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Re: [EnergyPlus_Support] Hard to believe results?



The following warnings mean that the floor and roof surfaces are upside down, 
so your roof is not seeing any sunshine.

   ** Warning ** Floor Tilt=0.0, much less than expected tilt of 180, for 
Surface=ZN:001:FLOOR, in Zone=ZONE ONE
   ** Warning ** Roof/Ceiling Tilt=180.0, much greater than expected tilt of 0, 
for Surface=ZN:001:ROOF, in Zone=ZONE ONE

Reverse the order of the vertices on these two surfaces to fix this and use 
"report, surfaces, details;" to produce a listing of all surfaces to verify 
height, width, tilt and azimuth.

Fixing the above problem actually makes the zone even warmer now that the roof 
gets solar gains.  The primary driver in this model is the floor slab.  It is 
large, and the ground temperatures are set to +19C.  So the floor slab is 
heating the zone on the cold day and cooling the zone on the hot day.  

Mike
 

On 3 May 2004, at 22:35, David Strip wrote:

> The conventional wisdom among earth builders (rammed earth, adobe), at 
> least in New Mexico, is that insulating the south-facing wall is at best 
> a break-even proposition, energy-wise. I developed a very simple model 
> in an attempt to test this theory without resorting to full-scale 
> building. The model is very simple - four walls, roof, floor. 4 design 
> days - 2 winter, 2 summer. There is no heat source of the building other 
> than the sun. The part that surprises me is that even with an 
> unrealistically cold day (-20 C high, delta C 20, but plenty of NM sun), 
> the steady state temp is a balmy 13C, which I find very hard to believe. 
> This is one of my first attempts at using EnergyPlus, so I suspect I'm 
> doing something very wrong to be getting this result. Any help will be 
> appreciated.
> 
> The .idf file is in the problem submittals areas with the title 
> rammed_earth.idf
> 
> 
> 
> 
> 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@xxxxxxxx



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