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Thermal Properties
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A Thermal and Moisture Transport Property Database for Common
Building and Insulating Materials
Final Report from ASHRAE Research Project 1018-RP
Principal Investigator : Mavinkal K Kumaran
Key Researchers: John C Lackey
Nicole Normandin
Fitsum Tariku
David van Reenen
04 July 2002
2 Table of Content Page No. Executive Summary 4
Examples of Applications of Various Test Methods:
Hygrothermal Properties of Aerated Concrete and Gypsum Board 12
Hygrothermal Properties of OSB 1 29
Hygrothermal Properties of OSB 2 36
Hygrothermal Properties of OSB 3 43
Hygrothermal Properties of Plywood 1 50
Hygrothermal Properties of Plywood 2 57
Hygrothermal Properties of Plywood 3 64
Hygrothermal Properties of Fibreboard 71
Hygrothermal Properties of Eastern White Cedar 78
Hygrothermal Properties of Western Red Cedar 85
Hygrothermal Properties of Spruce 92
Hygrothermal Properties of Eastern White Pine 99
Hygrothermal Properties of Southern Yellow Pine 106
Hygrothermal Properties of Composite Wood Siding 113
Hygrothermal Properties of Clay Brick 120
Hygrothermal Properties of Mortar 127
Hygrothermal Properties of Stucco 134
Hygrothermal Properties of Fibre Cement Board 141
Hygrothermal Properties of Cement Board 148
Hygrothermal Properties of Lime Stone 154
Hygrothermal Properties of Low-density Glassfibre Batt Insulation 160
Hygrothermal Properties of Cellulose Insulation 164
Hygrothermal Properties of Expanded Polystyrene Insulation 169
Hygrothermal Properties of Extruded Polystyrene Insulation 173
Hygrothermal Properties of Spray Polyurethane Foam Insulation 176
B1115.13
3 Hygrothermal Properties of Polyisocyanurate Insulation 179
Hygrothermal Properties of Low-density Polyurethane Foam Insulation 182
Hygrothermal Properties of #15 Felt 186
Hygrothermal Properties of 10 min Paper 189
Hygrothermal Properties of 30 min Paper 192
Hygrothermal Properties of 60 min Paper 195
Hygrothermal Properties of Spun Bonded Polyolefin Membrane 198
Hygrothermal Properties of Bonded Polyolefin Membrane (Crinkled ) 201
Hygrothermal Properties of Vinyl Wallpaper 204
Hygrothermal Properties of Primer and Latex paint 207
Hygrothermal Properties of EIFS Base Coat and Finish Coat 214
Appendix I: How Well Should One Know the Hygrothermal Properties of Building
Materials ? 217
Appendix II: Experimental and Analytical Investigations on the Drying Processes
Undergone by Aerated Concrete. 223
B1115.13
4
EXECUTIVE SUMMARY
This report presents results from a set of hygrothermal tests that were systematically
carried out on many building materials that are currently used in North America. The materials
include several wood based products, several species of wood, masonry products, cladding
materials, sheathing membranes, insulation products, one limestone, a primer and a latex paint
and a vinyl wallpaper. The properties that were determined include thermal conductivity,
equilibrium moisture content, water vapour permeance or permeability, water absorption
coefficient, moisture diffusivity and air permeance or permeability. Test conditions and details on
test specimens are given for each test. Many sets of primary data as well as their uncertainties
are reported. Also, wherever possible results are statistically analyzed to estimate probable
uncertainties in the derived values of various hygrothermal properties.
Principal Investigator:
Kumar Kumaran
Principal Research Officer
Building Envelope and Structure Program
Institute for Research in Construction
National Research Council Canada
Ottawa, Ontario K1A 0R6
Canada
kumar.kumaran@nrc.ca
Phone: 613 993 9611
B1115.13
5
1. INTRODUCTION
ASHRAE Research project 1018-RP, Thermal and Moisture Transport Property
Database for Common Building and Insulating Materials was implemented to generate a set of
reliable and representative data on the hygrothermal properties of 30 common building materials.
Hygrothermal properties govern the details of heat, air and moisture transport through building
materials. A comprehensive list of the properties can be found in the project report B-1115.3
dated 1 April 1999 that was issued to ASHRAE from the Institute for Research in Construction.
That report also contains the definitions of the properties.
The project has now generated information on several hygrothermal properties of 38
materials. The properties that are compiled in this report include:
Dry density
Heat capacity
Thermal conductivity
Equilibrium moisture content (Sorption, Desorption and Pressure Plate Measurements)
Water vapour permeance or permeability
Water absorption coefficient
Moisture diffusivity and
Air permeance or permeability
Well-developed experimental procedures or international standard test procedures exist
to determine the properties listed above. The principles of the experimental procedures that are
used to determine the hygrothermal properties of building materials in the present investigation
are given below. Heat capacity data that are reported here are taken from a document published
by the International Energy Agency Annex 24 [1]. Density data reported here are the averages of
the densities of many test specimens (conditioned to laboratory environment, approximately
21 C and 50 % RH) for each material, calculated from direct measurements on the weight and
on the geometric dimensions that are used to characterize each test specimen. Further details on
each experimental procedure and data analyses may be found in the project report referred to
above.
B1115.13
6 Thermal Conductivity of Dry Materials
The heat conduction equation is directly used to determine the thermal conductivity of dry
materials. Equipment that can maintain a known unidirectional steady state heat flux (under
known constant boundary temperatures) across a flat slab of known thickness is used for the
measurements. The most commonly used equipment is the guarded hot plate apparatus or the
heat flow meter apparatus. ASTM Standards C 177, Standard Test Method for Steady-State Heat
flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate
Apparatus and C518, Standard Test Method for Steady-State Heat flux Measurements and
Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus are widely used
for this purpose. The latter is used in the present investigation. Similar standards are available
from the International Standards Organization and the European Union. In the ASTM Standards,
the heat conduction equation is written for practical applications as:
= Ql/(AT) (1)
Where,
Q = Heat flow rate across an area A
l = Thickness of test specimen
T = Hot surface temperature Cold surface temperature
The thermal conductivity calculated according to (1) is called apparent thermal
conductivity. It is a function of the average temperature of the test specimen.
Equilibrium Moisture Content from Sorption/Desorption Measurements
For sorption measurements, the test specimen is dried at an appropriate drying
temperature to constant mass. While maintaining a constant temperature, the dried specimen is
placed consecutively in a series of test environments, with relative humidity increasing in stages,
until equilibrium is reached in each environment. Equilibrium in each environment is confirmed by
periodically weighing the specimen until constant mass is reached. From the measured mass
changes, the equilibrium moisture content at each test condition can be calculated and the
adsorption isotherm drawn.
The starting point for the desorption measurements is from an equilibrium condition very
near 100% RH. While maintaining a constant temperature, the specimen is placed consecutively
in a series of test environments, with relative humidity decreasing in stages, until equilibrium is
reached in each environment. Equilibrium in each environment is confirmed by periodically
weighing the specimen until constant mass is reached. Finally, the specimen is dried at the
B1115.13
7 appropriate temperature to constant mass. From the measured mass changes, the equilibrium
moisture content at each test condition can be calculated and the desorption isotherm drawn.
A new CEN standard 89 N 337 E is under development for the determination of
Hygroscopic Sorption Curve. ASTM C16 Committee also is developing a standard.
Equilibrium Moisture Content from Pressure Plate (Desorption) measurements:
The test specimens are saturated with water under vacuum. Those are then introduced in
a pressure plate apparatus that can maintain pressures up to 100 bar for several days. The plates
in perfect hygric contact with the specimens extract water out of the pore structure until an
equilibrium state is established. The equilibrium values for moisture contents in the specimens
and the corresponding pressures (measured as the excess over atmospheric pressure; the
negative of this value is referred to as the pore pressure while the absolute value is the suction)
are recorded. The equilibrium pressure, ph, can be converted to a relative humidity, , using the
following equation:
hpRTMln = (4)
Where,
M = the molar mass of water
R = the ideal gas constant
T = the thermodynamic temperature and
= the density of water
A Nordtest Technical Report [6] briefly describes a procedure for pressure plate
measurements and reports the results from an interlaboratory comparison. No standard
procedure is yet developed for the determination of suction isotherm.
Water Vapour Permeability/Permeance
The vapour diffusion equation is directly used to determine the water vapour permeability
of building materials [2]. The measurements are usually done under isothermal conditions. A test
specimen of known area and thickness separates two environments that differ in relative humidity
(rh). Then the rate of vapour flow across the specimen, under steady-state conditions (known rhs
as constant boundary conditions), is gravimetrically determined. From these data the water
vapour permeability of the material is calculated as:
B1115.13
8
p = Jvl/(Ap) (2)
Where,
Jv = Water vapour flow rate across an area A
l = Thickness of the specimen
p = Difference in water vapour pressure across the specimen surfaces
Often, especially for membranes and composite materials, one calculates the water
vapour permeance, l , of a product at a given thickness from the above measurements as:
l = Jv/(Ap) (3)
ASTM Standard E96, Test Methods for Water Vapour Transmission of Materials,
prescribes two specific cases of this procedure- a dry cup method that gives the permeance or
permeability at a mean rh of 25 % and a wet cup method that gives the permeance or
permeability at a mean rh of 75 %. A new CEN Standard 89 N 336 E is being developed in the
European Union based on ISO standard. More recently a number of technical papers that deal
with various technical aspects, limitations and analyses of the experimental data of these
procedures have appeared in the literature [3-5].
For many hygroscopic materials, such as wood and wood products, the water vapour
permeability/permeance is a strong function of the local relative humidity and increases with rh.
The ASTM Standard E 96 is being revised to address this behaviour of building materials more
quantitatively. For practical building applications, in addition to the traditional dry and wet cup
conditions, it is desirable to determine the permeance or permeability of hygroscopic materials at
a mean rh of 85 %. This can be done using the wet cup method of E96, but the rh in the humidity
chamber shall be maintained at 70 %.
Water Absorption Coefficient:
One major surface of each test specimen is placed in contact with liquid water. The
increase in mass as a result of moisture absorption is recorded as a function of time. Usually,
during the initial part of the absorption process a plot of the mass increase against the square
root of time is linear. The slope of the line divided by the area of the surface in contact with water
is the water absorption coefficient1.
1 When this method was applied to membranes, the membranes were put in perfect hygric contact with a substrate such as OSB.
B1115.13
9
A new CEN Standard 89 N 370 E on the determination of water absorption coefficient is
under development.
