KTH ROYAL INSTITUTE
OF TECHNOLOGY
The importance of the design phase in Energy
Quality Management: an example of the
application of the parametric analysis
Marco Molinari, Ph.D.
Department of Automatic Control, KTH
1
Outline
• Background
• Energy efficiency targets in the built
environment
• Tools for analysis: S.E.P.E.
• S.E.P.E.in practice: performance
improvement with exergy analysis
• GSHP improvement through integrated
design
• Current research
• Conclusions
2
Energy use in the world: the need for
reduced and more sustainable energy use
World total primary energy
supply
World End-Use Energy, 2009
14000
Other
12000
10000
Combustible
renewables and
waste
87%
Commerce
and public
services
8%
Agriculture
forestry
2%
Non
specified
2%
Hydro
Industry
36%
Mtoe
8000
32%
Nuclear
6000
Gas
4000
Coal/peat
2000
Oil
0
1973
Residential
24%
Transport
28%
2008
year
Source: IEA 2010
Total: 8353 MTOE
Source: IEA 2011
3
Energy and exergy efficiency
Energy supply type in buildings
Source: Fraunhofer IBP
Source: Mure Odyssey database
4
Can we improve our energy management
by means of exergy concepts?
• Energy quality (exergy) mismatch between supply
and demand indicates potential for energy
management improvements
• Main hindrances:
• Lack of a shared understanding of the advantages
of the exergy approach
• No standardized exergy analysis calculation tools
available
• Need for demonstration projects
5
Examples of available exergy analysis software
programs: IEA ECBCS Annex 49
• Human Body Exergy Calculation
• Cascadia – An Exergetic Approach to
Neighbourhood Design
• Pre-Design Tool for buildings exergy
analysis
• 
DPV Tool
• S.E.P.E. – Software for Exergy
Performance Assessment
6
S.E.P.E. HVAC components
•
•
Generators
–
HPs,
–
chillers
–
boilers
–
solar collectors
–
DH
Heat exchangers
•
•
•
Distribution components
–
Ducts/pipes
–
Fans and pumps
Emission systems
–
radiators
–
FH
–
air units
–
controllers
Simplified building envelope
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Component example: boiler
8
Example of S.E.P.E. HVAC system assembly
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Improvement of heat pumps COP
performance with S.E.P.E.
T10
T11= 55°
DHW
T9
T12= 10°C
Heat
Exchanger
2
T8
Tset= 22°C
Reservoir
Heat
Exchanger
1
T2
T4
T5
P2
Heat Pump 2
T7
Floor
Heating
System
Reservoir
T1
T3
Heat
Exchanger
3
P1
Heat Pump 1
T6
Reservoir
T0
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Results
COP
COP
4.5
4.5
4.3
4.1
3.9
3.7
3.5
3.3
3.1
2.9
4.3
4.1
3.9
3.77
3.7
3.5
3.3
3.12
3.1
3.03
3.03
2.9
0
5
10
Heat exchanger 2 area [m2]
15
4,17
4.05
3.92
3.77
20
40
Reservoir 1 temperature [°C]
The same physical system can achieve different performance if
the subsystems are not properly matched
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How to extend these results to other fields:
design of ground source heat pumps
Building heated area:
8000 m2
Locations: Stockholm
and Madrid
Parametric study
• Building envelope
– Walls and roof insulation
• Borehole field
http://sustainableenergysystemz.com/the-benefits-of-ground-source-heat-pumps/1679/
– Borehole spacing
– Number of boreholes
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Madrid
Results: Stockholm
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Current research at KTH:
advanced control strategies in buildings
14
Conclusions
• Conceptual and calculation tools for energy quality
management already exist and are now mature enough to
shift from research to applications
• The application of exergy concepts can be highly valuable
to the improvement of the design of buildings, especially in
connection to parametric analysis
• Examples of improved design of buildings and buildings
components based on exergy principles are needed to
show the potential improvements in energy quality
management
• Advanced controls schemes and exergy can be an
innovative match to further decrease the overall energy
used in buildings
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Thank you for your attention!
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