[TRNSYS-users] type 660 simple building model

[Thibaut VITTE]

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
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