modelGlazedElements
Information
This model calculates the heat flow by solar gains through each glazed element k. The heat flow is given by
Φsol,k =Fsh,k Isol,k gfac (1-Fframe) Awin,k
where Fsh,k is the shading reduction factor which is set to 1 by default, Isol,k is the solar irradiance per square meter of surface area, gfac is the total solar energy transmittance of the trasparent element, Fframe is the frame area fraction, and Awin,k is the overall area of the glazed element in square meters.
Additionally, an extra heat flow is modeled to represent the thermal radiation emitted towards the sky as
Φr,k =hr ΔTsky Rse Uk Ak
where hr is the external radiative heat transfer coefficient which is approximated as 5 ε W/m2K (where ε is the emissivity for the thermal radiation of the external surface), and ΔTsky is the average temperature difference between the external air temperature and the apparent sky temperature.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | n | ||
| Modelica.Units.SI.Area[:] | AWin | Area of windows | |
| Real[:] | coeFac | Coefficient of g-factor reduction | |
| Modelica.Units.SI.CoefficientOfHeatTransfer | UWin | U-value of windows | |
| Modelica.Units.SI.Angle[:] | surTil | Tilt angle of surfaces | |
| Modelica.Units.SI.Angle[:] | surAzi | Azimuth angle of surfaces | |
| Real | eps | 0.9 | Emissivity of external surface |
| Modelica.Units.SI.ThermalInsulance | surRes | 0.04 | External surface heat resistance |
| Real | gFac | Energy transmittance of glazings | |
| Real | winFra | Frame fraction of windows | |
| Real | shaRedFac | 1 | Shading reduction factor |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.BoundaryConditions.WeatherData.Bus | weaBus | ||
| Modelica.Blocks.Interfaces.RealOutput | solRadWin | Solar radiation through windows |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| BoundaryConditions.SolarIrradiation.DirectTiltedSurface[n] | HDirTil | Direct solar irradiation on surface | |
| Modelica.Blocks.Math.Gain[n] | solRad | Solar radiation trasmitted through windows | |
| BoundaryConditions.SolarIrradiation.DiffusePerez[n] | HDifTil | Diffuse solar irradiation on surface | |
| Modelica.Blocks.Math.Gain[n] | theRadWin | Extra thermal radiation through windows | |
| Modelica.Blocks.Math.Add[n] | addWin | Total solar gains through windows | |
| Modelica.Blocks.Math.Product[n] | HDirAng | Direct solar irradiation considering incident angle of surface | |
| Utilities.Math.Polynomial[n] | polynomial | Ratio of direct solar irradiation considering incident angle of surface |
Revisions
-
May 15, 2024, by Alessandro Maccarini:
Added the parametercoeFacin order to vary the g-factor as a function of the incident angle of the surface. -
Mar 16, 2022, by Alessandro Maccarini:
First implementation.