[TRNSYS-users] TRNBUILD Type 56 crawl spaces

David Bradley bradley at tess-inc.com
Wed Jul 5 11:14:03 PDT 2006


Franck,
   Crawlspaces are usually accounted for in one of two ways.

   The simplest way is to define a zone for the crawlspace and to make the 
floor in the zone above into an "ADJACENT" type wall. Energy transfer 
through the walls of the crawlspace is then calculated by defining BOUNDARY 
walls that contain whatever material forms the walls and floor of the 
crawlspace (usually concrete) and an effective, massless equivalent 
insulation to account for the soil. The temperature on the back side of the 
BOUNDARY walls is usually calculated using the Kasuda ground temperature 
correlation (Type77).

   The more complex (but arguably more correct) approach is to use a ground 
coupling component such as the ones in the TESS Ground Coupling Library. 
These components define a volume of soil surrounding the crawlspace on its 
four sides and bottom, breaking the volume up into finite elements called 
nodes. At each TRNSYS iteration, the models take the Type56 calculated 
surface temperature of the walls and floor of the crawlspace zone as 
inputs. They perform a 3 dimensional finite element energy balance on the 
nodes in the near-field and return the temperature of the crawlspace 
wall/soil boundary to Type56. The near-field is surrounded by a far-field 
that acts as an infinite energy source / sink. Far field soil temperature 
are governed by depth and time of year.
Kind regards,
  David


At 09:08 7/3/2006, franck clottes wrote:
>Hi,
>
>How to take into account floors with crawl spaces in trnbuild?
>
>Best regards,
>
>F.C.
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>TRNSYS-users mailing list
>TRNSYS-users at engr.wisc.edu
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