modelDiffuseIsotropic

Diffuse solar irradiation on a tilted surface with an isotropic sky model

Extends from Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.PartialSolarIrradiation (Partial model that is used to compute the direct and diffuse solar irradiation).

Information

This component computes the hemispherical diffuse irradiation on a tilted surface using an isotropic model. The irradiation is a sum composed of diffuse solar irradiation and radiation reflected by the ground. For a definition of the parameters, see the User's Guide.

References

P. Ineichen, R. Perez and R. Seals (1987). The Importance of Correct Albedo Determination for Adequately Modeling Energy Received by Tilted Surface, Solar Energy, 39(4): 301-305.

Parameters

Type	Name	Default	Description
Modelica.Units.SI.Angle	til (from PartialSolarIrradiation)		Surface tilt
Real	rho	0.2	Ground reflectance
Boolean	outSkyCon	false	Output contribution of diffuse irradiation from sky
Boolean	outGroCon	false	Output contribution of diffuse irradiation from ground

Connectors

Type	Name	Description
Modelica.Blocks.Interfaces.RealOutput	H (from PartialSolarIrradiation)	Radiation per unit area
WeatherData.Bus	weaBus (from PartialSolarIrradiation)	Bus with weather data
Modelica.Blocks.Interfaces.RealOutput	HSkyDifTil	Diffuse solar irradiation on a tilted surface from the sky
Modelica.Blocks.Interfaces.RealOutput	HGroDifTil	Diffuse solar irradiation on a tilted surface from the ground

Components

Type	Name	Default	Description
Modelica.Blocks.Math.Add	add		Block to add radiation

Revisions

May 15, 2026, by Jianjun Hu:
Changed the class type from block to model.
This is for IBPSA, #2122.
November 14, 2015, by Michael Wetter:
Added min, max and unit attributes for rho.
June 6, 2012, by Wangda Zuo:
Added contributions from sky and ground that were separated in base class.
May 24, 2010, by Wangda Zuo:
First implementation.