AutomatedBuildings.com Column - Everything gets old

Many of the systems that go into a commercial building are anticipated to have a long lifetime. We expect building materials such as structural steel or concrete to last for the life of the building. The mechanical and electrical systems are expected to have a service life that may be from 15 – 40 years depending upon the systems selected. At the same time though, there are parts of the building that have fairly short lives. For example, carpet and paint may only be expected to last for five years before it needs to be refreshed. If we start looking at the owner’s equipment we find that much of the IT gear, such as PC’s, printers, and networking equipment, may have a service life of 2 – 5 years before it is functionally obsolete.

So where do controls and BAS fit in this mix? Well since they are part of the mechanical system, it seems reasonable to expect them to last for up to 40 years. In reality some parts of the control system (such as dampers or valves) might very well last that long. But the vast majority of the control system is similar to the owner’s IT gear than mechanical equipment and is going to have a much shorter life span. How short? The answer is “it depends”. Here are some general rules of thumb:

Software: Expect to do regular updates every few years. Software updates may provide additional features and functions, but are just as likely to repair “bugs”. Software updates are also needed to deal with ongoing changes to operating systems, hardware drivers, etc. Some owners use a service contract to keep software up to date. If you aren’t under some type of agreement you should plan on budgeting for periodic updates.
Building / Network Controller Hardware: Most larger controllers, which are connected to a network, share hardware and firmware with PC’s. This is hardware that is rapidly evolving and the semi-conductors, drivers, and other components are often only available to OEMs for a 2 – 5 year period. Many BAS suppliers may stockpile parts but after a certain period of time these products reach what is called “end of life” after which replacing failed parts becomes difficult if not impossible.
Application Specific Controllers: The smaller controllers used for I/O controlling equipment such as fan coils, VAV boxes, and rooftops also suffer from obsolescence. In many cases, these devices may have a lifespan that is 5 – 7 years.

Open Systems and Obsolescence:

One of the goals of using an open protocol based system is to be able to avoid obsolescence. While it may not make the problem go away, it does give options for dealing with system components that have reached end of life. Owners that are using open protocol systems such as BACnet or LonMark can often select replacement controllers from a variety of suppliers in addition to the OEM. If an owner has an older, proprietary system, replacing obsolete devices may provide the ability to move over to open systems. Owners need to be sure to ask for this functionality from their suppliers – to be sure that their upgraded system is open.

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