ISO 9346:2007 建物および建築材料の湿熱性能—物質移動の物理量—用語, 語彙 | ページ 6

3.1

humidity by volume

V in kg/m³

mass of water vapour divided by the volume of the gaseous mixture

Note 1 to entry: Humidity by volume is the same as the partial mass density of water vapour, ρ_v.

Note 2 to entry: At saturation, the notations v_sat and ρ_v,sat are used.

3.2

humidity by mass

X in kg/kg

mass of water vapour divided by the mass of dry air

Note 1 to entry: At saturation, the notation x_sat is used.

3.3

partial water vapour pressure

p_v in Pa

partial pressure of water vapour in a gaseous mixture

Note 1 to entry: At saturation, the notation p_sat is used.

3.4

relative humidity

φ

3.5

specific enthalpy

h in J/kg

enthalpy divided by mass

3.5.1

specific latent enthalpy of evaporation (or condensation)

h_e in J/kg

3.5.2

specific latent enthalpy of melting (or freezing)

h_m in J/kg

3.6

moisture content mass by volume

w in kg/m³

mass of evaporable water divided by volume of dry material

Note 1 to entry: The method of evaporating water from a moist material shall be stated.

3.7

moisture content volume by volume

ψ in m ³ /m ³

volume of evaporable water divided by volume of dry material

Note 1 to entry: The method of evaporating water from a moist material shall be stated.

3.8

moisture content mass by mass

u in kg/kg

mass of evaporable water divided by dry mass of material

Note 1 to entry: The method of evaporating water from a moist material shall be stated.

3.9

degree of saturation

S

mass of water in a porous body divided by the mass of water at saturation

Note 1 to entry: The method of reaching saturation shall be stated.

3.10

Suction

S in Pa

pressure difference between the pore water pressure and the ambient total pressure

3.11

moisture flow rate

G in kg/s

mass of moisture transferred to or from a system divided by time

Note 1 to entry: Moisture flow rate denotes a flow of water vapour, a flow of liquid water or both phases together.

3.12

density of moisture flow rate

g in kg/(m²·s)

moisture flow rate divided by area

Note 1 to entry: Density of moisture flow rate denotes density of a flow of water vapour, of liquid water, or both.

3.13

water vapour diffusion coefficient in the air

D in m²/s

quantity D defined by the following relation:

where

	is the vector density of water vapour flow rate in air;
v	is the humidity by volume.

Note 1 to entry: Fick's law describes water vapour diffusion in air.

3.14

water vapour permeability

δ_v in m²/s

δ_p in (m·s·Pa)

quantities δ_v and δ_p defined by the following relations:

• a) permeability with regard to humidity by volume

  

• b) permeability with regard to partial water vapour pressure

  

where

	is the vector density of water vapour flow rate;
v	is the humidity by volume in the pores;
pv	is the partial water vapour pressure in the pores.

Note 1 to entry: Water vapour trans­mission through porous materials can be related to different driving mechanisms. Humidity by volume or partial vapour pressure are commonly used.

Although part of the moisture flow is in the liquid phase, the water vapour permeability measured by the methods in ISO 12572 is used in calculations as if only vapour diffusion was occurring (see, for example, ISO 13788).

The transfer coefficients are dependent on the level of the corresponding relative humidity or moisture content of the material.

3.15

water vapour permeance

W_v in m/s

W_p in kg/(m²·s·Pa)

3.16

water vapour resistance

Z_v in s/m

Z_p in m²·s·Pa/kg

3.17

water vapour resistance factor

μ

Note 1 to entry: The water vapour resistance factor indicates how much greater the resistance of the material is compared to an equally thick layer of stationary air at the same temperature.

3.18

water vapour diffusion-equivalent air layer thickness

s_d in m

thickness of a motionless air layer which has the same water vapour resistance, as the material layer

3.19

moisture diffusivity

D_w in m²/s

quantity Dw defined by the following relation:

where

	is the vector density of moisture flow rate;
w	is the moisture content mass per volume.

Note 1 to entry: Moisture diffusivity and moisture conductivity are principally used to describe moisture transfer in the liquid phase, but they include also the gaseous phase.

