September 2010 |
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This article originally appeared in the August
2010 issue of Ecolibrium, the official journal of
AIRAH, and is reprinted with
permission. |
Last month, following the receipt of funding from the AusIndustry Green Building Fund, AIRAH announced its intention to produce two manuals seen as critical to the efficient operation of Australia’s existing building stock.
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Both manuals, the Australian Best Practice
Guideline for Controls (DA28) and the Australian Best Practice Guideline
for Commissioning and Retro-commissioning (DA27) will be the first of their
kind in Australia.
“It is widely recognised that one of the major areas of improvements to be made
in the commercial built environment contributing to a reduction of energy, water
and greenhouse emissions is through commissioning and retro-commissioning
initiatives, and through good-practice design, installation, calibration,
programming and operation of controls systems,” says AIRAH CEO Phil Wilkinson,
M.AIRAH.
“By producing new guidelines for controls, and commissioning and
retro-commissioning, the Institute will be addressing subject matter for which
there is a pressing need,” he says, adding that AIRAH, recognising the
importance of addressing these issues, will match the Green Building Fund
contribution dollar for dollar.
In light of this announcement, Ecolibrium put together its own small panel of
industry representatives to look at the issues the Controls Subject Matter
Expert Working Group will be considering between now and the Guidelines’
targeted completion date of May next year.
Included in the discussion was group chair Jon Clarke, M.AIRAH. Clarke is
associate, controls and integration, for Norman Disney & Young’s Sydney
operation.
Also part of our panel were Mark Mitchell, general manager (projects) for A.G.
Coombs, and Nirosha Munasinghe, product development manager for Open General.
Ecolibrium: Why is the Australian Best Practice
Guideline for Controls needed?
Mitchell: Building controls are now more important than ever. It comes
down to the difference between am HVAC system that simply works and a system
that works while using the minimum amount of energy, and controls are at the
heart of that difference. An Australian best practice guideline will help
achieve best practice through the establishment of technical, functional and
commissioning standards for performance outcomes.
Clarke: The building management system (BMS) controls industry covers a
broad section of disciplines, so understanding the fundamentals of mechanical,
electrical and information technology is paramount to getting the best
performance out of a building in terms of sustainability and comfort.
This guide will hopefully help bridge the gap between consultants, controls
engineers and building operators.
Munasinghe: It is needed to address the inconsistencies of building control
strategies from building to building. Also, it needs to address the lack of
governance in controls from the specification provided by the consultants to the
end results after the building is commissioned.
Ecolibrium: It seems then that the controls sector has
suffered from segmentation. Your thoughts?
Mitchell: The controls sector has typically been organised around a small
number of proprietary vendors, and had only limited opportunity to benefit from
knowledge sharing and continuous improvement towards industry best practice.
Industry has previously sought to address this through facility or
project-specific design specifications, which are often too aspirational, or
paradoxically often outdated.
Ecolibrium: Jonathon, you also believe the skills
shortage is having an impact?
Clarke: There are good product engineers that understand how to write the
controls code inside out. There are also good mechanical engineers who
understand the requirements of a building to maintain conditions, but getting an
engineer who understands both intimately is a rare occurrence. Generally,
specifications fall short of the detail required to accurately write the
controls code. In a very competitive industry, the controls suppliers only
provide the bare minimum to meet the intent of the specification. On more than
one occasion I have seen controls code barely resemble the specification at all.
Munasinghe: I’ve seen many personnel who are involved in programming BMS
systems that do not have the knowledge or the expertise to complete the tasks.
Programs are being copied from old projects which do not suit the current
project.
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Ecolibrium: Are controls still considered something of
a “black art” then?
Clarke: The short answer to that is yes, unfortunately they are. This is
mainly due to a combination of lack of understanding from the building
operator’s point of view, and that most systems hide the control code from the
operator and have poor functional descriptions.
I have often had building operators tell me that the controls guy has attended
the site to fix a problem, but no one knows what he has done or understands the
report, if there is one.
Mitchell: Controls are perceived to be less tangible and transparent than
other HVAC elements within a building; from a client perspective this often
leads to incomplete understanding. In recent years this has been compounded with
the increased reliance on network (ITC) knowledge and the integration with
security system packages.
