Part 1: Commercial Buildings
Massachusetts recently adopted a new energy code that promises to improve building efficiency. The merits of the new legislation are on display in Boston’s current building boom. At construction sites across the city, the latest energy saving building insulation, ultra-efficient windows and weather sealing technologies can be seen. One glaring shortcoming of code type approaches for driving efficiency is their record of ensuring the proper operation and performance of building systems. Unfortunately, the elements of energy codes that result in profound improvements in the performance of building exteriors and construction techniques are proving to be only marginally effective in ensuring that heating, ventilation and air conditioning equipment, computerized building automation systems and lighting controls attain the desired energy reductions. The good news is that the addition of a number of software requirements and solutions could address these shortcomings in a cost effective manner.
The updated building energy codes rely on comprehensive specifications and spreadsheets that set improved minimum requirements. As a troubling number of LEED certified buildings have demonstrated in the past, detailed design specifications and comprehensive operational testing requirements struggle to ensure that many of the most energy intensive systems in buildings actually meet their efficiency potential. Despite the best efforts of engineers charged with commissioning and ensuring that new equipment is properly configured, many systems in new facilities do not function as intended. Problems can compound as buildings are used, settings are changed and the operating staff struggle with increasingly complex equipment. Surveying the challenge, it appears increasingly unlikely that the validation and operational testing called for in updated codes has a high likelihood of catching the volume of the energy intensive deficiencies that tax many new structures. Each year hundreds of technologies emerge in the building mechanical and electrical market. Mastering the subtleties of just one of these platforms can take weeks. Failure to identify a problem with 1 of the 10 or more field configurable settings on equipment like a high efficiency heater can adversely affect the performance of multiple other building systems.
A case study of the depth of this challenge is highlighted by a project in Cambridge, Massachusetts. An audit conducted in 2013 of the LEED certified Cambridge City Hall Annex building revealed that the heating equipment installed as part of a comprehensive rebuild project in 2003 was operating only marginally more efficiently than electric resistance heat. The ground source heat pump system that was intended to demonstrate the potential to dramatically reduce energy consumption was found to be consuming almost as much energy as old meter spinning technologies from decades earlier. Similarly, the expensive networked lighting control system was largely disabled and a number of portions of the roof mounted solar PV installation were not operational.
The comprehensive construction project completed at the site was well orchestrated and was closed out consistent with the highest commissioning standards. The project scope included the creation of a comprehensive energy use simulation software model of the building that was developed to ensure systems like the heating equipment met the notable sustainability goals of the project. Following construction, building systems were thoroughly tested and an impressive validation report was assembled. The building was later commissioned a second time in an attempt to address mechanical and electrical problems that were identified following building occupancy. The configuration and settings for the heat pump system were checked, validated and confirmed to be configured per the engineering specifications. However, actual energy consumption and notable electrical spikes during cold weather clearly documented that commissioning alone does not ensure efficient operation of all systems.
The framework for a solution to the type of problem experienced in Cambridge may be on display when Massachusetts residents take their cars for an annual emissions inspection. Gone are the days of running cars at idle with a probe in the tailpipe for pollution testing. With complex electronic combustion controls, manufactures learned that they could game idling tests. The EPA uncovered firms optimizing idle emissions, while at the same time programming other speeds without regard for pollution. Today’s answer to ensuring realistic engine performance has been to require that all new cars run and record standard emissions test procedures under typical driving conditions. Tests utilize sophisticated onboard emission equipment and follow a prevailing protocol. In short, they use standardized software to monitor technology and improve efficiency.
A number of fairly simple enhancements to computerized automation systems that control building equipment show similar promise to the automotive emission solution. The software aids in the process of identifying operational deficiencies and is the first step in automating the optimization of building efficiency.
Below is a graphic produced by basic equipment tracking software that was added to a building found to have rampant problems with heating and cooling areas at the same time. In the case of this example, there were just over 400 very dated heating/cooling units in use. When the cooling valves fail, the equipment defaults to full air conditioning. Prior to the software upgrade, heating could run for months to compensate for a broken cooling unit before the problem was recognized.
The software tool now assists building staff in quickly identifying problems. The basic format of the graphic enables even junior staff to better understand key drivers of energy consumption at their facility. Heating and cooling spaces simultaneously is a common deficiency; regardless, with today’s highly adaptive building controls, it is one of the most challenging types of excess energy use to combat. With minor modifications to account for differences in equipment, the same approach can be adapted to assist in actively tracking operation at most buildings. The secondary graphical link was added based on a suggestion from the building staff. The information shows the data point that is normally responsible for excess use of heat. For the building in question, the link further expedites the process of identifying the source of problems.
Another building graphic with near universal value for many building types is shown below:
Presenting data according to this format creates a graphical snapshot to help diagram how all of the mechanical components associated with a specific HVAC unit are operating.
In comparison to the more typical graphic that is used to represent fan systems on most building computerized control platforms (shown next), the first image provides a valuable histogram of how the equipment operates over time and clearly outlines what happens when weather conditions vary.
Similar software is proving to be cost effective for optimizing the operation of many building systems. Without this type of aid, resolving even the most common energy deficiencies requires an advanced understanding of the inner relationships of building equipment and is often extremely time consuming. It is important to recognize that in today’s competitive real estate world, onsite staffing is limited. With this in mind, it is often not possible for building personnel to handle the urgent issues of the day in parallel with the type of complex diagnostics needed to optimize efficiency. Similarly, there are considerable obstacles that prevent energy and commissioning engineers from addressing system level problems. Identifying difficulties like those that plagued the Cambridge City Hall Annex frequently requires a number of days to establish what equipment and data points need to be monitored. Once trend tracking is initiated, months of data collection are required to produce relevant and actionable historical records of what is causing problems. Because an auditor’s time onsite is limited, either the trends are not initiated or data compiled after the site visit is not acted on. Thus it is common for multiple energy audits to report similar deficiencies that are never resolved.
There are a number of powerful software offerings that notably exceed the capabilities of what is being proposed. The solutions outlined herein are not framed to compete with these platforms. The intent is to encourage, through additions to the energy code, the standardized use of capabilities that are native to most computerized building automation systems. Essentially, the expansion of energy codes to include “canned code” that provides a valuable overview of how building systems are operating. Given the building communities’ limited knowledge of the energy saving potential of emerging software, it is likely that the added exposure gained from code requirements would increase interest in full system platforms.
The adage that “you can’t change what you don’t see” is certainly true in the building efficiency industry. One of the leading cause of wasted energy in facilities is often that stake holders at all levels do not know of and fully grasp problems that are taking place every day. Adding low cost optimization software to the building energy codes will increase the transparency of building energy use and enable efficiency legislation to meet its potential.
Photo Credit: Boosting Green Buildings/shutterstock