• The benefits of refrigerant and water energy as energy sources combined in one system
  • Refrigerant circuit between outdoor unit and HBC controller
  • Water circuit from HBC controller to indoor units
  • Highly efficient solution based on 2 pipe system technology
  • Prototype already in use

Nuremberg / Ratingen, 9 October 2012 – At Chillventa 2012 in Nuremberg, Mitsubishi Electric presented a Hybrid City Multi system on the market for the first time, which combines the ,benefits of refrigerant and water as energy sources in one system. The tech-nology is based on the company’s VRF R2 system and consists of a City Multi series VRF R2 outdoor unit and a specially developed HBC controller, which distributes the refrigerant and shifts the heating and cooling energy. With the Hybrid City Multi system, energy is transferred from the refrigerant to water via two plate heat exchangers, which then supplies the indoor units from a central location in the building. The unit is already in operation as a prototype in the Ratingen-based manufacturer’s new administration building.

“Firstly, with this ground-breaking innovation we are meeting increasingly stricter requirements in terms of the F-Gas Regulation and thus the use of refrigerants. As with our new Hybrid VRF-system, we are kind of self-sufficient,” explains Michael Lechte, Marketing Manager of Mitsubishi Electric, Living Environment Systems. “Secondly, we can offer an impressive, highly efficient solution if for example a building has to be cooled and heated using water as the energy source.”

In this context, Hybrid City Multi technology uses the advantages of both a water and refrigerant conducting system. The high efficiency of a VRF system is achieved in this way, for example. At the same time a relatively high outside temperature can be applied in the air outlet. “We can now offer a highly efficient alternative to classic chiller / fan coil applications, in particular to companies and hotel chains, who do not want to install any direct expansion in their rooms,” Lechte explains the prospects for this. Two inverter controlled pumps are used in the HBC controller, which ensure that exactly the required amount of water is fed to the end units. “Water pumping stations, buffer tanks, anti-freeze and glycol are no longer an issue as a result,” says Lechte.

In addition, there is significantly less effort required in terms of planning and plant design, compared to a classic 4 pipe system. The basis for this is the energy shift within a building: whilst heat has to be drawn from one part of the building, another area needs heat. This can be shifted through the pipe network, thus making sensible use of it. In the process, the outdoor unit in this networked system differentiates between predominantly heating and cooling operation. Due to the energy shift and heat recovery of this technol-ogy, waste heat in summer for example can be used for hot water supply. Just as with standard VRF R2 systems, COPs up to 8 are possible.

“This technology was specifically developed for the needs of modern building architec-ture and maximum efficiency in using the available cooling energy and heat energy. Our aim is to highlight how comprehensive, highly efficient solutions based on renewable energy sources can be developed to fully supply buildings with heat and air conditioning using our products,” concludes Lechte.