Influence of the Thermal Inertia in the European Simplified Procedures for the Assessment of Buildings’ Energy Performance

Abstract

This study aims to highlight the importance of thermal inertia in buildings. Nowadays, it is possible to use energy analysis software to simulate the building energy performance. Considering Italian standards, these analyses are based on the UNI TS 11300 that defines the procedures for the national implementation of the UNI EN ISO 13790. These standards require an energy analysis under steady-state condition, underestimating the thermal inertia of the building. In order to understand the inertial behavior of walls, a cubic Test-Cell was modelled through the dynamic calculation code TRNSYS and three different wall types were tested. Different stratigraphies, characterized by the same thermal transmittance value, composed by massive elements and insulating layers in different order, were simulated. Through TRNSYS, it was possible to define maximum surface temperatures and to calculate thermal lag between maximum values, both external and internal. Moreover, the attenuation between external surface temperatures and internal ones during summer (July) was calculated. Finally, the comparison between Test-Cell's annual energy demands, performed by using a commercial code based on the Italian standard UNITS 11300 and the dynamic code, TRNSYS, was carried out.

Evaluation of Different Urban Microclimate Mitigation Strategies through a PMV Analysis

“…Deciding which building properties to select depends on the direct observation of the site [68][69][70][71][72], while the inside temperature of indoor spaces is set to 299 K [73].…”

Maintenance and Energy Optimization of Lighting Systems for the Improvement of Historic Buildings: A Case Study

“…From a general point of view, when dealing with buildings, the energy [46][47][48][49][50][51] and maintenance [52] analyses are extremely important. For this reason, after discussing all these improvements in lighting due to the development of the post-renovation scenario, the comparison between the two scenarios is performed using the commercial software ecoCALC [37].…”

Investigating the Dynamic Thermal Behavior of Building Envelope in Summer Conditions By Means of in-Field Continuous Monitoring

“…In the European Union about the 40% of the total energy consumed in terms of primary energy is associated to buildings (Asdrubali et al, 2008), mainly for ventilation, air conditioning and humidity control purposes (Salata et al, 2014a;Tariku et al, 2015). Therefore, improving the thermal-energy performance of buildings is a point of strength within the set of measures necessary to reduce global energy demand and, consequently, environmental impact in terms of greenhouse gas emissions and air pollution (Evangelisti et al, 2014). In particular, the optimization of the performance of building envelope plays a key role in reducing the overall building thermal-energy requirement.…”

“…Accordingly, the European regulations such as the Directives 2010/31/EU (OJEU, 2010) and 2012/27/EU (OJEU, 2012) highlighted the importance of considering the specific external and internal climatic conditions while assessing the efficacy of the measures for buildings energy saving, enhancing the summer performance (Stazi et al, 2014). Furthermore, the mentioned standards underestimate the thermal inertia of the building, since the energy analysis is carried out through semi-stationary methods under steady-state conditions (Evangelisti et al, 2014). Nevertheless, more complex transient evaluation tools are needed in order to assess the effect of envelope improvements and innovative strategies on indoor comfort and energy requirements (Stazi et al, 2014), i.e., dynamic analysis methods.…”

“…The feature that characterizes the Test-Rooms compared to similar experimental fields is the use of complete envelope solutions and realistic conventional materials, e.g., terracotta bricks, cement based plasters and reinforced concrete structure, in order to represent typical configurations of existing buildings. In this way, the influence of dynamic properties of building components, such as (a) envelope reflectance (Doya et al, 2012;Revel et al, 2014), (b) thermal inertia (Evangelisti et al, 2014), or (c) walls-roof-ceiling layers position (Stazi et al, 2014;Bond et al, 2013;Kossecka and Kosny, 2002), which are neglected in regulations for building design in Italy, can be evaluated. In particular, the present study has the aim of comparing the effect of such envelope properties in the hygro-thermal behavior of the test-buildings in summer conditions.…”