# Boundaries¶

Definitions related to the boundary conditions of the ground domain.

**Example:**

```
Boundaries:
Far-Field Width: 40.0 # [m]
Deep-Ground Depth: 40.0 # [m]
Deep-Ground Boundary Condition: ZERO-FLUX # AUTO | CONSTANT-TEMP | ZERO-FLUX
Indoor Air Temperature: 295.0 # [K]
```

## Indoor Air Temperature Method¶

Allows the user to choose between having a constant indoor temperature for the duration of the simulaiton or to reference temperatures from a file.

Required: |
No |

Type: |
Enumeration |

Values: |
`FILE` or `CONSTANT` |

Default: |
`CONSTANT` |

## Indoor Air Temperature File¶

If Indoor Air Temperature Method is `FILE`

the indoor dry-bulb temperature (in Kelvin) will be set using hourly values defined in a comma separted value (CSV) file.

**Example:**

```
Indoor Air Temperature File:
Name: ../path/to/file.csv
Index: [1,1]
```

Required: |
No |

Type: |
Compound object |

### Index¶

A list of two values corresponding to the row and column where the hourly data begins in the file. A value of `[0, 0]`

starts at the first row and first column. A value of `[0,1]`

starts at the first row and second column.

Required: |
Yes |

Type: |
List [2] of integers |

## Indoor Air Temperature¶

If Indoor Air Temperature Method is `CONSTANT`

the indoor dry-bulb temperature will be set using this value. If Indoor Air Temperature Method is `FILE`

, then this is not required.

Required: |
Depends |

Type: |
Numeric |

Units: |
K |

## Outdoor Air Temperature Method¶

Allows the user to choose between having a constant outdoor temperature for the duration of the simulaiton or to reference temperatures from the weather file.

Required: |
No |

Type: |
Enumeration |

Values: |
`WEATHER-FILE` or `CONSTANT` |

Default: |
`WEATHER-FILE` |

## Outdoor Air Temperature¶

If Outdoor Air Temperature Method is `CONSTANT`

the outdoor dry-bulb temperature will be set using this value. If Outdoor Air Temperature Method is `WEATHER-FILE`

, then this is not required.

Required: |
Depends |

Type: |
Numeric |

Units: |
K |

## Local Boundary Layer Thickness¶

Local boundary layer thickness used for calculating local wind speeds from weather file wind speeds.

Required: |
No |

Type: |
Numeric |

Units: |
m |

Default: |
370 |

## Local Terrain Exponent¶

Local terrain exponent used for calculating local wind speeds from weather file wind speeds.

Required: |
No |

Type: |
Numeric |

Units: |
dimensionless |

Default: |
0.22 |

## Far-Field Width¶

Distance from the interior wall surface to the edge of the domain.

Required: |
No |

Type: |
Numeric |

Units: |
m |

Default: |
40 |

## Deep-Ground Depth¶

Distance from the grade level to the bottom of the domain.

Required: |
No |

Type: |
Numeric |

Units: |
m |

Default: |
40 |

## Deep-Ground Boundary Condition¶

Specifies the type of boundary condition to apply at the deep-ground boundary. Options are:

`ZERO-FLUX`

, which applies a zero heat flux boundary,`AUTO`

, which applies a constant temperature equal to the average outdoor dry-bulb temperature from the weather file, and`CONSTANT-TEMP`

, which applies a user-specified constant temperature (see Deep-Ground Temperature).

Required: |
No |

Type: |
Enumeration |

Values: |
`ZERO-FLUX` , `AUTO` , or `CONSTANT-TEMP` |

Default: |
`ZERO-FLUX` |

## Deep-Ground Temperature¶

If Deep-Ground Boundary Condition is `CONSTANT-TEMP`

, then this value specifies the temperature applied to the deep-ground boundary.

Required: |
Depends |

Type: |
Numeric |

Units: |
K |

## Convection Calculation Method¶

Specifies how convection coefficients are calculated. Options are:

`AUTO`

, which calculates dynamic convection coefficients based on temperature difference, wind speed, and wind direction.`CONSTANT`

, which applies a user-specified convection coefficients to interior and exterior surfaces (see Interior Convection Coefficient and Exterior Convection Coefficient). This is used primariliy for IEA BESTEST calculations.

Required: |
No |

Type: |
Enumeration |

Values: |
`AUTO` or `CONSTANT` |

Default: |
`AUTO` |

## Interior Convection Coefficient¶

If Convection Calculation Method is `CONSTANT`

, then this value specifies the convection coefficient applied to interior surface boundaries (slab floor, interior foundation wall, and interior insulation).

Required: |
Depends |

Type: |
Numeric |

Units: |
W/m^{2}-K |

## Exterior Convection Coefficient¶

If Convection Calculation Method is `CONSTANT`

, then this value specifies the convection coefficient applied to exterior surface boundaries (grade, exterior foundation wall, and exterior insulation).

Required: |
Depends |

Type: |
Numeric |

Units: |
W/m^{2}-K |

## Wall Top Boundary Condition¶

Specifies how the boundary condition along the wall top is calculated. Options are:

`ZERO-FLUX`

, which applies a zero heat flux boundary condition along the wall top. This implies that heat flux above the wall top is one dimensional and does not flow through the wall top boundary.`LINEAR-DT`

, which applies a linear change in temperature across the wall top (see `Wall Top Temperature Difference`_). This is used only to represent the constraints of the IEA BESTEST analytical solution in case GC10a.

Required: |
No |

Type: |
Enumeration |

Values: |
`ZERO-FLUX` or `LINEAR-DT` |

Default: |
`ZERO-FLUX` |

## Wall Top Interior Temperature¶

If Wall Top Boundary Condition is `LINEAR-DT`

, then this value specifies the interior temperature at the wall top. This is used only to represent the constraints of the IEA BESTEST analytical solution in case GC10a.

Required: |
Depends |

Type: |
Numeric |

Units: |
K |

## Wall Top Exterior Temperature¶

If Wall Top Boundary Condition is `LINEAR-DT`

, then this value specifies the exterior temperature at the wall top. This is used only to represent the constraints of the IEA BESTEST analytical solution in case GC10a.

Required: |
Depends |

Type: |
Numeric |

Units: |
K |