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Getting Past the Building-Performance Brick Wall

Sept. 3, 2013
The process of designing and implementing a building-control system has remained unchanged for decades, even as the potential to improve building performance has grown enormously.

It is sobering to read through the studies and statistics that show quite convincingly that the energy performance of commercial buildings has not advanced at all over the last decade or so. Even more discouraging is the number of new buildings that underperform from an energy standpoint. What’s happening here? Is the industry really that incompetent that it cannot do any better?

No, it’s not a result of incompetence. It is what I call the “Brick Wall Syndrome.” Put in the simplest terms, the challenge of actually achieving higher-performing buildings is more than any one of the independent entities in the industry can solve. As a result, no solution is developed, and the industry has hit a brick wall in building-energy performance.

In a nutshell, commercial buildings on average use roughly twice the amount of energy as would be required if their operation were fully optimized. Here’s why: At the end of the last century a number of important energy efficiency developments took place. Variable-speed drives, condensing boilers, and high efficiency chillers/unitary equipment all were developed over a short time span. Along with improved building-envelope technologies, these offered the industry incredible advances in overall building operating efficiency. But almost none of that energy-reduction potential has been realized.

Leaders in the industry have come to understand that most potential energy-performance advances are now captured not with component efficiency, but rather with how components are integrated to operate together most efficiently. For example, in most commercial buildings today, simultaneous heating and cooling caused by poor control is still a major problem. I recently talked to the energy manager of a large campus who told me he was surprised to find a project to save cooling energy by raising the chilled water temperature and reducing its pressure in cooler weather resulted in almost the same amount of heating as cooling saved — and both were substantial. This was almost entirely because of unintended overlap between heating and cooling in campus buildings.

What we have learned is that, within limits, individual component efficiency is not the major factor in advancing building performance. Rather, the key is control. There are three elements to effective building control. The first is control that effectively coordinates all the components of each system and then all the systems together to generate and distribute heating, cooling, airflow, and lighting as efficiently as possible. The second is control that effectively distributes these resources to where the needs are in the building. The third is control that continually evaluates system operation and both alerts operations and maintenance support and automatically compensates system operation when a component or system is not performing as it should.

Each of these fundamental elements is sadly lacking in building control systems as they are designed, implemented, and operated today. And it is not surprising to see why. Currently, control software is conceptualized in a one-of-kind basis for buildings by engineering teams that often have no experience with modern controls. These teams incorporate outdated concepts that restrict the ability of system components to operate so as to achieve overall efficient operation. The engineer’s concept document, known as the “sequence of operations” is then handed to the contractor’s selected controls subcontractor, who, independent of the engineer, integrates those crude sequences into an actual software operations scheme. That software is then massaged during startup and commissioning until a workable status is achieved. At that time it is all turned over to an operations staff whose only support, if any, comes from the implementer.

The result of this disconnected process is the crude building controls we see operating in buildings today. They’re only a marginally better than the old-fashioned mechanical control systems used before digital controls. The problem is that no one in this loose chain of events can do anything to change the outdated process because no one has the authority or control over — not to mention the understanding of — all the other stages of the process. So the process has remained unchanged for decades as its potential to improve building performance has grown enormously.

It’s well past time to make the changes needed to capture the enormous overall building performance improvements that are so close and available, yet so difficult to achieve today. Here’s how to do it. Buildings simply need performance standards with modest penalties to those that fail to achieve them. It’s shameful that the federal government has to date abdicated its responsibility in this critical area of our national interest, and we should all encourage it to become more proactive. But in the meantime, forward-thinking states, regions, and cities can and should take up the challenge. Employing phased-in annual performance requirements that are based on actual utility use with a target of, say, 50 percent reduction by 2030 would be relatively easy to set up and administer. And it would allow the industry itself to figure out how to develop most effectively the needed changes to the outdated process it now uses.  It is the most straightforward way I can envision to challenge the industry to provide the building performance we all know is possible!

 I invite your thoughts, comments, and good ideas about this article. Please contact me at [email protected].

Thomas Hartman, PE, is principal of The Hartman Co., Georgetown, TX. He can be reached at 254/793-0120, or by e-mail at [email protected].