By Rita Tatum
Building Automation Article Use Policy
The building automation system is unquestionably important in achieving energy savings. But over time, the initial benefits of automation begin eroding. “When facility managers want to ensure their buildings are running at peak performance, BAS optimization is key to meeting that initiative,” says Jay Stark, director of building automation at Parallel Technologies.
Stark explains that the BAS acts as the building’s central nervous system. When it is not working properly, he says, “performance in terms of comfort and energy use degrade.”
In an ideal world, the building automation system would be set-it-and-forget-it. In that perfect world, once a new system was installed, it would operate at peak performance throughout its life until advances in technology, changes in facility needs, or other external factors justified replacement. But the real world is more complex. Gradually, after the BAS in installed, energy bills begin rising, along with building occupants’ complaints about comfort. Some areas are too hot, while others are too cold. The humidity is too high or too low. HVAC systems seem to be getting louder in the workplace, leading to noise complaints.
Experts agree that periodically optimizing the BAS is essential to ensure building systems are running within their initial design parameters. Over time, many things can and do go wrong. Depending on the brand and type of BAS, many obstacles can prevent or diminish “a good BAS controls system from properly passing critical information around within the network,” says Gary Pabst, president of BCSE-RCx.
Pabst believes human actions rather than controls are frequently the culprit. “Operators change or override occupancy schedules, lock temperature set points, and put bandages on systems instead of finding solutions,” maintains Pabst. For example, he says, “BAS operators tend to override energy saving reset parameters when a hot/cold call comes in.”
There are a multitude of specific problems that can arise as the years pass.
One common challenge is incorrect building or room pressurization. “Because of pressurization, air might be brought in from undesired locations, causing hot, cold, or condensation issues within the building,” explains Troy Windom, automation manager at Dewberry.
Other common problems include simultaneous heating and cooling, and waterside economizers not running when they should.
Because the BAS touches so many other systems, optimization measures extend beyond BAS. Operation of mechanical equipment, even with the best controls, slips in performance in as little as 18 months, according to Pabst.
Signs of trouble
Rising energy use and more frequent occupant comfort complaints are the two most common warning signs that optimization is needed.
“If the building’s energy usage continually is going up and there haven’t been major changes to the building, then the rising energy usage should be an alarm bell to get in and figure out where the energy is going,” says Stark.
The financial impact of a sharp, unexpected energy increase could significantly impact the bottom line, “causing the owner to have to pay for the issue for the next year in higher energy cost,” says Windom. He calls energy savings the single biggest reason for facility managers to optimize the BAS.
Another warning condition is the age of the system. “A typical controls system lasts 15 years,” says Stark. “Mechanical equipment can need some major overhauling at the 15 to 20 year mark too. So anything that hasn’t been thoroughly looked at in more than 15 years is a red flag.” Many experts recommend optimization at much shorter intervals to prevent the situation from falling into a “red-flag” state.
For specialized facilities, other factors also may indicate the need for BAS optimization. “Examples include infection control in a hospital or avoiding lost research in a laboratory because of failed space conditions,” points out Windom.
Pabst contends that cost should never limit performing an optimization. “Optimization usually has a less than one year return on investment,” Pabst points out. “The results speak for themselves.”
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