Designing For Energy-Efficient Operations and Maintenance
One eye-opening finding from the author’s survey of 168 professionals: only 40% of their facilities even monitor building performance. How much money does that waste? Read on for the flaws and opportunities found in these buildings’ O&M and in how expertise is deployed from design through occupancy.
The building industry is in the early stages of a dramatic shift. HVAC design engineers, contractors, facility managers, and building operators are being asked to embrace the concepts of sustainable, high-performance buildings. These buildings require successful utilization of advanced control sequences, integration of O&M management decisions starting with the design process, and implementation of processes that will help energy-efficiency goals continually penetrate the entire building lifecycle, from design into operations.
Keeping up with changes within the industry is challenging enough. Understanding how these changes are challenging others within the profession and determining what is needed to meet these new demands can be even more difficult. I conducted a survey of 168 facility managers, engineers, maintenance service providers, and construction professionals to provide insight about the current practices, challenges, and needs of maintenance and energy management practices within North America.
The focus of the survey was on both energy and maintenance management practices because there is an interdependent (but often disconnected) link between building energy performance and maintenance, both of which are key practices for sustainable, high-performance buildings. As shown in Figure 1, maintenance is necessary to achieve efficient building energy performance. When energy performance data are available, it is possible to proactively determine maintenance requirements. This link is often disconnected because:
Maintenance budgets are often the first to be cut within a facility manager’s budget.
Within discussions of energy efficiency, the installation of high-efficiency systems is often the focus, with little to no discussion of how systems will be maintained after installation to ensure efficient operation over the equipment lifecycle.
Within many medium-to-large organizations, the organizational structure of the facility management team places energy managers and maintenance managers within separate departments, providing few opportunities to interact and share data.
This article will summarize the findings from the survey while also providing practical suggestions to overcome current challenges. Since the building industry is made up a diverse group of professionals, the article concludes with practical applications specifically for building owners, facility managers, HVAC design engineers and building operators.
The results of the survey represent the responses of 168 professionals, from various fields across the design, build, and operations community. Professionals represented included facility managers (37%), mechanical or energy engineers (26%), commissioning agents (5%), maintenance service providers (5%), and several other professional groups (27%). The services provided by the respondents were nearly balanced (Figure 2).
The types of commercial buildings that the survey participants work in or provide services to are shown in Table 1. As shown in Table 1, the survey participants represent a wide variety of commercial building types.
Energy Management Findings
The energy management findings can be categorized by two common themes: setting energy management goals and energy-performance data management. The survey found that energy-performance goals were set 66% of the time during design.
However, the majority of respondents did not know if building energy performance was validated or if goals were met. As shown in Figure 3, only 13% of respondents stated that they always knew if the goals were met, and 21% stated that they almost always knew if the goals were met. This means that when goals are set, only about half of the people know if the energy management goals were actually met. When considering these data, it should be noted that these findings likely have a positive bias (as the case with many surveys that inquire about if work practices are performed), and actual percentages of goal setting during design and knowing if the goals have been met may be lower.
Multiple questions were asked about the collection and analysis of energy-performance data. Although the primary function of most building control systems today is for equipment operation, scheduling, and sequencing, these systems also have the ability to collect, trend, and help to calculate energy consumption at the systems and equipment level. As more facility managers and building operators consider (or reconsider) how to use BAS and/or other technologies such as energy information systems or other software as an energy management tool, the following are important:
When quantifying energy performance, data collected at equivalent time intervals, such as every 15 minutes (normalized) were found to be of greater use than data collected at changes in condition (change in value, COV).
Many BAS are initially setup for equipment operation and used primarily by building operators who find COV to be useful for system and equipment operation. Thus, when a BAS is to be used for energy management, it may be necessary to set up multiple time-based trends, in addition to the COV trends used by the building operators.
To use a BAS as an energy management tool, it is important to archive data. Although BAS data dumping is currently more common than data archiving, the findings of the survey suggest that more people are recognizing the need for data storage methods.
Seventy percent of survey respondents stated that archived data were more important than short-term storage (30% stated short-term storage was more important).
Ninety-four percent of survey respondents stated that archived data are more important than low-cost storage methods (6% stated that low-cost storage methods are more important).
Although many commercial buildings have BAS, these systems are underutilized. In many cases, trends are not set up, reports are not generated, and advanced control strategies that can reduce energy consumption are not used. Additionally, the survey found that 40% of the facilities represented by survey respondents monitor building energy performance.
As a result of current industry practices, two challenges were identified:Communication paths are not in place between HVAC designers, facility managers, and building operators. As a result, it is difficult to understand which energy-efficiency design goals were met and should be applied on future projects and which goals need refinement before being applied on a second project.
There is a growing understanding of how BAS can be used as an energy management tool. However, most BAS are not currently configured or have the capacity to archive data and to collect detailed energy-consumption data at the system and equipment level using submeters and sensors.
To solve these challenges requires re-evaluation of current design practices, including the determination of functional requirements and support from contractors to ensure system functionality during installation, startup, and turnover for operations. To meet these challenges, survey respondents suggested the following industry changes are necessary:
Facility managers need to be more involved during design and construction.
