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Stefan PlesserDr.-Ing.
Head of Energy and Quality Management Group, Institute for Building Services and Energy Design (IGS), Technische
Universität Braunschweig, Braunschweig, Germanyand Synavision Owner and Managing Director, Bielefeld,
Germany | Ole TeisenChief Consultant, Project Manager at
Sweco, Copenhagen, Denmark |
A tale of sustainability: To
achieve a Gold-level certification, a building owner integrates energy
efficient supply systems in his building like a CHP, a heat pump, a solar
thermal collector and an absorption chiller. The low calculated energy demand
grants additional credits for certification. Shortly after handover, he
notices that some of the systems don’t seem to work the way they should. It
turns out that the management of the different systems is quite a challenge
and had never really been specified in the design phase. Some systems can’t
even communicate with each other. After months of claim management and
frustrating attempts to find out how the system-as-a-whole should
work, the operation staff decided to keep the heating and cooling valves in a
large air handling unit constantly open to create constant energy demand. The
systems now run smoothly due to the continuous consumption of heating and
cooling energy at the same time. And the owner lived disillusioned ever after. |
The above
case could be a joke, but unfortunately it is not. Furthermore, it is
representing a common scenario where a lot of participants with good intentions
don’t have the understanding of the technical complexity of a modern building.
In this article we try to outline some of the tools we can use to support proactive quality management
instead of reactive quality assurance or even worse need for improvement as a
result of the construction that does not meet the requirements of the owner.
Europeans
spend more than 90% of their lifetime in the buildings. Therefore, indoor
environment should be a priority for a design and operation. Since buildings
also cause 35% of all CO2-emissions, energy efficiency is no
less important either. As a consequence, Europe has taken important steps
towards better buildings. Today, innovative technologies allow high performance
and nearly zero energy buildings providing excellent IEQ. Moreover, over the
last years, ambitious building codes have been continuously asking for higher
standards and lower energy consumption. As a result, energy consumption in
operation of the new buildings has decreased – at least in some types of
building and systems. At the same time a phenomenon has become evident: those
new buildings with their ventilation and automation systems turn out to be
rather complicated technical systems apparently being a huge challenge to
designers, engineers, construction companies and facilities manager – and even
to owners and users. As a consequence, the performance gap appeared: buildings
do not work as intended. They miss their initial performance targets in
operation. This is doubly costly: first the design and construction cause
additional cost and then, later, operation cost are also higher than expected.
This is an economic and ecologic no-go.
Solutions
to this problem can be found in other industries: quality management. The term
“Quality” is a colloquially often used to refer do a characteristic of an
object or generally something “good”. In engineering, “quality” describes the
degree, to which a set of inherent characteristics of an object fulfills
requirements. Consequently, “quality management” is a process of supporting the
fulfillment of requirements. Since today building suffers greatly from a
performance gap, the bottom line is that we have a deficit in quality
management for building performance.
Quality Management and Digitalization for
Building PerformanceIn 2012 a new 6,000 m² domicile was handed over
from the design-build contractor to the owner. Various Danish media described
the construction process as a success and all parties were satisfied with the
result. The designers were particularly satisfied with the technical
solutions: – ”Everything was tested before the building was put to
service” – The
building achieved an architectural prize Despite the fine words from
all the dignitaries the employees working in the building kept complaining
about the indoor climate. After the design professionals have tried to map
the reason for the complains and after them the client advisor, a skilled Cx-team was invited to verify the indoor Climate. At this
time, it is four years after hand-over. The Cx team did the
following observations and measurements: ·
Unhealthy air ·
Very
varying air velocities in the working areas ·
Too little
supply of fresh air ·
Poor
distribution of the fresh air supplied from ventilation system ·
Rapid rise
of temperatures when the sun hits the facade The ventilation system is
designed as a Constant Air Volume system (CAV) despite meeting rooms operate
with Variable Air Volume (VAV) ⟶Pressure
oscillates in the air distribution ducts, the system can’t obtain the values
in the balancing report No measuring points on hydronic systems ⟶Hydronic balancing is not possible The story continues: Ventilation system extracts air above ceiling without distribution ducts and Chill Beams are installed without following the requirements of the producer ⟶Draft Architectural solution with windows in aluminum cassettes bolted to the outside of the facade ⟶Temperatures in the Cassettes up to 72°C, inner surface
temperature measured on the glass 35–40°C ·
Radiators
are heating, also in the summer ·
Solar
screens operate after a control sequence that is not described ·
The whole cooling system is running constantly – also in the winter – to
keep IT-installations cold Conclusion ·
The owner’s
indoor climate requirements are not met ·
Indoor
conditions are so bad that it is not allowed to have employees working in the
building ·
50%
dissatisfied employees ·
Energy
consumption out of control ·
Costly
renewal of all technical installations and new cooling and ventilation
concept necessitating new installations above ceilings and new ceiling system
to be implemented while the building is in use |
What is the
performance gap that we aim to eliminate with quality management? It is often
seen as energy consumption higher than budgeted. But energy is still cheap and
for owners it is often much more serious if for example the indoor climate is
negatively affecting the productivity of the employees. As you can read in the
case above, the performance gap is a complex thing both to map and to handle.