Moisture Diffusivity:
Moisture diffusivity, Dw, defines the rate of movement of water, Jl , within a material,
induced by a water concentration gradient according to the following equation:
Jl = - 0 Dw grad u (5)
Where,
0 = density of the dry material
u = moisture content expressed as mass of water / dry mass of material
In the experimental procedure, liquid water in contact with one surface of a test specimen
is allowed to diffuse into the specimen. The distribution of moisture within the specimen is
determined as a function of time at various intervals until the moving moisture front advances to
half of the specimen. Gamma spectroscopy is used as the experimental technique. The data are
analyzed using the Boltzmann transformation [7,8 ] to derive the moisture diffusivity as a function
of moisture content.
There is no standard test procedure for the determination of moisture diffusivity. There
are many publications in the literature that describe the technical and experimental details [9-12].
Air Permeability/ Permeance:
Test specimens with known areas and thickness are positioned to separate two regions
that differ in air pressure and the airflow rate at a steady state and the pressure differential across
the specimen are recorded. From these data the air permeability, ka is calculated as:
ka = Jal/(Ap) (6)
Where,
Ja = Air flow rate across an area A
l = Thickness of the specimen
p = Difference in air pressure across the specimen surfaces
B1115.13
10
Often, especially for membranes and composite materials, one calculates the air
permeance, Ka , of a product at a given thickness from the above measurements as:
Ka = Ja/(Ap) (7)
ASTM Standard C 522, Standard Test Method for Airflow Resistance of Acoustical
Materials prescribes a method based on this principle. Bomberg and Kumaran[13] have extended
the method for general application to building materials.
References
1. M K Kumaran, Final Report, Volume 3, Material Properties, International Energy Agency
Annex 24 Report, Published by K. U. Leuven Belgium, 1996.
2. Joy F. A. and Wilson, A. G., Standardization of the Dish Method for Measuring Water
Vapour Transmission, Proceedings of the International Symposium on Humidity and
Moisture, Washington, D. C., Vol. 4, Chapter 31, 1963, pp 259-270.
3. Hedenblad, G., Moisture Permeability of Some Porous Building Materials, Proceedings of
the 4th Symposium, Building Physics in the Nordic Countries, Espoo,Volume 2, 1996, 747-
754.
4. Hansen, K. K. and Lund, H. B., Cup Method for Determination of Water Vapour
Transmission Properties of Building Materials. Sources of Uncertainty in the Method,
Proceedings of the 2nd Symposium , Building Physics in the Nordic Countries, Trondheim,
1990, pp 291-298.
5. Lackey, J. C., Marchand, R. G., and Kumaran, M. K., A Logical Extension of the ASTM
Standard E96 to Determine the Dependence of Water Vapour Transmission on Relative
Humidity, Insulation Materials: Testing And Applications: Third Volume, ASTM STP 1320, R.
S. Graves and R. R. Zarr, Eds, American Society for Testing and Materials, West
Conshohocken, PA, 1997, pp 456-470. Also Kumaran, M. K., An Alternative Procedure for
the Analysis of Data from the Cup Method Measurements for Determination of Water Vapour
Transmission Properties, Journal of Testing and Evaluation, JTVEA, Vol. 26 , pp. 575-581,
1998.
6. Hansen, M. H., "Retention Curves Measured Using Pressure Plate and Pressure Membrane,"
Nordtest Technical Report 367, Danish Building Research Institute, 1998, p 63.
B1115.13
11 7. Bruce, R. R. and Klute, A, "The Measurement of Soil Diffusivity," Soil Science Society of
America Proceedings. Vol. 20, pp. 251-257, 1956.
8. Kumaran, M.K., Mitalas, G.P., Kohonen, R., Ojanen, T, "Moisture transport coefficient of pine
from gamma ray absorption measurements," Collected Papers in Heat Transfer, 1989 :
Winter Annual Meeting of the ASME (San Francisco, CA, USA, 1989) pp. 179-183,
1989(ASME Heat Transfer Division vol. 123).
9. Marchand, R.G. and Kumaran, M. K., "Moisture diffusivity of cellulose insulation," Journal of
Thermal Insulation and Building Envelopes, Vol. 17, pp. 362-377, 1994.
10. Kumaran, M.K. and Bomberg, M.T., "A Gamma-spectrometer for determination of density
distribution and moisture distribution in building materials," Moisture and Humidity:
Measurement and Control in Science and Industry : Proceedings of International Symposium
(Washington, D.C., USA, 1985), pp. 485-90, 1985.
11. Filip Descamps., "Continuum and Discrete Modelling of Isothermal Water and Air Transfer in
Porous Media," Ph. D. Thesis, Katholieke Uniersity, Belgium, pp. 57-107, 1997.
12. Pel, L., "Moisture Transport in Porous Building Materials," Ph. D. Thesis, Eindhoven
University of Technology, the Netherlands, pp. 47-80, 1995.
13. Bomberg, M. T.and Kumaran, M.K., " A Test method to determine air flow resistance of
exterior membranes and sheathings," Journal of Thermal Insulation, Vol.9, pp. 224-
235,1986.
B1115.13
12 2. Examples of Applications of Various Methods to determine the Hygrothermal Properties of Aerated Concrete and Interior Gypsum Board.
The test conditions reported in this section for different test methods are
generally followed throughout the project. Also, the procedures used in this
section for data reduction and analyses are followed for all materials in this
report. A: Aerated Concrete
The test specimens used for various measurements reported here are taken from one block of aerated concrete, approximately 1 X 1 x 1.5 in size.
Density: (460 15) kg m-3
Heat Capacity (According to International Energy Agency Annex 24 Report2): 840 J K-1 kg-1
Thermal Conductivity: Measurements are according to ASTM Standard C518; 30 cm X 30cm specimens are used in
these measurements. The temperatures of the plates are maintained within 0.02 C for these
measurements, for 12 h period to confirm steady state.
Table 2.1. Thermal Conductivity of Aerated Concrete.
Specimen Thickness
mm
Hot Surface Temperature
C
Cold Surface Temperature
C
Conductivity
W m-1 K-1
24.24 31.51 9.75 0.121
24.24 11.45 -2.44 0.119
Note: The heat flow meter apparatus is built to measure the heat transmission characteristics of
insulating materials and for those materials the measurement uncertainties are within 2 %;
aerated concrete is more conductive than traditional insulation and the large heat fluxes
measured may give measurement uncertainties as high as 5 %.
2 M K Kumaran, Final Report, Volume 3, Material Properties, International Energy Agency Annex 24 Report, Published by K. U. Leuven Belgium, 1996
B1115.13
13 Sorption Desorption Measurements3: Either eight specimens, 40 mm X 40 mm X 20 mm each, or six specimens 40 mm X 40 mm X 6
mm each or three specimens, 40 mm X 40 mm X 6 mm each are used in these measurements;
the numbers in parentheses indicate the experimental uncertainties. Sorption:
Table 2. Sorption data for Aerated Concrete.
RH, % Temperature, C Moisture Content, kg kg-1
100, total saturation Lab at 22 (1) 1.72 (0.01), eight specimens
100, capillary saturation,
after 72 h immersion
Lab at 22 (1) 0.83 (0.02), six specimens
88.1 (1) 23.0 (0.1) 0.050 (0.002), three specimens
71.5 (1) 23.0 (0.1) 0.021 (0.001), three specimens
50.6 (1) 23.0 (0.1) 0.011 (0.001), three specimens
Desorption: Table 3. Desorption data for Aerated Concrete.
RH, % Temperature, C Moisture Content, kg kg-1
99.99 (0.01) Lab at 22 (1) 0.92 (0.13), eight specimens
99.98 (0.01) Lab at 22 (1) 0.81 (0.09), eight specimens
99.96 (0.01) Lab at 22 (1) 0.77 (0.07), eight specimens
99.93 (0.01) Lab at 22 (1) 0.75 (0.06), eight specimens 99.85 (0.01) Lab at 22 (1) 0.72 (0.05), eight specimens 99.78 (0.01) Lab at 22 (1) 0.70 (0.05), eight specimens 99.71(0.01) Lab at 22 (1) 0.68 (0.04), eight specimens 99.63 (0.01) Lab at 22 (1) 0.66 (0.04), eight specimens 99.47(0.01) Lab at 22 (1) 0.64 (0.04), eight specimens 98.90 (0.01) Lab at 22 (1) 0.55 (0.02), six specimens 97.81 (0.01) Lab at 22 (1) 0.34 (0.05), six specimens
88.1 (1) 23.0 (0.1) 0.063 (0.001), three specimens
71.5 (1) 23.0 (0.1) 0.022 (0.001), three specimens
50.6 (1) 23.0 (0.1) 0.011 (0.001), three specimens
Throughout this document, results from the pressure plate measurements are listed as desorption
data above 95 % RH.
3 In the hygroscopic range, the measurements are done using the proposed procedure for ASTM Standard C1498, which in turn is based on CEN 89 N 337 E, Hygroscopic Sorption Curve; at the higher range the pressure plate method is used. Details of the pressure plate method are
B1115.13
14 Water Vapour Transmission (WVT) Rate measurements4: For each test condition, 3 circular specimens, each 15 cm in diameter, are used. Table 2.4. Dry Cup Measurements on Aerated Concrete Specimens: The numbers in parentheses indicate the experimental uncertainties for RH and temperature and standard errors for WVT rate, obtained from statistical analyses of the data at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
20.11 50.6 (1) 22.9 (0.1) 1.09E-06 (5.5E-09)
20.56 50.6 (1) 22.9 (0.1) 1.14E-06 (5.6E-09)
20.44 50.6 (1) 22.9 (0.1) 1.03E-06 (4.0E-09)
20.11 71.5 (1) 22.7 (0.1) 1.69E-06 (6.0E-09)
20.56 71.5 (1) 22.7 (0.1) 1.79E-06 (3.3E-09)
20.44 71.5 (1) 22.7 (0.1) 1.63E-06 (5.3E-09)
20.11 88.1 (1) 23.3 (0.1) 2.18E-06 (6.5E-09)
20.56 88.1 (1) 23.3 (0.1) 2.30E-06 (4.4E-09)
20.44 88.1 (1) 23.3 (0.1) 2.23E-06 (5.6E-09)
Table 2.5. Wet Cup Measurements on Aerated Concrete Specimens: The numbers in parentheses indicate the experimental uncertainties for RH and temperature and standard errors for WVT rate, obtained from statistical analyses of the data at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
20.29 71.7 (1) 22.7 (0.1) 1.30E-06 (1.7E-08)
20.34 71.7 (1) 22.7 (0.1) 1.40E-06 (1.4E-08)
20.11 71.7 (1) 22.7 (0.1) 1.49E-06 (1.5E-08)
20.29 87.8 (1) 23.2 (0.1) 1.13E-06 (1.5E-08)
20.34 87.8 (1) 23.2 (0.1) 9.60E-07 (1.0E.08)
20.11 87.8 (1) 23.2 (0.1) 9.69E-07 (1.0E.08)
The average thickness of still air in the cups in both series is 11 mm
given by: Hansen, M. H., "Retention Curves Measured Using Pressure Plate and Pressure Membrane," Nordtest Technical Report 367, Danish Building Research Institute, 1998, p 63. 4 Measurements are done as described by: Lackey, J. C., Marchand, R. G., and Kumaran, M. K., A Logical Extension of the ASTM Standard E96 to Determine the Dependence of Water Vapour Transmission on Relative Humidity, Insulation Materials: Testing And Applications: Third Volume, ASTM STP 1320, R. S. Graves and R. R. Zarr, Eds, American Society for Testing and Materials, West Conshohocken, PA, 1997, pp 456-470.
