[TRNSYS-users] Thermal mass is not considered in Type 56 simulation!!

[Amr Alaaeldin Elesawy]

Dear Mehrdad,
Hope you are doing well.

The results you are getting make sense, you have quite a massive and
insulated unit with no ventilation whatsoever.
- When you have massive components in your unit, the fluctuation of the
indoor temperatures reduces a lot, and
- With no ventilation (especially no induced ventilation by night, to make
the night purge ventilation effect), and
- With the insulation, you are reducing the heat exchange between the
inside and outside.
Therefore, these results are normal.

I'm working with multi-story residential buildings, and in the beginning I
had very massive buildings with a fixed ventilation of 0.5 m/s and I used
to get such results, especially that I'm working with hot climates...

I noticed also that we're talking about a temperature range of 12-19
degC... Have you tried to check the results in the summer?

All the best,
Amr


On Thu, Jul 24, 2014 at 7:05 AM, Mehrdad Farshchi <mehrdadfarshchi at gmail.com
> wrote:

> Dear Jochen,
>
>
>
> Thank you for your email. I have modelled and simulated a simple
> rectangular building (15m x10m) in Sydney with Trnsys 17 software. Then
> using the Trnsys library I have edited the building components in order to
> make a heavy weight building as follows:
>
>
>
> Floor = BST_H_FLO                   (see the figure attached)
>
> External Wall = BST_H_EXT   (see the figure attached)
>
> Roof= BST_H_ROO                  (see the figure attached)
>
>
> Although Infiltration, Ventilation, Heating, Cooling and Comfort regime
> are off, the observed thermal lag was very low (less than an hour). Even I
> changed the wall concrete thickness to 0.4m and the result for the air
> temperature (TAir_H_0.4) did not show any changes in terms of thermal lag
> (please have a look at the graph attached)
>
> Tambient: ambient temperature ,
>
> TAIR_H_0.1:  air temperature of air node with above mentioned building
> component and setting and
>
> TAIR_H_0.4 : air temperature of air node with above mentioned building
> component and setting the wall concrete thickness to 0.4m.
>
>
>
> I wonder if you could please let me know how to resolve this issue.
>
>
>  Kind Regards
> Mehrdad
>
>
>
>
>
> On Thu, Jul 17, 2014 at 6:40 PM, hotline <hotline at transsolar.com> wrote:
>
>>  Dear Mehrdad,
>>
>>
>>
>> TYPE 56 considers thermal masses. I can imagine that you’ve set a high
>> ventilation rates.
>>
>> If so, you might compare the surface temperatures or the operative
>> temperature instead.
>>
>>
>>
>> Best
>>
>>
>>
>>
>> *_________________________________________________________________________________________*
>> *_________*
>>
>>
>>
>> *Jochen Lam*
>>
>> TRNSYS Software Team
>>
>>
>> *Transsolar Energietechnik GmbH*
>>
>> Curiestraße 2
>>
>> 70563 Stuttgart
>>
>> Fax:        +49 711 67976-11
>> Email:    jlam at transsolar.com
>>
>> Web:      www.trnsys.de
>>
>>
>>
>> *Von:* TRNSYS-users [mailto:trnsys-users-bounces at lists.onebuilding.org] *Im
>> Auftrag von *Mehrdad Farshchimonfared
>> *Gesendet:* Mittwoch, 16. Juli 2014 06:12
>> *An:* trnsys-users at cae.wisc.edu
>> *Betreff:* [TRNSYS-users] Thermal mass is not considered in Type 56
>> simulation!!
>>
>>
>>
>> Dear Trnsys users,
>>
>>
>>
>> I have modelled a residential building with different building components
>> (including different thermal masses) using Trnsys 3d, Type 56 . The
>> simulation results show no thermal lag between hourly inside air
>> temperature of each zone even if, the heavy materials are used. It is weird
>> as it seems that Trnsys does not take into account the thermal mass of
>> walls, floors and etc.
>>
>>
>>
>> Have you come across with this problem previously?
>>
>>
>>
>> If  yes, I wonder if you could please let me know how to resolve this
>> issue as soon as possible.
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Kind Regards
>>
>> Mehrdad
>>
>> _______________________________________________
>> TRNSYS-users mailing list
>> TRNSYS-users at lists.onebuilding.org
>> http://lists.onebuilding.org/listinfo.cgi/trnsys-users-onebuilding.org
>>
>>
>
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>
>


-- 
Amr Alaaeldin Elesawy

*PhD Student | Building Engineering*
*Department of Architecture, Built Environment and Construction Engineering
(A.B.C.)*
Politecnico di Milano, Italy
+39 327 056 0018
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