A building management system - (BMS)

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The university wanted to implement a cohesive building management strategy, and gain greater control of a large number of legacy systems on the campus, including heating, air-conditioning and ventilation (HVAC), access control, and fire alarm systems. They also wanted to monitor and manage water and energy consumption. Many of the building systems did not link back to estates for central control. This made it difficult to monitor, manage and control the systems, and therefore deliver a consistent level of service to staff and students. Remote access to the control systems was just as important. The university wanted to be able to set time schedules, change building temperature set points, see alarms on failures, and check issues remotely without having to physically send an engineer to site.

What is a Building Management System and how does it work?

The BMS is a "stand alone" computer system that can calculate the pre-set requirements of the building and control the connected plant to meet those needs. Its inputs, such as temperature sensors and outputs, such as on/off signals are connected into outstations around the building. Programmes within these outstations use this information to decide the necessary level of applied control. The outstations are linked together and information can be passed from one to another. In addition a modem is also connected to the system to allow remote access. The level of control via the BMS is dependent upon the information received from its sensors and the way in which its programmes tell it to respond to that information. As well as offering a precise degree of control to its environment, it can be made to alarm on conditions that can't meet specification or warn of individual items of plant failure. Occupancy times for different areas are programmed into the Building Management System such that the plant is brought on and off to meet the occupier requirements. These times are often under optimum start control. This means that the heating plant is enabled, at a varying predetermined time, to ensure that the heated space is at the set desired temperature for the start of the day. The Building Management System therefore, based on the outside air temperature the space temperature and the building structure, determines the plant start time.

Why do we need a Building Management System?

All Buildings have some form of mechanical and electrical services in order to provide the facilities necessary for maintaining a comfortable working environment. These services have to be controlled by some means to ensure, for example, that there is adequate hot water for sinks, that the hot water in the radiators is sufficient to keep an occupied space warm, that heating with ventilation and possibly cooling is provided to ensure comfort conditions wherever, irrespective of the number of occupants or individual preferences. Basic controls take the form of manual switching, time clocks or temperature switches that provide the on and off signals for enabling pumps, fans or valves etc. The purpose of a Building Management System (BMS) is to automate and take control of these operations in the most efficient way possible for the occupiers/business, within the constraints of the installed plant. In addition to its control functions, a BEMS typically monitors and records a wealth of information relating to conditions within a building and the operation of the HVAC and other services. Increasingly its duties also include the logging of energy-meter readings, a trend that is likely to continue as demand for sub-metering grows.

On most systems, data and settings are accessed through PC-based graphical user interfaces (supervisors). In their modern form these powerful devices allow the user to quickly navigate to the information they want to see and view it in a form that is easy to understand. When the supervisor is enabled to function as a web server, its displays can be viewed from any PC on an organization's IT network - or via the Internet - a standard web browser being all that is needed. Importantly, the data and settings available to a user can be exactly tailored to that person's needs.

When A BMS supervisor is enabled to function as a web server, its displays can be viewed from any PC using just a standard web browser.

Andover Controls has supplied building control solutions to the University of Derby for over ten years. Over the last five years, all of the university's Andover systems have been upgraded to Infinity- enabling the Estates Department staff to monitor and control the environmental and security requirements of the campuses from a number of PC based workstations.

Installed within each of the main facilities, the central teaching facility, learning resource centre, central catering facility and undergraduate and postgraduate accommodation buildings. Some of the measures which are critical to the buildings' environmentally sustainable design and which are controlled by the Infinity system include:

  • Mixed mode ultra Löw-pressure ventilation.
  • Use of the building structure to provide airflow ducts (floor voids, corridors and staircases) and air tempering (mass concrete structure).
  • Thermal wheels to provide the most efficient heat exchange and thus retain heat and cool air within the buildings.
  • Shade louvres, tilting blinds and awnings to reduce solar gain yet increase natural daylight.
  • Improved natural light levels to reduce the need for artifical lighting.
  • The use Low energy lights, activated by people presence (PIR)

Ninety per cent of businesses believe there would be a better uptake of building management systems (BMS) if the technology was more user-friendly and cost effective, according to a survey carried out by TAC Satchwell.

The research showed that cost is proving a major barrier to many smaller businesses and organisations taking on building control technology, while the technology itself is perceived to be too specialised and inaccessible.

TAC Satchwell's survey also revealed that 20 per cent of businesses believed there was not enough buy-in for building controls at a boardroom level.

Simon Ward from TAC Satchwell, said that this could change following the publication of the Government-commissioned Stern Report, which claims that global warming could cost the world economy $9trillion over the next 25 years. Ward believes the product will allow small and medium sized businesses, as well as small-scale public sector construction projects, to make the most of the long-term cost savings that BMS can bring.

He said: "Building controls have arguably always been about economies of scale.

It makes perfect sense to use BMS on larger projects, where the cost of installing the technology can be offset quickly by substantial energy savings.

The case is less obvious when dealing with smaller buildings. Smaller organisations have neither had the financial clout nor the specialised skills to take building controls and facilities management seriously. "When it comes to saving energy, it is also vital to ensure that any schemes have the full support of everyone in the organisation.

TAC Satchwell helped deliver energy savings of 12% and cost savings of £55,000 in just 18 months.

The role of facilities management has grown rapidly over the last 20 years from a largely unrecognised area of business in the 1980s into a multi billion pound industry.

However, according to Richard Strode at BMS specialists TAC Satchwell, it is not just the value of the industry that has changed. The responsibilities held by facilities managers are evolving too. "The scope of work undertaken by today's facilities managers is remarkably variable and some estimates put the industry's value as high as £180 billion in the UK alone (CFM 2004).

Increasingly, facilities managers are expected to carry the world on their shoulders - they have become the new guardians of the environment.

The Climate Change Levy, the EU Energy Performance of Buildings Directive, the EU Emissions Trading Scheme, Part L regulations and Building Log Books are all ensuring that energy is increasingly on the corporate agenda.

A facilities manager is now expected to carefully balance the needs of employees for a safe and comfortable environment and those of the employer to reduce energy costs and enhance the bottom line, with those of the Government to reduce carbon emissions.

Instead, it needs to provide them with the tools necessary to have a chance of meeting their energy conservations targets. The most effective way of doing this is through user-friendly technologies such that can efficiently and economically control, check and analyse building operations to help manage and minimise energy usage.

Developments which enables secure access to networks via a web browser, and the Andover Continuum Wireless Solution give facilities managers the opportunity to save the planet remotely". "This ability to access a building's data, around the clock from anywhere in the world, makes fine-tuning that energy management just that little bit easier - especially for managers of multiple sites".