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basics:building_physics_-_basics:thermal_bridges:tbcalculation:examples:ewfs [2016/08/09 14:30] – created mschuerenbasics:building_physics_-_basics:thermal_bridges:tbcalculation:examples:ewfs [2022/08/08 12:14] (current) – yaling.hsiao@passiv.de
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 ====== Exterior wall on floor slab ====== ====== Exterior wall on floor slab ======
 A typical connection detail is shown below:  A typical connection detail is shown below: 
  
-{{ :picprivate:aussenwand_auf_bodenplatte_abb_4.png?nolink |}}+{{ :picopen:aussenwand_auf_bodenplatte_abb_4.png? |}} 
 + 
 +{{ :picopen:aussenwand_auf_bodenplatte_abb_5.png?800 |}}
  
-{{ :picprivate:aussenwand_auf_bodenplatte_abb_5.png?nolink&800 |}} 
  
 **Note!** //Before preparing the calculation model, it should be checked which building component layers are relevant for the calculations and which can be disregarded. Thus for example, blinding layers can be disregarded which do not have any significant insulating effect on account of their material or due to their water permeability. It should also be considered whether poorer rated values apply for perimeter insulation which is outside of the moisture barrier or sealing layers.//  **Note!** //Before preparing the calculation model, it should be checked which building component layers are relevant for the calculations and which can be disregarded. Thus for example, blinding layers can be disregarded which do not have any significant insulating effect on account of their material or due to their water permeability. It should also be considered whether poorer rated values apply for perimeter insulation which is outside of the moisture barrier or sealing layers.// 
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 The following U-value results for the exterior wall: The following U-value results for the exterior wall:
  
-{{ :picprivate:aussenwand_auf_bodenplatte_abb_6.png?nolink&800 |}}+{{ :picopen:aussenwand_auf_bodenplatte_abb_6.png?800 |}}
  
-{{ :picprivate:aussenwand_auf_bodenplatte_abb_7.png?nolink&800 |}}+{{ :picopen:aussenwand_auf_bodenplatte_abb_7.png?800 |}}
  
 \\ \\
 ===== Calculation model ===== ===== Calculation model =====
  
-First,  an overall model is prepared for calculating the  conductance $L_{2d}$. If the actual size of the building is not known, B‘ can be selected for the option B, but it should not be too small ($B' > 5 \, \text{m}$). $B' = 7{,}992 \, \text{m}$ was selected here (including the exterior wall) //[Note: With some heat flow software programs the dimensions in the models may have inconvenient decimal places; however this is not of any significance]//. The floor slab is only modelled up to the axis of symmetry and thus has the length $\frac{B'}{2}=4{,}996 \, \text{m}$. The height of the exterior wall should be three times as high as the area to be examined. It is essential that the length is measured based on the exterior references, that is, up to the lower edge of the perimeter insulation. The same dimensional reference should be used in the respective [[planning:calculating_energy_efficiency:phpp_-_the_passive_house_planning_package |PHPP]] calculation. In the example shown here, the length of the exterior wall is 2.03 m. The block of earth should be modelled with a size of at least $2{,}5 \cdot B'$. +First,  an overall model is prepared for calculating the  conductance $L_{2d}$. If the actual size of the building is not known, B‘ can be selected for the option B, but it should not be too small ($B' > 5 \, \text{m}$). $B' = 7{,}992 \, \text{m}$ was selected here (including the exterior wall) //[Note: With some heat flow software programs the dimensions in the models may have inconvenient decimal places; however this is not of any significance]//. The floor slab is only modelled up to the axis of symmetry and thus has the length $\frac{B'}{2}=3{,}996 \, \text{m}$. The height of the exterior wall should be three times as high as the area to be examined. It is essential that the length is measured based on the exterior references, that is, up to the lower edge of the perimeter insulation. The same dimensional reference should be used in the respective [[planning:calculating_energy_efficiency:phpp_-_the_passive_house_planning_package |PHPP]] calculation. In the example shown here, the length of the exterior wall is 2.03 m. The block of earth should be modelled with a size of at least $2{,}5 \cdot B'$. 
 In the following illustration all relevant reference dimensions and boundary conditions are included. Ultimately, it is irrelevant which boundary conditions for the temperature are used for determining the conductances; however, it is recommended that those should be used which will be needed later on for determining the surface temperatures. The lower part of the illustration shows the calculation of the conductance $L_{2d}$, this results from the heat flow calculated using the heat flow software program. In the following illustration all relevant reference dimensions and boundary conditions are included. Ultimately, it is irrelevant which boundary conditions for the temperature are used for determining the conductances; however, it is recommended that those should be used which will be needed later on for determining the surface temperatures. The lower part of the illustration shows the calculation of the conductance $L_{2d}$, this results from the heat flow calculated using the heat flow software program.
  