Munasinghe: The good news is that controls software is moving towards a
web environment, and integrating with IT networks that are accessible to a wide
audience. Therefore, more and more people are starting to be aware of the BMS
and starting to interact with it, especially with energy management data.
However, there does need to be continuous improvement in BMS software to report
different levels of data to different audiences.
Mitchell: There’s nothing wrong with controls being a “black” box – this
is essential for technology vendors’ profitability and subsequent development of
new technologies. However, they shouldn’t and can’t continue to be a black art.
We do need to demystify controls and make the black box more translucent.
Everybody around the black box, from consultants, designers and builders, to
contractors, property managers, maintainers and owners, all need to understand
how it works, what it does and what its attributes, issues and limitations are.
Ecolibrium: How linked in is the commissioning process?
Clarke: BMS commissioning will continue to be a bone of contention until
the construction industry recognises that it’s not just about blowing air!
Time is always compressed, and the BMS is the last to get finished as it is
dependent upon the building services being complete. These days BMS systems are
high-tech and closely aligned with IT systems, but are still being procured by
mechanical contractors.
Mitchell: It is one of the single biggest issues facing our industry at
present. Forces such as reduced construction programs, limited commissioning
durations and a lack of expert personnel are collectively leading to poorly
commissioned systems.
This, however, is the new project delivery status quo, so as an industry we need
to better adapt.
Munasinghe: From a project point of view, lack of proper commissioning
and a mismatch in the end results and specification is a major issue. As long as
the air conditioning is working fine there are no complaints from the tenant,
therefore other issues of building management are not addressed.
There are many cases that I have seen where after the end of the commissioning
phase, the BMS does not exactly function to the original specification. The
controls company is usually the last to access a building, and due to the time
pressure, the controls normally do the minimum requirements. The typical
optimising strategies, alarming and logging is left out for another time and in
most cases these are incomplete.
Ecolibrium: What are some of the solutions to this
issue?
Mitchell: Earlier installation completion, factory software application
testing and a focus on all aspects of commissioning, including better
commissioning management and coordination, improved integration of controls
commissioning, with building systems commissioning to achieve performance
outcomes, and specific things like field wiring pre-commissioning, functionality
testing, front-end-to-field-device testing and seasonality testing.
Clarke: When commissioning time is running out flooding the floor with
labour is not the answer. The commissioning process should be considered during
the design, and engaging the controls supplier as early as possible helps to
mitigate some of the issues. Commissioning and final tuning should also carry on
during building occupancy in conjunction with operator training. “Soft landings”
is the correct approach.
Ecolibrium: Traditionally, building owners haven’t
employed anyone to check that the building is operating correctly from a
controls/BMS point of view. Is this changing?
Clarke: Building owners are becoming more involved with their asset
performance, especially with a focus on energy, and the KPIs of the building
operators. This is a good thing, as it raises the awareness of how important the
BMS is.
Mitchell: Our considerable experience has proved the benefit of a
client-representative “superintendent” role to provide surety of the controls
commissioning outcome. However, the controls sector should not be reliant on
such externals watchdogs, and take a position of increased ownership of the
intended client outcome. Further, this should be better integrated with the
transition to operation and longer term tuning and maintenance of the system.
Munasinghe: It needs to be a proactive process. BMSs are starting to
gather a lot of data and needs to use this data as intelligence to start
predicting events. It also needs to give more information back to the tenant for
them to be more involved with the BMS systems.
For example, most systems have fancy energy dashboards reporting energy usage,
which are generally seen only by the facility management. They should be
extended to be more educational, and be displayed at foyers and receptions for
the tenant to see the critical data of the building. The more data tenants see,
it will encourage them to be part of the building management process and be more
involved in reducing energy.
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Ecolibrium: Nirosha, being closely involved with
hardware and software, what are some of the issues there?
Munasinghe: From a market point of view there are less and less
small/medium-type controls hardware and software companies due to mergers and
acquisitions. Larger players dominate the market, and most of them are heading
towards having limited distribution channels, with the preference of completing
projects by the controls company itself. This is leaving many integrators
without the controls product to process for the end client, and larger controls
manufacturers charging premium prices from the client.
Also from a products point of view, most controls manufacturers are transforming
their product range to open systems, with BACnet, LonWorks and web technologies.
