### Abstract

Original language | English |
---|---|

Pages (from-to) | 254-267 |

Number of pages | 13 |

Journal | Solar Energy |

Volume | 81 |

Issue number | 2 |

DOIs | |

Publication status | Published - 2007 |

### Fingerprint

### Keywords

- solar radiation models
- empirical validation
- building energy simulation
- uncertainty analysis
- mechanical engineering
- solar energy

### Cite this

*Solar Energy*,

*81*(2), 254-267. https://doi.org/10.1016/j.solener.2006.03.009

}

*Solar Energy*, vol. 81, no. 2, pp. 254-267. https://doi.org/10.1016/j.solener.2006.03.009

**Empirical validation of models to compute solar irradiance on inclined surfaces for building energy simulation.** / Loutzenhiser, P.G.; Manz, H.; Felsmann, C.; Strachan, P.A.; Frank, T.; Maxwell, G.M.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Empirical validation of models to compute solar irradiance on inclined surfaces for building energy simulation

AU - Loutzenhiser, P.G.

AU - Manz, H.

AU - Felsmann, C.

AU - Strachan, P.A.

AU - Frank, T.

AU - Maxwell, G.M.

PY - 2007

Y1 - 2007

N2 - Accurately computing solar irradiance on external facades is a prerequisite for reliably predicting thermal behavior and cooling loads of buildings. Validation of radiation models and algorithms implemented in building energy simulation codes is an essential endeavor for evaluating solar gain models. Seven solar radiation models implemented in four building energy simulation codes were investigated: (1) isotropic sky, (2) Klucher, (3) Hay-Davies, (4) Reindl, (5) Muneer, (6) 1987 Perez, and (7) 1990 Perez models. The building energy simulation codes included: EnergyPlus, DOE-2.1E, TRNSYS-TUD, and ESP-r. Solar radiation data from two 25 days periods in October and March/April, which included diverse atmospheric conditions and solar altitudes, measured on the EMPA campus in a suburban area in Duebendorf, Switzerland, were used for validation purposes. Two of the three measured components of solar irradiances - global horizontal, diffuse horizontal and direct-normal - were used as inputs for calculating global irradiance on a south-west façade. Numerous statistical parameters were employed to analyze hourly measured and predicted global vertical irradiances. Mean absolute differences for both periods were found to be: (1) 13.7% and 14.9% for the isotropic sky model, (2) 9.1% for the Hay-Davies model, (3) 9.4% for the Reindl model, (4) 7.6% for the Muneer model, (5) 13.2% for the Klucher model, (6) 9.0%, 7.7%, 6.6%, and 7.1% for the 1990 Perez models, and (7) 7.9% for the 1987 Perez model. Detailed sensitivity analyses using Monte Carlo and fitted effects for N-way factorial analyses were applied to assess how uncertainties in input parameters propagated through one of the building energy simulation codes and impacted the output parameter. The implications of deviations in computed solar irradiances on predicted thermal behavior and cooling load of buildings are discussed.

AB - Accurately computing solar irradiance on external facades is a prerequisite for reliably predicting thermal behavior and cooling loads of buildings. Validation of radiation models and algorithms implemented in building energy simulation codes is an essential endeavor for evaluating solar gain models. Seven solar radiation models implemented in four building energy simulation codes were investigated: (1) isotropic sky, (2) Klucher, (3) Hay-Davies, (4) Reindl, (5) Muneer, (6) 1987 Perez, and (7) 1990 Perez models. The building energy simulation codes included: EnergyPlus, DOE-2.1E, TRNSYS-TUD, and ESP-r. Solar radiation data from two 25 days periods in October and March/April, which included diverse atmospheric conditions and solar altitudes, measured on the EMPA campus in a suburban area in Duebendorf, Switzerland, were used for validation purposes. Two of the three measured components of solar irradiances - global horizontal, diffuse horizontal and direct-normal - were used as inputs for calculating global irradiance on a south-west façade. Numerous statistical parameters were employed to analyze hourly measured and predicted global vertical irradiances. Mean absolute differences for both periods were found to be: (1) 13.7% and 14.9% for the isotropic sky model, (2) 9.1% for the Hay-Davies model, (3) 9.4% for the Reindl model, (4) 7.6% for the Muneer model, (5) 13.2% for the Klucher model, (6) 9.0%, 7.7%, 6.6%, and 7.1% for the 1990 Perez models, and (7) 7.9% for the 1987 Perez model. Detailed sensitivity analyses using Monte Carlo and fitted effects for N-way factorial analyses were applied to assess how uncertainties in input parameters propagated through one of the building energy simulation codes and impacted the output parameter. The implications of deviations in computed solar irradiances on predicted thermal behavior and cooling load of buildings are discussed.

KW - solar radiation models

KW - empirical validation

KW - building energy simulation

KW - uncertainty analysis

KW - mechanical engineering

KW - solar energy

UR - http://dx.doi.org/10.1016/j.solener.2006.03.009

U2 - 10.1016/j.solener.2006.03.009

DO - 10.1016/j.solener.2006.03.009

M3 - Article

VL - 81

SP - 254

EP - 267

JO - Solar Energy

JF - Solar Energy

SN - 0038-092X

IS - 2

ER -