-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
1/18
DETERMINATION METHOD OF THERMAL
CONDUCTIVITY OF BUILDING PARTS IN SITU
THROUGH IR IMAGING BY MINIMIZING THE
INFLUENCE OF ENVIRONMENTAL PARAMETERS
G. FIVOS SARGENTIS, A. CHATZIMPIROS and N. SYMEONIDIS
11th International Conference on Environmental Science and TechnologyChania, Crete, Greece, 3 5 September 2009
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
2/18
INTRODUCTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
3/18
INTRODUCTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
4/18
INTRODUCTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
5/18
INTRODUCTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
6/18
INTRODUCTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
7/18
INTRODUCTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
8/18
INSIDE
TEMPERATURE
2
Q1
Q
t La
1x
2 3Q
dx
OUTSIDE
2t
Lit
1t
aaC ia
t2
x'1
xd
2
Q
Lat
Q1
Q32
C a a a i
t1
tLi
C
t2
x1
x2
d
Lat
Q1
Q3
Q2
a a a i
t1
tLi
Qs
Qs1
Qs2
Qs3
I N S I D E
TEMPERATURE
OUTSIDE INSIDE
TEMPERATURE
OUTSIDE
The variation of the surface temperatures in three cases: (a) theoretical, (b) in
case of win (blue arrows) and (c) in case of solar radiation (red arrows)
INTRODUCTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
9/18
4.0C
19.0C
5
10
15
13,3C
31,0C
15
20
25
30
AR01
AR02
METHOD DESCRIPTION Test example
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
10/18
5
0
tL
d
10
152
t
C
20
t1
Lit
0
5
15
10
dd
2t
Lt
1t
tL
0
5
10
15
C
20
Lit
2t
C
20t
1
Lit
+ ~~
Qs
TEMPERATURE
t
5
0
tL
d
10
15
20
tt 1
2
C
Li
TEMPERATURE
TEMPERATURE
TEMPERATURE
Environmental aspects of infrared imaging testing
METHOD DESCRIPTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
11/18
In this method of analysis, the parameters used are:
tLa: outside temperature
tLi: inside temperature
t1 : surface temperature (interior)
t2 : surface temperature (exterior)
ax
: surface conductivity
K: thermal conductivity of part of the buildings envelope
R: thermal resistance of part of the buildings envelope =1/K
: thermal resistance of the material
K
Calculations
L1
METHOD DESCRIPTION
?
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
12/18
aFAN
CalculationsMETHOD DESCRIPTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
13/18
1/
aFAN
ai
K
CalculationsMETHOD DESCRIPTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
14/18
1/
aa
ai
K in situ
CalculationsMETHOD DESCRIPTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
15/18
K in situ KAbsence of solar influence
94% 74%
efficiency factor:
1,00
2,00
3,00
4,00
5,00
6,00
7,00
1,00 2,00 3,00 4,00 5,00 6,00 7,00
1,00
2,00
3,00
4,00
5,00
6,00
7,00
1,00 2,00 3,00 4,00 5,00 6,00 7,00
CalculationsMETHOD DESCRIPTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
16/18
K in situ KPresence of solar influence
70% 67%
efficiency factor:
1,00
2,00
3,00
4,00
5,00
6,00
7,00
1,00 2,00 3,00 4,00 5,00 6,00 7,00
1,00
2,00
3,00
4,00
5,00
6,00
7,00
1,00 2,00 3,00 4,00 5,00 6,00 7,00
CalculationsMETHOD DESCRIPTION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
17/18
Difficulties in applying the method in specific type of materials with high thermal
storage capacity, such as stone.
Experimental data show that for the application of the method for the calculation of the
thermal conductivity in this type of materials, the following conditions should apply:
Elimination of environmental interruption (solar energy, wind)
Maximization of the temperature difference (indoor outdoor)
Stable thermal flow for more than three hours
Therefore, the optimal measurement is taken during cold winter nights, and at the
same time when inside temperature of the building is the highest possible.
So the method is defined to provide results for the thermal behaviour of different parts
of a building with precision of more than 80% if the following conditions apply:
Stable thermal flow between indoor and outdoor system for more than 1
hour
Minimum variation of the outdoor temperature
Difference between indoor and outdoor temperatures superior to 15C
No measurements are taken while there is solar radiation on the building.
DISCUSSION
-
8/6/2019 DETERMINATION METHOD OF THERMALCONDUCTIVITY OF BUILDING PARTS IN SITUTHROUGH IR IMAGING BY MINIMIZING THEINFLUENCE OF ENVIRONMENTAL PARAMETERS G. FIV
18/18
CONCLUSIONS
Through this method, infrared imaging, mostly used as an
approach for qualitative analysis in buildings, becomes aquantitative analysis tool for improving the accuracy of the
in situ determination of the thermal conductivity of
buildings materials.
Based on this method, existing buildings parts can beevaluated quantitatively with regard to their thermal
conductivity, which is related to the buildings energy
requirements. In addition, failures in buildings envelopes,
such as thermal bridges, can be detected and analysed
quantitatively, while also measures for improving theinsulation of buildings can be evaluated through
quantitative and accurate data.