B1115.13
15 Derived Water Vapour Permeability5 Table 2.6. The dependence of water vapour permeability of Aerated Concrete on relative humidity.
RH, % Permeability kg m-1 s-1 Pa-1
RH, % Permeability kg m-1 s-1 Pa-1
10 1.12E-11 60 2.76E-11 20 1.33E-11 70 3.34E-11 30 1.59E-11 80 4.07E-11 40 1.91E-11 90 5.00E-11 50 2.29E-11 100 6.21E-11
The relation between WVT rate and Chamber RH is shown in Figure 1.
Rank 1 Eqn 8002 [Exponential] y=a+bexp(-x/c)
r2=0.993 DF Adj r2=0.992 FitStdErr=1.17e-07 Fstat=965
a=-7.41e-07 b=7.54e-07 c=-61.21
0 20 40 60 80 100CHAMBER RH, %
0
5e-07
1e-06
1.5e-06
2e-06
2.5e-06
3e-06
3.5e-06
W V
T R
ate,
kg
m-2
s-1
Figure 2.1. All data are interpreted as dry cup measurements; RH inside the cup is zero and chamber RH is the RH outside the cup.
5 The analysis is done as described in : Kumaran, M. K., An Alternative Procedure for the Analysis of Data from the Cup Method Measurements for Determination of Water Vapour Transmission Properties, Journal of Testing and Evaluation, JTVEA, Vol. 26 , pp. 575-581, 1998.
B1115.13
16 The numeric summary of the analyses is listed below. The commercial software package called
TabbleCurve2 is used for the curve fit. The terminology below is from the package.
The equation that represents the relation between x = chamber RH and y = WVT rate is
[Exponential] y= a + b exp(-x/c)
r2 , Coefficient of Determination = 0.993
Fit Std Error = 1.7E-07
F-value = 965
Parameter. Value Std Error t-value 90% Confidence Limits
a -7.41e-07 2.1e-07 -3.5 -1.12e-06 -3.69e-07
b 7.54e-07 1.9e-07 4.0 4.23e-07 1.08e-06
c -61.2 7.5 -8.1 -74.5 -47.9
From the above statistics, the estimated uncertainty in the derived value of the permeability may
be up to 28 %.
Note that all water vapour transmission data are combined to give one curve in Figure 2.1, and
dry cup and wet cup measurements are not independently analyzed. This approach is the same
as that described and applied to the plywood data in the reference document: Kumaran, M. K.,
An Alternative Procedure for the Analysis of Data from the Cup Method Measurements for
Determination of Water Vapour Transmission Properties, Journal of Testing and Evaluation,
JTVEA, Vol. 26 , pp. 575-581, 1998.
This same approach is followed throughout this document.
B1115.13
17 Water Absorption Coefficient6: Five test specimens, 5 cm X 5 cm X 5 cm each, were used in these measurements. Water is maintained at (22 1) C. The numbers in parentheses give the standard deviations.
Table 2.7. Water absorption data for Aerated Concrete.
Square Root of time, s
Water Absorption kg m-2
7.75 0.93 (0.13) 13.42 1.24 (0.17) 17.32 1.41 (0.21) 24.49 1.73 (0.25) 30.00 1.96 (0.29) 38.73 2.29 (0.34) 45.83 2.55 (0.37) 54.77 2.87 (0.44) 64.81 3.20 (0.47) 73.48 3.48 (0.53) 81.24 3.71 (0.56) 91.65 4.05 (0.62) 101.00 4.31 (0.69)
Linear regression using all the data from the first linear part of the absorption process for the five specimens gives: Water Absorption Coefficient for the major surfaces = 0.036 0.002 kg m-2 s-.
6 The procedure used is based on: CEN/TC 89/WG 10 N95 Determination of water absorption coefficient, 1994-07-07.
B1115.13
18 Moisture Diffusivity:
Gamma ray method7 is used to measure the distribution of moisture in three test specimens, 5 cm X 23 cm X 2.4 cm each, during the moisture uptake through the edge. The principle of the methodology is described by Kumaran et. al8. Marchand and Kumaran9 have reported the procedure used for the data reduction.
The running average method that is described by Marchand and Kumaran gives the
characteristic curve shown in Figure 2, for this aerated concrete. Several hundreds of data pairs obtained on the three test specimens, in 36 sets of measurements over a period of seven days are included in the analysis.
0
50
100
150
200
250
300
0 0.0001 0.0002 0.0003 0.0004 0.0005 0.0006
Running Avg. Boltzmann Variable, m s-
Run
ning
Avg
. Moi
stur
e C
onte
nt, k
g m
-3
Figure 2.2. The characteristic curve for aerated concrete resulted from moisture uptake and distribution measurements.
7 Kumaran, M.K. and Bomberg, M.T., "A Gamma-spectrometer for determination of density distribution and moisture distribution in building materials," Moisture and Humidity: Measurement and Control in Science and Industry : Proceedings of International Symposium (Washington, D.C., USA, 1985), pp. 485-90, 1985. 8 Kumaran, M.K., Mitalas, G.P., Kohonen, R., Ojanen, T, "Moisture transport coefficient of pine from gamma ray absorption measurements," Collected Papers in Heat Transfer, 1989 : Winter Annual Meeting of the ASME (San Francisco, CA, USA, 1989) pp. 179-183, 1989(ASME Heat Transfer Division vol. 123). 9 Marchand, R.G. and Kumaran, M. K., "Moisture diffusivity of cellulose insulation," Journal of Thermal Insulation and Building Envelopes, Vol. 17, pp. 362-377, 1994.
B1115.13
19
The moisture diffusivity derived from the above characteristic curve is given in Table 8.
Table 2.8. The dependence of moisture diffusivity of Aerated Concrete on moisture content.
Moisture Content
kg kg-1
Diffusivity
m2 s-1
Moisture Content
kg kg-1
Diffusivity
m2 s-1
0.087 8.72E-09 0.326 3.44E-09
0.109 5.47E-09 0.348 3.64E-09
0.130 4.32E-09 0.370 3.91E-09
0.152 3.76E-09 0.391 4.29E-09
0.174 3.44E-09 0.413 4.81E-09
0.196 3.26E-09 0.435 5.56E-09
0.217 3.16E-09 0.457 6.71E-09
0.239 3.12E-09 0.478 8.71E-09
0.261 3.13E-09 0.500 1.3E-08
0.283 3.19E-09 0.522 2.89E-08
0.304 3.29E-09 0.543 5.15E-08
Note: The area enclosed by the characteristic curve in Figure 2 is ~ 0.033 kg m-2 s- and
this value is very close to the water absorption coefficient = 0.036 kg m-2 s- that was directly
determined. This should be the case and the correspondence between the two shows the internal
consistency of the two methods. However, the uncertainty in the derived moisture diffusivity is
estimated to be as high as 30 to 50 %.
The diffusivity derived from moisture distribution data during a water uptake process may
not quantitatively describe a drying process for all building materials. Earlier works at the Institute
for Research in Construction show that for a cement-based sheathing board10 and for several
OSB test specimens under various boundary conditions11 the drying process is reasonably well
described using the diffusivity that has been derived from a water uptake process.
For the present investigation, two series of drying experiments were conducted on this
same aerated concrete. Details of these investigations are given in Appendix II. Both series of
investigations reported there suggest that the diffusivity determined from a wetting process
describes the drying process with reasonable accuracy.
10 See Appendix I 11 Maref, W., Kumaran, M. K., Lacasse, M. A., Swinton, M. C. and van Reenen, D. Laboratory Measurements and Benchmarking of an Advanced Hygrothermal Model. Accepted for publication: 12th International Heat Transfer Conference, August 18-23, 2002, Grenoble (France).
B1115.13
20 Air Permeability:
Bomberg and Kumaran12 have reported the principle of the method used in these
measurements. Appendix XIII of the Client Report to ASHRAE, B-1115.3 A Thermal and
Moisture Transport Property Database for Common Building and Insulating Materials 1018-RP
dated 1 April 1999 reports the details. Three circular test specimens (thickness 20.29 mm, 20.56
mm, 20.34 mm), each approximately 15 cm in diameter, are used in these measurements. The
measurements are conducted at a temperature = (22 1) C.
The summary of the statistical analyses of all data obtained from two series of
measurements on each specimen is shown in Figure 3 as three separate sets.
0
0.05
0.1
0.15
0.2
0.25
0 100 200 300 400 500 600 700 800
Pressure Difference (Pa)
Flow
, l m
-2 s
-1
Data Points Mean PermeanceUpper Confidence Interval Lower Confidence Interval
Figure 2.3. The dependence of airflow rate on pressure difference for aerated concrete.
For the range of pressure differences between 25 Pa and 700 Pa, the flow rate linearly
varies with the pressure difference. The air permeability is (4.9 2.6) E-09 kg m-1 Pa-1 s-1.
12 Bomberg, M. T. and Kumaran, M.K., " A Test method to determine air flow resistance of exterior membranes and sheathings," Journal of Thermal Insulation, Vol.9, pp. 224-235,1986.
B1115.13
21
B: Interior Gypsum Board
The test specimens used for various measurements reported here are taken from 4 X 8 sheets of a commercial product with a nominal thickness of . A paper layer is adhered to the major surfaces and all test specimens included this paper layer. Labels on the product say the following: Manufactured to exceed standards Can/CSA-A82.27 and ASTM C 36.
Thickness: (12.50 0.03) mm
Density: (625 7) kg m-3
Heat Capacity (From International Energy Agency Annex 24 Report13): 870 J K-1 kg-1
Thermal Conductivity: Measurements are according to ASTM Standard C518; 30.6 cm X 30.6 cm specimens are used
in these measurements. The temperatures of the plates are maintained within 0.05 C for these
measurements, for 12 h period to confirm steady state.
Table 2.9. Thermal conductivity of gypsum board.
