Re: [TRNSYS-users] TRNSYS PROBLEM (THERMAL CAPACITANCE)

[David BRADLEY via TRNSYS-users <trnsys-users@lists.onebuilding.org>]

Ilyas and Pierre,

  Make sure too that the timestep you have chosen for your simulation is appropriate. TRNSYS controller models can make one control decision per timestep and if the timestep is too long then overheating and undercooling can occur, especially in zones that have lower thermal capacitance. I typically use timesteps ranging between 1 and 5 minutes for HVAC system simulations.

kind regards,

 David

On 02/07/2017 18:19, Ilyas KHELIFA KERFAH wrote:

Hello,

I modeled with TRNSYS an apartment with heating in the corridor.  I had a problem that the temperature of the rooms does not increase gradually so I multiply the thermal capacitance * 50 in all the rooms and the corridor. This model gave a good result for the rooms. But in the corridor where the heating is installed, I find that the temperatures increase and decrease in a single shot without warming and cooling time rate. 

N.B. for the exchange of air between the pieces I put a pipe with a flow of 450 kg / h between all the rooms. thank you.

Best regards,

Ilyas and pierre Etienne 

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David BRADLEY
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Thermal Energy Systems Specialists, LLC
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