Buildings.HeatTransfer.Data.Glasses

Package with thermophysical properties for window glas

Information

This package implements thermophysical properties for window glass.

Since the infrared transmissivity is part of the Window 6 data and since it depends on the glass thickness, the glass thickness is a parameter that is set for all glass layers. This configuration is different from the records for gas properties, which do not yet set the value for the thickness of the gas gap.

The table below compares the data of this record with the variables used in the WINDOW 6 output file.

Note that

the surface a is usually the outside-facing surface, and the surface b is usually the room-facing surface.
by the term solar, we mean the whole solar spectrum. Data in the solar spectrum are used for computing solar heat gains.
by the term infrared (or infrared), we mean the infrared spectrum. Data in the infrared spectrum are used for thermal radiation that is emitted by surfaces that are around room or ambient temperature.
WINDOW 6 uses spectral data in the calculation of optical properties of window systems, whereas the model in this library uses averages over the whole solar or infrared spectrum.

Buildings library variable name	WINDOW 6 variable name
tauSol	Tsol
rhoSol_a	Rsol1
rhoSol_b	Rsol2
tauIR	Tir
absIR_a	Emis1
absIR_b	Emis2

The solar transmittance tauSol and the solar reflectances rhoSol_a and rhoSol_b are vectors. For regular glass, these vectors have only one element. For electrochromic glass, users can enter an arbitrary number of elements, where each element is for a particular window state. The dimension of the three vectors tauSol, rhoSol_a and rhoSol_b must be equal.

The example Buildings.ThermalZones.Detailed.Examples.ElectroChromicWindow shows how these data can be used to darken the window. A control signal of uWin=0 in the room model corresponds to the first entry of the data, which typically is the clear state, whereas uWin=1 corresponds to the last entry, which typically is the dark states. For intermediate control signals, the optical properties are interpolated using the model Buildings.HeatTransfer.Windows.BaseClasses.StateInterpolator.

Extends from Modelica.Icons.MaterialPropertiesPackage (Icon for package containing property classes).

Package Content

Name	Description
Generic	Thermal properties of window glass
ID100	Generic Bronze Glass 3.1mm. Manufacturer: Generic.
ID101	Generic Bronze Glass 5.7mm. Manufacturer: Generic.
ID102	Generic Clear Glass 3.048mm. Manufacturer: Generic.
ID103	Generic Clear Glass 5.7mm. Manufacturer: Generic.
Electrochromic	Electrochromic Glass 6mm. Manufacturer: Generic.

Buildings.HeatTransfer.Data.Glasses.Generic

Thermal properties of window glass

Information

This record implements thermophysical properties for window glass. See Buildings.HeatTransfer.Data.Glasses for instructions.

Extends from Modelica.Icons.Record (Icon for records).

Parameters

Type	Name	Default	Description
Length	x	0.003	Thickness [m]
ThermalConductivity	k	1	Thermal conductivity [W/(m.K)]
TransmissionCoefficient	tauSol[:]	{0.6}	Solar transmittance [1]
ReflectionCoefficient	rhoSol_a[:]	{0.075}	Solar reflectance of surface a (usually outside-facing surface) [1]
ReflectionCoefficient	rhoSol_b[:]	{0.075}	Solar reflectance of surface b (usually room-facing surface) [1]
TransmissionCoefficient	tauIR	0	Infrared transmissivity of glass [1]
Emissivity	absIR_a	0.84	Infrared absorptivity of surface a (usually outside-facing surface) [1]
Emissivity	absIR_b	0.84	Infrared absorptivity of surface b (usually room-facing surface) [1]

Modelica definition

record Generic "Thermal properties of window glass" extends Modelica.Icons.Record; parameter Modelica.Units.SI.Length x=0.003 "Thickness"; parameter Modelica.Units.SI.ThermalConductivity k=1 "Thermal conductivity"; parameter Modelica.Units.SI.TransmissionCoefficient tauSol[:]={0.6} "Solar transmittance"; parameter Modelica.Units.SI.ReflectionCoefficient rhoSol_a[:]={0.075} "Solar reflectance of surface a (usually outside-facing surface)"; parameter Modelica.Units.SI.ReflectionCoefficient rhoSol_b[:]={0.075} "Solar reflectance of surface b (usually room-facing surface)"; parameter Modelica.Units.SI.TransmissionCoefficient tauIR=0 "Infrared transmissivity of glass"; parameter Modelica.Units.SI.Emissivity absIR_a=0.84 "Infrared absorptivity of surface a (usually outside-facing surface)"; parameter Modelica.Units.SI.Emissivity absIR_b=0.84 "Infrared absorptivity of surface b (usually room-facing surface)"; end Generic;

Buildings.HeatTransfer.Data.Glasses.ID100

Generic Bronze Glass 3.1mm. Manufacturer: Generic.

Parameters

Type	Name	Default	Description
Length	x	0.0031	Thickness [m]
ThermalConductivity	k	1.0	Thermal conductivity [W/(m.K)]
TransmissionCoefficient	tauSol[:]	{0.646}	Solar transmittance [1]
ReflectionCoefficient	rhoSol_a[:]	{0.062}	Solar reflectance of surface a (usually outside-facing surface) [1]
ReflectionCoefficient	rhoSol_b[:]	{0.063}	Solar reflectance of surface b (usually room-facing surface) [1]
TransmissionCoefficient	tauIR	0	Infrared transmissivity of glass [1]
Emissivity	absIR_a	0.84	Infrared absorptivity of surface a (usually outside-facing surface) [1]
Emissivity	absIR_b	0.84	Infrared absorptivity of surface b (usually room-facing surface) [1]

Modelica definition

record ID100 = Buildings.HeatTransfer.Data.Glasses.Generic ( x=0.0031, k=1.0, tauSol={0.646}, rhoSol_a={0.062}, rhoSol_b={0.063}, tauIR=0, absIR_a=0.84, absIR_b=0.84) "Generic Bronze Glass 3.1mm. Manufacturer: Generic.";

Buildings.HeatTransfer.Data.Glasses.ID101

Generic Bronze Glass 5.7mm. Manufacturer: Generic.

