers a significant opportunity to cut emissions further. Heat pumps generate waste cool as a by-product, while traditional chiller systems produce waste heat. In many hospitals, this waste energy is simply expelled into the atmosphere. However, by connecting these systems, hospitals can capture and redistribute energy more efficiently. At Carrier, we’ve seen hospital chillers that are pumping


hot air into the atmosphere while the heat pumps are pumping cold air into the atmosphere. By changing to a water-based system, we can connect them both and


The NHS is on a mission to become the world’s first Net Zero national health service.


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