Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
If you're explicitly modelling every floor of a building, the ceiling surface of a zone should simply connect the above floor surface as boundary conditions, and vice versa. If you're instead only modelling a sample floor (without zones below/above) and using floor multipliers, then both of your options are "OK" (either floor & ceiling surfaces are adiabatic, or floor surfaces connect the above ceiling surfaces. The floor construction should reverse/match the ceiling construction. Heat will be stored in your floor/ceiling constructions, even under adiabatic conditions.
To your 2nd question, would this still be linked to the use of floor multipliers? The answer would depend on what's taking place inside the unconditioned zone (processes or lighting loads in there?), the boundary conditions of the other surfaces of this unconditioned zone (facing outdoors? or simply facing other _conditioned_ zones?), etc. We'd need to know more before venturing a suggestion.
| | 2 | No.2 Revision |
If you're explicitly modelling every floor of a building, the ceiling surface of a zone should simply connect the above floor surface as boundary conditions, and vice versa. If you're instead only modelling a sample floor (without zones below/above) and using floor multipliers, then both of your options are "OK" (either floor & ceiling surfaces are adiabatic, or floor surfaces connect the above ceiling surfaces. The floor construction should reverse/match the ceiling construction. Heat will be stored in your floor/ceiling constructions, even under adiabatic conditions.
To your 2nd question, would this still be linked to the use of floor multipliers? The answer would depend on what's taking place inside the unconditioned zone (processes or lighting loads in there?), the boundary conditions of the other surfaces of this unconditioned zone (facing outdoors? or simply facing other _conditioned_ conditioned zones?), etc. We'd need to know more before venturing a suggestion.
| | 3 | No.3 Revision |
If you're explicitly modelling every floor of a building, the ceiling surface of a zone should simply connect the above floor surface as boundary conditions, and vice versa. If you're instead only modelling a sample floor (without zones below/above) and using floor multipliers, then both of your options are "OK" (either floor & ceiling surfaces are adiabatic, or floor surfaces connect connect the above ceiling surfaces. The floor construction should reverse/match the ceiling construction. Heat will be stored in your floor/ceiling constructions, even under adiabatic conditions.
To your 2nd question, would this still be linked to the use of floor multipliers? The answer would depend on what's taking place inside the unconditioned zone (processes or lighting loads in there?), the boundary conditions of the other surfaces of this unconditioned zone (facing outdoors? or simply facing other conditioned zones?), etc. We'd need to know more before venturing a suggestion.
| | 4 | No.4 Revision |
If you're explicitly modelling every floor of a building, the ceiling surface of a zone should simply connect the above floor surface as boundary conditions, and vice versa. If you're instead only modelling a sample floor (without zones below/above) and using floor multipliers, then both of your options are "OK" (either floor & ceiling surfaces are adiabatic, or floor surfaces connect the above ceiling surfaces. The floor construction should reverse/match the ceiling construction. Heat will be stored in your floor/ceiling constructions, even under adiabatic conditions.
To your 2nd question, would this still be linked to the use of floor multipliers? The answer would depend on what's taking place inside the unconditioned zone (processes or lighting loads in there?), the boundary conditions of the other surfaces of this unconditioned zone (facing outdoors? or simply facing other conditioned zones?), etc. We'd need Need to know more before venturing a suggestion.
