[TRNSYS-users] Trnsys Type56 Thermal mass problem

[David BRADLEY]

Albert,

  Thermal mass is definitely considered by Type56. Sometimes highly 
thermally massive walls cause problems for the algorithm that computes 
the transfer functions for the walls and one of the workarounds that 
people use is to define the wall as having an R-value only (i.e. no 
thermal mass). If you had to make that simplification for your rammed 
earth walls it would explain why you are not seeing the impact of the 
thermal mass. It also occurs to me that if the time delay caused by the 
thermal mass is /almost/ but not quite 24 hours then it could look as 
though the lag was negative.

kind regards,

  David



On 01/26/2021 07:52, Albert Cavero Carreras via TRNSYS-users wrote:
> Hello,
>
> I am doing a comparison between a conventional building and another 
> with the external walls made of rammed earth, which has a big thermal 
> mass. I have simulated both of the with the Type56 in Simulation 
> Studio and I have obtained this results. I do not know why but the 
> decrement factor is the same for both constructions and the thermal 
> lag is negative. I have simulated it during summer and during winter 
> time and also I haven't considered ventilation or any time of heating 
> or cooling. I have already seen some emails in your webpage from 
> people asking if the thermal mass is considered in the type56.
>
> Thank you,
>
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> TRNSYS-users at lists.onebuilding.org
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-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
3 North Pinckney Street - suite 202
Madison, WI  53703 USA

P:+1.608.274.2577
d.bradley at tess-inc.com

http://www.tess-inc.com
http://www.trnsys.com

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