Abstract Buildings are accountable for around 40% of the European energy consumption. Installing thermal insulation is an effective approach to improve the energy efficiency of the building envelope. Internal insulation is often the only renovation option in the case of historic buildings with worth-preserving masonry facades. However, it can lead to several moisture problems related to the rain load, such as mould growth, wood rot and frost damage. Hydrophobizing the facade reduces water absorption by the materials, while decreasing their drying rate, threatening the desired outcome. The paper evaluates the impact of hydrophobization when combined with internal insulation. To understand the hygrothermal effect of hydrophobization on internally insulated walls, it is important to examine how the hydrophobic layer of the masonry can be accurately modeled and how the hygrothermal response of the wall configuration changes after treatment. A significant increase in the thermal conductivity of capillary saturated samples compared to dry samples was experimentally measured. The hydrophobic model is able to predict the hygrothermal behavior of the hydrophobized brick, using experimental results from water uptake and drying tests as reference, as well as in the component level, using as reference relative humidity and temperature measurements in a mock-up wall. The current results indicate that hydrophobization contributes positively towards a moisture-safe construction with reduced heat losses when applied before or in parallel with internal insulation. These findings confirm that hydrophobization can successfully be combined either with a capillary-active or a water-vapor-tight internal insulation system, providing a moisture-safe energy renovation of building enclosures.

中文翻译：

---

疏水化和内部绝缘砌体墙的湿热性能 - 基于实验结果模拟疏水化的影响

摘要 建筑约占欧洲能源消耗的 40%。安装隔热材料是提高建筑围护结构能源效率的有效方法。对于具有值得保护的砖石外墙的历史建筑，内部隔热通常是唯一的翻新选择。然而，它会导致一些与雨水有关的潮湿问题，例如霉菌生长、木材腐烂和霜冻损坏。对立面进行疏水化处理会减少材料的吸水率，同时降低它们的干燥速度，从而威胁到预期的结果。该论文评估了疏水化与内部绝缘结合时的影响。要了解疏水化对内部隔热墙的湿热效应，重要的是要检查砌体的疏水层如何准确建模，以及墙体结构的湿热响应在处理后如何变化。与干燥样品相比，毛细管饱和样品的热导率显着增加，通过实验测量。疏水模型能够预测疏水化砖的湿热行为，使用吸水和干燥测试的实验结果作为参考，以及在组件级别，使用模型墙中的相对湿度和温度测量作为参考。目前的结果表明，在内部绝缘之前或与内部绝缘并行应用时，疏水化对防潮结构有积极贡献，减少了热损失。