The ability to measure and benchmark building performance is an integral component of Smart Grid technologies; building owners that implement data collection systems now will be better positioned for Smart Grid adoption down the road.
By: H. Jay Enck, CxAP, HBDP, Commissioning and Green Building Solutions Inc., Duluth
With utility costs rising apparently with little end in sight, many building owners and operators view the potential of Smart Grids and their associated technologies with excitement. The transition of the century-old U.S. power grid, which is the largest interconnected web of technology and machinery on Earth, into a Smart Grid has begun, with technological advancements being implemented in transmission efficiency, integration of intermittent power sources such as solar and wind, distributed combined heat and power systems, and smarter buildings.
Already, Smart Grid pilot projects are showing promising results. In North Carolina, 100 Fayetteville residents and businesses cut energy use an average of 20% during a six-month pilot in 2010. As these systems come online, they can have enough impact to reduce the building of new power plants—an expense that is largely borne by the residential and commercial sectors.
On an individual basis, businesses in some areas are reaping minor benefits from Smart Grid technologies such as two-way communication enabled by smart meters. For example, some business owners currently power down noncontinuous, noncritical operations—from computers and printers to production line assemblies—based on real-time utility pricing—during designated times of peak power usage and rates. Even critical machinery such as cooling and refrigeration systems is being duty-cycled periodically without affecting operational effectiveness.
Many commercial, institutional, and industrial facilities allow utilities to bring on power generation assets automatically to meet utility-grid peak demand and manage alternative energy source integration with the electrical power grid. These are the baby steps that only hint at what lies ahead.
Much work and coordination is needed and underway by the utility, building, and government sectors to make widespread Smart Grid deployment a reality. Owners of existing buildings that are not yet able to participate in these programs may be asking their engineers how they can speed up the process.
While it’s beneficial to stay engaged with local utilities and thereby be apprised of available Smart Grid projects, the reality is that outside forces and factors play a large role in when Smart Grid benefits will be available to a given location. Astute engineers can show building owners that analysis of existing configurations now to identify internal operational improvements—and where it is possible to implement them—is the best way to prepare for Smart Grid technology.
These improvements and the data that drive them, both of which focus on making the buildings smart in themselves, provide real-time feedback on the building’s performance through information gathered from smart utility meters, advanced metering systems, building equipment sensors, occupant surveys, and other mechanisms (see Figure 1). Not only do building performance indicators provide management and operations staff with the information to operate a building for maximum economic, environmental, and social performance in the short term, but the data they provide create valuable benchmarks for building performance over time.
Act, don’t react
An increasing number of building owners are embracing the concepts of recommissioning and retro-commissioning to ensure maximum efficiency of their buildings and, in some cases, bring buildings back to original operational goals. However, since these planned “interventions” are often large, big-budget projects, it is easy for business owners to reject them in the present, opting to plan for them when the economic climate improves.
This reluctance does not negate the fact that changes made by controls contractors and operational staff after completion of construction in even the newest buildings can result in degradation of building performance. These changes also affect occupant satisfaction and productivity, and impact a firm’s ability to achieve the Triple Bottom Line (social, environmental, and economic) benefits that are considered best practices in building construction and operation today.
By encouraging monitoring, effective analysis, and correction, coupled with viewing improvements as modular components and prioritizing them properly, engineers can help building owners achieve benefits with minimal expense and operational disruption. Three areas of potential improvement that deserve attention long before Smart Grid adoption (due to their potential to involve substantial improvements in performance) are:
- Conduct occupant satisfaction and productivity surveys, and act on the information received
- Analyze (and possibly improve) existing BAS and the success with which information is extracted from them and used to increase efficiency
- Evaluate metering points for utilities to determine if information is sufficient or if additional metering points are needed to provide useful data.
Conduct and act upon occupant surveys
An occupant survey is a vital source of information for improving both a building’s performance and the productivity of the occupants within it. Surveys help owners determine which building services and design features work as intended, and where problems are causing the occupants to intervene or be less productive than optimal.
Occupants who are dissatisfied with their environment will install fans, electric heaters, additional lighting, and other personal improvements—all of which can reduce the satisfaction of other occupants and negatively impact operating costs. Fear of reprisal may prohibit occupants from answering surveys honestly, so respondents should be reassured that all comments are welcome and will be handled sensitively.
Surveys should encourage participants to move beyond the typical enhancements to less-common issues. For example, an occupant might be placing paper over air registers/diffusers because he is cold, or running portable air purifiers because he has a perception, however untrue, that the air in the building is not clean.
