Building Operating Management

Expand or Replace the BAS? Five Issues to Consider

By James Piper, P.E.   Building Automation

For more than two decades, building automation systems have been shown to be valuable for a wide range of facility types. During this time, systems have vastly expanded in both capacity and capability. Interoperability has allowed standalone systems to be merged into a single, comprehensive system. Wireless technology has helped to reduce installation costs while increasing system flexibility. Advances in computer technology have slashed equipment costs while vastly improving system performance. Software improvements have made the systems easier to use.

Building automation systems, like all other building components, have a finite life. As they age, it becomes more difficult and expensive to keep them operating effectively. Components for replacement or expansion become harder to find. Frequently, manufacturers cut off support to older systems, rendering them obsolete. When factoring in advances in system capabilities, facility executives face a challenging question: Is it better to expand an existing system or to replace it?

A good way to answer to that question is with a five-step process: determining the facility automation needs, reviewing the capabilities of the existing system, identifying the limitations of the existing system, understanding the benefits of a new system, and weighing the options.

Facility Automation Needs

Perhaps the most important step, and yet the one most often skipped, in the expand-or-replace evaluation process, is the identification of the facility’s automation needs. Too many systems are sold by the “wow” factor. Facility executives are given the demonstration that includes all of the bells and whistles of a new generation automation system, and they are sold.

New generation systems are powerful and have capabilities unheard of even ten years ago. The graphics can present an impressive picture of what is going on within different areas of the facility. But those capabilities are useful only if they meet some specific existing need of the facility. Investing in system capabilities that are not needed is simply a waste of money.

Start with a function assessment. Building automation systems perform a wide range of functions, including energy management, HVAC system operation, security management, asset management and financial analysis. Examine how those functions are currently being carried out. Are the systems that are currently performing those functions able to seamlessly transfer data, or must data from one system be entered manually into another system? What level of control is being exercised over energy-using systems?

Identify additional functions that would benefit the facility. System designs and capabilities have seen tremendous improvements in just the past five years. New functions have been added and old ones have been upgraded and enhanced. Look at how the facility is currently being operated, what functions are being performed, and how a building automation system might be used to support or enhance those operations.

When identifying the automation needs for a facility, remember that facility needs, like the facilities themselves, are not static. Tenants change. Tenants’ needs change. Even the way that energy is purchased changes. Automation needs must take into consideration these future changes.

Next, identify and rank the goals for why the expansion or replacement project is being considered. The goals should be narrow and specific, such as reducing facility energy use by 10 percent or reducing the maintenance backlog by one day. Clearly defined goals that identify what facility executives want to get out of the new system will help to identify the data the systems will need and who will need access to it. Clear goals will also decrease the chances that the completed system will either under-perform or be overly complex and costly.

Review the Existing System

One of the most important factors to consider when reviewing the capabilities of the existing system is that most existing systems are not used to their full potential. Some functions included in the original system may not have been needed when it was first installed. Management may have decided that other functions required too much effort or the collection of too much data to be of value. Still other functions may have been used initially, but dropped due to the lack of manpower or simply because they were too difficult to use.

Before making a decision to invest in a new system to gain additional system capabilities, make certain that they are not already available with the current system.

A review of existing capabilities must extend beyond the system itself to the building systems and components the BAS will be interfacing with. Having the ability to control the operation of all building HVAC equipment is a feature needed if managing facility energy use is one of the primary goals of the system. If the HVAC systems themselves do not have the controls of the type and level of sophistication needed, then the energy savings impact of the new system will not reach its full potential.

Existing System Limitations

Another factor to consider is the limitations of existing systems. Evolution in the building automation field has brought changes not only in what the systems can accomplish but also in how they accomplish it. While this has led to increased system performance at a lower cost, it has also made many older systems obsolete. Many of those systems simply are not compatible with the architecture employed in new system designs. As a result, if any changes are made to the existing system, they must be made using components compatible with that system.

There’s another side to obsolescence. Manufacturers understandably promote the new systems while phasing out the older ones. While most will continue to support older systems for a period of time, there comes a point when it is no longer economically feasible for them to do so. When this occurs, these older generation systems become orphaned systems. Replacement and expansion parts become difficult or impossible to find. Service support may no longer be available. At that point, facility executives may be looking at total system replacement.

