Walls

Walls are the primary component of the building envelope, separating conditioned spaces from the outdoors and other unconditioned areas.

Wall Assignments

Automatic Detection

HVAKR automatically identifies wall segments based on space geometry:

• Exterior walls - Space boundaries at the building perimeter
• Interior walls - Shared boundaries between spaces
• Party walls - Walls shared with adjacent buildings

Manual Assignment

Override automatic detection:

1. Select a space boundary segment
2. Click to open wall properties
3. Choose interior, exterior, or party wall
4. Assign a wall type

Wall Properties

Orientation

The cardinal direction the wall faces (N, NE, E, SE, S, SW, W, NW). Affects:

• Solar heat gain on the exterior surface
• Transmission calculations

Area

Calculated from the segment length and floor height. You can override this for non-standard situations.

Wall Type

Links to the wall type definition from Basis of Design. Determines:

• U-value for transmission calculations
• Mass for thermal lag calculations
• Color for solar absorption

Interior vs. Exterior

Exterior Walls

Walls separating conditioned space from outdoors:

• Subject to outdoor design temperatures
• Include solar absorption effects
• Affect both heating and cooling loads

Interior Walls

Walls between conditioned spaces:

• Usually no heat transfer if spaces are at the same temperature
• May need to account for temperature differences between spaces

Party Walls

Walls shared with adjacent buildings:

• Often treated as adiabatic (no heat transfer)
• May need special consideration if adjacent is unconditioned

Below-Grade Walls

Basement walls below ground level:

• Use ground temperature instead of outdoor air
• Different calculation method than above-grade

Advanced Features

Thermal Bridges

Account for structural elements that bypass insulation:

• Steel studs through insulation
• Concrete slab edges
• Window frames and mullions

Solar Shading

External shading affects solar absorption:

• Overhangs reduce solar gain
• Adjacent buildings may shade walls
• Seasonal variation in sun angle

Common Issues

Missing Wall Assignments

Spaces with unassigned exterior boundaries will show warnings. Assign wall types to all exterior segments.

Inconsistent Boundaries

Adjacent spaces should share the same wall type at their common boundary. HVAKR alerts you to inconsistencies.

Incorrect Orientation

Verify that wall orientations match the building’s true orientation. Incorrect orientations affect solar calculations.