Water Cooled VRV-WII
(18/02/2005)
Water Cooled VRV-WII extends system's application possibilities. Daikin Europe NV has extended the operational scope of its acclaimed VRVII inverter driven dx air conditioning system with a new water cooled version.
The new system is designed for use in new build commercial projects where no roof or external space is available for outdoor condensing units or where stringent noise restrictions apply. It can also however, be fitted to an existing chilled water/cooling tower circuit during refurbishment operations. Also, the system layout allows operation independent of the ambient condition. The tailor made engineering of the water side combined with flexible VRV technology enables high tech customised and highly efficient solutions to be realised.
Cooling is achieved by means of a plate heat exchanger, located within the condensing unit casing and supplied with water at temperatures between 10° C and 45° C from a cooling tower/dry cooler and if necessary, a boiler.
Available in 10, 20 and 30HP models, the water cooled VRV-WII operates on R-410A refrigerant and will be available in both heat pump and heat recovery versions. The condensing unit is remarkably compact at 1000 x 780 x 550mm, lightweight (150kg) and can be installed in space saving ‘double decker’ fashion in a plant room. As many as13 different types of Daikin indoor units in 75 different models from 0.8 to 10HP capacity are compatible with the new system and up to 32 can be connected to the 30HP system.
Nominal cooling capacities range from 27.3 to 81.9kW with heating capacities from 31.5 to 94.5kW. COPs of 5.21and EERs of 4.53 are achieved at full load operation. Operating sound pressure is 51dBA.
Like the standard VRVII, the water cooled system is technically advanced in its use of purpose designed dc reluctance inverter controlled scroll compressors throughout the range – an important factor in its achievement of high COP's. The dc motor maintains high efficiency levels in the most frequently used ‘mid’ to ‘low’ required capacities, thereby reducing electricity consumption and costs. Powerful neodymium magnets (7 times more powerful than ferrite types) within the motor, increase torque and produce much higher power output to electrical input than can be generated by conventional motors. Optimising the sine wave curve of the motor also results in smoother rotation and enhanced motor efficiency.
Other important VRVII features are also retained in the water cooled version. Evaporative capacity for example, is increased by means of the innovative ‘Sce-bridge circuit’, which adds super cooling prior to the expansion cycle. The use of this circuit maximises both COPs and EERs.
Environmental consciousness too, continues to be emphasised by the use of R-410A refrigerant and lead free soldered PCBs. Also, the built in refrigerant recovery function enables all expansion valves to be opened to allow refrigerant to be drained from the piping circuit.
VRVII ease of installation facilities common to the new system include the use of simple 2 wire non shielded transmission linking condensing unit(s) to multiple indoor units via a single 2 core wire. Furthermore, the use of power connection outlets on the side and front of the condensing unit simplifies installation and maintenance. Similarly, retention of the Daikin ‘Super wiring’ technique makes it easy to retrofit the system for remote control simply by connecting it to the condensing units.
The system is supported by a full range of indoor units comprising 2 and 4 way blow ceiling cassettes, special 600 x 600mm low noise multi flow cassette, ceiling mounted corner, built in ducted, ceiling suspended, wall mounted, floor standing, flexi type and concealed floor standing models.
Compatible with the complete Daikin suite of advanced air conditioning monitoring and control systems (Intelligent Controller, Intelligent Manager, BACnet Gateway and LONWorks Compatible Gateway), the water cooled VRVII offers high energy saving, precisely controlled and monitored air conditioning solutions to medium to large sized commercial building projects.
