In a perfect world, buildings would perform as well as they did the day they were built. Unfortunately, it doesn’t work that way. Mechanical parts wear out, settings change, qualified maintenance staff turns over, the list goes on. In time, we experience a phenomenon in our buildings called building energy drift. Simply stated, without tuning up our buildings now and then, we run the risk of discovering they are not performing as intended. The consequence is higher operational costs, higher utility bills and the need for capital replacements.
One thing is certain in the green building world, a highly energy-efficient building operated inefficiently will not perform to peak capability. The first major study done on the anticipated energy performance of buildings certified under LEED for New Construction was undertaken in 2008 by the New Buildings Institute, Portland, Ore. The study, which can be found here, highlighted that many of the buildings were performing as intended, but 25 percent of the buildings were performing significantly worse than anticipated.
Not all buildings age the same way or have the same level of maintenance. Proactive preventative maintenance and upgrades often give way to reactive replacement. The reality is that there can be as much as a 10 to 30 percent drift of energy costs in a building over time if not maintained properly.
A Tuneup for Buildings
Commissioning is the process that we use to check the performance of our buildings. It is a third-party verification procedure to ensure that building systems are operating as the design team intended. The building owner typically hires a commissioning agent to act on his or her behalf to investigate the building and report on findings. Commissioning agents are generally mechanical engineers or building-energy experts that have a credential from a reputable commissioning trade group, such as the Building Commissioning Association, Beaverton, Ore.
The commissioning process involves detailed examination of the mechanical, electrical and plumbing systems of a building to determine if they are functioning as designed. Issues that can be discovered range from fans connected so they run in reverse rotation, HVAC controls out of sequence, HVAC systems that call simultaneously for heating and cooling, and pumps running in reverse rotation. Mechanical equipment can wear out over time or have components improperly replaced.
The human element is also a cause of decreased energy performance in our buildings. Maintenance and operations staff may not receive proper training on the equipment or knowledge is lost when staff turnover occurs. Implementing a staff training program and regular refresher courses may help prevent errors.
In every instance of commissioning in which I have been involved, the energy savings discovered pays back the cost of the commissioning agent’s fees in less than one year. Mistakes get made in the construction process every day, most not intentionally. But if these mistakes are not discovered and corrected, you may be paying extra in utility costs for years to come.
Everyone knows the adage, “you can’t manage what you don’t measure”. In the past, sophisticated building-management systems (BMS) were needed to monitor HVAC and electrical equipment and give real-time feedback and trouble indications. The problem is these types of building-management systems are not common in small buildings. Thankfully, it’s becoming easier to measure performance of building systems through advanced technology.
The cost to install a BMS was not practical for a small building with more simplistic mechanical and electrical equipment. Retrofitting was not generally an option because of the need to run complex electrical and data wiring in hard-to-reach places. However, several manufacturers are now making BMS systems specifically geared toward retrofitting smaller buildings using equipment sensors with wireless technology. The equipment sensors send a wireless signal to a data-collection box connected to the internet, and real-time equipment performance feedback and trouble reports are generated. Some systems will send trouble alerts directly to a cell phone when a piece of equipment operates outside of the set points. Getting real-time feedback about how building systems are performing has never been easier.
Another way to keep tabs on building performance is to implement a thorough preventative maintenance plan. Too often today we are reactive rather than proactive when it comes to maintaining our buildings. We wait until something is broken before replacements happen or only make repairs that may prevent system failure and occupant discomfort.
Implementing a preventative maintenance program requires a thorough understanding of the existing condition and expected useful life of the building equipment. A preventative maintenance plan will help a building owner to properly budget for the repairs and replacements over time rather than be surprised when a piece of equipment breaks down unexpectedly.
Buildings can be expensive to operate. When we’re not paying attention to the efficiency of our buildings, utility and operational costs have a tendency to creep up. The key to keeping away the dreaded building energy drift is a proactive commissioning and preventative maintenance approach that will address immediate issues and plan for future repairs and replacements. Hiring a qualified commissioning agent to examine your building is one of the smartest things you can do to help keep energy and operational costs in check.