Toshiba launches 3-pipe VRF system
The launch of Toshiba’s latest 3-pipe heat-recovery VRF air-conditioning system, SHRM-e, builds on the success of the SMMS-e VRF system, which had an ESEER (European Seasonal Energy Efficiency Rating) of over seven for all capacities. Developments in key technologies in the latest system include the compressor and intelligent control system — supported by incremental improvements in almost all system components. R410A is the refrigerant.
All units in the latest range have an ESEER greater than seven, and most of them achieve greater than eight.
The new rotary compressor uses a 2-stage compression process to improve efficiency and performance. Wear surfaces on compression vanes are treated with a coating that gives outstanding hardness, wear resistance and reliability. It enables compressor speed to be higher, increasing displacement volume by up to 50% compared to the previous generation of VRF systems. This enables a higher duty to be obtained from a smaller compressor, with less power.
Continuous heating can be provided in heat-pump mode. Heating is not interrupted during defrost cycles, which is made possible by the use of a new hot-gas bypass control that simultaneously defrosts outdoor heat-exchanger coils while enabling the indoor unit to continue to deliver heat.
Separate setpoints for heating and cooling improve comfort and enhance energy efficiency. The setpoint for heating is lower than that for cooling. When the space temperature rises above the heating setpoint, units are kept off until the cooling setpoint is reached. Likewise, as the space cools below the cooling setpoint, heat is not delivered until the heating set point is reached. Another benefit of this approach to control is to extend operational life.
A new commissioning and validation tool enables engineers to read and write data to the condensing unit using a smart phone. Testing and commissioning can be carried out without taking the covers off the unit.
Improvements in pipework and connectivity double total pipework length to 1000 m and increase the maximum length between an outdoor unit and fan-coil unit from 15 to 50 m.
David Dunn, director and general manager of Toshiba Air Conditioning and CIAT, said, ‘SHRM-e represents a leap forward for heat-recovery VRF technology and sets the new industry benchmark in this competitive sector of the market.’
