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I am trying to simulate the initial heating process of a cold room with an underfloor heating using an active layer.
My problem is that TALM "node temperature of active layer" always starts at 20 °C.
The "Initial zone temp." in Zone -> Initial Values is set to 12°C. The connected ground temperature is also set to constant 12 °C. I am using weather data connected to the other Building inputs like TAMB, TSKY, ....
At the start of the simulation this results in a postive heat transfer QCOMI "energy from inside surf. incl. conv. to air and longwave
radiation to other surfaces" although the underfloor heating is "off" (no inlet mass flow).
In this example TSI starts at 16 °C (mean value between TALM and TAIR).
Other example:
TGround and "Initial zone temp." set to 8 °C -> Result: TALM starts at 20 °C, TSI starts at 14 °C
What I would suggest is that you run your simulation for a day (simulation time, not real time!!) with a constant 12C (or whatever is appropriate) flowrate going through your active layer. That will precondition the system to get rid of built-in initial values. You can set up your integrators and printers to start a day late or your can start your simulation on 8736 and run it through 17520 but start your integrators and printers at 8760.
kind regards,
David
