Planning for cost-effective upgrading
In any large organisation, the building-management system will typically control about 60 to 80% of the energy spend.
Investing in a new BMS system is a major decision for most organisations. Richard Urwin considers how to make the most of that investment.The benefits of using a building-management system are well documented. Energy is generally recognised as the third largest cost for businesses after the people and the buildings, so careful energy management can make a real difference to the bottom line. Energy spend
It is now unusual for any medium size or large organisation not to use a BMS for energy management, and this system will typically control about 60 to 80% of the energy spend. With the impact of the Climate Change Levy and rising utility costs increasing this overhead, it is becoming essential to ensure that the BMS is operating as efficiently and effectively as possible. However, technology doesn’t stay still, and it often seems as if both software and hardware can be out of date immediately we choose to invest in it. Building-management systems are no exception to this, and there are always new models with increased functionality on the market, which could make managing a building easier and more cost effective. This leaves many facility or energy managers with a dilemma, as finding the budget for even a small upgrade can be difficult when such a major investment has already been made in the initial system. This problem is magnified when the upgrade involves moving to a whole new system, with the financial outlay for the new system, in addition to the potential downtime while it is being installed. Pressure
These issues mean there never seems to be a good time to change, and companies may often be left with underperforming systems and lose out on the energy and monetary savings that could otherwise be achieved. With the pressure to cut budgets ever present, whether or not to upgrade is a tough decision, and companies need to weigh up the initial outlay with the potential timeframe for this to be recouped through energy savings. The best approach is to avoid these problems when making the initial investment, for example by choosing a BMS with a clear upgrade path, from a supplier with a proven track record of keeping pace with changes in technology and standards. For example, choosing a system using Internet Protocol (IP) addressing will allow organisations to ‘piggy back’ on other network investments in their buildings, such as a corporate Ethernet, with a variety of business and building services applications. This has the double benefit of reducing the number (and the associated cost) of cable networks, while providing a more unified view of the systems operating in a building. A word of caution is needed, however. To achieve acceptance from the IT community for sharing a network on a client’s site, the BMS must be able to prove it is a good ‘IT citizen’. One of the key criteria is the communications traffic the BMS will generate. This is not a problem if, as in the case of Invensys Sigma, the maximum traffic between the server and the controllers is below 1% of the available bandwidth at 10 Mb. Common standards
The increasingly open architecture of modern building-management systems also allows organisations to adopt common standards. A modern BMS will provide multiple communication options. With Invensys Sigma, for example, this means Ethernet, ARCNET, and the proprietary Sigma protocol, plus integration of LON, BACnet, Modbus and other protocols to allow monitoring and reporting from multiple third party systems. When choosing a BMS for the first time, it is also worth researching the manufacturer’s commitment to ‘backwards compatibility’ as well as its investment in developing future technology. The average sensor can still be in service after 20 or 30 years, yet software has a much shorter lifespan. Just look at how quickly we have moved from Windows 3.1 to Windows XP, and many manufacturers will plan for these changes. Ideally, clients will be able to retain most of their field and controller hardware while maintaining compatibility with the latest PC-based system, by simply fitting new controller firmware or a cost-effective plug-in replacement PCB. Minimise additional investment
For those organisations already using a building-management system and wanting to move to a completely new system, but who want to minimise the additional investment as much as possible, there are options available to avoid replacing all the hardware and BMS infrastructure within the building. Integrators address this need. An example is Satchwell’s BAS Integrator, which gives existing BAS 2800+ users the option to move more cost effectively to the Sigma system. BAS Integrator is software based and resides on a Sigma server. It seamlessly links the two systems together to provide a common user interface via the Sigma system, providing core Sigma functionality across the whole of the integrated system. Depending on the particular installation, a total upgrade may still prove the best route, but such integration is a valuable option, particularly suited to larger sites unable to afford a full hardware upgrade. Furthermore, because the implementation can be phased and is predominantly software based, there will be minimal downtime. There are a number of ways in which users can try to avoid completely writing off a large investment in their building management system while still ensuring their technology is as up to date as possible. With more and more organisations constantly striving to save both energy and cost, maximising your BMS is increasingly essential. Richard Urwin is Satchwell’s European product business manager with Climate Controls Europe, PO Box 57, Farnham Road, Slough, Berks SL1 4UH.