PhD student Helle Lohmann Rasmussen from Center for
Facilities Management, DTU Management Engineering, Technical University of
Denmark, has mapped various types of performance gap [[1]] in Figure 1.
Figure 1. Figure A Facilities Manager’s typology of
performance gaps.
The
complexity of buildings and the variety of causes for the performance gap
indicate the challenge to implement an effective quality management.
Somehow, quality
management is of course a part of any building. Construction needs verifiable
calculations for their statics that are engineered and cross-checked, concepts
for fire protection need to be defined in early design stages and should be
tested before handover and every elevator is frequently being inspected.
Usually, these tests are being carried out by a third party along well-defined
testing procedures usually by technical experts for the very field.
Building
performance as a whole though is not covered by an effective quality management
process. In fact, well-defined third-party testing is often only applied in the
still very rare buildings undergoing a certification process for
sustainability, e.g. DGNB, HQE, BREEAM or LEED. They give credits for the
application of certain quality management procedures.
Figure 2. Quality management services as part of
certification schemes.
Two of
these procedures have evolved as particularly reliable and valuable services –
even independently form certification schemes – and they are becoming
increasingly popular: Technical Monitoring and Commissioning.
As a core
aspect, both services have in common that they should be provided by an
independent third-party that is explicitly not responsible for the design,
construction and operation of the building. This independence is a prerequisite
for the effective service and a transparent communication of any deficit
detected by the quality management procedures.
Technical
Monitoring follows very closely the principal concept of quality by testing the
fulfillment of requirements and thereby establishing a quality control loop for
building performance. The service focusses on the precise definition of
requirements as the basis for quality management and the application of testing
procedures for those requirements.
Figure 3. Quality Control loop.
The quality
control loop as defined for technical monitoring consists of four essential
elements listed in Table 1.
Table 1.
Phases of the quality control loop for technical monitoring
Target values | Target values define measurable requirements for buildings and its systems. This may include the maximum level of CO2-concentration in a conference room, the coefficient of performance of a chiller plant or the set point of a supply air temperature of an air handling unit at a certain ambient air temperature. |
Measured values | The measured values are the values obtained from building or system operation. The building has to be technically able to provide this data, e.g. via its building management system or additional metering devices. They need to precisely correspond to the target values. |
Evaluation procedures | To be able to check whether a building fulfills its requirements, TMon applies evaluation procedures to compare the measured values versus the target values. Here it becomes apparent that both need to be defined very carefully to allow a meaningful evaluation: If one uses for example the overall energy consumption of a building as a target value, this value will be very uncertain due to assumptions in design as well as through the actual use of the building that is affected by – among others – tenants moving in step by step, changes in use and user behavior. |
Actions | To actually improve building performance, TMon needs to communicate its findings effectively into the project. Any evaluation therefore needs to provide reliable and transparent results that can be delivered to engineers, contractors and maintenance personnel in time to be recognized and to allow appropriate response. |
If these
four elements are implemented well into a building project, usually starting
with the definition of “testable” requirements in the design phase, TMon can deliver a timely and very cost-effective support
for any building project. In addition to the immediate control loop within a
project, TMon also sets up a long tail loop: It
allows to derive reliable experiences to learn for future projects.