Specimen Thickness
mm
Hot Surface Temperature
C
Cold Surface Temperature
C
Conductivity
W m-1 K-1
12.51 5.27 -4.94 0.16
12.51 29.24 18.89 0.16
12.51 5.42 -4.91 0.16
12.51 29.62 19.03 0.16
The heat flow meter apparatus is built to measure the heat transmission characteristics of
insulating materials and for those materials the measurement uncertainties are within 2 %;
gypsum board is very conductive and the large heat fluxes measured may give measurement
uncertainties as high as 5 %.
13 M K Kumaran, Final Report, Volume 3, Material Properties, International Energy Agency Annex 24 Report, Published by K. U. Leuven Belgium, 1996
B1115.13
22 Sorption Desorption Measurements14: Up to twelve specimens, 41 mm X 41 mm each, are used in these measurements; the numbers in parentheses indicate the experimental uncertainties.
Table 2.10 Results from sorption/ desorption measurements.
a) Sorption:
RH, % Temperature, C Moisture Content, kg kg-1
100, total saturation* Lab at 22 (1) 1.13 (0.02), six specimens
100, capillary saturation Lab at 22 (1) 0.689 (0.003), four specimens
94 (2) Lab at 22 (1) 0.042 (0.04), 12 specimens
90.8 (1) 23 (0.1) 0.018 (0.02), three specimens
70.5 (1) 23 (0.1) 0.0065 (0.0003), three specimens
50.5 (1) 23 (0.1) 0.0040 (0.0002), three specimens
* Total saturation under vacuum though destroys the rigidity, one careful measurement could be
performed on each specimen.
b) Desorption:
RH, % Temperature, C Moisture Content, kg kg-1
88.3 (1) 23.3 (0.1) 0.0182 (0.0004), 12 specimens
84.8 (1) 23.0 (0.1) 0.0169 (0.0004), 12 specimens
71.5 (1) 23.0 (0.1) 0.0132 (0.0003), 12 specimens
50.4 (1) 23.0 (0.1) 0.0099 (0.0002), 12 specimens
Pressure plate measurements were not applicable for this material; full saturation destroys the
integrity of the test specimens.
14 Measurements are done using the proposed procedure for ASTM Standard C1498, which in turn is based on CEN 89 N 337 E, Hygroscopic Sorption Curve.
B1115.13
23 Water Vapour Transmission (WVT) Rate measurements15: For each test condition, 3 circular specimens, each 15 cm in diameter, are used. Table 2.11. Dry Cup Measurements: The numbers in parentheses indicate the experimental uncertainties for RH and temperature and standard errors for WVT rate, obtained from statistical analyses of the data at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
12.50 50.3 (1) 22.9(0.1) 2.99E-06 (1.3E-08)
12.48 50.3 (1) 22.9(0.1) 2.93E-06 (5.2E-09)
12.44 50.3 (1) 22.9(0.1) 2.94E-06 (9.0E-09)
12.50 70.3 (1) 23.0(0.1) 4.12E-06 (1.1E-08)
12.48 70.3 (1) 23.0(0.1) 4.18E-06 (1.3E-08)
12.44 70.3 (1) 23.0(0.1) 4.28E-06 (1.6E-08)
12.50 89.8 (1) 22.9(0.1) 5.65E-06 (2.0E-08)
12.48 89.8 (1) 22.9(0.1) 5.85E-06 (6.1E-09)
12.44 89.8 (1) 22.9(0.1) 5.77E-06 (1.1E-08)
Table 2.12. Wet Cup Measurements: The numbers in parentheses indicate the experimental uncertainties for RH and temperature and standard errors for WVT rate, obtained from statistical analyses of the data at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
12.51 70.4 (1) 22.9(0.1) 2.44E-06 (1.2E-08)
12.50 70.4 (1) 22.9(0.1) 2.47E-06 (1.2E-08)
12.43 70.4 (1) 22.9(0.1) 2.53E-06 (1.5E-08)
12.51 90.0 (1) 22.9(0.1) 1.02E-06 (1.3E-08)
12.50 90.0 (1) 22.9(0.1) 1.03E-06 (1.2E.08)
12.43 90.0 (1) 22.9(0.1) 1.02E-06 (1.1E-08)
The average thickness of still air in the cups for both series is 15 mm.
15 Measurements are done as described by: Lackey, J. C., Marchand, R. G., and Kumaran, M. K., A Logical Extension of the ASTM Standard E96 to Determine the Dependence of Water Vapour Transmission on Relative Humidity, Insulation Materials: Testing And Applications: Third Volume, ASTM STP 1320, R. S. Graves and R. R. Zarr, Eds, American Society for Testing and Materials, West Conshohocken, PA, 1997, pp 456-470.
B1115.13
24 Derived Water Vapour Permeability16 Table 2.13. Dependence of water vapour permeability on relative humidity.
RH, % Permeability kg m-1 s-1 Pa-1
RH, % Permeability kg m-1 s-1 Pa-1
10 2.96E-11 60 4.49E-11 20 3.21E-11 70 4.91E-11 30 3.48E-11 80 5.38E-11 40 3.78E-11 90 5.91E-11 50 4.12E-11 100 6.52E-11
The relation between WVT rate and Chamber RH is shown below.
d:\tblcurve\ashrae gypsum.txtRank 1 Eqn 8002 [Exponential] y=a+bexp(-x/c)
r2=0.999 DF Adj r2=0.999 FitStdErr=8.22e-08 Fstat=8078a=-7.78e-06 b=7.79e-06 c=-161.2
0 20 40 60 80 100CHAMBER RH, %
0
1e-06
2e-06
3e-06
4e-06
5e-06
6e-06
7e-06
W V
T R
ate,
kg
m-2
s-1
Figure 2.4. Dependence of WVT Rate on RH difference for gypsum board; all measurements are interpreted as dry cup measurements.
16 The analysis is done as described in : Kumaran, M. K., An Alternative Procedure for the Analysis of Data from the Cup Method Measurements for Determination of Water Vapour Transmission Properties, Journal of Testing and Evaluation, JTVEA, Vol. 26 , pp. 575-581, 1998.
B1115.13
25 The numeric summary of the analyses is listed below. The commercial software package called
TabbleCurve2 is used for the curve fit. The terminology below is from the package.
The equation that represents the relation between x = chamber RH and y = WVT rate is
[Exponential] y= a + b exp(-x/c)
r2 , Coefficient of Determination = 0.999
Fit Std Error = 8.3E-08
F-value = 8077.8
Parameter. Value Std Error t-value 90% Confidence Limits
a -7.77e-06 1.0e-06 -7.6 -9.6e-06 -6.0e-06
b 7.79e-06 1.0e-06 7.7 6.00e-06 9.57e-06
c -161.2 15.5 -10.4 -188.6 -133.7
From the above statistics, the estimated uncertainty in the derived value of the permeability may
be up to 16 %.
B1115.13
26 Water Absorption Coefficient17: Four test specimens, 51 mm X 51 mm each, were used in these measurements. Water is maintained at (22 1) C. The numbers in parentheses give the standard deviations.
Table 2.14a. As water is absorbed across the major surface.
Square Root of time, s
Water Absorption kg m-2
7.7 0.03 (0.01) 13.4 0.05 (0.01) 19.0 0.06 (0.02) 25.7 0.08 (0.01) 34.6 0.09 (0.01) 42.4 0.10 (0.01) 52.0 0.13 (0.01) 62.4 0.14 (0.01) 84.9 0.16 (0.02)
105.4 0.19 (0.01) 115.9 0.20 (0.02) 130.8 0.23 (0.02) 143.2 0.24(0.02)
Linear regression of the data from the first linear part of the absorption process gives: Water Absorption Coefficient for the major surfaces = 0.0019 0.0001 kg m-2 s-. Table 2.14b. As water is absorbed along the edge of the board.
Square Root of time, s
Water Absorption kg m-2
7.7 3.6 (0.2) 13.4 5.6 (0.1) 17.3 7.25 (0.1) 20.5 8.53 (0.1) 24.5 10.16 (0.07) 30.0 12.42 (0.1) 34.6 14.22 (0.07) 38.7 15.87 (0.03) 42.4 17.33 (0.06) 52.5 19.65 (0.01) 60.0 20.32 (0.05)
Linear regression of the data from the first linear part of the absorption process gives: Water Absorption Coefficient for the edge = 0.399 0.003 kg m-2 s-.
17 The procedure used is based on: CEN/TC 89/WG 10 N95 Determination of water absorption coefficient, 1994-07-07.
B1115.13
27 Moisture Diffusivity:
Gamma ray method18 is used to measure the distribution of moisture in three test specimens, 5 cm X 23 cm each, during the moisture uptake through the edge. The principle of the methodology is described by Kumaran et. al19. Marchand and Kumaran20 have reported the procedure used for the data reduction.
The moisture diffusivity derived using all data on all three test specimens is listed below.
Table 2.15. Moisture diffusivity of gypsum board at various moisture contents.
Moisture Content
kg kg-1
Diffusivity
m2 s-1
Moisture Content
kg kg-1
Diffusivity
m2 s-1
0.032 2.09E-08 0.528 3.35E-07
0.064 3.81E-08 0.544 2.84E-07
0.096 5.36E-08 0.560 2.54E-07
0.128 6.98E-08 0.576 2.36E-07
0.160 8.82E-08 0.592 2.24E-07
0.192 1.1E-07 0.608 2.17E-07
0.224 1.34E-07 0.624 2.13E-07
0.256 1.6E-07 0.640 2.12E-07
0.288 1.87E-07 0.656 2.15E-07
0.320 2.13E-07 0.672 2.2E-07
0.352 2.44E-07 0.688 2.29E-07
0.384 2.91E-07 0.704 2.42E-07
0.400 3.3E-07 0.720 2.63E-07
0.416 3.91E-07 0.736 2.94E-07
0.432 5.07E-07 0.752 3.46E-07
0.448 8.22E-07 0.768 4.45E-07
0.464 4.13E-06 0.784 7.11E-07
0.480 1.47E-06 0.800 2.55E-06
0.496 8.46E-07
18 Kumaran, M.K. and Bomberg, M.T., "A Gamma-spectrometer for determination of density distribution and moisture distribution in building materials," Moisture and Humidity: Measurement and Control in Science and Industry : Proceedings of International Symposium (Washington, D.C., USA, 1985), pp. 485-90, 1985. 19 Kumaran, M.K., Mitalas, G.P., Kohonen, R., Ojanen, T, "Moisture transport coefficient of pine from gamma ray absorption measurements," Collected Papers in Heat Transfer, 1989 : Winter Annual Meeting of the ASME (San Francisco, CA, USA, 1989) pp. 179-183, 1989(ASME Heat Transfer Division vol. 123). 20 Marchand, R.G. and Kumaran, M. K., "Moisture diffusivity of cellulose insulation," Journal of Thermal Insulation and Building Envelopes, Vol. 17, pp. 362-377, 1994.
