Two years after a complete HVAC infrastructure replacement by Trane, the partnership with Mater Dei Hospital's in Malta has been a clear success.

Since completion, the transformation project has helped the hospital avoid the use of 2.5 million liters of diesel fuel, a reduction of around 6,000 metric tons CO2e of direct emissions. The system, now with central, automated control and heat recovery capability has resulted in over 58% savings in fossil fuel related energy use. They greatly improved both outdoor and indoor air quality.

The project's cost savings led to further investment in energy efficiency and air quality improvement projects. The Italian Trane team worked with the facility contractor for other heat recovery and repurposing opportunities.


“When Mater Dei Hospital decided to replace the existing installation, it was decided to investigate whether the existing heat recovery system can be improved. Trane’s water-sourced heat pump chillers have a maximum condenser temperature much higher than the previous configuration,” shared Ramon Tabone, Senior Mechanical Engineer with the hospital. “That is what made the project possible and resulted in considerable diesel fuel savings and reduction in CO2 emissions to the environment.”

The initial new installation consisted of a unique combination of electric technologies, including 14 Sintesis Prime RTAF heat recovery air-cooled chillers, 3 RTWF water-to-water heat pumps, controls and Trane's BMS Tracer SC system.

To further extend the heat recovery capabilities, it was decided to install:
A 4th XStream™ RTWF G water-to-water Heat pump:
1 x RTWF 360 HE R1234ze
at 70°C - for the main hospital building
2 x City RTSF water-to-water Heat pump
RTSF 100 A B R1234ze
at 80°C - for the oncology hospital

The heat recovery option allows to reuse the energy extracted from the cooling process. The City RTSF heat pumps elevate the temperature up to 80°C to produce comfort heating and hot sanitary water. Another advantage of the RTSF heat pumps is the small footprint making them the ideal solution for restricted spaces.


Over the course of the project, Trane has become a one-stop resource for the hospital, creating an effective partnership while supporting the facility's distinctive challenges.

With their high-efficiency, cleaner and better operations, Mater Dei Hospital can now meet strict IEQ standards, including dehumidification requirements, while also monitoring and reducing energy use. Right-sized maintenance services also extend the useful life of the equipment and ensure peak operating performance.

The additional three heat pump units help the hospital reach 2.2 MW of electrification of heating, completing their full transition to low-GWP refrigerants. Moving forward, the system will reduce the hospital’s annual diesel fuel consumption by ~1 million liters, preventing approximately 2,700 mtCO2e from entering the atmosphere annually.

Mater Dei Hospital The facility is now a step closer towards achieving net-zero carbon operations, preserving the country's minimal natural resources.

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Project highlights

Location: Malta

Market application: Healthcare

Customer need: Comfort cooling and heating

Products installed:
• Energy saving option: Heat recovery
• 1 x XStream™ RTWF G water-to-water HeatPump
• 2 x City RTSF water-to-water Heat pump

Cooling Capacity: 961 kW

Heating Capacity: 1672 kW

Featured products

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)
  • Minimized refrigerant charge with stainless steel plate heat exchangers

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Featured products

XStream™ RTWF Water-to-Water Heat Pump

Product name: XStream™ RTWF Water-to-Water Heat Pump

At a glance:

  • Market-leading reliability with Trane's renowned, robust screw compressor technology
  • Minimized refrigerant charge with Trane patented CHIL falling film evaporator
  • Series counterflow heat exchanger design

Product page