[esp-r] FW: surface fluxes

[王菊花]

Dear Achim,
    I am sorry I have't expressed my minds clearly.I know there is no  straightforward way to calculate U-value,which is exactly what I mean.So I want to find an easy way to do that,U=Q/¨ST.Q is the heat conduction of the double-skin facade.¨ST is the temperature difference of interior and exterior surfaces.As you say,using a simple tool like WIS can calculate U value.But there are many openings for the exterior glass of double-skin facade in my model,so there is ventilation between the air gap and environment.I realize this by building zones for the air gap area and flow connections for the openings.I try to  use result analysis > surface fluxes> conduction(inside) or conduction(other face) facility in esp-r,the output results are all zero.Maybe it is not practical to calculate U value in this way,I thought out another way to do this.I can use WINDOW5.0 to calculate U value of double-skin facade without ventilation,then campare loads of double-skin facade with and without ventilation in esp-r,divide the load difference by ¨ST.Suppose the result is ¨SU,then plus ¨SU with U value of double-skin facade without ventilation.Does the final result make sense?Anxiously expecting your kind answers.Many thanks.
 
 
 
 
 


CC: esp-r at lists.strath.ac.uk
From: achim.geissler at intergga.ch
To: luckygrass100 at hotmail.com
Subject: Re: [esp-r] surface fluxes
Date: Sat, 15 May 2010 19:20:29 +0200

Hi  


not sure what you mean. What turned out zero? All the values in the res-variables you name? Or your subsequent calculations? Anyway, there is no straightforward way to extract the U-value (if that is what you mean with comprehensive transfer coefficient) of a double facade construction. 


I would recommend using a simple tool like WIS to compare your window / facade constructions in regard to basic parameters (g-value, U-value). And look at overall loads to compare the impact on the building as a system.


Regards
Achim





On May 15, 2010, at 1:31 PM, Íõ¾Õ»¨ wrote:

Dear Dear all£¬
   I am puzzled again.I am simulating an low-carbon building with double-skin facade for the south facade.I need calculate out the comprehensive transfer coefficient h(W/m2.K),then compare it with that of normal single window.I was thinking maybe I can output the temperature and heat conduction of the interior and exterior surfaces.But when I used the surface fluxes facility,and choosed conduction(inside) or conduction(other face),it turned out all zero.Why?



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