# 4.20 DOOR

DOOR constructs a subobject belonging to the current SURFACE. The azimuth, tilt, ground reflectivity and exterior conditions associated with the door are the same as those of the owning surface, although the exterior surface conductance and the exterior absorptivity can be altered.

**drName**

Name of door.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

63 characters | none | No | constant |

**drArea= float**

Overall area of door.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

ft^{2} | x \(>\) 0 | none | Yes | constant |

**drModel= choice**

Provides user control over how CSE models conduction for this door:

QUICK | Surface is modeled using a simple conductance. Heat capacity effects are ignored. Either drCon or drU (next) can be specified. |

DELAYED, DELAYED_HOUR, DELAYED_SUBOUR | Surface is modeled using a multi-layer finite difference technique which represents heat capacity effects. If the time constant of the door is too short to accurately simulate, a warning message is issued and the Quick model is used. drCon (next) must be specified – the program cannot use the finite difference model if drU rather than drCon is specified. |

AUTO | Program selects Quick or appropriate Delayed automatically according to the time constant of the surface (if drU is specified, Quick is selected). |

FD or FORWARD_DIFFERENCE | Selects the forward difference model (used with short time steps and the CZM/UZM zone models) |

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

choices above | AUTO | No | constant |

Either drU or drCon must be specified, but not both.

**drU= float**

Door U-value, NOT including surface (air film) conductances. Allows direct entry of U-value, without defining a CONSTRUCTION, when no heat capacity effects are to be modeled.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

Btuh/ft^{2}-^{o}F | x \(>\) 0 | Determined from drCon | if drCon not given | constant |

**drCon= conName**

Name of construction for door.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

name of a CONSTRUCTION | none | unless drU given | constant |

**drLThkF= float**

Sublayer thickness adjustment factor for FORWARD_DIFFERENCE conduction model used with drCon surfaces. Material layers in the construction are divided into sublayers as needed for numerical stability. drLThkF allows adjustment of the thickness criterion used for subdivision. A value of 0 prevents subdivision; the default value (0.5) uses layers with conservative thickness equal to half of an estimated safe value. Fewer (thicker) sublayers improves runtime at the expense of accurate representation of rapid changes.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

x \(\ge\) 0 | 0.5 | No | constant |

**drExAbs= float**

Door exterior solar absorptivity. Applicable only if sfExCnd of owning surface is AMBIENT or SPECIFIEDT.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

Btuh/ft^{2}-^{o}F | x \(>\) 0 | same as owning surface | No | monthly-hourly |

**drInAbs= float**

Door interior solar absorptivity.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

0 \(\le\) x \(\le\) 1 | 0.5 | No | monthly-hourly |

**drExEpsLW= float**

Door exterior long wave (thermal) emittance.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

0 \(\le\) x \(\le\) 1 | 0.9 | No | constant |

**drInEpsLW= float**

Door interior long wave (thermal) emittance.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

0 \(\le\) x \(\le\) 1 | 0.9 | No | constant |

**drInH= float**

Door interior surface (air film) conductance. Ignored if drModel = Forward_Difference

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

Btuh/ft^{2}-^{o}F | x \(>\) 0 | same as owning surface | No | constant |

**drExH= float**

Door exterior surface (air film) conductance. Ignored if drModel = Forward_Difference

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

Btuh/ft^{2}-^{o}F | x \(>\) 0 | same as owning surface | No | constant |

When drModel = Forward_Difference, several models are available for calculating inside and outside surface convective coefficients. Inside surface faces can be exposed only to zone conditions. Outside faces may be exposed either to ambient conditions or zone conditions, based on drExCnd. Only UNIFIED and INPUT are typically used. The other models were used during CSE development for comparison. For details, see CSE Engineering Documentation.

Model | Exposed to ambient | Exposed to zone |
---|---|---|

UNIFIED | default CSE model | default CSE model |

INPUT | hc = drExHcMult | hc = drxxHcMult |

AKBARI | Akbari model | n/a |

WALTON | Walton model | n/a |

WINKELMANN | Winkelmann model | n/a |

MILLS | n/a | Mills model |

ASHRAE | n/a | ASHRAE handbook values |

**drExHcModel= choice**

Selects the model used for exterior surface convection when drModel = Forward_Difference.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

choices above | UNIFIED | No | constant |

**drExHcLChar= float**

Characteristic length of surface, used in derivation of forced exterior convection coefficients in some models when outside face is exposed to ambient (i.e. to wind).

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

ft | x \(>\) 0 | 10 | No | constant |

**drExHcMult= float**

Exterior convection coefficient adjustment factor. When drExHcModel=INPUT, hc=drExHcMult. For other drExHcModel choices, the model-derived hc is multiplied by drExHcMult.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

x \(\ge\) 0 | 1 | No | subhourly |

**drExRf= float**

Exterior roughness factor. Typical roughness values:

Roughness Index | drExRf | Example |
---|---|---|

1 (very rough) | 2.17 | Stucco |

2 (rough) | 1.67 | Brick |

3 (medium rough) | 1.52 | Concrete |

4 (Medium smooth) | 1.13 | Clear pine |

5 (Smooth) | 1.11 | Smooth plaster |

6 (Very Smooth) | 1 | Glass |

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

drExHcModel = WINKELMANN: 1.66 else 2.17 | No | constant |

**drInHcModel= choice**

Selects the model used for the inside (zone) surface convection when drModel = Forward_Difference.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

choices above (see drExHcModel) | UNIFIED | No | constant |

**drInHcMult= float**

Interior convection coefficient adjustment factor. When drInHcModel=INPUT, hc=drInHcMult. For other drInHcModel choices, the model-derived hc is multiplied by drInHcMult.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

x \(\ge\) 0 | 1 | No | subhourly |

**endDoor**

Indicates the end of the door definition. Alternatively, the end of the door definition can be indicated by the declaration of another object or by END.

Units | Legal Range | Default | Required | Variability |
---|---|---|---|---|

none | No | constant |

**Related Probes:**