Water, rather than traditional refrigerant is at the heart of the indoor units. This means there is minimal risk of refrigerant leaking into small confined spaces. Hybrid VRF minimises the need for leak detection, reducing the total cost of the system and on-going maintenance of the leak detection system itself.
In commercial buildings, additional leak detection systems specific to air conditioning are often installed to safeguard occupants due to increasing safety regulations. This affects hotels in particular, where air conditioners are installed in the room space and occupant safety is critical.
A leak detection system is designed to trigger an alarm if refrigerant was to leak into the room space and shut down the system to try and prevent harm to the occupants. These systems can be expensive and add to the cost of design, build and maintenance.
Throughout a system’s lifetime, annual testing and the recalibration of leak detection sensors adds significant cost to a VRF system. Using Hybrid VRF instead, minimises this need and could provide as much as 30% in maintenance savings over 15 years.
* Based on a real project using costs from a Mitsubishi Electric Business Solutions Partner in the United Kingdom.
NB: Image for representation only
This is the point where the refrigerant circuit transfers its energy to the sealed water system. There are two sets of Plate Heat Exchangers, both placed at opposite ends in the HBC. Both sets provide hot water in heating mode or cold water in cooling mode. During mixed mode, one set provides hot water while the other provides cold water to its respective flow header.
Each set of Plate Heat Exchangers has a DC Inverter Driven Water Pump. This circulates the closed loop water system between the HBC and indoor units. The discharge flow rate from the pump is controlled by the Valve Block.
A Valve Block is connected between each flow and return port of the HBC.
This Valve Block has two features;
Expansion tank (field supplied) and water filling loop (field supplied)