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Re: [EnergyPlus_Support] Re: COMIS & window transmitted solar
Thanks!
lee
At 11:23 AM 8/20/2004 -0500, you wrote:
>Modeling a completely open window is an interesting case. The windoglass
>material module requires certain checks to be valid. My initial tests
>generated several errors:
>
> ** Thermal transmittance + front thermal emissivity not < 1.0
> ** Thermal transmittance + back thermal emissivity not < 1.0
> ** Front solar reflectance not > 0.0 and < 1.0
> ** Back solar reflectance not > 0.0 and < 1.0
> ** Front visible reflectance not > 0.0 and < 1.0
> ** Back visible reflectance not > 0.0 and < 1.0
> ** Solar transmittance + front solar reflectance not < 1.0
> ** Solar transmittance + back solar reflectance not < 1.0
> ** Visible transmittance + front visible reflectance not < 1.0
> ** Visible transmittance + back visible reflectance not < 1.0
>
>
>I finally ended up with this material:
>
>MATERIAL:WINDOWGLASS,
> Open Air, !- Name
> SpectralAverage, !- Optical Data Type
> , !- Name of Window Glass Spectral Data Set
> .001, !- Thickness {m}
> .99998, !- Solar Transmittance at Normal Incidence
> .00001, !- Solar Reflectance at Normal Incidence: Front Side
> .00001, !- Solar Reflectance at Normal Incidence: Back Side
> .99998, !- Visible Transmittance at Normal Incidence
> .00001, !- Visible Reflectance at Normal Incidence: Front Side
> .00001, !- Visible Reflectance at Normal Incidence: Back Side
> .99998, !- IR Transmittance at Normal Incidence
> .00001, !- IR Hemispherical Emissivity: Front Side
> .00001, !- IR Hemispherical Emissivity: Back Side
> .00001, !- Conductivity {W/m-K}
> 1, !- Dirt Correction Factor for Solar and Visible
> Transmittance
> No; !- Solar Diffusing
>
>For the Chicago winter and summer design days, this results in an overall
>transmittance of 0.989, reflectance of 0.0107, and absorptance of
>0.0000176 for
>most of the day.
>
>Mike
>
>
>On 19 Aug 2004, at 9:12, leeslwong wrote:
>
> >
> > Mike,
> >
> > If I want to the result of the mean air temperature of the room with
> > ventilation and solar heat effect which is the real case I think, so
> > that I
> > should change the solar transmittance of the glass to 0.9999. Then,
> > the
> > temperature and the rate of thermal comfort will become more
> > realistic
> > situation of the room. Is it the correct way I can do?
> >
> > lee
> >
> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Michael J. Witte"
> > <mjwitte@g...> wrote:
> > > The COMIS model only calculates infiltration and mixing flow rates,
> > it has no
> > > impact on the window solar calculations. So, you are correct, that
> > the window
> > > solar gain is modeled as if the windows are closed at all times.
> > >
> > > Mike
> > >
> > >
> > > On 18 Aug 2004, at 11:42, leeslwong wrote:
> > >
> > > > Hi,
> > > >
> > > > I simulated a case that a room has 2 windows (one is facing to
> > east
> > > > and the other is facing to west). Using the COMIS method, the
> > window
> > > > are scheduled to open all the time. After the simulation, the air
> > > > flow rates are normal and acceptable. But when I am looking at
> > the
> > > > window/zone transmitted solar, the result is adnormal because it
> > is
> > > > assumed the windows are still there (close). It is what I think.
> > Is
> > > > it the windows are still be closed when calculating transmitted
> > solar
> > > > and the windows are opened when calculating the COMIS ventilation
> > at
> > > > the same time? Or I am wrong?
> > > >
> > > > Thanks
> > > >
> > > > lee
> > > >
> > > >
> > > >
> > > >
> > > > The primary EnergyPlus web site is found at:
> > > > http://www.energyplus.gov
> > > >
> > > > The group web site is:
> > > > http://groups.yahoo.com/group/EnergyPlus_Support/
> > > >
> > > > Attachments are not allowed -- please post any files to the
> > appropriate folder
> > > > in the Files area of the Support Web Site.
> > > >
> > > > Yahoo! Groups Links
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> > > ========================================================
> > > Michael J. Witte, GARD Analytics, Inc.
> > > EnergyPlus Testing and Support
> > > EnergyPlus-Support@g...
> >
> >
> >
> >
> > The primary EnergyPlus web site is found at:
> > http://www.energyplus.gov
> >
> > The group web site is:
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> >
> > Attachments are not allowed -- please post any files to the appropriate
> folder
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> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> >
>
>
>
>========================================================
>Michael J. Witte, GARD Analytics, Inc.
>EnergyPlus Testing and Support
>EnergyPlus-Support@xxxxxxxx
>
>
>
>
>
>The primary EnergyPlus web site is found at:
>http://www.energyplus.gov
>
>The group web site is:
>http://groups.yahoo.com/group/EnergyPlus_Support/
>
>Attachments are not allowed -- please post any files to the appropriate
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