Hybrid Variable Refrigerant Flow (HVRF) air conditioners are a recent new development in the field of building air conditioning, reducing by 40 % the quantity of R-410A in the system and delivering a COP (Coefficient of Performance) over 6.
The new system works without using refrigerant in occupied spaces and reducing the refrigerant quantity is meeting the purpose of the F-Gas Regulation HFC phase down.
At the heart of the HVRF is a controller box combining two separate heat exchangers which are each connected to an inverter driven water pump and a set of control valves. The 2 exchangers provide hot water in heating mode, cold water in cooling mode or, in mixed mode, send simultaneously to their respective circuits hot or cold water. Hot water is available at around 45 C and chilled water at 10 C.
The controller sends to each user the required volume of hot or cold water corresponding to the temperature he selected. In this way, an office can be heated and at the same time the neighbouring meeting room cooled.
Other than the testing required by the F-gas Regulation, no additional leak detection equipment as should be requested by Standard CEN – EN378 is required in the building, since there is no refrigerant in occupied spaces.
Source (in French) : La RPF.fr