Siemens exercises control for mental-health trust
To support the safe and secure operation of its new personality disorder unit, Newcastle, North Tyneside and Northumberland Mental Health Trust has installed a building-management system based on the Apogee range from Siemens Building Technologies. This new unit, along with premises for existing adult forensic services, provides secure accommodation for people with personality disorders and for medium-secure patients. The first phase, a pilot project, has 10 single-occupancy rooms with en-suite shower, washing and toilet facilities. The BMS controls HVAC, lighting and all domestic services for these areas. Energy-efficiency targets are very demanding. The BMS is also required to limit the amount of water delivered to each room — partly to conserve water, but also to prevent deliberate attempts at flooding. Water is controlled by pushbuttons. If a button is pushed too many times, the BMS generates an alarm and shuts off water to the room. Choosing pushbuttons and items such as temperature sensors for the wards and departments posed unusual requirements. The possibility of occupants using equipment in the rooms to harm themselves had to be minimised and it had to be designed so that it would be impossible to attach a ligature. The installation for this first phase comprises a central PC with three modular outstations, to which are connected about 60 valves and 40 sensors. The BMS also monitors and controls the temperature of DHW to minimise the risk of legionella and the heat-recovery system that is part of the HVAC installation. It also handles alarm generation and can send alarm messages to off-site technicians. Gas-fired condensing boilers serve underfloor heating, the flow to which is modulated by the BMS via zone-control valves at strategically placed manifolds. The air-handling plant has internal plate heat exchangers, the operation of which is controlled by the BMS according to the temperature of the air being recirculated. Communal areas are heated by radiant panels and cooled by air-conditioning units. The temperature maintained by the air conditioning is adjustable from the BMS, which ensures that heating and cooling do not operate at the same time. Further gains in energy efficiency are achieved by reducing bedroom ventilation during the day. This is achieved by operating a zone damper and controlling the speed of the supply fan via its variable-speed drive. The time from orders being placed to the BMS being operational was less than four months. To ensure that the BMS would be ready in the shortest possible time, Siemens assisted contractor Emcor Drake & Scull by providing supervision throughout the installation and jointly commissioning the services. Following the success of the first phase, Apogee equipment has been specified for the much larger second phase, a new building to accommodate 45 people, plus community teams and administrators. This phase will be Ethernet based. In addition to the functions provided for the first phase, it will directly control absorption chillers and CHP plant, as well as providing test facilities for emergency lighting.