A Discussion on Winter Indoor Hygrothermal Conditions and Hygroscopic Behaviour of Plasters in Southern Europe

Alessandra Ranesi,Paulina Faria,Rosário Veiga,Magda Posani

doi:10.3390/infrastructures7030038

Abstract

In Southern European countries, due to the specific climate, economy and culture, a permanent heating practice during winter is not widely adopted. This may have a significant effect on the performance of indoor coating materials, typically tested considering hygrothermal conditions in the range of 33–75% relative humidity (RH) and 20–25 °C, which are common in continuously heated buildings. In this study, the indoor climate of four bedrooms located in Lisbon, Portugal, was monitored under operational conditions. Based on the data monitored in the case studies, characteristic ranges of indoor hygrothermal conditions were defined and compared to those considered in standard test procedures. In addition, numerical simulations were adopted to compare the hygroscopic performance of four plasters under operational conditions observed on-site. Results show that the four rooms, intermittently heated or unheated, do not provide comfort conditions over 50% of the wintertime, with temperatures lower and RH higher than the ones recommended by the standards. The MBVs resulting from simulations (under operational conditions) are qualitatively in agreement with the MBVs obtained under standard testing conditions. Nonetheless, future studies are recommended to evaluate if standard tests are quantitatively representative of the hygroscopic performance of coating materials in the Southern European scenario.

Highlights

Publisher’s Note: MDPI stays neutralThe importance of indoor environmental quality (IEQ) is currently largely acknowledged, due to the extended amount of time people spend indoors [1]
This study aims to evaluate the indoor hygrothermal conditions in four case studies located in Lisbon (Portugal) and intends to open a discussion on the applicability of standard tests on the moisture buffering ability of building materials, in the context of Southern Europe
According to the collected data, during winter the outdoor temperature and relative humidity were in the ranges 1–26 ◦ C and 40–100% RH, respectively, with T

Summary

Introduction

Publisher’s Note: MDPI stays neutralThe importance of indoor environmental quality (IEQ) is currently largely acknowledged, due to the extended amount of time people spend indoors [1]. The study of parameters such as indoor thermal comfort [2–4], indoor air quality [5], perceived quality [6] and the correlation with human health [7] gained importance in research. In this context, increasing attention has been paid to the use of building materials [8] and hygroscopic coating systems [9,10] that can help to passively regulate indoor relative humidity (RH). To evaluate and compare the moisture buffering ability of materials, the NORDTEST protocol [15,16] is often adopted This test procedure was defined by a research group working on the specific scenario of North European countries [17] and it is based on with regard to jurisdictional claims in published maps and institutional affiliations

Objectives

Methods

Results

Conclusion