Re: [EnergyPlus_Support] Window Conduction Heat gain

["k bk planetkbk@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx>]

I did try to see if I could do a U.A.DeltaT using the surface temperatures. The variables "Surface Window Front Face Temperature Layer 1" and "Surface Window Back Face Temperature Layer 1" were available in the RDD file. But for some reason the values were all output as zeros.

Another option was to use the window heat balance. As per equation 6.439 from the engineering manual. If I subtract the "window surface inside face internal gains radiation heat gain rate" from the window surface inside face convection heat gain rate". What is left would be the conduction through the window (Assuming no internal shading devices). Does this seem a reasonable.

thanks!

On Tue, May 10, 2016 at 8:30 AM, Jean Marais jeannieboef@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

 

Basically, e+ contructions require a certain amount of mass to insure numerical stability (see thermal diffusivity). That is one reason why window assemblies run on a seperate model. This model calculates all the associated effects that effectively deturmine the surface temperature of the glazing (which plays a role in the convective heat transfer to the zone air node AND infrared heat transfer exchange with other zone surfaces as well as solar beam and diffuse of radiation transmitted).

To find the correct variable check the rdd file. If it's not there as an equivalent for windows, then you may need to do some math with the others to get there.

On 9 May 2016 8:21 pm, "k bk planetkbk@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

 

Hello,

          I am trying to output the hourly window conduction heat gain, But there does not appear to be a output for it. Not sure why this it not available for windows, although it is available for opaque surfaces via:

"Surface Inside Face Conduction Heat Transfer Rate"

Could someone provide some hints.

thanks

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Posted by: k bk <planetkbk@xxxxxxxxx>

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