[Bldg-sim] Simulation Used in Over 60% High Performance Building Database

[Michael J. Witte]

On 3 Jun 2002, at 20:30, Shefali Rajendra Modi wrote:

> I am working on a simulation in energy plus and have a few questions.
> 
> The rpt weather file does not provide all weather information such as
> barometric pressure for design days, snow reflectance, etc. Where
> can one get this information.

There are two main sources of design day data.  In the 
EnergyPlus\DataSets folder, the file BLASTDesignDays.idf contains 
dozens of design day definitions for primarily U.S. locations which 
are already in EnergyPlus format.  For other locations, data is 
available in the ASHRAE Handbook of Fundamentals, Chapter 27.

> 
> Secondly, I am studying heat performance of a double skin envelope in
> comparision to a single glass surface. Would it be recommended to use the
> trombe wall for the inside convection algorithm for the double skin or is
> it better to create the airspace as a second zone?

You need to do both.  The inside convection algorithm applies to the 
interior surface of every wall (not to the inside of wall cavities).  
So, your trombe space of the double skin space needs to be treated as 
a separate zone.  Understand, though, that it may not be possible 
with current features to truly represent your double-skin facade, 
depending on how it is configured.

> 
> Thirdly, the program prevents me from creating a glass wall and a
> window has to be part of a wall. Its surface area cannot be equal to
> the wall surface. Has anyone tried modeling a curtain wall
> or something similar? How have you circumvented this?

Windows are the only objects which can transmit sunlight.  So, a 
glass wall is created by placing a window wall so that the window 
covers nearly the entire wall (it is true that there must be a small 
nonzero area of wall left over).  For curtainwalls, however, you may 
have opaque sections as well as window sections.  For this case, 
specify the base wall as having glass as it's exerior layer, and then 
size the windows to cover just the light-transmitting section of the 
curtainwall.  Note that the opaque glass layer must be 
MATERIAL:REGULAR, not MATERIAL:WINDOWGLASS.



========================================================
EnergyPlus Testing and Support      
EnergyPlus-Support at gard.com

======================================================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM