As part of UK Public Sector Decarbonisation Scheme (PSDS), Derby College was awarded funds to carry out heat decarbonisation and energy efficiency measures including the replacement of the existing gas-fired boilers with heat pumps at Broomfield Hall Campus.


Trane UK supplied a high efficiency thermal system comprising 1 x Conquest CXAX air-cooled Heat pump and 1 x City RTSF water-to-water Heat pump.

This combination of Air Sourced and Water Sourced Heat Pumps installed in cascade configuration provides a renewable energy alternative to traditional gas fired boilers:

• 600kW of Heating
• Up to 80°C of leaving water temperature
• Low GWP refrigerant with low impact on the environment (R454B and R1234Ze)


This project represents a best practice example of Trane thermal systems that reduce operating costs and CO2 emissions while improving indoor air quality. The low-carbon heating solution installed at Broomfield Hall fully replaces the existing gas boilers. It will help Derby college achieve:
• 790,000 kWh annual energy savings
• 160 tons in CO2 annual emission reduction
• Total Efficiency Ratio (TER) improved by 400%.

The project recieved two recognitions:
• Highlighted in the UK government's decarbonization summary report of January 2022
• People's Choice Award at EHPA 2022 Forum.

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Project highlights

Location: United Kingdom

Market application: Comfort heating

Customer need:

Products installed:
• 1 x Conquest CXAX air-cooled Heat pump
• 1 x City RTSF water-to-water Heat pump

Heating Capacity: 600 kW

Featured products

Product name: Conquest CXAX Air-to-Water Heat Pump

At a glance:

  • Compact design: reduced footprint and low-profile design
  • Reversible operation: cooling or heating
  • Optimized for R454B low GWP refrigerant and high seasonal efficiency

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Featured products

City™ RTSF Water-to-Water Heat Pump

Product name: City™ RTSF Water-to-Water Heat Pump

At a glance:

  • 99.5% reliability rate with screw compressor technology and Adaptive Frequency™ Drive as standard
  • Fully optimized for HFO R1234ze (<1 GWP). Available with R515B as an alternative
  • Minimized refrigerant charge with stainless steel plate heat exchangers

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