To do this in rapid time, they are adding a layer into their current proprietary
systems to open up the systems. But this adds extra hardware such as gateways
and extra software layers, introducing many applications to complete the tasks.
This is starting to confuse the end user about what is open and what isn’t, and
also the workflow in the software to complete the task. This needs to be
addressed with better education of both the system integrators and end users.
Ecolibrium: And what are some of the latest
innovations?
Munasinghe: As mentioned earlier, software is moving away from a desktop
environment to web-based systems that have access to a wider audience. Also,
there is improvement in user graphics, in particular with energy reporting.
There are more dynamic data displayed in 3D graphics for more realistic views of
the building to the user.
The input/output of the physical hardware has not changed immensely over the
decade but the devices are smarter. The devices are integrating more with other
devices due to open system protocols.
Ecolibrium: Does the battle between BACnet and LonWorks
still exist, or has one protocol taken over?
Munasinghe: Both exist in the market but generally they have found their
own markets without large competition. In Australia, BACnet is the preferred
protocol in most new building and retrofit specifications, but in Europe there
are many LonWorks devices, in particularly in the area of street light control
using power line communications. In North America both protocols are present but
my feeling is that BACnet is starting to become the preferred protocol.
Mitchell: We have recently seen an increased prevalence of BACnet systems
in the market. However, we see both technologies comparable in terms of practice
performance. From a client perspective, the bigger issue here is that while
technically possible, true, open, multi-vendor control systems do not in reality
exist, despite the intentions of such interoperability standards.
Clarke: The trouble is there is still a misconception of what these
protocols can provide. Having a BACnet or LonWorks system still requires a level
of service from the system manufacturer. I have had a number of discussions with
clients who were under the impression that if they chose an open system, they
could go to any provider for service and maintenance, but this is simply not the
case.
Ecolibrium: Are controls and BMS still the most obvious
low-hanging fruit in existing, poor-performing buildings?
Clarke: The BMS is the first place to look for building performance
information. It will certainly provide information that can indicate where
problems would be. Low-hanging fruit usually points to incorrect time schedules
and set-points.
Mitchell: We are regularly asked by facility owners and operators to
review their control systems for improved performance outcomes. Usually controls
haven’t been set up as a tuning tool, so the first challenge is to get headend
interfaces to the point where they can be used to optimise the building’s
systems.
We are actively involved in the optimisation of energy systems in a wide range
of buildings around Australia, and this usually results in energy efficiency
improvements of between half and one and half stars, with some exceptional
outcomes in excess of that. These relatively low-cost enhancements often also
result in tangible improvements to occupant comfort.
Jon
Clarke |
Ecolibrium: Further to that,
what are some of the easy things that can be done with controls to have building
systems perform better?
Clarke: Getting them to operate as they were intended would be a good
start! Time schedules, optimum start and economy cycles operating correctly will
have direct impact on building performance. VAV systems with fixed static
pressure set-points are generally wasteful of energy.
Mitchell: Other examples include the selection and implementation of the
correct control strategies for the application, comprehensive system
commissioning by skilled technical resources, the improved configuration of
control systems as a true diagnostic and optimisation tool, and correct seasonal
building tuning, for 12 months and beyond.
Munasinghe: Keep it simple. There are many specifications with many
optimising control algorithms that do not behave in reality as in theory, or the
engineer programming the system lacks the knowledge to program the system, which
is preventing simple control strategies from performing. Also, if optimising
algorithms are implemented, it has to be carefully tested and retuned throughout
the lifecycle of the building.
Ecolibrium: Is it as simple as bad controls, bad
building?
Clarke: Optimum building performance is a fine balance between
maintaining conditions and minimum energy draw. The control system has the tools
to create this balance, and is therefore instrumental to the performance.
Mitchell: Just as well-configured controls can be used to extract
significant energy efficiency improvements out of building systems, poorly
configured and commissioned control systems can be severely detrimental to
building performance, including in the areas of occupant comfort, environmental
outcomes and operator confidence.
The concept of “bad controls” is a slight misnomer, as most systems offer
similar fundamental technological performance. So it tends to be the extent to
which these systems are correctly configured and commissioned that should be
regarded as “good” or “bad”, which is ultimately correctable.
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