Since TMon is based upon individual functional target values, it
can be applied with an individually defined scope e.g. on individual systems
and values. The option to choose an appropriate scope
supports the cost effectiveness of the service.
When we
talk about Commissioning, we talk about a process. Commissioning is often
misunderstood as “testing in the end”. The direct translation of the English
word has led to many misunderstandings. It is therefore essential that we
distinguish between the “event of commissioning” which means “starting up” and
the “Commissioning Process” that consists of a sequence of activities spread throughout the construction
process, from the pre-design phase to at least one year into operation.
Many
building owners are asking “Why do I have to pay for Commissioning, has it not
been included since the beginning of time?” The simple answer to that is: “Yes,
the event of Commissioning has always been included, and it might also have
been sufficient before, but with the complexity of today’s buildings, you have
to do something extra”.
In Figure 4 it is illustrated that faults, misunderstandings and demand for
clarifications occur through the whole construction project and not only in the
construction phase.
Figure 4. Possible causes of mistakes throughout the construction
process.
The
Commissioning process starts in the pre-design phase and formally ends one year
after completion. It does not take over any of the
activities, that the designers and the contractors are already hired to do;
they still have to manage the quality of their own delivery and balance their
own installations.
Commissioning
(Cx) follows a broader scope than TMon.
In addition to the “pure” specification and testing within Technical
Monitoring, Cx includes a variety of additional
services ranging from checking the of design documents, operationability,
for example the accessibility of air handling units for maintenance services to
functional testing of systems (Life-cycle cost calculations are good tools for
that), O&M documentation and supervision of building maintenance personnel
training.
The
Commissioning Process can be illustrated in a simplified manner as shown in Figure 5.
Figure 5. The Commissioning process made simple.
The
complete Commissioning Process typically consists of a facilitation of the
owner to set up measurable requirements for the process, minimum of two
operations-focused cross-disciplinary design reviews, sample performance
testing of systems and indoor climate, planning of digital hand-over of O&M
and documentation and planning of user training. In the operations phase the
Commissioning Process continues as “On-going Commissioning” or
“Monitoring-Based Commissioning”. Technical Monitoring should always be
included as a core service of Commissioning.
In a
popular way one could say that the Commissioning Process contains all quality
management activities needed to facilitate and pass the tests of the Technical
Monitoring.
To
illustrate the complex relations and connections within modern buildings, the
flowchart below shows some of the prerequisites for TMon
an Commissioning tests. It is very useful to include the tracking of all these
QA documents listed here in the Commissioning Process to facilitate that
systems are completed and quality assured before they participate in a
cross-disciplinary test.
Figure 6.
Pre-required data for technical monitoring and commissioning. [© Ole Teisen 2018, Sweco A/S]
The
potential of a better quality as well as of TMon and Cx has been shown in numerous studies. For Technical
Monitoring, that since 2017 in some German states is mandatory for public
buildings, a study at Technische Universität Braunschweig
[[2]] showed a return on invest of less
than one year for Technical Monitoring. These numbers have been confirmed by
about 250 TMon projects on more than 3,000 systems we
did at synavision with our Digital Test Bench.
On
commissioning, Evan Mills has analyzed 399 Commissioning projects, 322 on
existing buildings and 22 on new constructions[[3]]. He found that
the pay-back time for investment in a Commissioning Process that was 4.2 years
for new constructions and 1.1 years for existing buildings. In the same study
is found that the Commissioning Process costs ½–1% of construction costs. The
study is renewed in the end of 2018. The own experience in Sweco
is that pay-back time for new constructions are much lower than in the US. All
the Commissioning projects the company has managed have paid back before
hand-over in found deficiencies that would have been costly to redo later.
Deficiencies are rooted in all stages of the construction process, and if they
are found when testing and monitoring the completed construction, they usually
are costly to fix. This can be illustrated by the curves in Figure 7.
Figure 7.
Deficiencies found when testing and monitoring the completed construction are
usually costly to fix.
