Details:SurfaceCoatings - Versionsgeschichte

SebSta: /* Surface Coatings */

2013-06-13T12:43:38Z

Surface Coatings

← Nächstältere Version		Version vom 13. Juni 2013, 14:43 Uhr
Zeile 25:		Zeile 25:
	<P>		<P>
	If you nevertheless want to explicitly include membranes or other thin surface layers		If you nevertheless want to explicitly include membranes or other thin surface layers
	in the component assembly, please refer to the notes in [[Membranes \| reference: Membranes]].		in the component assembly, please refer to the notes in [[Details:Membranes \| reference: Membranes]].
	</P>		</P>
	<P>		<P>

Barbara: /* Surface Coatings */

2009-03-23T10:20:10Z

Surface Coatings

← Nächstältere Version		Version vom 23. März 2009, 12:20 Uhr
Zeile 37:		Zeile 37:
	to arrive at the total water vapor transfer resistance used in the calculation. So for		to arrive at the total water vapor transfer resistance used in the calculation. So for
	an ordinary naked wall surface, simply set s<SMALL>d</SMALL> = 0 m.<BR>		an ordinary naked wall surface, simply set s<SMALL>d</SMALL> = 0 m.<BR>
	~~ <BR>~~
	</P>		</P>

Zeile 43:		Zeile 42:
	<P>		<P>
	The definition of the vapor diffusion thickness (s<SMALL>d</SMALL>-value) is discussed		The definition of the vapor diffusion thickness (s<SMALL>d</SMALL>-value) is discussed
	in ~~reference:~~ [[Details:WaterVaporDiffusion \| Water Vapor Diffusion]].		in [[Details:WaterVaporDiffusion \| reference: Water Vapor Diffusion]].
	</P>		</P>
	<P>		<P>

Len am 30. September 2008 um 12:58 Uhr

2008-09-30T12:58:57Z

← Nächstältere Version		Version vom 30. September 2008, 14:58 Uhr
Zeile 25:		Zeile 25:
	<P>		<P>
	If you nevertheless want to explicitly include membranes or other thin surface layers		If you nevertheless want to explicitly include membranes or other thin surface layers
	in the component assembly, please refer to the notes in [[~~Details:~~Membranes \| reference: Membranes]].		in the component assembly, please refer to the notes in [[Membranes \| reference: Membranes]].
	</P>		</P>
	<P>		<P>

Len: /* Surface Coatings */

2008-09-30T12:57:47Z

Surface Coatings

← Nächstältere Version		Version vom 30. September 2008, 14:57 Uhr
Zeile 11:		Zeile 11:
	[[1D:Dialog_Assembly \| component assembly]], you may allow for its effect on		[[1D:Dialog_Assembly \| component assembly]], you may allow for its effect on
	water vapor transport in these cases by only		water vapor transport in these cases by only
	[[1D:~~Dialog_Surface~~ \| applying a separate diffusion resistance		[[1D:Dialog_SurfaceTransferCoefficients \| applying a separate diffusion resistance
	at the surface]]. In WUFI's [[1D:Dialog_OptionsUnitSystem \| SI mode]] this		at the surface]]. In WUFI's [[1D:Dialog_OptionsUnitSystem \| SI mode]] this
	resistance is specified in terms of the thickness of a stagnant air layer with the same diffusion resistance, i.e. you enter the corresponding		resistance is specified in terms of the thickness of a stagnant air layer with the same diffusion resistance, i.e. you enter the corresponding
Zeile 25:		Zeile 25:
	<P>		<P>
	If you nevertheless want to explicitly include membranes or other thin surface layers		If you nevertheless want to explicitly include membranes or other thin surface layers
	in the component assembly, please refer to the notes in		in the component assembly, please refer to the notes in [[Details:Membranes \| reference: Membranes]].
	[[Details:Membranes \| reference: Membranes]].
	</P>		</P>
	<P>		<P>

Len: Die Seite wurde neu angelegt: = Surface Coatings =
Walls may have a surface 'coating' which does not affect their thermal behaviour but impedes [[Details:WaterVaporDiffusion | water vapor diffu...

2008-08-13T11:02:59Z

Die Seite wurde neu angelegt: = Surface Coatings = Walls may have a surface 'coating' which does not affect their thermal behaviour but impedes [[Details:WaterVaporDiffusion | water vapor diffu...

Neue Seite

= Surface Coatings =


Walls may have a surface 'coating' which does not affect their thermal behaviour but
impedes [[Details:WaterVaporDiffusion | water vapor diffusion]], e.g. paint coats,
wallpapers, vapor retarders, laminations, an impregnation which alters the pore space
close to the surface etc.


Instead of including a separate, often extremely thin layer in the
[[1D:Dialog_Assembly | component assembly]], you may allow for its effect on
water vapor transport in these cases by only
[[1D:Dialog_Surface | applying a separate diffusion resistance
at the surface]]. In WUFI's [[1D:Dialog_OptionsUnitSystem | SI mode]] this
resistance is specified in terms of the thickness of a stagnant air layer with the same diffusion resistance, i.e. you enter the corresponding
[[Details:WaterVaporDiffusion | vapor diffusion thickness]] (sd-value).


Thus, you may simulate the effect of a vapor retarder by setting the v.d.t. to
10 m (e.g.) at the respective surface. But more massive components like gypsum board
(sd ≈ 0.1 m) or renderings may also be replaced by their
sd-value, as long as their effect on the hygrothermal behaviour of the
entire building component is limited to their diffusion resistance.


If you nevertheless want to explicitly include membranes or other thin surface layers
in the component assembly, please refer to the notes in
[[Details:Membranes | reference: Membranes]].


Because of the boundary air layer which exists at every wall surface, there is always
some surface transfer resistance to the water vapor diffusion flow (cf.
[[Details:WaterVaporTransfer | reference: Water Vapor Transfer
Coefficients]]. The sd-value discussed here only describes an
additional resistance that is caused by factors like those enumerated above.
That is, WUFI adds the resistance resulting from the internally computed natural water
vapor transfer coefficient and the sd-value due to some coating (if any)
to arrive at the total water vapor transfer resistance used in the calculation. So for
an ordinary naked wall surface, simply set sd = 0 m. 
  



The definition of the vapor diffusion thickness (sd-value) is discussed
in reference: [[Details:WaterVaporDiffusion | Water Vapor Diffusion]].


The vapor diffusion thicknesses of surface coatings (if any) are entered in the
[[1D:Dialog_SurfaceTransferCoefficients | dialog "Surface Transfer
Coefficients"]]. There, WUFI offers a list of predefined coatings with their
respective vapor diffusion thicknesses for selection; a user-defined value may be entered
as well.


Please note that if you select, say, a metal foil from the list, only
the sd-value at the component surface is set accordingly; other
properties of the foil, such as its low radiation absorptivity or its impermeability
to rain, must be specified separately by setting the appropriate
[[1D:Dialog_SurfaceTransferCoefficients | surface properties]].

Details:SurfaceCoatings - Versionsgeschichte

SebSta: /* Surface Coatings */

Barbara: /* Surface Coatings */

Len am 30. September 2008 um 12:58 Uhr

Len: /* Surface Coatings */

Len: Die Seite wurde neu angelegt: = Surface Coatings = Walls may have a surface 'coating' which does not affect their thermal behaviour but impedes [[Details:WaterVaporDiffusion | water vapor diffu...

Len: Die Seite wurde neu angelegt: = Surface Coatings =
Walls may have a surface 'coating' which does not affect their thermal behaviour but impedes [[Details:WaterVaporDiffusion | water vapor diffu...