Some limitations of existing systems may not be the result of the system’s architecture, but rather the way the system has been operated and maintained. Over the life of a building automation system, the system’s manufacturer routinely releases upgrades to the system’s software, firmware and hardware. Unfortunately, some system owners fail to keep up with these upgrades. These upgrades often serve to correct past operating problems as well as to offer system enhancements. Without them, system performance will suffer, particularly in comparison to new and upgraded systems.

It is important to talk to those who operate, maintain and work with the existing systems to identify strengths and weaknesses in those systems that management may not be aware of. The operating staff can also help to determine if the number of problems is remaining constant, increasing or decreasing.

Finally, determine how well the existing system is being maintained. What might be perceived as a system limitation may be the result of a lack of proper maintenance. And if the existing system is not being properly maintained, how can management ensure that the new system will not suffer the same consequences?

Benefits of New Technology

One of the most significant benefits of replacing a system is the ability to take advantage of new system technologies. Consider the use of a wireless communication infrastructure. In wired systems, the cost of installing the communication cabling typically accounts for one-third of the installation cost of a system. But those costs don’t stop there. Every time a device is changed, moved or added, changes must be made to the communications cabling. In wireless systems, those costs are largely avoided.

Replacing a BAS also staves off obsolescence. All system designs have a finite service life, typically around 10 years. If a seven-year-old system is expanded or upgraded, it may slightly extend its service life, as long as the manufacturer continues to support it. In contrast, a new system would reset the clock on both service life and manufacturer support.

System replacement also offers facility executives the opportunity to more closely match system features and capabilities with facility needs. Expanding or upgrading an existing system may bring system features and facility needs into close agreement, but chances are that alignment will never be as close as could be achieved with a complete replacement.

Weighing the Options

After examining how well the current system is meeting the needs of the facility, as well as what new options are available in the latest generation of building automation systems, it is time to evaluate the options. For existing and possible replacement systems, develop a list of all the positive and negative aspects of each system. In addition to the features and limitations of the systems, consider other factors, such as how easy the system is to operate, the level of training required for both operators and mechanics to use the system, how well the system is supported by the manufacturer, and how difficult it is to obtain service and spare parts.

Another important factor to consider is if there is a mechanism for upgrading the current system so that it is compatible with the latest generation system from that manufacturer. If an upgrade path is available, chances are that an upgrade could approach the level of functionality of a system replacement at a much lower cost.

All systems also have a limit on their maximum size. As systems approach this size limit, they can experience significant decreases in performance. If the current system is approaching this limit, or if any planned expansion results in the system approaching this limit, that’s an argument for system replacement. Maxing out a system severely limits future changes and growth, as well as performance.

Finally, it’s useful to consider the relationship with the vendor that supports the existing system. Vendor issues weigh heavily in the decision-making process. Nevertheless, be careful not to confuse a lack of vendor support for poor system performance.

Several rules of thumb can help when choosing between expanding the existing system or replacing it:

  1. If the existing system is still supported by the manufacturer, has the capability of performing all of the functions needed and has sufficient capacity to expand by 50 percent, consider expanding rather than replacing.
  2. If the performance of the existing system is an issue, and the software and firmware have not been upgraded to their latest versions, investigate whether an upgrade would improve performance, how much it would cost, and how those costs compare to the cost of replacement.
  3. If the lack of proper maintenance has led to the situation where replacement is a consideration, address the maintenance issue first. Clearly if maintenance will restore the existing system, it may not be necessary to replace it. But if the system is replaced without addressing maintenance, the cycle will repeat itself.
  4. If the existing system is an orphan that cannot be upgraded, replacement most likely will be the best option.
  5. Compare the cost of upgrading the existing system to the cost of replacing it. If the existing system is more than ten years old, and the replacement cost is less than 125 percent of the cost to upgrade or expand, replace the system.

James Piper, PhD, PE, is a writer and consultant who has more than 25 years of experience in facilities management. He is a contributing editor for Building Operating Management.

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  posted on 5/1/2008   Article Use Policy

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