 <WRAP centeralign> <WRAP centeralign>
 **Calculating the conductance**  **Calculating the conductance** 
-<latex> 
 $L_{2d}$  $L_{2d}$ 
-</latex> 
 </WRAP> </WRAP>
  
-{{ :picprivate:aussenwand_auf_bodenplatte_abb_8a.png?nolink&600 |}} 
  
-{{ :picprivate:aussenwand_auf_bodenplatte_abb_8b.png?nolink&600 |}}+{{ :picopen:01_updated_-_aussenwand_auf_bodenplatte_abb_8a.png?600 |}} 
 + 
 +{{ :picopen:aussenwand_auf_bodenplatte_abb_8b.png?600 |}} 
 + 
 + 
 +<WRAP centeralign>  
 +$$ 
 +\dot{q} = 19{,}488 \, \frac{\text{W}}{\text{m}} 
 +$$ 
 +</WRAP>
  
 <WRAP centeralign>  <WRAP centeralign> 
-<latex> +$$ 
-$$\.q = 19{,}488 \, \frac{\text{W}}{\text{m}}$$ \\ +\large{L_{2d} = \frac{\dot{q}}{T_i-T_e} = \frac{19{,}488}{30} = 0{,}6496 \, \frac{\text{W}}{\text{m} \cdot \text{K}}} 
-$$L_{2d} = \frac{\.q}{T_i-T_e} = \frac{19{,}488}{30} = 0{,}6496 \, \frac{\text{W}}{\text{m} \cdot \text{K}}}$$  +$$
-</latex>+
 </WRAP> </WRAP>
  
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 <WRAP centeralign> <WRAP centeralign>
 **Conductance of the floor slab**  **Conductance of the floor slab** 
-<latex> 
 $L_{BP}$  $L_{BP}$ 
-</latex> 
 </WRAP> </WRAP>
  
-{{ :picprivate:aussenwand_auf_bodenplatte_abb_9a.png?nolink&600 |}} +{{ :picopen:02_updated_-_aussenwand_auf_bodenplatte_abb_9a.png?600 |}} 
-{{ :picprivate:aussenwand_auf_bodenplatte_abb_9b.png?nolink&600 |}}+{{ :picopen:aussenwand_auf_bodenplatte_abb_9b.png?600 |}} 
 + 
 + 
 +<WRAP centeralign>  
 +$$ 
 +\dot{q} = 14{,}023 \, \frac{\text{W}}{\text{m}} 
 +$$ 
 +</WRAP>
  
 <WRAP centeralign>  <WRAP centeralign> 
-<latex> +$$ 
-$$\.q = 14{,}023 \, \frac{\text{W}}{\text{m}}$$ \\ +\large{L_{BP} = \frac{\dot{q}}{T_i-T_e} = \frac{14{,}023}{30} = 0{,}4674 \, \frac{\text{W}}{\text{m} \cdot \text{K}}}  
-$$L_{BP} = \frac{\.q}{T_i-T_e} = \frac{14{,}023}{30} = 0{,}4674 \, \frac{\text{W}}{\text{m} \cdot \text{K}}}$$  +$$
-</latex>+
 </WRAP> </WRAP>
  
