[esp-r] Re: Strange results from TIM simulations

[paul strachan]

Dear Wong,

Look the the solar gains, temperatures, fluxes etc in the zone you are 
using to represent the air space between the TIM and the mass wall. It 
should help you to understand what is happening in your model.  I'll 
separately send you an old paper from 1994 where we compared 
measurements and predictions  of the temperature profile through a 
facade of transparent insulation over a mass wall. It was modelled using 
a similar approach to the one you have adopted. The results of the 
comparison were quite positive.

Regards
Paul

Ing Liang Wong wrote:
> Dear all,
>  
> I have created new material, construction and optical databases for a 
> TIM construction, which has the following thermo-physical and optical 
> properties:
>  
> 1) external glass pane
> R-Value: 0.01
> Density: 2710
> Spec. heat capacity: 837
> Thermal conductivity: 0.76
> Absorption at 0, 40, 55, 70, 80 angles: 0.016, 0.018, 0.019, 0.020, 0.021
>  
> 2) PMMA capillaries
> R-Value: 0.55
> Density: 30
> Spec. heat capacity: 1400
> Thermal conductivity: 0.04
> Absorption at 0, 40, 55, 70, 80 angles: 0.02, 0.025, 0.03, 0.035, 0.04
>  
> 3) Internal glass pane
> R-Value: 0.01
> Density: 2710
> Spec. heat capacity: 837
> Thermal conductivity: 0.76
> Absorption at 0, 40, 55, 70, 80 angles: 0.016, 0.018, 0.019, 0.020, 0.021
>  
> Overall transmission at 0, 40, 55, 70, 80 angles: 0.74, 0.702, 0.570, 
> 0.463, 0.377
>  
> I have conducted simulations to a model with a TI-glazing and TI-wall 
> (a separate zone as air space in between TI-glazing and wall mass). 
> The strange thing is:
>  
> 1) when I modified the optical properties (increase or decrease the 
> values of overall trans and absorption), the results did not changed 
> at all. Anyone who had experienced this problem before?
>  
> 2) the zone energy loss (5197.39kWh) was more than energy gain 
> (3432.64kWh), which is not the characteristic of TIM.
>  
> Anyone can help in this case?
>  
> Thank you.
>  
>  
> Regards,
> Wong
> ------------------------------------------------------------------------
>
> _______________________________________________
> esp-r mailing list
> esp-r at lists.strath.ac.uk
> http://lists.strath.ac.uk/mailman/listinfo/esp-r

-- 
***************************************************************
Dr P A Strachan                   email: paul at esru.strath.ac.uk
ESRU, Dept. of Mechanical Eng.          phone: +44 141 548 2041
University of Strathclyde                 fax: +44 141 552 5105
Glasgow G1 1XJ, UK                 http://www.esru.strath.ac.uk
***************************************************************