B1115.13
28 Air Permeability:
Bomberg and Kumaran21 have reported the principle of the method used in these
measurements. Appendix XIII of the Client Report to ASHRAE, B-1115.3 A Thermal and
Moisture Transport Property Database for Common Building and Insulating Materials 1018-RP
dated 1 April 1999 reports the details. Three circular test specimens, thickness = (12.50 0.02)
mm, each approximately 15 cm in diameter, are used in these measurements. The
measurements are conducted at a temperature = (22 1) C.
The summary of the statistical analyses of all data obtained from two series of
measurements on each specimen is shown below.
Linear Regression of All Specimens
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0 100 200 300 400 500Pressure Difference, Pa
Flow
, l m
-2 s
-1
Data Points Mean PermeanceUpper Confidence Interval Lower Confidence Interval
Figure 2.5. Dependence of airflow rate on pressure difference for gypsum.
For the range of pressure differences between 25 Pa and 400 Pa, the flow rate linearly
varies with the pressure difference. The air permeability is (4.16 0.07) E-09 kg m-1 Pa-1 s-1.
21 Bomberg, M. T. and Kumaran, M.K., " A Test method to determine air flow resistance of exterior membranes and sheathings," Journal of Thermal Insulation, Vol.9, pp. 224-235,1986.
B1115.13
29
1. HYGROTHERMAL PROPERTIES OF ORIENTED STRAND BOARD -1
The test specimens used for various measurements reported here are taken from one board of a commercial product, 4 X 8 with a nominal thickness of . The strands of this product are manufactured from poplar and aspen.
Density: (650 30) kg m-3
Heat Capacity (From International Energy Agency Annex 24 Report22): 1880 J K-1 kg-1
Thermal Conductivity: Measurements are according to ASTM Standard C518; 30.5 cm X 30.5 cm specimens are used
in these measurements. The temperatures of the plates are maintained within 0.04 C for these
measurements, for 12 h period to confirm steady state. Heat flow is perpendicular to the major
surfaces.
Table 3.1. Thermal Conductivity of OSB 1.
Specimen Thickness
mm
Hot Surface Temperature
C
Cold surface Temperature
C
Conductivity
W m-1 K-1
12.66 27.26 21.41 0.102
12.66 3.88 -3.20 0.0984
12.53 27.22 21.40 0.102
19.50 3.90 -3.17 0.0974
Note: The heat flow meter apparatus is built to measure the heat transmission characteristics of
insulating materials and for those materials the measurement uncertainties are within 2 %. This
same uncertainty is applicable to OSB.
22 M K Kumaran, Final Report, Volume 3, Material Properties, International Energy Agency Annex 24 Report, Published by K. U. Leuven Belgium, 1996
B1115.13
30 Sorption Desorption Measurements23: Up to nine specimens, 40 mm X 40 mm each at the full board thickness are used in these
measurements; the numbers in parentheses indicate the experimental uncertainties.
Sorption: Table 3.2. Sorption data for OSB 1.
RH, % Temperature, C Moisture Content, kg kg-1
100, total saturation Lab at 22 (1) 1.35 (0.05), six specimens
100, total saturation Lab at 22 (1) 1.24 (0.07), nine specimens
48.9 (1) 23 (0.2) 0.046 (0.001), three specimens
69.1 (1) 23 (0.2) 0.078 (0.001), three specimens
88.6 (1) 23 (0.2) 0.148 (0.005), three specimens
Desorption:
Table 3.3. Desorption data for OSB 1.
RH, % Temperature, C Moisture Content, kg kg-1
99.8(0.1) Lab at 22 (1) 0.595 (0.002), six specimens
99.3 (0.1) Lab at 22 (1) 0.42 (0.02), six specimens
92.3 (1) 23.0 (0.2) 0.200 (0.003), two specimens
90.3 (1) 23.0 (0.2) 0.176 (0.006), three specimens
69.4 (1) 23.0 (0.2) 0.100 (0.002) two specimens
49.9 (1) 23.0 (0.2) 0.079 (0.001), two specimens
Note: Pressure plate measurements at 22 C on four similar products gave the following results
for equilibrium moisture contents at relative humidity very close to 100 %.
Table 3.3a. Desorption data for four similar OSB products.
RH, % Moisture Content, kg kg-1
99.997 1.16 (0.11), 12 specimens
99.993 1.09 (0.12), 12 specimens
99.98 1.06 (0.11), 12 specimens
99.93 0.88 (0.12), 12 specimens
23 In the hygroscopic range, the measurements are done using the proposed procedure for ASTM Standard C1498, which in turn is based on CEN 89 N 337 E, Hygroscopic Sorption Curve; at the higher range the pressure plate method is used. Details of the pressure plate method are given by: Hansen, M. H., "Retention Curves Measured Using Pressure Plate and Pressure Membrane," Nordtest Technical Report 367, Danish Building Research Institute, 1998, p 63.
B1115.13
31 Water Vapour Transmission (WVT) Rate measurements24: For each test condition, 3 circular specimens, each 15 cm in diameter, are used. Table 3.4. Dry Cup Measurements on OSB 1 specimens: The numbers in parentheses indicate the experimental uncertainties for RH and temperature; for WVT Rate the numbers indicate the standard errors according to a linear regression of data on water vapour transmission rate at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
12.19 49.3 (1) 23.1 (0.1) 3.50E-08 (3.4E-10)
12.21 49.3 (1) 23.1 (0.1) 4.77E-08 (3.8E-10)
12.21 49.3 (1) 23.1 (0.1) 5.23E-08 (3.2 E-10)
12.19 69.2 (1) 23.3 (0.1) 6.56E-08 (8.2E-10)
12.21 69.2 (1) 23.3 (0.1) 8.62E-08 (7.8E-10)
12.21 69.2 (1) 23.3 (0.1) 8.67E-08 (6.2 E-10)
12.19 91.2 (2) 22.9 (0.2) 1.01E-07 (3.4E-09)
12.21 91.2 (2) 22.9 (0.2) 3.02E-07 (4.6E-09)
12.21 91.2 (2) 22.9 (0.2) 2.71E-07 (3.6E-09)
Table 3.5. Wet Cup Measurements on OSB 1 specimens: The numbers in parentheses indicate the experimental uncertainties for RH and temperature; for WVT Rate the numbers indicate the standard errors according to a linear regression of data on water vapour transmission rate at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
12.31 69.0 (1) 23.2 (0.1) 1.77E-07 (2.2E-09)
12.40 69.0 (1) 23.2 (0.1) 1.54E-07 (1.7E-09)
12.38 69.0 (1) 23.2 (0.1) 1.80E-07 (1.9E-09)
12.31 90.5 (2) 23.3 (0.2) 2.56E-07 (4.0E-09)
12.40 90.5 (2) 23.3 (0.2) 1.40E-07 (2.5E-09)
12.38 90.5 (2) 23.3 (0.2) 1.86E-07 (4.8E-09)
The average thickness of still air in the cups for both series is 15 mm
24 Measurements are done as described by: Lackey, J. C., Marchand, R. G., and Kumaran, M. K., A Logical Extension of the ASTM Standard E96 to Determine the Dependence of Water Vapour Transmission on Relative Humidity, Insulation Materials: Testing And Applications: Third Volume, ASTM STP 1320, R. S. Graves and R. R. Zarr, Eds, American Society for Testing and Materials, West Conshohocken, PA, 1997, pp 456-470.
B1115.13
32 Derived Water Vapour Permeability25 Table3.6. The dependence of water vapour permeability of OSB 1 on relative humidity.
RH, % Permeability kg m-1 s-1 Pa-1
RH, % Permeability kg m-1 s-1 Pa-1
10 4.39E-14 60 1.27E-12 20 1.61E-13 70 1.70E-12 30 3.44E-13 80 2.19E-12 40 5.91E-13 90 2.75E-12 50 9.00E-13 100 3.37E-12
From the TableCurve statistics, the estimated uncertainty in the derived value of the permeability
may be higher than 50 %. The scatter in the WVT data for this product is unusually high for a
building material.
25 The analysis is done as described in : Kumaran, M. K., An Alternative Procedure for the Analysis of Data from the Cup Method Measurements for Determination of Water Vapour Transmission Properties, Journal of Testing and Evaluation, JTVEA, Vol. 26 , pp. 575-581, 1998.
B1115.13
33 Water Absorption Coefficient26: Four test specimens, 5 cm X 5 cm each, were used in these measurements. Water is maintained at (22 1) C. The absorption is across the major surface. The numbers in parentheses give the standard deviations.
Table 3.7. Water absorption data for OSB 1.
Square Root of
time, s Water Absorption
kg m-2 7.75 0.09 (0.02)
13.42 0.07 (0.02) 17.32 0.08 (0.03) 24.49 0.09 (0.02) 30.00 0.10 (0.02) 38.73 0.10 (0.02) 48.99 0.11 (0.02) 64.81 0.14 (0.02) 93.27 0.18 (0.04) 112.78 0.21 (0.04) 131.22 0.24 (0.05) 145.33 0.27 (0.06) 168.82 0.30 (0.06) 290.55 0.49 (0.09) 314.17 0.55 (0.09) 337.19 0.59 (0.10) 412.43 0.73 (0.12)
Linear regression using all the data listed above Water Absorption Coefficient for the major surface = 0.0016 0.00003 kg m-2 s-.
26 The procedure used is based on: CEN/TC 89/WG 10 N95 Determination of water absorption coefficient, 1994-07-07.
B1115.13
34 Moisture Diffusivity:
Gamma ray method27 is used to measure the distribution of moisture in three test specimens, 6.5 cm X 25 cm each, during the moisture uptake in a direction parallel to the major surfaces (that is across the edges). The principle of the methodology is described by Kumaran et. al28. Marchand and Kumaran29 have reported the procedure used for the data reduction.
The moisture diffusivity derived from the gamma ray measurements is given in Table 8.
Table 3.8. The dependence of moisture diffusivity of OSB 1 on moisture content; the moisture transport is parallel to the major surfaces.
Moisture Content
kg kg-1
Diffusivity
m2 s-1
Moisture Content
kg kg-1
Diffusivity
m2 s-1
0.200 8.55E-11 0.369 5.37E-11
0.215 8.05E-11 0.385 5.23E-11
0.231 7.61E-11 0.400 5.12E-11
0.246 7.23E-11 0.415 5.01E-11
0.262 6.89E-11 0.431 4.93E-11
0.277 6.6E-11 0.446 4.86E-11
0.292 6.33E-11 0.462 4.81E-11
0.308 6.09E-11 0.477 4.78E-11
0.323 5.88E-11 0.492 4.77E-11
0.338 5.69E-11 0.508 4.79E-11
0.354 5.52E-11 0.523 4.85E-11
The uncertainty in the derived moisture diffusivity is estimated to be as high as 30 to 50 %.