3.20

moisture conductivity

λm in kg/(m·s·Pa)

quantity λ_m defined by the following relation:

where

	is the vector density of moisture flow rate;
s	is the suction.

Note 1 to entry: Moisture diffusivity and moisture conductivity are principally used to describe moisture transfer in the liquid phase, but they include also the gaseous phase.

3.21

surface coefficient of water vapour transfer

β_v in m/s

β_p in kg/(m²·s·Pa)

3.22

moisture differential capacity

ζ in kg/m³

Note 1 to entry: This value indicates the tangent of the hygroscopic sorption curve.

3.23

thermal diffusion coefficient of moisture

D_T in kg/(m·s·K)

quantity D_T defined by the following relation;

where

	is the vector density of moisture flow rate;
T	is the temperature.

Note 1 to entry: The thermal diffusion coefficient is dependent on how the flow related to moisture gradients is described.

3.24

water sorption coefficient

A in kg/(m ² ·s ^1/2 )

3.25

water penetration coefficient

B in m/s ^1/2

3.26

air flow rate

R in m³/s

volume of air transferred to or from a system divided by time

3.27

density of air flow rate

r in m³/(m²·s)

air flow rate divided by area

3.28

permeability of a porous medium

k in m ²

quantity k defined by the following relation:

where

	is the vector density of air flow rate in a porous medium;
p	is the fluid pressure;
η	is the dynamic viscosity of the fluid at constant temperature.

3.29

air permeance

K in m³/(m²·s·Pa)

Note 1 to entry: The term, K , for air permeance includes the effect of the viscosity of air at constant temperature.

3.30

air resistance

S in m ² ·s·Pa/m ³

3.31

density of gas flow rate

M in kg/(m²·s)

mass of gas passing through a material as a function of time and area of surface, under specified conditions

Note 1 to entry: For the case of gas transfer through a material bound by parallel surfaces, this is often referred to as “gas transmission rate”.

Note 2 to entry: An alternative form of definition is in use where “amount of substance” replaces “mass” and with the corresponding units written in terms of the unit mole instead of kilogram.

3.32

gas permeability

P in kg/(m·s·Pa)

product of the gas permeance and the perpendicular distance between the surfaces of the material under consideration

Note 1 to entry: This is only quanti­fiable for heterogeneous materials and systems.

Note 2 to entry: An alternative form of definition is in use where “amount of substance” replaces “mass” and with the corresponding units written in terms of the unit mole instead of kilogram.

3.33

gas permeance

Q in kg/(m ² ·s·Pa)

mass of gas passing through a material as a function of time, area of surface and pressure difference

Note 1 to entry: An alternative form of definition is in use where “amount of substance” replaces “mass” and with the corresponding units written in terms of the unit mole instead of kilogram.

3.34

gas diffusion coefficient

D in m²/s

rate of gas diffusion through a material

Note 1 to entry: See also 3.13.

Note 2 to entry: An alternative form of definition is in use where “amount of substance” replaces “mass” and with the corresponding units written in terms of the unit mole instead of kilogram.

3.35

gas solubility

c in kg/kg

mass of permeant gas as a function of mass of permeated material under a specified pressure of permeant

Note 1 to entry: An alternative form of definition is in use where “amount of substance” replaces “mass” and with the corresponding units written in terms of the unit mole instead of kilogram.

3.36

gas solubility coefficient

S in Pa ^{− 1}

gas solubility divided by the permeant pressure

Note 1 to entry: The relationship S = c/p is Henry's Law ここで, c is a function of the permeant gas, the permeated material and temperature.

Note 2 to entry: An alternative form of definition is in use where “amount of substance” replaces “mass” and with the corresponding units written in terms of the unit mole instead of kilogram.

3.37

gas permeability coefficient

P_c in m²/(s·Pa)

product of the diffusion coefficient and the solubility coefficient

Note 1 to entry: An alternative form of definition is in use where “amount of substance” replaces “mass” and with the corresponding units written in terms of the unit mole instead of kilogram.