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[EnergyPlus_Support] Re: problem with thermal radiation

Hi,

i had a look fast into the idf and at the Surface Construction Element, Material  Template all definded materials have the same solar and visible absoption fraction of 0.7 and for the last two walls there is no input (defaul value is 0). 

I think for metall a solar and visibel absorption fraction of 0.2- 0.3 should be used:

I use for e.g.:

- white painted walls =  0.3 
- floors = 0.7
- interior walls = 0.5 (because of pictures and furnitures) 

 
Probably in adddition the thermal absorption should be adjusted, but i am not aware of that,

hope it helps , Marie 
 

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, reza m <reza.energy@...> wrote:
>
> Hi,
> I investigate on thermal radiation and its effects
> I have two alternative materials
> 1- external wall ( with two metal layers)
> 2- external wall2 (with out metal)
> The difference between two simulations  was very poor and thermal radiation
> energy loos by the wall that has this material wasn't change.
> 
>   A9C38D:Surface Ext Thermal Radiation Heat Loss to Outdoors [kWh](Monthly)
> 
>    *with out Reflector* * with Reflector*  January 108.8691475 108.8541296
> February 128.5922864 128.6258381  March 251.0705809 250.9363295  April
> 395.7446768 395.1045226  May 566.9424429 567.0461548  June 587.9205448
> 587.9979196  July 638.0636581 638.0444506  August 516.8364084 516.6539877
> September 348.7579962 348.6593856  October 215.2195033 215.3210677  November
> 122.2107265 122.2722356  December 90.07916896 90.1409641
> 
> do you have any idea?
> 
> 
> what should i do to have better result for radiation
> i attached my IDF file
> thank you in advance for your time
> REZA
>




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