The Challenge: Eight Toshiba heat recovery VRF systems, operating with R410A, were installed at the striking large office block in Slough to meet a requirement to make the most of the north-south orientation of the building to save energy.
Eight Toshiba heat recovery VRF systems, operating with R410A, were installed at the striking large office block in Slough to meet a requirement to make the most of the north-south orientation of the building to save energy.
The four storey building with its double height entrance lobby occupies 4239 sq m. Working with Performance Specification Consultants David Franklin and Kelly Taylor Associates, Toshiba Accredited Installer Cross Refrigeration both designed and installed the large air conditioning system. Cross Refrigeration is headquartered in Ireland, the company also has a considerably presence in the UK where their areas of specialization include Air Conditioning, Commercial, Industrial Refrigeration and Fruit Ripening.
Twenty-four Toshiba Super Heat Recovery Module (SHRM) outdoor units make up the eight 84 kW systems. They supply 160 Toshiba ducted indoor units. The total system capacity is 682 kW. This is a large system and demonstrates that VRF is being used in larger and larger office buildings, particularly where floor-by-floor flexibility is required.
The orientation of the building means that while cooling is being used on the south side the offices on the north side of the building will receive ‘free’ heating via the heat recovery heat exchange system in the air conditioning installation. The building’s design has other energy efficient features built-in, such as zoned, occupant-sensitive lighting. The fresh air ventilation is provided by an energy-efficient Carrier air handling unit.
The Toshiba Interactive Intelligence controls enable interfacing with the building’s Building Management System giving individual zone control down to the level of each indoor unit. So the control is not only floor by floor but area by area. Energy use is monitored on a floor by floor basis in case the building is let on this basis at some time in the future.
Toshiba VRF systems are proving increasingly popular in the latest new office energy monitored building services regimes. It is vital today on two counts to be able to monitor the energy use of ac systems – firstly it is important to ensure you have an efficient system contributing effectively to your obligations under Part L and secondly so many large office blocks are split into shared tenancy that it is important to be able to give each tenant precise energy use billing.
The contract team was a collaboration of high calibre companies specialising in their various fields, with Gilbert Ash from Belfast as the main building contractor, JBE Building Services from Ballymena as the mechanical and electrical services contractor/coordinator who recruited the services of Cross Refrigeration Armagh as their specialist air conditioning sub-contractor for the project, responsible for supplying, installing and commissioning the Toshiba VRF systems.