[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

unexpected behaviour

Hi!

I have observed some strange behaviour while simulating a (virtual) building
in TRNSYS 15. The following happend:

- i have set up a (virtual) building (Type56) with two zones (Zone1, Zone2)
- Zone1 has an adjacent concrete wall (thickness 0.40m) and an adjacent
active Wall (0.15m concrete - active layer - 0.15m concrete) to Zone2
- Zone1 1 also has an external wall (direction north) consist of 0.30m
concrete and 0,05m thermal insulation
- Zone2 only have these adjacent walls to Zone1
- Zone2 is kept exactly at 20°C by accordingly set up heating and cooling
regimes
- Abient and fictive sky temperatur are set to 20°C - no solar radiation
- the inlet fluid temperature of the active layer is also at 20°C

If i simulate this setup the temperature of Zone1 drops to 19,6°C and
oscilates at this value after about 15 hours. Inner surfaces temperatures at
Zone1 are below 20°C as well. The outside surface temperature of the
external wall is above 20°C. How could this happen? Every input is set to
exactly 20°C but the temperature drops. Is this a problem of floating point
precision? Where does the energy come from - where did the energy go?

Thanks for your help.

Sebastian Zwietz
<zwietz@ivi.fhg.de>