4 FM quick reads on Building automation
1. Five Rules of Thumb Can Aid Decision to Replace or Upgrade BAS
Today's tip from comes from James Piper, contributing editor for Building Operating Management: Use these five rules of thumb to evaluate whether to replace or expand the building automation system.
Building automation systems, like all other building components, have a finite life. As they age, they become more difficult and expensive to keep operating. Components for replacement or expansion become harder to find. And frequently, manufactures cut off support to older systems, rendering them obsolete. When one factors in advances in system capabilities, facility executives face a challenging question: Is it better to expand an existing system or to replace it?
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 how 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. 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 costs is less than 125 percent of the cost to upgrade or expand, replace the system.
2. Free Handbook Can Help With Tracking, Improving Building Performance
Today's tip from Building Operating Management: A new, free handbook can help facility managers track and improve building performance for energy and building systems.
The Building Performance Handbook offers advice on tools that can be used to monitor the energy and system performance of buildings. Performance tracking is aimed at continuous improvement of building systems and operations. There are four elements to performance tracking:
• Collect data and track the performance of the HVAC and lighting systems, plus energy use data.
• Identify performance problems.
• Diagnose problems and identify solutions.
• Fix problems and verify results.
To help facility managers build a business case, the handbook identifies a range of benefits from performance tracking, including enhanced occupant satisfaction, reduced energy costs and increased property values.
There are three basic tools for performance tracking: energy benchmarking, utility bill analysis and the building automation system, which can help to collect and analyze data, identify and solve problems, and track results. In addition, the handbook identifies advanced tools for energy and system tracking that include energy information systems, building automation systems, and fault detection and diagnostic tools. But none of those tools can be most effective unless the appropriate management framework is in place. The handbook identifies six elements of an effective management framework:
1. Allocate resources, including making time for staff to analyze and act on performance data and providing training.
2. Identify a team, which should include both top management and operating staff, along with a champion.
3. Set specific performance goals.
4. To motivate staff, consider incentives ranging from creating recognition programs to linking bonuses to energy performance.
5. Ensure accountability with well defined reporting policies.
6. Include performance tracking goals in contracts.
The handbook was written by PECI, a non-profit organization devoted to energy efficiency, and funded by the California Commissioning Collaborative.
3. Basic Ways That Building Control Systems Can Help Save Energy
Today's tip from Building Operating Management: Building control systems offer a variety of basic energy saving capabilities.
There are a variety of energy saving strategies built into the energy management function of the current generation of controls. The energy savings from these functions can help justify the cost of new or upgraded energy management system.
One basic function is automatic stop-start. While this saves energy by turning equipment off at scheduled times, a more powerful strategy can be more effective. Known as stop-start optimization, this approach goes beyond a schedule by considering indoor and outdoor temperature to decide when a piece of HVAC equipment should be started and stopped.
Another important function is the system's ability to change set points automatically in response to changing conditions inside or outside of the building. A simple example is the air-side economizer cycle. When the temperature and humidity of outdoor air are appropriate, that outdoor air can be brought into a building without being heated or cooled.
A control system can also optimize the operation of chillers, boilers, cooling towers and pumps, adjusting equipment operation on the basis of loads.
A sophisticated strategy is called load shedding. That strategy adjusts HVAC equipment operation to reduce energy use. This may be done when a building is in danger of setting a new demand peak load, or it may be initiated in response to a signal from a utility.
As useful as these and other control strategies are, they can't be taken for granted. Over time, for example, start-stop schedules may cease to reflect actual building operations, possibly because of changes to the occupancy of a building. What's more, control strategies are all too often overridden by maintenance and operations staff. Those overrides are frequently intended to solve a problem, but the long term effect is often energy waste.
4. Consider Wireless Options When Planning a Controls Retrofit
Today's tip from Building Operating Management: Consider wireless options when planning a controls upgrade.
Controls retrofits can cut energy costs while improving occupant comfort and system flexibility. But taking the traditional hard-wired route can add significant cost and disruption to the project. In fact, the expense of installation for hard-wired projects can bump the overall project cost past the payback period that the company is willing to consider, sending energy savings down the drain.
Once it is installed, a wireless device offers flexibility throughout the life of a building. That's increasingly important, given the rising rates of change within facilities. That flexibility helps to ensure that energy savings are maintained. If changes in an office layout compromise the effectiveness of a hard-wired sensor, moving the device can be difficult and may not get done. With a wireless sensor, there's no need to rewire, so the chances of moving the device are far greater.
Today, wireless systems are available with a variety of measures to ensure security. Many require that any piece of data on the network must be able to show that it comes from a "trusted" source. Data that doesn't come from a trusted source is disregarded. What's more, most protocols add advanced encryption as another layer of security. And the use of proper firewalls and virtual networks for the building automation system increases security further.
Adding to the stability of wireless operation is the fact that today's communication technologies can change channels if an outside radio signal comes through on the frequency being used by the system. In fact, many systems are constantly changing channels to prevent the wireless signals from being interrupted or spied on.
A wide variety of controls manufacturers are offering wireless products, and experts say that many systems offer high performance and reliability. Today, anyone considering a controls retrofit ought to take a look at wireless options.