Occupant surveys should also incorporate concerns for productivity such as ambient noise. If personnel cannot work effectively because the office environment is open or established as a cubicle farm that does not sufficiently dampen the sound of nearby discussions, productivity will be affected. Likewise, perhaps some personnel do not have enough space to perform their work.
Try to uncover every physical constraint and indoor environmental quality complaint and then make a plan to address them. These benefits can be enormous, as productivity savings routinely exceed direct energy cost returns and provide significant savings.
In a typical building, energy costs average $1.50 to $2.50/sq ft per year, while salaries exceed $200/sq ft. Cutting energy use in half typically saves $1.00/sq ft. Boosting productivity just 5% saves more than $10/sq ft per year.
At the minimum, occupant surveys should collect input on:
- Acoustic quality
- Air quality
- Office furnishings
- Office layout
- Thermal comfort
- Nonspecific comments or concerns.
While surveying occupants, don’t overlook collecting opinions on building performance—even if they do not affect comfort. This is particularly important information to gain from operations and maintenance staff or those who travel frequently throughout the building.
Collectively, this information will suggest improvements to significantly improve building performance. A building’s environmental, social, and economic performance is a direct reflection of how efficiently it is operating and being maintained.
The goal is to minimize operating costs while meeting the specific needs of the occupants in execution of their daily missions. However, occupant surveys can also make it easier for engineers to justify recommended efficiency improvements. On the owner’s side, survey results provide beneficial information to be used in leasing office space and meeting regulatory requirements.
Analyze and monitor BAS
To effectively analyze building efficiency and identify improvements that may be recommended prior to Smart Grid adoption, engineers should encourage the collection of BAS input and output data on a historical basis (trending data). Metering data should also be rolled into the analysis.
Enabling a continuous flow of building system data is an initial, important step in modifying operating parameters. It positions building owners to engage power generation assets and power reduction strategies based on information from the Smart Grid when it becomes available.
Without a reliable, consistent measurement process, it is impractical (and potentially impossible) to make valid decisions on how to modify building operation in accordance with the information being supplied through the Smart Grid.
If these data are already being collected, the building may be ready for an analysis now:
- Isolate electrical loads by load type such as lighting, HVAC, plug, and process loads to provide great insight into the operation of the building and assist in establishing a baseline.
- Once the baseline is established, consumption can be adjusted based on a variety of factors such as weather, occupancy factors, and facility modifications. This provides a benchmark by load type, helping management and operators to identify where to look for issues and to determine whether the facility is within allowable operating tolerances.
- Recording trend data through the BAS provides detailed information on system interaction and operation that can help the operator solve performance issues.
Building owners and operations personnel often do not have the knowledge to analyze these data effectively. If this is the case, realizing long-term improvements will require making the data accessible to operational experts who can analyze them and suggest quick corrections of operational missteps that degrade the building’s performance.
If BAS infrastructure is seriously outdated and incapable of providing enough useful information, building owners may be able to upgrade their BAS installations or convert to a newer system. Preparation for Smart Grid adoption is an excellent time to ensure BAS solutions work effectively and provide the appropriate amount of data in a form the building owner can use effectively.
Whether the building owner decides to explore an upgrade or convert to a newer system, engineers should encourage him or her to reject options that perpetuate closed, proprietary solutions. BAS technology has moved from a model where proprietary systems with fixed life spans (approximately 15 years, historically) were the norm, to a more sustainable paradigm including the use of open protocols and network management tools. Furthermore, the sophistication of collection and analysis tools for open BAS systems has exploded.
Moving to an open, sustainable BAS standard—even for interconnectivity with legacy components—increases sustainability, reduces outlay, and expands options in the future. Not doing so can leave the owner trapped in an inflexible relationship where the vendor is in complete control of pricing and has less incentive to perform well. Open, interoperable communication protocols keep the owner in charge and improve vendor service through competition.
If a major retro-commissioning project is in the forecast, the time is optimal to update the BAS to facilitate continuous data collection. During retro-commissioning, the commissioning authority can verify that information is being accurately collected from the system, which is essential to ensuring a reliable data flow from the various inputs within the building’s systems.
If budgets are tight, many BAS providers offer support structures for legacy components that extend the life and functionality of the original BAS. These solutions are not always best practices and may require specialized installations and support. However, if cost effective, they can serve as a stop-gap until further improvements can be budgeted.
