Improvement to EN ISO 52016-1:2017 hourly heat transfer through a wall assessment: the Italian National Annex

Abstract

Energy efficiency in buildings is a crucial topic to reduce the worldwide energy consumptions and fight the climate change. A key aspect is the assessment of the heat transfer through the opaque elements of the building envelope. One way to do it is modelling the element as a resistors and capacitors network (RC), using the thermal-electrical analogy. In the hourly dynamic method introduced by the recently published standard EN ISO 52016-1:2017, each opaque element is modelled with a RC-network. Italy has implemented in the National Annex A of the Standard an alternative methodology for the definition of the number of nodes and position, based on the detailed layers' characteristics. In this work, the two methods are described and compared with the exact analytical solution for three cases under sinusoidal boundary conditions. In all the test cases, the results obtained applying the Italian Annex provide better results, with reduction of the error on the internal flux amplitude between 14% and 67%. In addition, it has been verified that the Italian model is actually well tuned. Indeed, the amplitude of the external flux is overestimated on average of only 3%, and the phase differences are limited (maximum ±1 hour). Lastly, also the effect of the change of number of nodes, and to move the nodes from the layers' mid-point to the interface, have been analysed, but none of these strategies were demonstrated able to increase significantly the model accuracy, which can be obtained only reducing the calculation timestep.

Accuracy of Simplified Modelling Assumptions on External and Internal Driving Forces in the Building Energy Performance Simulation

“…This approach allowed the authors to detect the use of constant surface heat transfer coefficients as the main cause of deviation in the outcomes. The effect of single assumptions on the simulation results have been so far investigated by Mazzarella et al [21]. The authors applied an analytical single process approach for the validation of the EN ISO 52016-1 conduction heat transfer model and of an improved version of this, introduced in the Italian National Annex of the standard.…”

Verification of Energy Usage Based on Standard Building Model Development of Low‐Rise Residential Buildings in South Korea

“…Advances in Civil Engineering standard model. Nonetheless, it provides variables and calculation formula for evaluating energy performance in buildings [34][35][36][37]. In particular, it is possible to calculate the heating and cooling loads using the time and monthly calculation method.…”

Durum-Wheat Straw Bales for Thermal Insulation of Buildings: Findings from a Comparative Energy Analysis of a Set of Wall-Composition Samples on the Building Scale

“…To improve the current calculation method, a new and more accurate approach is provided by the EN 52016 [28], consisting of an hourly energy-calculation procedure capable of accounting for the thermal inertia of buildings' envelopes. As this new methodology is quite recent, few studies are yet found in the literature, though one such [29][30][31][32][33] performed the first energy-analysis approach based on EN 52016.…”

“…According to Annex B of the UNI EN 52016 standard, each building envelope is modelled with five nodes (plus two nodes related to indoors and outdoors), interconnected by four thermal resistances (in addition to the ones related to radiative and convective resistances) and from one to five capacitances [28,33].…”