defining assembly for components of attached zones?

[burketthw]

I am modeling a small, single zone structure that has a ceiling and an unconditioned and unvented attic (the thermal barrier is at the ceiling). After using the building wizard, a model was created, identifying the attic as an attached zone. This seems accurate since it is unconditioned, but there is not the option to define the materials and assemblies of the roof and gable end. I think the material attributes would effect the heat and moisture flow even though they are not in contact with the conditioned space, especially because the attic is unvented. Is there a way to define these assemblies in a similar way to how I define the assemblies of simulated zone components?

Thanks for your help,
Lena

[mpazold]

The attached zone type is for zones where you predefine (e.g. measured values) or assume the indoor climate (with an optional climate). You also can apply the outdoor climate, without solar radiation. All components between attached zones, or attached zones an the outdoor climate are out of the simulation. Only components couple simulated zones with attached zones will be simulated, because of the heat- and moisture flow to the simulated zone.

However, if you want to simulate the attic, even without conditoning, you have to the set the zone type to be simulated. Then all transfers are taken into account for the simulation of the climate in this zone. Because of the unconditioned space, you can uncheck the "including HVAC" in the general zone tab for this zone. Or you can set the fraction this zone get from the hvac system to zero (HVAC -> System XX -> Share zone(s) Tab). Or you can set a wide range for the design conditions, for this zone. Then you get a freerunning simulated indoor climate in the attic and it is not directly influenced by the conditioning system.