PC access to a building
management system

Every building has heating or HVAC (heating, ventilation and air conditioning). In every case there is automated control to maintain a comfortable climate while minimising fuel consumed and energy wasted.

The degree of automation may be no more complex than most home central heating controls. Some buildings, however have a complex building management system. Most are somewhere in between.
But you can be sure there is that can be done in every case to make the HVAC system much more energyefficient, less expensive to run and also easier to use.

Automation saves energy and extends system life
Automated temperature control aims to provide the right temperature, in the right place, at the right time. Maintaining temperatures within close limits maximises comfort and saves energy. The heat provided by the boiler and other heat sources meets the demand – and that’s all.

A wireless zone system saves
fuel and reduces boiler wear

In small buildings such as surgeries, small professional businesses and retail premises, the ideal controls may be adapted from systems developed for homes. Energy savings can be made by splitting the system into separate heating zones with the same or similar time/temperature needs. This can be easily achieved on new and existing systems, without changing the plumbing, using a wireless zone system. It uses safe and reliable radio links from a central unit to wireless controllers on radiator valves and underfloor heating valves, which adjust automatically and individually to deliver desired temperatures.

Up to six time/temperature changes can be programmed for each day and a different program for each day of the week.

This type of system will also control boiler firing, to save fuel and reduce boiler wear. In common with most other modern controls, it includes Optimum Start, which learns the characteristics of the zone to vary the boiler start-up each morning, depending on the prevailing temperature. The user sets the time by which a desired temperature should be reached, not the boiler start time.

Building management systems
Larger buildings in the small-to-medium size range will benefit from a building management system. It provides the flexibility to view temperatures throughout the building, to adjust them instantaneously from a PC and to create a standard schedule for each zone or room.

Building management has moved forwards technologically in huge leaps and bounds over the past 15 years. From stand alone HVAC controls, it has progressed through proprietary automation systems to open networks with the possibility of integrating every building application. Industry standard networks ensure vendor independence, inter-operability and great versatility.

You can start small, with one, or a few building controllers and sensors, then expand your system with networked access and other components, as budgets allow.

A networked automation system, which is equally suited to existing and new buildings, will inevitably repay its cost very quickly by saving energy. There is no need to change boilers, radiators or pipework unless they need changing anyway.

Its aim is to maintain desired comfort conditions in each building location when it is required, without wasting energy by heating or cooling either to excess, or at times when the location is unoccupied.

It uses many techniques, such as monitoring the prevailing climate to adjust boiler start-up times, avoiding pumping heat where it is not required, considering the building’s heat loss characteristics and additional energy sources such as the sun, computers and body heat. It will ensure excessive system temperatures do not damage the system installation. It also prevents frost condensation damage to the heating system, building fabric and contents.

Using the automation system
However, while buildings need an automation system that takes a comprehensive view of many possible ways to save energy, all the clever stuff should work invisibly in the background, so those who may need to change the settings from day to day will never have to bother about the technicalities or programming. The system must be easy to operate and as intuitive as possible for non-technical personnel, especially in buildings where there are frequent changes to the rooms used and/or the way the rooms are used, such as hotels, conference centres, leisure centres and schools.

By choosing a user interface system that uses a standard web browser on a PC, and which is intuitive and therefore very easy to use and understand, they can easily prepare a standard schedule of rooms that will be used on each day of the week, from within the building or remotely via the web. They can also make changes instantly as needed, with a few mouse movements and clicks. For example, a school may need to extend the period of heating in certain rooms, for after-school activities.

System interface: on site or remote
The operator interface for HVAC plant has progressed from a collection of wall mounted instruments in the boiler room, to virtual controls displayed on a standard PC. This can be located within the building, connected anywhere on its local area network, or in another building using the enterprise’s wide area network, or a dial-up connection, or via the internet.

Password access enables authorised users to monitor and make changes to match climate conditions with room occupation. These personnel might be the caretaker, the facilities manager, a secretary or receptionist. Restrictions may apply so, for example, day-to-day users can alter room temperatures and heating timers but not boiler and system parameters.

A building manager can monitor all the buildings for which he or she has responsibility from his or her office, wherever the buildings are located: on the same campus, in the same town or on the other side of the world. The use of internet technology, specifically Internet Portocol (IP), allows a building system to be accessed by authorised personnel from anywhere in the world.

At a third level, the system can be accessed by remote maintenance/service personnel, either the building manager’s own service team or a specialist HVAC contractor who can monitor the system and react instantaneously to alarms. When a fault develops, the contractor will often be able to eliminate it before building residents are aware of a problem.

Control over existing IP network can cut costs
The adoption of internet technologies significantly simplifies the installation of building automation and reduces costs dramatically. With a web-enabled controller, the existing IP network (Ethernet LAN/WAN) can be used for plant controllers, as well as the web browsers used for information and control. There is no need for a separate control network. When these controllers are fully LonWorks and BACnet compatible, they can interface with all the devices in the building automation system, from sensors and room controllers to plant actuators, from any manufacturer.

An IP-enabled building controller can host a huge variety of applications, in addition to traditional HVAC, such as energy management (including optimum start/stop), night purge and maximum load demand; supervisory functions for lighting, sun-blind, heat and energy metering and more.

Energy management
The system allows building managers to monitor each building’s energy consumption and review trends in temperature and fuel usage. This can reveal places where energy is being wasted, leading to further savings. Information from many buildings can be collected at a central point using the internet. It provides instant data on energy costs in each building and how they vary from day to day, week to week and month to month.

If the computer network or internet connection fails, the heating system continues to work and can be controlled manually from the boiler panel if necessary.

The system is an ‘electronic caretaker’, consistently applying self-adaptive tuning programs. It avoids delivering heat to parts of a building where it is unnecessary to maintain temperatures, so avoiding the boiler from running unnecessarily and heat being wasted by heating pipes, not radiators or heat exchangers. It considers outdoor temperatures, the building’s heating/cooling storage mass and heat gains, such as from the sun, human body heat and electrical equipment.

Integrated systems
In the largest buildings, an integrated system can provide complete control of all a building’s core systems, such as HVAC, security, access control and fire, as well as other real-time and historical information.

Operators and executives can have access to comprehensive reporting capabilities on each of these subsystems, either as preconfigured standard reports or customised to the facility’s needs.

Don’t be frightened!
The keys to successful system implementation and achievement of energy savings, are products and software which have been well thoughtout, well proven and configured to the specific needs of your building. Don’t be frightened off by the implied complexity! Your system components will be well proven and include a wealth of know-how gained from many other buildings. You can choose such a system with hundreds of different selectable applications and parameter settings to make setting up easy.

The controllers and other devices are connected on a LonWorks industry standard network, which is future-proof. Networked automation of a building’s HVAC system is no longer a luxury but a ‘must have’ now there is high awareness of climate change and the need to reduce energy costs. Your choice of a proven, sophisticated yet user-friendly system such as described here will make energy saving altogether painless.

Harry Swinbourne is UK business manager at Centraline by Honeywell.

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