applying trnsys simulations for the conservation of an...

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



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



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





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



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



Outline

• Introduction


‣ The model

‣ Configurations

• Conclusions



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



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



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



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



initial

Visitor management

Actual interventions

Outline

• Introduction


‣ Geometry

‣ Configurations

• Conclusions



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





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

applying trnsys simulations for the conservation of an...

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