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EPA integrate H&V controls for a better environment

Oak House

The South Western Area Health Board (SWAHB) area extends from South County Dublin to include County Kildare and West County Wicklow. The Board serves a population in excess of 500,000 and has a staff of over 4,000 who deliver a wide range of Health and Social Services.


Background

The SWAHB head office is located just outside Dublin city centre at Naas in County Kildare. This newly constructed building was originally designed for multi-tenant occupation and the stand-alone nature of the various installed control systems reflected this.

  • A Cylon Unitron controller was located in the rooftop plantroom for fresh air handling and temperature make-up
  • Each floor had a seperate boiler circuit with perimeter radiators, controlled by a seperate Cylon control system
  • There were discrete Mitsubishi City Multi MJ103 controllers located in the riser of each floor
  • A separate stand-alone Cylon controller served the Reception Area Underfloor heating panel
  • A local time switch controlled the Domestic Hot Water System

Each system was supplied with LCD display panels for local system access, but there was no inter-relationship between them. The consequences of this were potentially both poor building performance and costly over-use of plant. The Facilities Manager was left with a situation where there were six separate stand alone control locations in the building and no central alarm reporting facility. In addition, the Mitsubishi system had not been provided with any time-clock controls, so the system relied upon good practice by office workers in switching the air conditioning off at night. Generally, however, it was found that air conditioning was left enabled continually, heating and cooling the office space 24 hours a day. There was no co-ordination of control where an area was served by both the air conditioning and the radiator circuits. This resulted in simultaneous heating and cooling of areas served by both systems. Therefore the challenge was:

  • To better co-ordinate the on-site systems
  • To provide time controls for the air conditioning system
  • To integrate the controls and facilitate the efficient use of energy
  • To provide the Facilities Manager with an interface to the complete controls installation

Solution

Dublin-based Environmental & Process Automation (EPA) Ltd provided a design scheme which both eliminated the on-site conflicts, and enhanced the facilities available to the end-user.

  • Firstly, all stand-alone Cylon controls were connected with their own co-ordinating network, allowing the central H&V controls to inter-operate
  • This was then connected to the Mitsubishi air conditioning system using a Compass network
  • Finally, the integrated Compass network was supervised by an ObSys package installed in the reception area and used by administrative staff

The integrated solution now provides the Facilities Manager with a seamless graphical interface for both the Cylon and the Mitsubishi systems. ObSys provides a common method of handling time schedules, allowing a series of occupancy zones to be set up for the building which enable and disable all systems. Adjustable setpoints (for temperature comfort levels, for example) are made using an identical technique regardless of the underlying system. Similarly, data logs (of temperature recordings or meter readings) and alarm conditions are all easily reviewed and adjusted from the Facilities Manager's PC. Much of the time, ObSys is providing these facilities itself, logging data for subsequent display, holding time schedules, and so on.

Additionally, an ObvEngine within Obsys gave integration control just where it was needeed. ObvEngine was programmed by EPA to co-ordinate the systems with logical and boolean algorithms, creating interlocks to efficiently and economically achieve the required comfort levels within the building. Cooling is now never enabled whenever heating is required. Moreover, given that the central boiler plant is more energy-efficient than the air conditioning system at heating alone, the heating cycle of the air conditioning system is never used in the "warm-up" phase of the building's optimised start regime, putting the full heating load onto the radiator system during that time.

Analysis of the energy usage for the building is ongoing, and should provide useful supporting data for the work carried out by EPA.

Integrator's perspective

Gerry Moran, EPA's MD Gerry Moran, Managing Director for EPA, comments "We were delighted that such a complex set of inter-related problems were overcome simply and quickly by the North solution. The power of the ObvEngine was a particular highlight, allowing us to set up the necessary soft-wired interlocks we needed with ease. The client is keen to see just how much money he will save because of our involvement!"

PRODUCTS

CP/CYLON/RS232 Compass Point for Cylon h&v control system
CP/MITSCITY/RS232 Compass Point for Mitsubishi City Multi air conditioning system
CP/COL/RS232 Compass Point for PC connection
OBS/1500 ObSys with 1500 licence units

INSTALLATION & ENGINEERING

EPA logo

ENVIRONMENTAL & PROCESS AUTOMATION LTD
Ashtech House
Ballbin Road
Ashbourne
County Meath
Republic of Ireland

Tel: +353 (1) 835 1744
Fax: +353 (1) 835 2359
Web: www.epaltd.com

Contact: Gerry Moran
Email: gerry@epaltd.com