The ability to implement a BAS upgrade in a building is based on the entity operating inside it. This strengthens the case for planning—and at least partially upgrading—before Smart Grid arrival, as it allows appropriate scheduling to maximize benefits and cost savings to the owner.
Evaluate metering points
Owners of newer buildings may assume their metering and monitoring systems are sufficient and data from them are being adequately integrated into efficiency analyses. Many newer buildings incorporate Web-based control/monitoring and advanced metering of energy and water.
In reality, the newest buildings can suffer from the greatest shortcomings, especially if there was no commissioning element in place at the time of construction. For example, some newer buildings have excellent envelope designs that were completely negated by poor installation.
Conversely, older buildings that have been through retro-commissioning or benefit from an ongoing commissioning effort can be performing as well or better than new buildings that were constructed without commissioning and/or clear energy-efficiency benchmarks in place.
In the case of one university building project with which this engineering firm was involved post-construction, the university could have saved $500,000 in 5 years if it had instituted a monitoring-based commissioning process at the end of construction. Fortunately, it’s never too late to start monitoring, collecting, and analyzing data.
It is beneficial for building owners to examine their metering points, the data collected from them, and how they are being used. In many cases, installing additional submeters can provide insight into previously unrecognized problems.
These data should also be incorporated with BAS data for the most precise analysis of efficiency over time. Adding submetering that rolls up into and is saved with the BAS data adds tremendous value to the owner by providing direct correlation between how a building is operated and its utility consumption.
The graph shown in Figure 2 is an example of how an owner gets value from submetering. This graph shows phantom (or vampire) electrical loads, which suck energy through electrical equipment left in standby mode or turned off during unoccupied or nonuse periods. Typical sources of phantom loads are computers, monitors, televisions, sound systems, instant coffee makers, and electric space heaters that occupants often use for personal comfort.
Phantom electrical loads exist in almost every building and can consume a significant amount of energy. According to the U.S. Dept. of Energy, phantom loads may consume as much as 6% of the energy expended in the U.S.—the equivalent of the power produced by nine nuclear power plants.
The graph in Figure 2 is of a typical two-story office building. This information is compared with information from the National Energy Renewable Laboratory (NREL), which has studies from comparable office projects that have yielded similar results. The orange and blue lines represent first- and second-floor electrical plug loads.
Studies our company has performed on a variety of buildings—and studies performed by the NREL—indicate that plug demand is reduced by only 50% during unoccupied periods. In this case, that represents an approximate constant unoccupied plug load of 3 kW. This 3 kW load translates into approximately 8,750 kWh of energy, which is equivalent to 8 metric tons of carbon dioxide emissions per year.
To determine viability for submetering, existing facilities without segregation of loads must be considered individually. Existing buildings can often be submetered cost effectively by floor but not by load type. Even with the limitation of metering segregated loads, great value can be derived using a whole-building metered approach in combination with data from the BAS or independent sensor system.
The old adage “fail to plan and plan to fail” could not be more true than in building sustainability and efficiency. Failure to plan for Smart Grid adoption will cost companies time and money, lower the bricks-and-mortar assets value, and can sacrifice occupant goodwill down the road.
Analyses and planning for a Smart Grid adoption also give building owners and their engineers a chance to root out problems and inefficiencies that have cropped up during previous improvements but have gone unidentified. For example, occupant complaints about comfort are often resolved with quick fixes that lead to conflicts with other systems.
It is an inescapable fact that you cannot manage what you do not measure. Improving performance and reducing environmental impact requires persistence in monitoring, evaluation, and correction of the building’s performance, which is an essential part of being able to maximize the benefit associated with Smart Grid implementation. To maintain and improve building performance, occupant satisfaction, and the owner’s bottom line, building operators need a feedback loop to let them know how their systems are performing and a road map on what needs adjusting.
Other actions beneficial for building owners prior to Smart Grid arrival include:
- Creating a plan to activate energy-producing assets to supplement utility power and reduce peak demand
- Improving efficiency through combined heat and power strategies that provide both chilled and heated water from waste heat
- Using thermal sinks to store energy and reduce energy consumption during peak demand periods
- Shifting activities to allow for temporary energy reductions.
The efforts detailed in this article should be completed before considering alternative energy implementation. The reality is that the current power grid is appallingly inefficient: 70% of the energy consumed is lost in production and 20% is lost in transmission. To put this in perspective, the DOE estimates that if the nation’s grids were just 5% more efficient, the energy savings would equate to eliminating the fuel and greenhouse gas emissions from 53 million cars.