27 Kumaran, M.K. and Bomberg, M.T., "A Gamma-spectrometer for determination of density distribution and moisture distribution in building materials," Moisture and Humidity: Measurement and Control in Science and Industry : Proceedings of International Symposium (Washington, D.C., USA, 1985), pp. 485-90, 1985. 28 Kumaran, M.K., Mitalas, G.P., Kohonen, R., Ojanen, T, "Moisture transport coefficient of pine from gamma ray absorption measurements," Collected Papers in Heat Transfer, 1989 : Winter Annual Meeting of the ASME (San Francisco, CA, USA, 1989) pp. 179-183, 1989(ASME Heat Transfer Division vol. 123). 29 Marchand, R.G. and Kumaran, M. K., "Moisture diffusivity of cellulose insulation," Journal of Thermal Insulation and Building Envelopes, Vol. 17, pp. 362-377, 1994.
B1115.13
35 Air Permeability:
Bomberg and Kumaran30 have reported the principle of the method used in these
measurements. Appendix XIII of the Client Report to ASHRAE, B-1115.3 A Thermal and
Moisture Transport Property Database for Common Building and Insulating Materials 1018-RP
dated 1 April 1999 reports the details. Three circular test specimens (thickness 12.29, 12.23 and
12.26 mm), each approximately 13 cm in diameter, are used in these measurements. The
measurements are conducted at a temperature = (22 1) C.
The summary of the statistical analyses of all data obtained from two series of
measurements on each specimen is shown in Figure 1 as three separate sets.
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0 200 400 600 800 1000
Pressure Difference, Pa
Flow
, l m
-2 s
-1
Data Points Mean PermeanceUpper Confidence Interval Lower Confidence Interval
Figure 3.1. The dependence of airflow rate on pressure difference for OSB 1.
For the range of pressure differences between 25 Pa and 900 Pa, the flow rate linearly
varies with the pressure difference. The air permeability is (9.6 3.2) E-10 kg m-1 Pa-1 s-1.
30 Bomberg, M. T. and Kumaran, M.K., " A Test method to determine air flow resistance of exterior membranes and sheathings," Journal of Thermal Insulation, Vol.9, pp. 224-235,1986.
B1115.13
36 4. HYGROTHERMAL PROPERTIES OF ORIENTED STRAND BOARD -2
The test specimens used for various measurements reported here are taken from one board of a commercial product, 4 X 8 with a nominal thickness of 3/8. The strands of this product are manufactured from balsam poplar and trembling aspen.
Density: (660 30) kg m-3
Heat Capacity (From International Energy Agency Annex 24 Report31): 1880 J K-1 kg-1
Thermal Conductivity: Measurements are according to ASTM Standard C518; 30.5 cm X 30.5 cm specimens are used
in these measurements. The temperatures of the plates are maintained within 0.04 C for these
measurements, for 12 h period to confirm steady state. Heat flow is perpendicular to the major
surfaces.
Table 4.1. Thermal Conductivity of OSB 2.
Specimen Thickness
mm
Hot Surface Temperature
C
Cold surface Temperature
C
Conductivity
W m-1 K-1
10.25 27.04 21.40 0.0944
10.25 3.66 -3.16 0.0909
9.85 27.16 21.39 0.0812
9.85 3.70 -3.36 0.0778
Note: The heat flow meter apparatus is built to measure the heat transmission characteristics of
insulating materials and for those materials the measurement uncertainties are within 2 %. This
same uncertainty is applicable to OSB.
31 M K Kumaran, Final Report, Volume 3, Material Properties, International Energy Agency Annex 24 Report, Published by K. U. Leuven Belgium, 1996
B1115.13
37 Sorption Desorption Measurements32: Up to nine specimens, 40 mm X 40 mm each at the full board thickness are used in these
measurements; the numbers in parentheses indicate the experimental uncertainties.
Sorption: Table 4.2. Sorption data for OSB 2.
RH, % Temperature, C Moisture Content, kg kg-1
100, total saturation Lab at 22 (1) 1.21 (0.10), six specimens
100, total saturation Lab at 22 (1) 1.26 (0.08), nine specimens
48.9 (1) 23 (0.2) 0.046 (0.001), three specimens
69.1 (1) 23 (0.2) 0.076 (0.001), three specimens
88.6 (1) 23 (0.2) 0.147 (0.005), three specimens
Desorption:
Table 4.3. Desorption data for OSB 2.
RH, % Temperature, C Moisture Content, kg kg-1
99.8(0.1) Lab at 22 (1) 0.606 (.009), six specimens
99.3 (0.1) Lab at 22 (1) 0.393 (0.005), six specimens
92.3 (1) 23.0 (0.2) 0.173 (0.003), two specimens
90.3 (1) 23.0 (0.2) 0.162 (0.005), three specimens
69.4 (1) 23.0 (0.2) 0.091 (0.001), two specimens
49.9 (1) 23.0 (0.2) 0.069 (0.001), two specimens
32 In the hygroscopic range, the measurements are done using the proposed procedure for ASTM Standard C1498, which in turn is based on CEN 89 N 337 E, Hygroscopic Sorption Curve; at the higher range the pressure plate method is used. Details of the pressure plate method are given by: Hansen, M. H., "Retention Curves Measured Using Pressure Plate and Pressure Membrane," Nordtest Technical Report 367, Danish Building Research Institute, 1998, p 63.
B1115.13
38 Water Vapour Transmission (WVT) Rate measurements33: For each test condition, 3 circular specimens, each 15 cm in diameter, are used. Table 4.4. Dry Cup Measurements on OSB 2 specimens: The numbers in parentheses indicate the experimental uncertainties for RH and temperature; for WVT Rate the numbers indicate the standard errors according to a linear regression of data on water vapour transmission rate at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
9.86 49.3 (1) 23.1 (0.1) 2.70E-08 (1.8E-10)
9.98 49.3 (1) 23.1 (0.1) 4.64E-08 (4.1E-10)
9.98 49.3 (1) 23.1 (0.1) 1.88E-08 (1.9 E-10)
9.86 69.2 (1) 23.2 (0.1) 5.51E-08 (7.9E-10)
9.98 69.2 (1) 23.2 (0.1) 8.86E-08 (1.3E-09)
9.98 69.2 (1) 23.2 (0.1) 3.95E-08 (2.1 E-10)
9.86 92.8 (2) 22.7 (0.1) 2.80E-07 (4.3E-09)
9.98 92.8 (2) 22.7 (0.1) 2.77E-07 (2.6E-09)
9.98 92.8 (2) 22.7 (0.1) 1.93E-07 (2.8E-09)
Table 4.5. Wet Cup Measurements on OSB 2 specimens: The numbers in parentheses indicate the experimental uncertainties for RH and temperature; for WVT Rate the numbers indicate the standard errors according to a linear regression of data on water vapour transmission rate at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
9.94 69.0 (1) 23.2 (0.1) 2.33E-07 (1.2E-09)
9.76 69.0 (1) 23.2 (0.1) 2.53E-07 (1.8E-09)
9.65 69.0 (1) 23.2 (0.1) 3.44E-07 (2.6E-09)
12.31 90.5 (2) 23.0 (0.3) 2.21E-07 (3.5E-09)
12.40 90.5 (2) 23.0 (0.3) 1.19E-07 (1.0E-09)
12.38 90.5 (2) 23.0 (0.3) 1.57E-07 (2.2E-09)
The average thickness of still air in the cups for both series is 15 mm
33 Measurements are done as described by: Lackey, J. C., Marchand, R. G., and Kumaran, M. K., A Logical Extension of the ASTM Standard E96 to Determine the Dependence of Water Vapour Transmission on Relative Humidity, Insulation Materials: Testing And Applications: Third Volume, ASTM STP 1320, R. S. Graves and R. R. Zarr, Eds, American Society for Testing and Materials, West Conshohocken, PA, 1997, pp 456-470.
B1115.13
39 Derived Water Vapour Permeability34 Table 4.6. The dependence of water vapour permeability of OSB 2 on relative humidity.
RH, % Permeability kg m-1 s-1 Pa-1
RH, % Permeability kg m-1 s-1 Pa-1
10 6.42E-14 60 8.11E-13 20 1.06E-13 70 1.35E-12 30 1.77E-13 80 2.27E-12 40 2.93E-13 90 3.83E-12 50 4.87E-13 100 6.54E-12
From the TableCurve statistics, the estimated uncertainty in the derived value of the permeability
may be higher than 50 %. The scatter in the WVT data for this product is unusually high for a
building material.
34 The analysis is done as described in : Kumaran, M. K., An Alternative Procedure for the Analysis of Data from the Cup Method Measurements for Determination of Water Vapour Transmission Properties, Journal of Testing and Evaluation, JTVEA, Vol. 26 , pp. 575-581, 1998.
B1115.13
40 Water Absorption Coefficient35: Four test specimens, 5 cm X 5 cm each, were used in these measurements. Water is maintained at (22 1) C. The absorption is across the major surface. The numbers in parentheses give the standard deviations.
Table 4.7. Water absorption data for OSB 2.
Square Root of
time, s Water Absorption
kg m-2 7.75 0.04 (0.01)
13.42 0.06 (0.02) 21.91 0.07 (0.02) 28.98 0.07 (0.02) 38.73 0.09 (0.02) 45.83 0.10 (0.03) 60.00 0.12 (0.03) 85.56 0.15(0.03) 106.77 0.18 (0.04) 127.28 0.21 (0.04) 140.71 0.23(0.04) 165.41 0.26(0.04) 288.58 0.46(0.07) 312.54 0.51(0.07) 335.41 0.55(0.08) 410.97 0.70(0.08)
Linear regression using all the data listed above Water Absorption Coefficient for the major surface = 0.0016 0.00003 kg m-2 s-.
35 The procedure used is based on: CEN/TC 89/WG 10 N95 Determination of water absorption coefficient, 1994-07-07.
B1115.13
41 Moisture Diffusivity:
Gamma ray method36 is used to measure the distribution of moisture in three test specimens, 6.5 cm X 25 cm each, during the moisture uptake in a direction parallel to the major surfaces (that is across the edges). The principle of the methodology is described by Kumaran et. al37. Marchand and Kumaran38 have reported the procedure used for the data reduction.
The moisture diffusivity derived from the gamma ray measurements is given in Table 8.
Table 4.8. The dependence of moisture diffusivity of OSB 2 on moisture content; the moisture transport is parallel to the major surfaces.
