Dear Trnsys users,I'm using type 660 to modelize "quickly" a simple building. Having troubles to analyse the results, I've tested it and compared it with regular type 56.
the building is an office building with high internal loads, large glazed surfaces. the heated area is 9200m², with an overall loss coefficient of 0.7 W/m²°C, 69 kJ/K.m3.
The annual results seem quite good, since I'm finding diffrences in annual heating/cooling loads less than 10%.
As far as temperatures and free floating building functionning (see picture attached), it's not that good, but I understand that a simple capacitance model is limited for that purpose.
But the problem is for maximum heating/cooling power. I have inputed night set back for cooling and heating. And I think that the whole building capacitance is taken into account when a moving setpoint is applied! Which implies great instantaneous power. ( 6 times greater than the one calculated by type 56.) (see picture). The wole building (air + walls) is heated or cooled when a setpoint changes (as I understand the model), which is not quite the reality..
Am I right? Is there a simple model that can calculate approximately the instantaneous power with moving setpoint (in Trnsys type 12, setpoints are only parameters)?
Thanks in advance. Thibaut
Attachment:
heating loads 400 1st hrs.png
Description: PNG image
Attachment:
temperature 1st 400 hrs.png
Description: PNG image
Attachment:
annual temperature.png
Description: PNG image
