[EnergyPlus_Support] Re: High Temperatures in Vented Cavity

["mapascualb" <mapascual@xxxxxxxxx>]

We are using regular materials but we have found the same problem in 
some cases.

In our file, if we just change the the thickness of the outter layer 
of the supporting wall by 0.01, the results changes from expected to 
physicaly impossible (surface outside temperature bigger than the 
exterior baffle temperature).

We are almost sure that this is a bug to be fixed, but in the 
meanwhile I would like to know if can trust the results of the cases 
that the simulation seems reasonable.

Thanks in advance. 




--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Griffith, Brent" 
<brent_griffith@...> wrote:
>
> OK, I looked at your file.  Your input file doesn't have any serious
> problems and the program should be working better for this case.  
We'll
> be filing this as a bug (change request).  
> 
>  
> 
> But the problem is that you have only "Regular-R" materials in the
> construction underneath the exterior cavity.  When I change your 
file to
> have a proper construction, the exterior cavity model behaves as one
> would expect.  Constructions should have some "Regular" materials or
> else there is no mass (and no heat capacity) in the surface.  This 
can
> lead to thermal instability in some cases (eg. "temperature out of
> bounds" error); I think you found a new one.  Until we can address 
this
> in the next release of the program, when using the advanced surface
> model for exterior cavity you should also use full descriptions of 
the
> construction's materials.   
> 
>  
> 
> Brent 
> 
> EnergyPlus Development Team
> 
>  
> 
> ________________________________
> 
> From: EnergyPlus_Support@xxxxxxxxxxxxxxx
> [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of 
bbuenounzeta
> Sent: Monday, December 10, 2007 12:52 AM
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> Subject: [EnergyPlus_Support] Re: High Temperatures in Vented Cavity
> 
>  
> 
> I have simulated the case with the 2.1 EnergyPlus and it performs 
in 
> the same way.
> 
> Bruno
> 
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> <mailto:EnergyPlus_Support%40yahoogroups.com> , Linda Lawrie 
<linda@>
> 
> wrote:
> >
> > This was one of the items that was addressed in the 2.1 release:
> > 
> > You should upgrade and see if this is still an issue.
> > 
> > Linda
> > 
> > EnergyPlus WebSite: http://www.energyplus.gov
> <http://www.energyplus.gov> 
> > Owner: EnergyPlus_Support list
> > Member: EnergyPlus Development Team
> > 
> > 
> > 
> > [Non-text portions of this message have been removed]
> >
> 
>  
> 
> 
> 
> [Non-text portions of this message have been removed]
>




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