Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Maxwell-Boltzmann Distribution: Problem Solving01:20

Maxwell-Boltzmann Distribution: Problem Solving

3.1K
Individual molecules in a gas move in random directions, but a gas containing numerous molecules has a predictable distribution of molecular speeds, which is known as the Maxwell-Boltzmann distribution, f(v).
This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by
3.1K
Radiation: Applications01:17

Radiation: Applications

2.0K
The average temperature of Earth is the subject of much current discussion. Earth is in radiative contact with both the Sun and dark space; it receives almost all its energy from the radiation of the Sun and reflects some of it into outer space. Dark space is very cold, about 3 K, so Earth radiates energy into it. For instance, heat transfer occurs from soil and grasses, the rate of which can be so rapid that frost can occur on clear summer evenings, even in warm latitudes.
The average...
2.0K
Radiation Pressure: Problem Solving01:09

Radiation Pressure: Problem Solving

956
The radiation pressure applied by an electromagnetic wave on a perfectly absorbing surface equals the energy density of the wave. The wave's momentum also gets transferred to the surface when an electromagnetic wave is entirely absorbed by it. The rate at which momentum is transmitted to an absorbing surface perpendicular to the propagation direction equals the force on the surface.
The average value of the rate of momentum transfer divided by the absorbing area represents the average force...
956
Influence of Earth's Curvature and Atmospheric Refraction on Leveling01:26

Influence of Earth's Curvature and Atmospheric Refraction on Leveling

1.2K
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...
1.2K
Absorption of Radiation01:05

Absorption of Radiation

1.5K
The rate of heat transfer by emitted radiation is described by the Stefan-Boltzmann law of radiation:
1.5K
Calculation of Electric Flux01:25

Calculation of Electric Flux

3.2K
Consider the electric field of an oppositely charged, parallel-plate system and an imaginary box between those plates. Let the bottom face of the box be ABCD, and the top face be FGHK. The electric field between the plates is uniform and points from the positive plate toward the negative plate. The calculation of this field's flux through the box's various faces shows that the net flux through the box is zero. Why does the flux cancel out here?
3.2K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

A Global Building Occupant Behavior Database.

Scientific data·2022
Same author

A structured open data collection on occupant behaviour in buildings.

Scientific data·2019
Same author

Monitored data on occupants' presence and actions in an office building.

Scientific data·2019
See all related articles

Related Experiment Video

Updated: Mar 22, 2026

Measurements of CO2 Fluxes at Non-Ideal Eddy Covariance Sites
09:05

Measurements of CO2 Fluxes at Non-Ideal Eddy Covariance Sites

Published on: June 24, 2019

8.5K

Computing diffuse fraction of global horizontal solar radiation: A model comparison.

Sokol Dervishi1, Ardeshir Mahdavi1

  • 1Department of Building Physics and Building Ecology, Vienna University of Technology, Vienna, Austria.

Solar Energy (Phoenix, Ariz.)
|April 12, 2016
PubMed
Summary

Accurate solar radiation data is crucial for building energy simulations. This study compares models for estimating the diffuse fraction of solar irradiance, finding some models provide reliable predictions, though calibration offers minor improvements.

Keywords:
Diffuse fraction modelsDiffuse irradianceMeasurementsSolar irradiance

More Related Videos

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass ADG Fresnel Lens for Concentrating Photovoltaics
09:00

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass ADG Fresnel Lens for Concentrating Photovoltaics

Published on: October 27, 2017

9.4K
In situ Grazing Incidence Small Angle X-ray Scattering on Roll-To-Roll Coating of Organic Solar Cells with Laboratory X-ray Instrumentation
06:49

In situ Grazing Incidence Small Angle X-ray Scattering on Roll-To-Roll Coating of Organic Solar Cells with Laboratory X-ray Instrumentation

Published on: March 2, 2021

6.8K

Related Experiment Videos

Last Updated: Mar 22, 2026

Measurements of CO2 Fluxes at Non-Ideal Eddy Covariance Sites
09:05

Measurements of CO2 Fluxes at Non-Ideal Eddy Covariance Sites

Published on: June 24, 2019

8.5K
Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass ADG Fresnel Lens for Concentrating Photovoltaics
09:00

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass ADG Fresnel Lens for Concentrating Photovoltaics

Published on: October 27, 2017

9.4K
In situ Grazing Incidence Small Angle X-ray Scattering on Roll-To-Roll Coating of Organic Solar Cells with Laboratory X-ray Instrumentation
06:49

In situ Grazing Incidence Small Angle X-ray Scattering on Roll-To-Roll Coating of Organic Solar Cells with Laboratory X-ray Instrumentation

Published on: March 2, 2021

6.8K

Area of Science:

  • Building science
  • Renewable energy
  • Atmospheric physics

Background:

  • Accurate solar radiation data, including direct and diffuse components, is essential for predicting building energy performance and solar energy system gains.
  • Measured solar irradiance data is often limited to global horizontal irradiance, necessitating methods to derive diffuse solar radiation components.
  • Numerous algorithms have been developed to estimate the diffuse fraction of solar irradiance.

Purpose of the Study:

  • To compare the performance of eight different models for estimating the diffuse fraction of solar irradiance.
  • To identify the best-performing models for predicting diffuse solar radiation.
  • To analyze the impact of model coefficient calibration for specific locations, using Vienna, Austria as a case study.

Main Methods:

  • Evaluation of eight established models for diffuse fraction estimation.
  • Utilized a database of measured solar irradiance data from Vienna, Austria.
  • Selected the top three performing models for in-depth analysis and coefficient calibration.

Main Results:

  • Some models demonstrated a relatively reliable ability to estimate the diffuse fraction of global irradiance.
  • The calibration of model coefficients using local data provided only a marginal improvement in performance.
  • The study identified specific models suitable for diffuse solar radiation estimation in similar climatic conditions.

Conclusions:

  • Certain mathematical models can effectively estimate diffuse solar irradiance fractions, crucial for building energy simulations.
  • While local calibration offers slight enhancements, the inherent performance of selected models is a key factor.
  • The findings support the use of validated models for improving the accuracy of solar energy predictions in the built environment.