Energy management goals need to be more clearly defined at the start of projects.
Goals set by building owners and/or corporate executive officers (CEOs) must be clearly set and be enforceable to reduce building energy consumption.
MAINTENANCE MANAGEMENT FINDINGS
The maintenance management questions within the survey focused on the maintenance of HVAC systems and the use of CMMS. Three themes emerged. The first theme was maintenance-management goal setting. Similar to Figure 3, Figure 4 shows whether maintenance goals are set during design and how often it is known if the goals for maintenance have been met after one year of building operation. From Figure 4, maintenance goals are set 56% of the time, with about 22% of respondents stating that they always or almost always know that maintenance goals set during design have been met one year after operation. Similarly to the statement made about energy-management goals, it is likely that these values have a positive bias. From the author’s experience as an HVAC design engineer and discussion of Figure 4 with seasoned HVAC design professionals, it is quite uncommon to discuss maintenance, much less set HVAC maintenance goals, during the design process.
The second theme was the contrast of maintenance-management goals and financial decision making. Often maintenance discussions are focused on return on investment and payback. Additionally, recommendations for equipment upgrades and replacements, as well as CMMS are often couched within financial terms. However, the results of the survey found that although financials are very important (49%) or important (42%) when deciding to implement a new maintenance management strategy, goals of the facility management team were found to be a larger factor in the decision making criteria (Figure 5). Therefore, it is suggested that financial decisionmakers seek to clearly understand project goals, not just demonstrate financial returns from implementing specific solutions.
The third theme that emerged was that CMMS are underutilized. Full utilization of a CMMS requires an accurate inventory of systems and equipment, maintenance histories, and a commitment to proactive maintenance management. However, the initial cost to complete an accurate inventory and populate the CMMS is not free and requires time. Additionally, as many facilities today rely heavily on reactive maintenance practices, it is uncommon for maintenance plans, using preventive-, predictive- or reliability-centered maintenance approaches to be populated within CMMS. Given maintenance management practices today, the most commonly used CMMS modules were those that did not require the population of asset records - the workorder generator, work-order tracking, and the storage of maintenance records.
Similarly to energy management, communication paths are not in place between HVAC designers, facility managers, and building operators to understand which HVAC system designs and layouts were maintainable or are being operated as designed. This is perhaps the largest maintenance management challenge because:
Most HVAC design engineers have not had the opportunity to gain extensive field experience.
Maintenance management practices are generally more reactive than proactive. Thus, it difficult to collect data about why certain designs or layouts may not have been maintainable or are operating as designed.
To meet this challenge, the current needs were identified:
Maintenance management goals need to be more clearly defined at the start of the project.
Facility managers knowledgeable about maintenance practices need to be more involved during design and construction of new buildings, major renovations, and equipment replacements.
In-house staff needs to receive more training about how to operate and maintain equipment, especially equipment and systems that are unique to high-performance buildings.
Helping the industry embrace the concepts of sustainable, high-performance buildings requires more than just reporting on current practices, challenges, and needs. Thus, the results of the survey are synthesized into questions that can be asked by building owners, facility managers, HVAC design engineers, and building operators when planning, implementing, or improving energy and/or maintenance management practices.
Questions for facility managers and building operators to ask when determining how to use a building automation system as an energy management tool:
What time-interval should data be collected (time interval or COV)?
What meters and sensors are installed? Are more meters or sensors needed to collect the data required to quantify system- and equipment-level energy performance?
What trend data should be collected? Who will use these data? What decisions can be made using these data? If it is necessary to manipulate the data, what tool(s) will be used (spreadsheets, report generator)?
Questions for building owners to ask when setting strategic goals for sustainability or energy efficiency:
What maintenance practices are currently in place? How are these practices currently impacting the energy efficiency of HVAC systems and equipment? Is it necessary to work with the facility-management team to ensure maintenance practices will support continued efficient operation of HVAC equipment and systems?
Are the sustainability and/or energy efficiency goals enforceable? Who will be responsible to track the progress of the goals and ensure they are met?
Do building operators and facility managers have the training needed to operate HVAC and BAS in a sustainable, energy-efficient manner?
Questions for the HVAC design engineer to help increase communication during the design, construction, and operations phases of a project:
• Considering current design practices and contract structures, what opportunities are there to interact and exchange lessons learned with facility managers and building operators?
• How can contract structures and project scopes be revised to increase opportunities for feedback on the maintainability and ease of operation of HVAC system designs and BAS? How can receiving this feedback increase the competitive advantage of design firms?
• What role and/or responsibilities should design engineers have regarding maintenance goals?
SUMMARY AND CONCLUSIONS
Energy and maintenance management are key parts of sustainable and energy-efficient design, construction, and operation of high-performance buildings. Given current industry practices, challenges, and needs, commitment to goal setting, accountability of goal achievement, collaboration across project teams and exchanging lessons learned between HVAC designers, facility managers, and building operators are necessary components of sustainable, energy, and maintenance management.
The author would like to thank the 168 professionals who completed the survey. Without their participation, this article would not have been possible.