Moisture Content
kg kg-1
Diffusivity
m2 s-1
Moisture Content
kg kg-1
Diffusivity
m2 s-1
0.197 7.07E-10 0.424 2.03E-10
0.212 6.21E-10 0.439 1.92E-10
0.227 5.52E-10 0.455 1.83E-10
0.242 4.95E-10 0.470 1.74E-10
0.258 4.47E-10 0.485 1.66E-10
0.273 4.07E-10 0.500 1.58E-10
0.288 3.73E-10 0.515 1.51E-10
0.303 3.43E-10 0.530 1.45E-10
0.318 3.17E-10 0.545 1.39E-10
0.333 2.95E-10 0.561 1.34E-10
0.348 2.75E-10 0.576 1.29E-10
0.364 2.57E-10 0.591 1.24E-10
0.379 2.41E-10 0.606 1.19E-10
0.394 2.27E-10 0.621 1.15E-10
0.409 2.14E-10 0.636 1.11E-10
The uncertainty in the derived moisture diffusivity is estimated to be as high as 30 to 50 %.
36 Kumaran, M.K. and Bomberg, M.T., "A Gamma-spectrometer for determination of density distribution and moisture distribution in building materials," Moisture and Humidity: Measurement and Control in Science and Industry : Proceedings of International Symposium (Washington, D.C., USA, 1985), pp. 485-90, 1985. 37 Kumaran, M.K., Mitalas, G.P., Kohonen, R., Ojanen, T, "Moisture transport coefficient of pine from gamma ray absorption measurements," Collected Papers in Heat Transfer, 1989 : Winter Annual Meeting of the ASME (San Francisco, CA, USA, 1989) pp. 179-183, 1989(ASME Heat Transfer Division vol. 123). 38 Marchand, R.G. and Kumaran, M. K., "Moisture diffusivity of cellulose insulation," Journal of Thermal Insulation and Building Envelopes, Vol. 17, pp. 362-377, 1994.
B1115.13
42 Air Permeability:
Bomberg and Kumaran39 have reported the principle of the method used in these
measurements. Appendix XIII of the Client Report to ASHRAE, B-1115.3 A Thermal and
Moisture Transport Property Database for Common Building and Insulating Materials 1018-RP
dated 1 April 1999 reports the details. Three circular test specimens (thickness 9.60, 9.72 and
9.84 mm), each approximately 13 cm in diameter, are used in these measurements. The
measurements are conducted at a temperature = (22 1) C.
The summary of the statistical analyses of all data obtained from two series of
measurements on each specimen is shown in Figure 1 as three separate sets.
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0 200 400 600 800
Pressure Difference, Pa
Flow
, l m
-2 s
-1
Data Points Mean PermeanceUpper Confidence Interval Lower Confidence Interval
Figure 4.1. The dependence of airflow rate on pressure difference for OSB 2.
For the range of pressure differences between 25 Pa and 600 Pa, the flow rate linearly
varies with the pressure difference. The air permeability is (9.8 1.4) E-10 kg m-1 Pa-1 s-1.
39 Bomberg, M. T. and Kumaran, M.K., " A Test method to determine air flow resistance of exterior membranes and sheathings," Journal of Thermal Insulation, Vol.9, pp. 224-235,1986.
B1115.13
43 5. HYGROTHERMAL PROPERTIES OF ORIENTED STRAND BOARD -3
The test specimens used for various measurements reported here are taken from one board of a commercial product, 4 X 8 with a nominal thickness of 7/16. The strands of this product are manufactured from birch, poplar and aspen.
Density: (650 30) kg m-3
Heat Capacity (From International Energy Agency Annex 24 Report40): 1880 J K-1 kg-1
Thermal Conductivity: Measurements are according to ASTM Standard C518; 30.5 cm X 30.5 cm specimens are used
in these measurements. The temperatures of the plates are maintained within 0.04 C for these
measurements, for 12 h period to confirm steady state. Heat flow is perpendicular to the major
surfaces.
Table 5.1. Thermal Conductivity of OSB 3.
Specimen Thickness
mm
Hot Surface Temperature
C
Cold surface Temperature
C
Conductivity
W m-1 K-1
10.87 27.66 21.73 0.0866
10.87 3.24 -2.78 0.0844
10.98 27.28 21.74 0.102
19.50 2.80 -2.93 0.0965
Note: The heat flow meter apparatus is built to measure the heat transmission characteristics of
insulating materials and for those materials the measurement uncertainties are within 2 %. This
same uncertainty is applicable to OSB.
40 M K Kumaran, Final Report, Volume 3, Material Properties, International Energy Agency Annex 24 Report, Published by K. U. Leuven Belgium, 1996
B1115.13
44 Sorption Desorption Measurements41: Up to nine specimens, 40 mm X 40 mm each at the full board thickness are used in these
measurements; the numbers in parentheses indicate the experimental uncertainties.
Sorption: Table 5.2. Sorption data for OSB 3.
RH, % Temperature, C Moisture Content, kg kg-1
100, total saturation Lab at 22 (1) 1.58 (0.16), six specimens
100, total saturation Lab at 22 (1) 1.60 (0.10), nine specimens
48.9 (1) 23 (0.2) 0.054 (0.001), three specimens
69.1 (1) 23 (0.2) 0.082 (0.001), three specimens
88.6 (1) 23 (0.2) 0.147 (0.005), three specimens
Desorption:
Table 5.3. Desorption data for OSB 3.
RH, % Temperature, C Moisture Content, kg kg-1
99.8(0.1) Lab at 22 (1) 0.627 (0.010), six specimens
99.3 (0.1) Lab at 22 (1) 0.391 (0.015), six specimens
90.3 (1) 23.0 (0.2) 0.174 (0.002), three specimens
69.4 (1) 23.0 (0.2) 0.099 (0.002), two specimens
49.9 (1) 23.0 (0.2) 0.079 (0.001), two specimens
Note:
Desorption measurements at the RH of 92.3% on the two specimens gave very different results
(0.15 and 0.55) for the equilibrium moisture content. The reason for this is unknown and the data
are excluded.
41 In the hygroscopic range, the measurements are done using the proposed procedure for ASTM Standard C1498, which in turn is based on CEN 89 N 337 E, Hygroscopic Sorption Curve; at the higher range the pressure plate method is used. Details of the pressure plate method are given by: Hansen, M. H., "Retention Curves Measured Using Pressure Plate and Pressure Membrane," Nordtest Technical Report 367, Danish Building Research Institute, 1998, p 63.
B1115.13
45 Water Vapour Transmission (WVT) Rate measurements42: For each test condition, 3 circular specimens, each 15 cm in diameter, are used. Table 5.4. Dry Cup Measurements on OSB 3 specimens: The numbers in parentheses indicate the experimental uncertainties for RH and temperature; for WVT Rate the numbers indicate the standard errors according to a linear regression of data on water vapour transmission rate at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
10.54 49.3 (1) 23.1 (0.1) 5.71E-08 (6.5E-10)
10.58 49.3 (1) 23.1 (0.1) 7.79E-08 (1.3E-09)
10.71 49.3 (1) 23.2 (0.1) 9.84E-08 (1.6 E-09)
10.54 69.1 (1) 23.3 (0.1) 1.13E-07 (1.9E-09)
10.58 69.1 (1) 23.3 (0.1) 1.48E-07 (1.8E-09)
10.71 69.1 (1) 23.3 (0.1) 1.75E-07 (1.9 E-09)
10.54 92.7(2) 22.7 (0.2) 3.31E-07 (3.0E-09)
10.58 92.7 (2) 22.7 (0.2) 3.39E-07 (1.5E-09)
10.71 92.7 (2) 22.7 (0.2) 3.55E-07 (2.4E-09)
Table 5.5. Wet Cup Measurements on OSB 3 specimens: The numbers in parentheses indicate the experimental uncertainties for RH and temperature; for WVT Rate the numbers indicate the standard errors according to a linear regression of data on water vapour transmission rate at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
10.81 69.1 (1) 23.2 (0.1) 3.26E-07 (3.2E-09)
10.90 69.1 (1) 23.2 (0.1) 2.81E-07 (4.5E-09)
10.85 69.1 (1) 23.2 (0.1) 2.89E-07 (3.6E-09)
10.81 91.9 (2) 23.3 (0.2) 3.12E-07 (4.5E-09)
10.90 91.9 (2) 23.3 (0.2) 1.22E-07 (1.6E-09)
10.85 91.9 (2) 23.3 (0.2) 9.06E-08 (8.6E-10)
The average thickness of still air in the cups for both series is 15 mm
42 Measurements are done as described by: Lackey, J. C., Marchand, R. G., and Kumaran, M. K., A Logical Extension of the ASTM Standard E96 to Determine the Dependence of Water Vapour Transmission on Relative Humidity, Insulation Materials: Testing And Applications: Third Volume, ASTM STP 1320, R. S. Graves and R. R. Zarr, Eds, American Society for Testing and Materials, West Conshohocken, PA, 1997, pp 456-470.
B1115.13
46 Derived Water Vapour Permeability43 Table 5.6. The dependence of water vapour permeability of OSB 3 on relative humidity.
RH, % Permeability kg m-1 s-1 Pa-1
RH, % Permeability kg m-1 s-1 Pa-1
10 2.56E-13 60 1.70E-12 20 4.01E-13 70 2.30E-12 30 6.02E-13 80 3.08E-12 40 8.73E-13 90 4.08E-12 50 1.23E-12 100 5.35E-12
From the TableCurve statistics, the estimated uncertainty in the derived value of the permeability
may be higher than 50 %. The scatter in the WVT data for this product is unusually high for a
building material.
43 The analysis is done as described in : Kumaran, M. K., An Alternative Procedure for the Analysis of Data from the Cup Method Measurements for Determination of Water Vapour Transmission Properties, Journal of Testing and Evaluation, JTVEA, Vol. 26 , pp. 575-581, 1998.
B1115.13
47 Water Absorption Coefficient : 44 Four test specimens, 5 cm X 5 cm each, were used in these measurements. Water is maintained at (22 1) C. The absorption is across the major surface. The numbers in parentheses give the standard deviations.
Square Root of
time, s Water Absorption
-2
7.75 0.05 (0.01) 13.42 0.06 (0.01) 18.97 24.49 0.09 (0.01)
0.10 (0.02) 42.43 0.12 (0.02) 54.77
Table 5.7. Water absorption data for OSB 3.
kg m
0.07 (0.02)
34.64
0.15 (0.03) 60.00 0.16 (0.03) 81.24 0.20 (0.03) 100.70 0.25 (0.04) 121.24 0.29 (0.04) 144.71 0.34 (0.04) 157.80 0.35 (0.05) 285.66 0.65 (0.10) 311.77 0.71 (0.11) 336.48 0.78 (0.11)
Linear regression using all the data listed above Water Absorption Coefficient for the major surface = 0.0022 0.00002 kg m-2 s-.