Minimizing a building’s energy consumption for optimal performance before the Smart Grid arrives is good for building owners, building occupants, and the environment. Done correctly, this will prepare for Smart Grid arrival—and achieve the venerated Triple Bottom Line—more easily than anyone would have predicted.
Enck is the founder and principal of Commissioning and Green Building Solutions Inc. He has conducted commissioning processes for more than $3.5 billion in construction, including the ASHRAE Headquarters renovation. He has more than 25 years of experience in engineering, construction, and building operations, and is a founding board member of the Atlanta Regional Chapter of U.S. Green Building Council.
Elements of an effective BAS
- Availability of compatible hardware and software: We have been conditioned to the idea that technology components must be interoperable. However interoperability among BAS systems is progressing slowly, and there is confusion in the marketplace regarding the best approach to standardization. BAS architecture should support hardware and software that is compatible not only with replacements from the same manufacturer but also with those of other manufacturers.
- Component cost effectiveness: When considering upgrades, plan for future obsolescence. The most cost-effective solution is one where the cost of individual system components that are likely to need replacement is less than the replacement cost of the entire system, provided they meet all other criteria.
- Availability of resources and information: A BAS fails to meet its mission if the information and training pivotal to successful operation and maintenance is inadequate or restricted. This includes the use of standardized components and tools, such as network management utilities, that will be familiar to the widest array of qualified operators.
- Embrace emerging technologies: The ability to support upgrades to capitalize on new technologies is equally important as the ability for a BAS to interface with as many legacy components as possible. Cloud-based (Web-based) monitoring and management, in particular, is emerging as an attractive solution to building owners for remote BAS control as well as for what it offers in remote access to operators and their management.
This article can be found in its entirety, with pictures, on CSE’s website HERE
As energy efficiency goals become common place in almost every area in the United States, project teams are taking advantage of the use of a building automation system (BAS) to aid in keeping a building running as efficient as the day it was opened. But are these building automation systems setup in a manner that will allow for the building operators to understand and maintain the building systems? Being a part of many commissioning projects has allowed me to view the “inner workings” of these building automation systems and witness how the control professionals are setting up the systems. More often than not, you find that control points have confusing names or are named something that does not allow for a building operator to understand what they are. If a building operator is unclear what he is looking at, the chances of the building efficiency being maintained decreases. It is important that the naming of control points in these building automation systems be adequate for long term maintainability and long term energy efficiency. As commissioning authorities, it is key during the commissioning testing phase of the project that a review of the control points is completed and comments to the contractors are given to eliminate confusion in naming of control points. Having this issue taken care of before building turnover will result in a better maintained building which will in turn lead to a greater chance of long term building efficiency.
In 2009 CxGBS® was contracted to provide retro-commissioning services and provide recommendations for a historical building in downtown Charleston, SC. The building was beautiful and designed with the highest quality in mind when they were first constructed, but was now tasked to lower energy use. During my first visit to do an assessment and investigation of the building’s operation and overall energy efficiency, I began by interviewing the building operations manager. He was a retired military mechanic that was somewhat ornery, but friendly just the same. Having worked in the military, he was very knowledgeable in all things mechanical and comfortable operating the recently updated Building Automation System. During our interview, he told us about the steps made to make the building more energy efficient, such as adding demand based ventilation and replacing their old chiller with a state of the art chiller. We then moved on to the issues that he observed in his day to day operations. The overwhelming problem that he encountered was high humidity in the building. It was due to the high humidity that he ran the building’s HVAC system 24 hours a day, and still had trouble keeping the humidity down. With the building located so close to the coast, he said that the moisture would come through the walls and raise the humidity if he turned the HVAC system off at night.
He then directed me to all of the drawings and documents. After thoroughly reviewing all of the building information, we proceeded to each major piece of equipment to observe their operation. The majority of the building was served by a giant air handler filling an entire room. When we climbed up to the room that held this massive air handler, I noticed that an injection fan, which was also in the room, was not running. When asked why the fan was not running, the building manager said that the fan was ordered to be turned off by a company engineer, in an effort to save energy. Everything began to make sense. That fan that was turned off was responsible for supplying all of the ventilation air to the building. As a result of the fan not running, the building was now negatively pressurized. Rather than conditioning outside air by controlling its path into the building, humid outside air was infiltrating through doors and window cracks.
The moral of the story: training and documentation are keys to maintaining a building. In this case, as operations staff had turned over, the correct operation of the building was lost and resulted in a severe humidity problem.