Adjust an Air Cavity

Air cavity refers to the space or gap between two adjacent surfaces in a building component, such as walls, roofs, or windows. The air cavity is a crucial element in building energy simulations as it affects the thermal and moisture performance of the component.

Air cavities are adjusted based on the degree to which it is ventilated. A higher degree of ventilation reduces thermal performance but may be necessary to address condensation risk. To understand how these impact the Total R-value of a Wall System, please refer to the calculation method.

Ventilation Strategy

To adjust an air cavity, hover over any air cavity material on the left of the screen and left-click the material icon in the top left corner. A detailed dropdown will then collapse, showing the assumed 'Ventilation' strategy. This can be updated for 'Unventilated', 'Slightly Ventilated' and 'Well Ventilated' scenarios.

Ventilation Exposure

Most ventilation strategies for Wall Systems are assumed to be from the external side. Where this is not the case, the 'Ventilation Exposure' setting allows the direction the air is exchanged with to be set 'To Internal'. If unsure, leave this set 'To External'.