In the
Commissioning Process, the hand-over of O&M documentation (and drawings
calculations, descriptions etc.) is usually handled through a digital tool. The
typical and well-proven option is to enter all data related to O&M, QM,
Balancing Reports, documentation, design and drawings together with the
documents of the Commissioning Process in the owners CMMS (Computerized
Maintenance Management System) system that then serves as the “Systems Manual”
hosting every related documentation.
In Sweco we have now projects, where we link the Systems
Manual (CMMS) and the building model. That opens up for help to find the
precise location of a specific maintenance task generated in the system. You
can also find the documentation for specific components and be guided into the
building model to see in what locations the component is placed.
This
linking between the Systems Manual and the Building Model is not very common
yet, and we still need to see, if owners in the future will route sufficient
resources to the FM staff to assure the maintaining and continuous update of
the model and the link to the Systems Manual. But the digital approach is
essential for quality management.
Although quality
management services are principally available, there are barriers for their
success. This became obvious through another quality management process: energy
inspections for air conditioning system as required by EPBD. These inspections
are mandatory in Germany since 2007 for every system with a cooling power of 12 kWth or more. The number of systems that have to be
inspected is estimated to be about 250,000 [[4]]. So far not more than 10% of these
systems actually have been inspected.
Buildings are becoming
technically sophisticated systems. Therefore, as in other industries, quality management becomes
an increasingly important part of the building process. Due to the complexity
and uniqueness of buildings, digitalization – generally speaking the transformation of
manual, human actions into data driven software-based processes – is a
prerequisite to facility quality management. The first steps of this
transformation started years ago when architects and engineers started to use
computer aided design tools instead of pencils to create plans. Now the
electronic design is to be further transformed into a digital building
information model (BIM) containing information far beyond the physical shape
of the construction like time of construction, product information and even
ongoing metering data. |
The reasons
may be various: lack of owners’ interest, lack of knowledge about the
inspection duty, lack of control by authorities. But one reason is evident: The
inspections usually require experienced experts to go on site and test the
systems. These engineers simply do not exist! There is already a lack of
engineers in the building industry so that additional services, if they are not
exceptionally well paid, will have difficulties to succeed. Therefore,
digitalization is an important opportunity for building performance. Not so
much to cut cost but to enable quality management at all.
In this
regard, TMon is of particular interest since the
quality loop of defining target values, collecting measured data, evaluation it
and communicating it to the project can be transformed completely into a
digital service. One example is our Digital Test Bench at Synavision,
which is currently proving its effectiveness within the EU funded Horizon 2020
project QUANTUM (www.quantum-project.eu). Our
software as a service offers tools to digitally specify target values, import
and evaluate data and produce a precise and transparent feedback. The software
can be applied in new construction with a focus on the startup phase or in
existing buildings e.g. for digital energy inspections. Due to the large extend
of digitalization, the process does not require significant expert knowledge
and in consequence can scale up massively and robustly.
Building
performance needs to be improved in Europe. The technologies are already at
hand. If we introduce quality management to ensure project success and if we
use the new opportunities of digitalization, chances are good to turn the
European building stock into a truly sustainable living environment.
·
IEA
ECBCS Annex 47
·
ASHRAE
Guideline 0-2013
·
ASHRAE
standard 202
·
BSRIA
“Soft Landings”
·
Danish
Standard DS 3090
·
LEED
ver. 4
·
DGNB
Danish version Criterion 1.7
[i] DIRECTIVE (EU) 2018/844 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 30 May 2018 amending Directive 2010/31/EU on the energy performance of buildings and Directive 2012/27/EU on energy efficiency.
[ii] The service is described e.g. by AMEV 135, VDI 6041 and also within the LEED certification as monitoring-based commissioning.
[[1]] Helle Lohmann Rasmussen (2018). A Facilities Manager’s typology of
performance gaps, Technical University of Denmark.
[[2]] Stefan Plesser et al. (2018) „GA Spec&Check. Entwicklung und Erprobung einer Methodik zur
Beschreibung, Abnahme und Überwachung von Funktionen der Gebäudeautomation“,
Technische Universität Braunschweig.
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