Daikin takes VRV air conditioning to taller and larger buildings
Daikin’s VRVIII air-conditioning system enables outdoor units of different capacities to be mixed in the same installation.
The ability of Daikin VRV air conditioning to serve larger and taller buildings has taken a significant step forward with the development of the third-generation VRVIII series. The capability to serve tall buildings has been boosted by the vertical separation between indoor and outdoor units being nearly doubled from 50 to 90 m. (There are said to be only four office blocks in the UK taller than 180 m). The total piping length has also been more than trebled, from 300 to 1000 m. Installation flexibility is enhanced by the maximum difference in length between the shortest and longest branches being 40 m. The capacity of a VRVIII heat-pump system ranges from 5 to 54 hp, compared with a maximum capacity for VRVII of 48 hp (cooling only 5 to 18 hp). Up to 64 indoor units can be connected to a single heat-pump system, compared with 48 previously. Numerous technical improvements enable a maximum COP of 3.80 to be achieved in cooling mode and 4.17 in heating — increases of 8%. Previous VRV systems have required all units to be of the same capacity, whereas VRVIII enables different sizes of unit to be combined in the same installation. Outdoor units could, for example, be selected to minimise space requirements or maximise COP. Diversity (capacity of indoor units compared to outdoor units) has been increased so that it is possible, for example, for a 10 hp VRVIII outdoor unit to be connected to 25 indoor units, compared with 16 for VRVII. This facility enables energy removed from one part of a building to heat other parts. Charging with refrigeration is an automatic process. No longer is it necessary to calculate the refrigerant charge required and monitor charging by weighing cylinders as charging proceeds. Installation is also simplified by oil-equalising piping not being required with two or more outdoor units — reducing piping time and associated insulation work. Enquiry Number 125