Maritim Antonine Hotel & Spa | Hitachi combined HVAC in Mellieħa, Malta

VRF – Chiller – Air-to-water

The place: a 4* resort goes through complete HVAC upgrade and extension

The Maritim Antonine Hotel & Spa is a resort overlooking the Mediterranean Sea, welcoming holidaymakers to enjoy the sea breeze and rich cultural heritage of Malta.

At the time of the project, the hotel needed a major HVAC upgrade, including:

  • Retrofit of the HVAC system for the existing building – replacing aging Hitachi chillers and diesel-fired boilers.  
  • Extension of accommodation spaces – the newly built guestrooms requiring cooling and heating system

The solution: a Hitachi HVAC mix of VRF, Chiller and air-to-water solutions to phase out of fossil fuels and reduce the energy footprint

Taking advantage of the extensive Hitachi Cooling & Heating line-up, the project manager combined different technologies to meet the hotel’s various needs.

In the existing building: The outdated Hitachi chillers were replaced by two new-generation Samurai heat pump screw chillers, to ensure reliable space cooling and heating. Embedding advanced modulation technology, the compressor load always matches the requested load, and thus accurate chilled water temperature is achieved without expensive inverter devices.

The domestic hot water is produced by a cascade installation of nine Yutaki S air-to-water heat pumps, combined with a 6,000L tank. This new heat pump water heating system enabled the previous diesel-fueled boilers to be scrapped, significantly reducing the hotel’s building carbon footprint.

"We've had a good experience with Hitachi Cooling & Heating products for a couple of years now, when several VRF systems were installed in the hotel's extension in 2018 and they proved to be reliable and energy efficient".

Mr. Robert Refalo, Titan International Ltd Service Manager (2020)


For the latest extension of the hotel, Hitachi VRF SET FREE SIGMA was chosen to cool and heat the guestrooms. Hitachi VRF systems are ideal for hotels, as they enable each unit’s operation to be controlled individually, so each guest can customize the temperature in their room as per their preference. VRF technology also saves energy, by delivering just the load necessary, especially thanks to exclusive SmoothDrive technology which accurately maintains just the right amount of capacity to meet the demand during part-load conditions. The system installed in the hotel totaled 11 outdoor units and 102 indoor units, for a 226HP (565kW) capacity. A CSNET Manager 2 centralized controller complemented the system, for 24/7 monitoring of the AC and error diagnosis.



Distributor: Titan International Ltd Service Manager




  1. The Maritim Antonine Hotel & Spa - Case study (PDF)
  2. The Maritim Antonine Hotel & Spa - Project Sheet (PDF)
  3. Projects Reference Catalog (PDF)


Mellieha, Malta


Retrofit + Building Extension

Year of installation


Total System Capacity

120HP (chillers) + 226HP /565kW (VRF)

VRF Outdoor Units

11x SIGMA SET FREE • Total capacity: 226 HP (565 kW)

VRF Indoor Units

15 Cassettes • 85 Medium Static Pressure Ducts • 2 High Static Pressure Ducts


9x Yutaki S80 (RWH-5.0NFWE) • Total capacity: 45HP • Triple-phase • Tank capacity: 6000 L • 3x cascade controllers (ATW YCC 01)


2x Heat Pump screw chillers Samurai L (RHME 60AH2)


Controllers Individual (PC-ARH) • Centralized Controller - CSNET Manager 2


Titan International Ltd Service Manager