Parameters

Type	Name	Default	Description
Length	x	0.0057	Thickness [m]
ThermalConductivity	k	1.0	Thermal conductivity [W/(m.K)]
TransmissionCoefficient	tauSol[:]	{0.486}	Solar transmittance [1]
ReflectionCoefficient	rhoSol_a[:]	{0.053}	Solar reflectance of surface a (usually outside-facing surface) [1]
ReflectionCoefficient	rhoSol_b[:]	{0.053}	Solar reflectance of surface b (usually room-facing surface) [1]
TransmissionCoefficient	tauIR	0	Infrared transmissivity of glass [1]
Emissivity	absIR_a	0.84	Infrared absorptivity of surface a (usually outside-facing surface) [1]
Emissivity	absIR_b	0.84	Infrared absorptivity of surface b (usually room-facing surface) [1]

Modelica definition

record ID101 = Buildings.HeatTransfer.Data.Glasses.Generic ( x=0.0057, k=1.0, tauSol={0.486}, rhoSol_a={0.053}, rhoSol_b={0.053}, tauIR=0, absIR_a=0.84, absIR_b=0.84) "Generic Bronze Glass 5.7mm. Manufacturer: Generic.";

Buildings.HeatTransfer.Data.Glasses.ID102

Generic Clear Glass 3.048mm. Manufacturer: Generic.

Parameters

Type	Name	Default	Description
Length	x	0.003	Thickness [m]
ThermalConductivity	k	1.0	Thermal conductivity [W/(m.K)]
TransmissionCoefficient	tauSol[:]	{0.834}	Solar transmittance [1]
ReflectionCoefficient	rhoSol_a[:]	{0.075}	Solar reflectance of surface a (usually outside-facing surface) [1]
ReflectionCoefficient	rhoSol_b[:]	{0.075}	Solar reflectance of surface b (usually room-facing surface) [1]
TransmissionCoefficient	tauIR	0	Infrared transmissivity of glass [1]
Emissivity	absIR_a	0.84	Infrared absorptivity of surface a (usually outside-facing surface) [1]
Emissivity	absIR_b	0.84	Infrared absorptivity of surface b (usually room-facing surface) [1]

Modelica definition

record ID102 = Buildings.HeatTransfer.Data.Glasses.Generic ( x=0.003, k=1.0, tauSol={0.834}, rhoSol_a={0.075}, rhoSol_b={0.075}, tauIR=0, absIR_a=0.84, absIR_b=0.84) "Generic Clear Glass 3.048mm. Manufacturer: Generic.";

Buildings.HeatTransfer.Data.Glasses.ID103

Generic Clear Glass 5.7mm. Manufacturer: Generic.

Parameters

Type	Name	Default	Description
Length	x	0.0057	Thickness [m]
ThermalConductivity	k	1.0	Thermal conductivity [W/(m.K)]
TransmissionCoefficient	tauSol[:]	{0.771}	Solar transmittance [1]
ReflectionCoefficient	rhoSol_a[:]	{0.070}	Solar reflectance of surface a (usually outside-facing surface) [1]
ReflectionCoefficient	rhoSol_b[:]	{0.070}	Solar reflectance of surface b (usually room-facing surface) [1]
TransmissionCoefficient	tauIR	0	Infrared transmissivity of glass [1]
Emissivity	absIR_a	0.84	Infrared absorptivity of surface a (usually outside-facing surface) [1]
Emissivity	absIR_b	0.84	Infrared absorptivity of surface b (usually room-facing surface) [1]

Modelica definition

record ID103 = Buildings.HeatTransfer.Data.Glasses.Generic ( x=0.0057, k=1.0, tauSol={0.771}, rhoSol_a={0.070}, rhoSol_b={0.070}, tauIR=0, absIR_a=0.84, absIR_b=0.84) "Generic Clear Glass 5.7mm. Manufacturer: Generic.";

Buildings.HeatTransfer.Data.Glasses.Electrochromic

Electrochromic Glass 6mm. Manufacturer: Generic.

Parameters

Type	Name	Default	Description
Length	x	0.006	Thickness [m]
ThermalConductivity	k	0.9	Thermal conductivity [W/(m.K)]
TransmissionCoefficient	tauSol[:]	{0.814,0.111}	Solar transmittance [1]
ReflectionCoefficient	rhoSol_a[:]	{0.086,0.179}	Solar reflectance of surface a (usually outside-facing surface) [1]
ReflectionCoefficient	rhoSol_b[:]	{0.086,0.179}	Solar reflectance of surface b (usually room-facing surface) [1]
TransmissionCoefficient	tauIR	0	Infrared transmissivity of glass [1]
Emissivity	absIR_a	0.84	Infrared absorptivity of surface a (usually outside-facing surface) [1]
Emissivity	absIR_b	0.84	Infrared absorptivity of surface b (usually room-facing surface) [1]

Modelica definition

record Electrochromic = Buildings.HeatTransfer.Data.Glasses.Generic ( x=0.006, k=0.9, tauSol={0.814, 0.111}, rhoSol_a={0.086, 0.179}, rhoSol_b={0.086, 0.179}, tauIR=0, absIR_a=0.84, absIR_b=0.84) "Electrochromic Glass 6mm. Manufacturer: Generic.";