Construction

Opaque construction: layers from the outside (side a) to the inside (side b), each split into nSta[i] sublayers of equal thickness (Buildings.HeatTransfer.Data.OpaqueConstructions.Generic and its nSta)

FastSmoothBuildings.Data.Construction, record (source)

Purpose

An opaque construction: its layers from the outside (side a) to the inside (side b), the split of each layer into sublayers of equal thickness, and the radiative properties of its two faces. The walls of Envelope read it (PartialOpaque).

Fields

Field	Meaning
nLay	number of layers
x, k, c, d	thickness, thermal conductivity, specific heat capacity and density of each layer
nSta[l]	number of sublayers of layer l: the states Buildings gives it, at most 3, in the closed-loop model; 1, a node at each layer boundary, in the model for optimal control
nNod	number of sublayers, the sum of nSta; there are nNod + 1 nodes, numbered from the outside
lay[j]	the layer of sublayer j
nod[b]	the node of layer boundary b (nLay + 1 of them, nod[1] = 1, nod[nLay + 1] = nNod + 1)
sub[m]	the nodes inside the layers (nNod − nLay of them)
absIR_a, absIR_b	long-wave emissivity of side a and side b
absSol_a, absSol_b	solar absorptance of side a and side b

The counts and the indices follow from nSta but are written out, without defaults: rumoca sizes arrays and evaluates subscripts from literal parameters only (see Translation into CasADi). For instance, four layers with nSta = {2, 2, 3, 1} have nNod = 8, lay = {1, 1, 2, 2, 3, 3, 3, 4}, nod = {1, 3, 5, 8, 9} and sub = {2, 4, 6, 7} (Examples.Constructions.CavityWall); with one sublayer a layer, nod = {1, 2, ..., nLay + 1} and sub = fill(0, 0).

Relation to Buildings

Buildings.HeatTransfer.Data.OpaqueConstructions.Generic and its nSta.

Parameters

Parameter	Type	Unit	Default	Description
nLay	Integer			Number of layers
x	Real	m		Thickness
k	Real	W/(m.K)		Thermal conductivity
c	Real	J/(kg.K)		Specific heat capacity
d	Real	kg/m3		Density
nNod	Integer			Number of sublayers, the sum of nSta
lay	Integer			Layer of each sublayer, from the outside
nod	Integer			Node of each layer boundary, from the outside (nod[1] = 1)
sub	Integer			Nodes inside the layers, from the outside
absIR_a	Real		0.84	Long-wave emissivity of side a (outside)
absIR_b	Real		0.84	Long-wave emissivity of side b (inside)
absSol_a	Real		0.84	Solar absorptance of side a (outside)
absSol_b	Real		0.84	Solar absorptance of side b (inside)

Revisions

• October 2026: moved from trano's FastModel.Data.