44 The procedure used is based on: CEN/TC 89/WG 10 N95 Determination of water absorption coefficient, 1994-07-07.
B1115.13
48 Moisture Diffusivity:
Gamma ray method45 is used to measure the distribution of moisture in three test specimens, 6.5 cm X 25 cm each, during the moisture uptake in a direction parallel to the major surfaces (that is across the edges). The principle of the methodology is described by Kumaran et. al46. Marchand and Kumaran47 have reported the procedure used for the data reduction.
The moisture diffusivity derived from the gamma ray measurements is given in Table 8.
Table 5.8. The dependence of moisture diffusivity of OSB 3 on moisture content; the moisture transport is parallel to the major surfaces.
Moisture Content
kg kg-1
Diffusivity
m2 s-1
Moisture Content
kg kg-1
Diffusivity
m2 s-1
0.200 4.17E-10 0.600 1.58E-10
0.231 3.57E-10 0.631 1.52E-10
0.262 3.15E-10 0.662 1.46E-10
0.292 2.84E-10 0.692 1.41E-10
0.323 2.59E-10 0.723 1.37E-10
0.354 2.4E-10 0.754 1.33E-10
0.385 2.24E-10 0.785 1.29E-10
0.415 2.1E-10 0.815 1.25E-10
0.446 1.98E-10 0.846 1.22E-10
0.477 1.88E-10 0.877 1.18E-10
0.508 1.79E-10 0.908 1.15E-10
0.538 1.71E-10 0.923 1.14E-10
0.569 1.64E-10
The uncertainty in the derived moisture diffusivity is estimated to be as high as 30 to 50 %.
45 Kumaran, M.K. and Bomberg, M.T., "A Gamma-spectrometer for determination of density distribution and moisture distribution in building materials," Moisture and Humidity: Measurement and Control in Science and Industry : Proceedings of International Symposium (Washington, D.C., USA, 1985), pp. 485-90, 1985. 46 Kumaran, M.K., Mitalas, G.P., Kohonen, R., Ojanen, T, "Moisture transport coefficient of pine from gamma ray absorption measurements," Collected Papers in Heat Transfer, 1989 : Winter Annual Meeting of the ASME (San Francisco, CA, USA, 1989) pp. 179-183, 1989(ASME Heat Transfer Division vol. 123). 47 Marchand, R.G. and Kumaran, M. K., "Moisture diffusivity of cellulose insulation," Journal of Thermal Insulation and Building Envelopes, Vol. 17, pp. 362-377, 1994.
B1115.13
49 Air Permeability:
Bomberg and Kumaran48 have reported the principle of the method used in these
measurements. Appendix XIII of the Client Report to ASHRAE, B-1115.3 A Thermal and
Moisture Transport Property Database for Common Building and Insulating Materials 1018-RP
dated 1 April 1999 reports the details. Three circular test specimens (thickness 10.91, 10.94 and
10.84 mm), each approximately 13 cm in diameter, are used in these measurements. The
measurements are conducted at a temperature = (22 1) C.
The summary of the statistical analyses of all data obtained from two series of
measurements on each specimen is shown in Figure 1 as three separate sets.
0
0.02
0.04
0.06
0.08
0.1
0.12
0 100 200 300 400 500
Pressure Difference, Pa
Flow
, l m
-2 s
-1
Data Points Mean PermeanceUpper Confidence Interval Lower Confidence Interval
Figure 5.1. The dependence of airflow rate on pressure difference for OSB 3.
For the range of pressure differences between 25 Pa and 400 Pa, the flow rate linearly
varies with the pressure difference. The air permeability is (2.2 1.0) E-09 kg m-1 Pa-1 s-1.
48 Bomberg, M. T. and Kumaran, M.K., " A Test method to determine air flow resistance of exterior membranes and sheathings," Journal of Thermal Insulation, Vol.9, pp. 224-235,1986.
B1115.13
50 6. HYGROTHERMAL PROPERTIES OF PLYWOOD - 1
The test specimens used for various measurements reported here are taken from one board of a commercial product, 4 X 8 with a nominal thickness of 3/4. The product is certified as conforming to Canadian plywood manufacturing standard CSA O151 Canadian Softwood Plywood.
Density: (445 5) kg m-3
Heat Capacity (From International Energy Agency Annex 24 Report49): 1880 J K-1 kg-1
Thermal Conductivity: Measurements are according to ASTM Standard C518; 30.5 cm X 30.5 cm specimens are used
in these measurements. The temperatures of the plates are maintained within 0.04 C for these
measurements, for 12 h period to confirm steady state. Heat flow is perpendicular to the major
surfaces.
Table 6.1. Thermal Conductivity of Plywood 1.
Specimen Thickness
mm
Hot Surface Temperature
C
Cold surface Temperature
C
Conductivity
W m-1 K-1
17.93 27.23 21.04 0.0929
17.93 3.98 -3.35 0.0887
17.74 27.22 21.05 0.0911
19.50 4.04 -3.32 0.0870
Note: The heat flow meter apparatus is built to measure the heat transmission characteristics of
insulating materials and for those materials the measurement uncertainties are within 2 %. This
same uncertainty is applicable to Plywood.
49 M K Kumaran, Final Report, Volume 3, Material Properties, International Energy Agency Annex 24 Report, Published by K. U. Leuven Belgium, 1996
B1115.13
51 Sorption Desorption Measurements50: Up to nine specimens, 40 mm X 40 mm each at the full board thickness are used in these
measurements; the numbers in parentheses indicate the experimental uncertainties. Sorption:
Table 6.2. Sorption data for Plywood 1.
RH, % Temperature, C Moisture Content, kg kg-1
100, total saturation Lab at 22 (1) 1.8 (0.1), six specimens
100, total saturation Lab at 22 (1) 1.9 (0.1), nine specimens
48.9 (1) 23 (0.2) 0.067 (0.001), three specimens
69.1 (1) 23 (0.2) 0.101 (0.001), three specimens
88.6 (1) 23 (0.2) 0.176 (0.005), three specimens
Desorption: Table 6.3. Desorption data for Plywood 1.
RH, % Temperature, C Moisture Content, kg kg-1
99.8(0.1) Lab at 22 (1) 0.99 (0.01), three specimens
99.3 (0.1) Lab at 22 (1) 0.66 (0.05) , three specimens
92.3 (1) Lab at 22 (1) 0.207 (0.002), three specimens
90.3 (1) 23.0 (0.2) 0.193 (0.002), three specimens
69.4 (1) 23.0 (0.2) 0.113 (0.003), two specimens
49.9 (1) 23.0 (0.2) 0.089 (0.001), two specimens
Note: Pressure plate measurements at 22 C on four similar products gave the following results
for equilibrium moisture contents at relative humidity very close to 100 %.
Table 6.3a. Desorption data for four similar plywood products.
RH, % Moisture Content, kg kg-1
99.98 1.23 (0.25), 12 specimens
99.93 0.94 (0.22), 12 specimens
50 In the hygroscopic range, the measurements are done using the proposed procedure for ASTM Standard C1498, which in turn is based on CEN 89 N 337 E, Hygroscopic Sorption Curve; at the higher range the pressure plate method is used. Details of the pressure plate method are given by: Hansen, M. H., "Retention Curves Measured Using Pressure Plate and Pressure Membrane," Nordtest Technical Report 367, Danish Building Research Institute, 1998, p 63.
B1115.13
52 Water Vapour Transmission (WVT) Rate measurements51: For each test condition, 3 circular specimens, each 15 cm in diameter, are used. Table 6.4. Dry Cup Measurements on Plywood 1 specimens: The numbers in parentheses indicate the experimental uncertainties for RH and temperature; for WVT Rate the numbers indicate the standard errors according to a linear regression of data on water vapour transmission rate at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
17.84 50.2 (1) 23.2 (0.1) 5.06E-08 (3.3E-10)
17.82 50.2 (1) 23.2 (0.1) 4.86E-08 (2.8E-10)
17.86 50.2 (1) 23.2 (0.1) 6.48E-08 (3.2E-10)
17.84 69.0 (1) 23.3 (0.1) 1.00E-07 (1.9E-10)
17.82 69.0 (1) 23.3 (0.1) 1.09E-07 (1.2E-09)
17.86 69.0 (1) 23.3 (0.1) 1.25E-07 (8.8E-10)
17.84 90.0(2) 23.2 (0.2) 5.21E-07 (5.7E-09)
17.82 90.0(2) 23.2 (0.2) 4.73E-07 (8.4E-09)
17.86 90.0(2) 23.2 (0.2) 5.24E-07 (8.0E-09)
Table 6.5. Wet Cup Measurements on Plywood 1 specimens: The numbers in parentheses indicate the experimental uncertainties for RH and temperature; for WVT Rate the numbers indicate the standard errors according to a linear regression of data on water vapour transmission rate at a steady state. Specimen Thickness
mm Chamber RH
% Chamber Temperature
C WVT Rate kg m-2 s-1
17.85 69.3 (1) 23.3 (0.1) 5.08E-07 (5.3E-09)
17.77 69.3 (1) 23.3 (0.1) 5.46E-07 (6.7E-09)
17.81 69.3 (1) 23.3 (0.1) 5.83E-07 (8.6E-09)
17.85 90.0 (2) 23.1 (0.2) 2.81E-07 (3.8E-09)
17.77 90.0 (2) 23.1 (0.2) 3.35E-07 (3.8E-09)
17.81 90.0 (2) 23.1 (0.2) 3.58E-07 (5.4E-09)
The average thickness of still air in the cups for both series is 15 mm
51 Measurements are done as described by: Lackey, J. C., Marchand, R. G., and Kumaran, M. K., A Logical Extension of the ASTM Standard E96 to Determine the Dependence of Water Vapour Transmission on Relative Humidity, Insulation Materials: Testing And Applications: Third Volume, ASTM STP 1320, R. S. Graves and R. R. Zarr, Eds, American Society for Testing and Materials, West Conshohocken, PA, 1997, pp 456-470.
B1115.13
53 Derived Water Vapour Permeability52 Table 6.6. The dependence of water vapour permeability of Plywood 1.
RH, % Permeability kg m-1 s-1 Pa-1
RH, % Permeability kg m-1 s-1 Pa-1
10 5.94E-14 60 3.87E-12 20 2.17E-13 70 6.12E-12 30 5.71E-13 80 9.20E-12 40 1.22E-12 90 1.33E-11 50 2.28E-12 100 1.88E-11
From the TableCurve statistics, the estimated uncertainty in the derived value of the permeability
is about 22 %.
52 The analysis is done as described in : Kumaran, M. K., An Alternative Procedure for the Analysis of Data from the Cup Method Mea
Recommended