Daikin brings inverter control to small R410A systems
Bringing R410A down to small
air-conditioning equipment is Daikin’s RZQ inverter series.
With the launch of its R410A RZQ inverter series, Daikin claims to the the first manufacturer to offer a full range of R410A inverters — from the smallest split to the largest VRV systems. Available in cooling/heating capacities from 6.9/7.8 to 12.1/13.7 kW, the single-phase RZQ is designed for light-commercial and residential applications. Based around Daikin’s well-proven reluctance DC compressor motor technology, the RZQ delivers high efficiency in the mid to low settings. The use of neodymium magnets in the motor maximises torque and enables high energy-efficiency ratios to be achieved. The DC fan motor used is also far more efficient than AC types. Energy-saving potential is further enhanced by the incorporation of a current sensor to minimise the difference between actual and predefined power consumption. A major installation benefit is provided by the ability to connect to existing R22 and R407C pipework with having to pre-clean it. This benefit results form the use of ether-based compressor oil rather than moisture-sensitive ester oils. Maximum pipe length has been increased to 75 m. COP is 3.8 in cooling mode and 3.82 in heating mode. There is a large range of indoor units (12 models in 27 variants). They can be used in pairs or in twin, triple or double-twin combinations. User comfort is improved by combined I-demand and predicted mean value (PMV) control. The optional I-demand kit limits power input and enables operating sound to be reduced. PMV control addresses the phenomenon whereby occupants can, at exactly the same room temperature, feel hot in summer and cold in winter. PMV control senses outdoor temperature, as well as occupant and radiated heat levels, and then sets and maintains room temperature at the most comfortable level.