Case Study: BOC Gases
The Priestley Centre, Guildford, Surrey, UK
Delta Partner: ACME Technical Services Ltd.
Background: BOC Gases operates globally in 70 countries, employing 53,000 people and with annual sales of €12.7 billion.
The BOC Priestley Centre in Guildford is the company’s UK headquarters and technical centre. The 124,000 square foot site houses 550 employees including senior scientists, engineers, technical and operational staff.
The Guildford site has been open since 1986 and ACME Technical Services Ltd has been servicing its building controls for the last 10 years.
The Challenge: ACME Technical Services Ltd were tasked with replacing the existing heating and cooling control system in the office areas, with a solution that could be easily operated by local users to improve the comfort of occupants and reduce energy consumption.
The previous control system consisted of multiple Variable Air Volume (VAV) boxes with standalone controllers that had no connection to zoned perimeter heating valves. The original VAV boxes could only be controlled manually and had a limited range of control options.
The new installation needed to be completed on time, on budget and with minimum disruption to the building’s occupants and their daily activities.
The Solution: An office refurbishment programme at the Priestley Centre began in 2007 and provided ACME Technical Services Ltd with an ideal opportunity to begin the upgrade programme. Other office areas had previously been upgraded where a change of use has occurred.
ACME sourced a more efficient system, which is based upon the open protocol, native BACnet technology manufactured by Delta Controls Inc. This comprised of an OrcaWeb client server, which is networked to a DSM-RTR router, DSC-1616E and DSC-1280E system controllers and DAC-322s application controllers.
Each DAC typically has an intelligent room thermostat - a BACstat, which provides a local temperature reading combined with easy-to-use interface technology. Local users are able to view a heating or cooling symbol, which shows the control mode that the VAV box is operating under.
In addition, a localised perimeter heating valve is also influenced by the DAC controllers to provide additional background heating. This prevents the simultaneous use of heating from the main plant and cooling from the VAV boxes, which improves the energy profile and comfort conditions in the space.
The temperature control of each VAV terminal unit has three modes of operation. Firstly, an Energy Hold Off Mode, which is controlled globally and is set by an area time schedule to turn off the temperature control of all VAV boxes.
Standby Mode can be deployed via a BMS user or a local user using the BACstat. In this mode the control dead-band is typically set to 3ºC, so as to offer a degree of control whilst also conserving energy. A third mode, Comfort Mode, operates similarly but on a reduced dead-band setting of 1ºC.
Those employees who have a localised BACstat are able to select their preferred mode and have the potential to make energy savings as a result.
Client Benefits: Further to the installation of the Delta Controls equipment, BOC is benefiting from a user-friendly, energy efficient heating and cooling control system at its Priestley Centre offices. Each BACstat enables individual users to manage their own environment to improve personal comfort and also generate significant cost and energy savings for the company.
Prior to this, the VAV boxes could only be controlled manually by office staff, which had the potential to disrupt the office environment and cause unproductive downtime.
BOC can also utilise the OrcaWeb server to view the data from the VAV box controls and adjust as appropriate. The OrcaWeb graphics are hosted on ACME Technical Services Ltd remote secure server, and the client gains access to the graphics via the Internet. This enables facilities managers to monitor the overall performance of the system, identify any potential problems and achieve optimum efficiencies where possible.
Customer Quote:: “ACME Technical Services delivered a quality installation which was on time and on budget,” says John Tripp, BOC Facilities Manager. “The Delta products have provided us with complete control over the heating and cooling of the office areas. In turn, this has improved comfort, increased energy savings and user interface adjustability.”