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 <WRAP centeralign> <WRAP centeralign>
 **Conductance of the exterior wall**  **Conductance of the exterior wall** 
-<latex> 
 $L_{AW}$  $L_{AW}$ 
-</latex> 
 </WRAP> </WRAP>
  
 <WRAP centeralign>  <WRAP centeralign> 
-<latex> +$$ 
-$$U_{AW} = 0{,}1205 \, \frac{\text{W}}{\text{m}^2 \cdot \text{K}}$$  +U_{AW} = 0{,}1205 \, \frac{\text{W}}{\text{m}^2 \cdot \text{K}}  
-$$L_{AW} = l_{AW} \cdot U_{AW} = 2{,}03 \cdot 0{,}1205 = 0{,}2446 \, \frac{\text{W}}{\text{m} \cdot \text{K}}}$$  +$$ 
-</latex>+</WRAP> 
 + 
 +<WRAP centeralign>  
 +$$ 
 +\large{L_{AW} = l_{AW} \cdot U_{AW} = 2{,}03 \cdot 0{,}1205 = 0{,}2446 \, \frac{\text{W}}{\text{m} \cdot \text{K}}}  
 +$$
 </WRAP> </WRAP>
  
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 <WRAP centeralign>  <WRAP centeralign> 
-<latex> +$$ 
-$$\Psi = L_{2d}-L_{AW}-L_{BP}=0{,}6496-0{,}2446-0{,}4674=-0{,}062 \, \frac{\text{W}}{\text{m} \cdot \text{K}}}$$  +\large{\Psi = L_{2d}-L_{AW}-L_{BP}=0{,}6496-0{,}2446-0{,}4674=-0{,}062 \, \frac{\text{W}}{\text{m} \cdot \text{K}}}  
-</latex>+$$
 </WRAP> </WRAP>
  
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 <WRAP centeralign> <WRAP centeralign>
 ** Determining the minimum surface temperature and**  ** Determining the minimum surface temperature and** 
-<latex> 
 $f_{Rsi}$  $f_{Rsi}$ 
-</latex> 
 </WRAP> </WRAP>
  
  
-{{ :picprivate:aussenwand_auf_bodenplatte_abb_10a.png?nolink&600 |}} +{{ :picopen:updated_03-_aussenwand_auf_bodenplatte_abb_10a.png?600 |}} 
-{{ :picprivate:aussenwand_auf_bodenplatte_abb_10b.png?nolink&600 |}}+{{ :picopen:aussenwand_auf_bodenplatte_abb_10b.png?600 |}}
  
 <WRAP centeralign>  <WRAP centeralign> 
-<latex> +$$ 
-$$f_{Rsi \, = \, 0{,}25} = \frac{17{,}4-(-10)}{20-(-10)} = 0{,}91$$  +f_{Rsi \, = \, 0{,}25} = \frac{17{,}4-(-10)}{20-(-10)} = 0{,}91  
-</latex>+$$
 </WRAP> </WRAP>
  
 ===== See also ===== ===== See also =====
-  * [[basics:building_physics_-_basics:heat_transfer:what_defines_thermal_bridge_free_design:thermal_bridge_calculation|Thermal bridge calculation]] +   
-  * [[basics:building_physics_-_basics:heat_transfer:what_defines_thermal_bridge_free_design:thermal_bridge_calculation:recommended_procedure|Ground-touching components: Recommended procedure]] + 
-  * [[basics:building_physics_-_basics:heat_transfer:what_defines_thermal_bridge_free_design:thermal bridge calculation|Examples of thermal bridge calculations]]+  * [[basics:building_physics_-_basics:thermal_bridges:tbcalculation|Thermal bridge calculation]] 
 + 
 +  * [[basics:building_physics_-_basics:thermal_bridges:tbcalculation:ground_contact:procedure]] 
 + 
 +  * [[basics:building_physics_-_basics:thermal_bridges:tbcalculation:examples]] 
 + 
  
basics/building_physics_-_basics/thermal_bridges/tbcalculation/examples/ewfs.1470745829.txt.gz · Last modified: 2016/08/09 14:30 by mschueren