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.
http://theenergycollective.com/matt-conway/2209986/steroids-efficiency-digital-solutions-juicing-building-energy-codes
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