RE: Ground temperature

[Michaël Kummert <kummert@xxxxxxxxxxxxx>]

Dear Helmi,

> At present, I.m taking a fixed ground temperature, with a very small
"convection" heat 
> transfer coefficient (0.002 kJ/h.m2). My idea is that the ground will be in
equilibrium 
> with the floor temperature, in that way, there is not a very important heat
exchange, that
> why I.m taking a little H back.
This surprises me. It seems to me that you neglect an important thermal
intertia (the ground volume that will follow the building temperature) and
that, depending on the wall insulation level and on the ground conductivity,
you may also neglect very important thermal losses. May be I am wrong...
Hopefully other users will have some comments on that.

> The third solution may be used since we add the finite difference model to
the deck, to 
> take in account the boundary conditions given by the heat flux into the
building. This 
> makes the simulation very hard and time consuming.
I agree with you. I think this is only justified if you are interested in a
building that tries to take advantage of the ground to reduce
heating/cooling loads (i.e. with very low thermal insulation in the floor).
Again, if any user has made some comparisons, I would be interested to know
the results.

Regards,

Michaël Kummert

_________________________________________________________

Michaël Kummert

Solar Energy Laboratory - University of Wisconsin-Madison
1303 Engr Res Bldg, 1500 Engineering Drive
Madison, WI 53706

Tel: +1 (608) 263-1589
Fax: +1 (608) 262-8464
E-mail: kummert@engr.wisc.edu

SEL Web Site: http://sel.me.wisc.edu 
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