[esp-r] Re: a problem about revealing the thermal mass effect on energy consumption by Esp-r

[esp-r at h-rd.org]

Citeren Gulsu Ulukavak Harputlugil <g.ulukavak.harputlugil at gmail.com>:

> Hi All,
>
> I have a very simple problem. ....

> Anyhow, I have a research on sensitivity analysis of the energy performance
> and one of the parameters that I evaluate is the effect of thermal mass. I
> have wall construction -from outside to inside-composed of plaster (2cm),
> insulation (PUR)(2cm), aerated concrete (20cm), plaster (2cm) and the
> u-value is 0.48 W/m2K. The specific heat of aerated concrete that I used is
> 840 J/kgK and the density is 500 kg/m3. I replaced aerated concrete with
> heavy mix concrete which has specific heat of 1000J/kgK and density of 2400
> kg/m3. In order to make u-value constant (it should be constant otherwise I
> can not see the effect of thermal mass alone) I changed the dimension of
> concrete from 20cm to 30cm and insulation from 2cm to 6cm. Thus the
> u-value stays constant (0.48W/m2K)  ....

Dear Gulsu,

if you just want to change the thermal mass, I would suggest that you do not
change the construction, but that you go to the database menu and make a project
copy of the materials database.  Then you can add a material, e.g. aerated
concrete - modified with the same physical properties as the origingal aerated
concrete, but with a different specific heat.  By substituting this material in
your construction database, you can have simulatioens where only the thermal
mass is different.

yours,

Marc Hoffmann
esp-r at h-rd.org