Influence of the Meteorological Record Length on the Generation of Representative Weather Files

Michele Libralato,Onorio Saro,Vincenzo Corrado,Alessandra De Angelis,Giovanni Murano

doi:10.3390/en13082103

Michele Libralato, Onorio Saro + Show 3 more

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https://doi.org/10.3390/en13082103

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Journal: Energies	Publication Date: Apr 23, 2020
Citations: 5	License type: CC BY 4.0

Affiliation: University of Udine, Polytechnic University of Turin

Abstract

Heat and moisture (HM) transfer simulations of building envelopes and whole building energy simulations require adequate weather files. The common approach is to use weather data of reference years constructed from meteorological records. The weather record affects the capability of representing the real weather of the resulting reference years. In this paper the problem of the influence of the length of the records on the representativeness of the reference years is addressed and its effects are evaluated also for the applicative case of the moisture accumulation risk analysis with the Glaser Method and with DELPHIN 6, confirming that records shorter than 10 years could lead to less representative reference years. On the other hand, it is shown that reference years obtained from longer periods are not representative of the most recent years, which present higher dry-bulb air temperatures due to a short-term climate change effect observed in all the considered weather records. An alternative representative year (Moisture Representative Year) to be used in building energy simulations with a strong dependence on moisture is presented.

Highlights

Energy efficiency is an increasingly imposed requirement for new buildings and renovations.One of the possibilities to achieve low energy consumptions is to increase the thermal resistance of the external walls
The influence of the meteorological record length for the generation of weather files of reference years has been evaluated for the moisture accumulation risk assessment for four weather stations in Northern Italy: Aosta, Bergamo, Torino and Udine
Two representative years construction method have been considered, the Typical Meteorological Year (TMY) used for building energy simulations, defined in ISO 15927-4:2005 [1], and the Moisture Representative Year (MRY), proposed in this work, to be used in heat and moisture transport simulations

Summary

Introduction

Energy efficiency is an increasingly imposed requirement for new buildings and renovations.One of the possibilities to achieve low energy consumptions is to increase the thermal resistance of the external walls. Energy efficiency is an increasingly imposed requirement for new buildings and renovations. Adding layers of insulation to existing building envelopes leads to lower thermal dispersion. The building energy simulation could be used to evaluate the energy savings and the effectiveness of the design choices. The simulations should be performed with the appropriate weather file, usually a single year hourly series of weather variables, used to calculate the boundary conditions of a building. If the intention of the designer is to simulate the most common weather conditions, for example to evaluate the heat losses though the envelope considering moisture transfer, a representative weather file could be used. In building energy simulations it is common practice to use the Typical Meteorological Year (TMY), defined in ISO

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