applying trnsys simulations for the conservation of an...
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Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
Applying TRNSYS simulations for the conservation of an
artwork. A case study
L. De Backer [email protected]
M. Van Belleghem
Supervisors:
Prof. A. Janssens
Prof. M. De Paepe
Presenter: L. De Backer
Outline
• Introduction
‣ Scope
‣ Description of case study
‣ Previous investigations
• A simulation study
• Conclusions
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
Introduction - Scope
Research project
• “Strategies for moisture modelling of historical buildings in order to reduce damage risks”
Part of project:
Case studies
• Detect phenomena critical for damage risk of cultural heritage
• Define modelling features that should be included to simulate interrelation between outdoor and indoor climate, building envelope and HVAC design in historical buildings
St-Bavo Cathedral ,
Ghent
• Measuring campaign
• Simulation study
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
The baptistery
Glazed enclosure
Baptistery
Church
Exterior
Introduction – description case study
Remaining part of the tower of the church
Baptistery
Glazed enclosure
Suspended concrete ceiling
Situated in the north-west tower
Painting
± 9,5m
± 8
m
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
The glazed enclosure Painting: ‘The adoration of the
mystic lamb’, H. & J. Van Eyck
Introduction – description case study
Steel frame:1m
Glass:3,4m
Steel frame:1m Concrete Ceiling
Floor
±5,6m
±3
,9m
The glazed enclosure
• 2008: Examination ‘monument guards’ revealed signs of damage
‣ 2010-2017: Start new documentation and restoration project, financed by the
Getty Foundation
Conclusion from measuring campaign: Climate was not sufficient.
What are the parameters for better passive conservation?
• Assessment tool: ASHRAE Classes
Temperature Relative Humidity Risks
ΔTshort/space ΔTseasonal ΔRHshort/space ΔRHseasonal
AA ±2°C ±5°C ±5% No changes No risk of mech.
damage
As
A
±2°C +5°C / -10°C ±5% ±10% Small risk of mech.
damage ±2°C +5°C / -10°C ±10% No changes
B ±5°C +10°C
max. 30°C
±10% ±10% Moderate risk to high-
vulnerability artefacts
but tiny risk to most
paintings
C <25°C (<30°C) 25-75% High risk of mech.
damage
D - <75% Prevent dampness
Introduction – conclusion
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
Introduction – Previous investigations &
Conclusion
Climate was not sufficient.
What are the parameters for better passive conservation?
Can the climate within the glass enclosure be easily improved with
low‐budget means, even if only temporarily?
• Aid of BES –software TRNSYS (TRNSYS v17):
• TRNSYS = transient systems simulation program
‣ A modular structure -> flexibility
‣ A large libraries of components
‣ Simulation of larger time periods
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
Outline
• Introduction
• A simulation study
‣ The model
‣ Configurations
• Conclusions
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
Zone 2: Glazed enclosure
Zone 1: Baptistery
BC: Church
BC: Exterior
Zone 3: Remaining part of the tower of the church: solar gain
0
20
40
60
80
100
120
8 9
10
11
12
13
14
15
16
17
18
nu
mb
er
of
vis
ito
rs
hours
Min/max Average Weekday Saturday Sunday
Distribution of the daily visitors in the baptistery based on CO2-measurements
Boundary conditions:
climate church: data loggers
Outdoor climate: Sterrenwacht of Ghent University
Internal Gains:
Lights: electrical power of the lights
Visitors: daily sold tickets and CO2-measurements
Airflows -> TRNFLOW:
Based on traces gas measurements
A simulation study – the model
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
A simulation study - Configurations
Configurations:
1. No climate control:
• Initial climate
• Only visitor management: number of people in the baptistery limited
2. Actual interventions:
• A radiant panel heating on the ceiling of the baptistery (set point: 12°C)
• A humidifier (set point 40% RH) in enclosure.
3. A single zone system:
• T & RH baptistery controlled
• No set point for cooling
• one of the options but because of financial reasons not practicable
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
Large short-term amplitudes of T and RH
variations
Configurations: No climate control
• 2zones: baptistery and glazed enclosure (2Z):
• underestimation of T in summer
• Overestimation in winter
• 3zones: baptistery, glazed enclosure and space above (3Z)
• With windows and sun: Best fitting in summer and winter
T [°C] enclosure
5
7
9
11
13
15
17
19
21
23
25
feb
mrt
apr
mei
jun jul
aug
RH [%] enclosure
2Z
3Z
Measured
High RH during cold weather
30
40
50
60
70
80
90
100
feb
mrt
apr
mei
jun jul
aug
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
A simulation study - Configurations
Radiant heating vs. initial climate with visitor management
5
7
9
11
13
15
21/02
26/02
3/03
8/03
13/03
20
30
40
50
60
70
80
90
100
21/02
26/02
3/03
8/03
13/03
T [°C] enclosure
RH [%] enclosure
ASHRAE classes
0%
20%
40%
60%
80%
100%
AA As A B C D -
Rates of satisfaction
Initial
T
RH
T&RH
Rad. heating + hum
T
RH
T&RH
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
initial
Visitor management
Actual interventions
Outline
• Introduction
• A simulation study
‣ Geometry
‣ Configurations
• Conclusions
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
Can the climate within the glass enclosure be easily improved with
low‐budget means, even if only temporarily?
Conclusion
• Visitors management:
• Avoids large daily variations in temperature and relative humidity
• Radiant heating system:
• Improvement of visitors comfort, but not the preservation conditions
• RH still fluctuates to much
• Solution at the moment not efficient
• Is “complicate” system needed if controlling of RH is wanted ?
• Small band 50/70 needed to obtain class A
• Looking at other option: using ventilation with outside air
Preliminary study:
Developing model to study effect of some configurations vs. initial climate
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
Ghent University - Department of Architecture and Urban Planning
Ghent University - Department of Heat, Flow and Combustion Mechanics
The aid of TRNSYS simulation for the conservation of an
artwork. A case study
L. De Backer [email protected]
M. Van Belleghem
Supervisors:
Prof. A. Janssens
Prof. M. De Paepe
Presenter: L. De Backer