[TRNSYS-users] Wind loss modeling

David Bradley bradley at tess-inc.com
Thu Sep 13 08:16:12 PDT 2007


John,
   Most of the building models in TRNSYS simply ask for the user to 
supply the external heat transfer coefficient so you can treat it 
however you like. The algorithm that I usually use is from ASRHAE:

h = (AA+BB*WindVel+CC*WindVel**2)*3.6

where h is the external convection coefficient in kJ/h.m2, AA, BB, 
and CC are empirical coefficients that depend on the exterior surface 
material and WindVel is the wind speed in m/s. The AA, BB and CC 
coefficients (again from ASHRAE) would be:

                         AA      BB      CC
Stucco          11.58   5.894   0.0
Brick                   12.49   4.065   0.028
Concrete                10.79   4.192   0.0
Wood                    8.23    4.00    -0.057
Smooth plaster  10.22   3.1     0.0
Glass                   8.23    3.33    -0.036

Cheers,
  David


At 13:30 9/12/2007, J.A. Palyvos wrote:
>Content-Type: multipart/alternative;
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>Dear all,
>
>I would appreciate any information on the external forced convection 
>algorithms (i.e. wind loss coefficient expressions) used in 
>TRNSYS.(I am aware of the McAdams/Jurges linear relation used in Type 19).
>
>Many thanks,
>
>J.A. Palyvos, NTUA
>Athens
>
>_______________________________________________
>TRNSYS-users mailing list
>TRNSYS-users at engr.wisc.edu
>https://www.cae.wisc.edu/mailman/listinfo/trnsys-users

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David BRADLEY                           2916 Marketplace Drive - Suite 104
Partner                                        Madison, WI 53719
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