450 FCUs and 54 outdoor condensing units form one of biggest Toshiba VRF projects to date
It’s the scale of the project which makes the name of a recent installation of VRF air conditioning particularly appropriate.
Landmark Manchester is one of the largest UK installations of Toshiba VRF equipment, with the new 180,000 sq ft multi-storey office development cooled and heated by a VRF system in a setting once dominated by chiller solutions.
The installation, led by mechanical and electrical contractor Castle Building Services with main contractor Bowmer + Kirkland, includes 450 high-performance Toshiba in-ceiling fan coil units (FCUs). The FCUs are connected to 54 Super Heat Recovery Multi Enhanced (SHRM-e) VRF outdoor condensers with intuitive control provided by TCUK TouchScreens and Black Pear Building Management System (BMS) interfaces.
“It is a magnificent building and a superb example of a Toshiba heat recovery VRF installation,” said Andrew Bradison, specification manager for Toshiba distributor Cool Designs. “With its best-in-class energy performance, the system operates with significantly reduced running costs, with savings continuing to accrue over the life-time of equipment. Flexible zoning enables the complex requirements of tenants to be accommodated, ensuring very high comfort and satisfaction levels.”
The client required the highest efficiency combined cooling and heating system possible for the premium quality building, incorporating heat recovery, in order to achieve a Building Research Establishment Environmental Assessment Method (BREEAM) standard of “Excellent”. The design is based on Toshiba’s 3-pipe heat recovery SHRM-e VRF air conditioning, which in addition to class-leading energy efficiency delivers an outstanding kW / kg refrigerant ratio, as defined in POL 01 of BREEAM.
The design, which follows the British Council for Offices standard BCO 2014, required each storey to be divided into separate dual systems to accommodate two potential tenants per floor. The system’s detailed zoning capabilities enable it to be adapted to the diverse requirements of occupants.
External plant for all floors – including the ground floor – is located on the roof, utilising the Toshiba system’s maximum drop of up to 90 metres from condensing units to fan coils on the floors below.
“This is a major VRF project and required close collaboration between all parties,” said David McSherry, Toshiba sales manager. “Due to the Toshiba SHRMe’s high specifications, it meets all the client’s requirements on energy, comfort, control, noise and on-site space utilisation. Most importantly, it delivers a comfortable, productive and efficient indoor environment for occupants.”
Due to the tight installation timetable and city centre location, Toshiba distributor Cool Designs carefully managed delivery slots throughout the project. This involved timing equipment arrival to coincide with a 30-minute window, which required taking into account transportation through Manchester’s busy shopping and business district. All delivery slots were achieved.
Toshiba’s three-pipe heat recovery VRF system claims a new industry benchmark for energy efficiency performance and continuous heating, achieving a world first of 8 ESEER (European Seasonal Energy Efficiency Ratio) in most capacities.
It is also said to deliver improvements across the board in terms of occupant comfort, ease of installation and breadth of building application. This has been made possible by developments in key technologies such as the compressor and intelligent control system, supported by a battery of incremental improvements in almost all system components.
New compressor: The new rotary compressor, developed and manufactured by Toshiba, uses a two-stage compression process for improved efficiency and performance. Wear surfaces on compression vanes are treated with a high-tech Diamond-Like Carbon (DLC) coating, giving outstanding hardness, wear resistance and reliability. It enables a significant increase in compressor rotation speed, resulting in a higher displacement volume – up to 50% greater than for the previous generation of VRF systems. The enables a higher duty to be obtained from a smaller compressor, with less power.
Genuine continuous heating: The SHRM-e is said to be unique in being able to provide continuous heating, with no requirement to stop during defrosts, as with rival systems. This is made possible by the use of a new hot-gas bypass control, which simultaneously defrosts outdoor heat exchanger coils, while allowing the indoor unit to continue operating in heating mode.
Intelligent control: A new approach to intelligent operation based on dual set points gives building occupants improved comfort and further enhances energy efficiency. It prevents the system from over-running and maximises the time it can operate in “off” mode, while at the same time ensuring comfort conditions within the building are maintained at all times. In addition to improved energy efficiency, this approach helps extend the operational life of equipment and further improve reliability.
Wireless commissioning and near field diagnostics: For installers, Toshiba’s new wireless commissioning and performance validation tool enables engineers to read and write data to the condensing unit using a smart phone, without making physical contact. It enables testing and commissioning to be carried out without taking the covers off the unit, said to be another industry first. The system allows performance data and status reports to be automatically emailed to the end users or engineer, enabling remote diagnosis and even system optimisation.
Improvements in pipework and connectivity: Improvements in pipework and connectivity give significant advantages in terms of system design and application. Maximum total pipework length for SHRM-e is 1000m (a full kilometre), double the previous allowable length, with the maximum actual length between an FS unit and a fan coil unit now 50m – versus 15m for the previous model.
Improved operating temperature range: Finally, as a result of the new compressor design and improved system controls, the operating temperature range has been significantly extended, and is now -10 to 46°C for cooling operation and -25°C to 15.5°C in heating mode.