Comparative Analysis of the Use of Thermal Insulation Materials Depending on Climatic Conditions and Comfort Microclimate Supply Systems

The use of thermal insulation materials to reduce the heating and cooling demand of the building in order to provide energy efficiency is the main solution. But there is a wide range of these products on the market and, therefore, the choice and application of these materials is a rather difficult task, since many factors must be taken into account, such as environmental safety, cost, durability, climatic conditions, application technology, etc. Basically, comfort microclimate systems are designed based on normative standards, where the thickness of the thermal insulation material is selected depending on the required heat transfer resistance. These values are calculated taking into account climate conditions, that is the duration of the heating period, as well as taking into account sanitary and hygienic requirements. This article discusses the thermal performance of building materials, and also provides a comparative analysis of the use of thermal insulation materials depending on climatic factors and on the system providing comfort microclimate. Based on the calculations by mathematical modeling and optimization, it is advisable to choose the thickness of the thermal insulation, taking into account the capital and operating costs of the comfort microclimate systems. Comparing the optimization data with the normative one, the energy efficiency of the building increases by 50-70% when applying the optimal thickness of the thermal insulation layer, and when the thermal insulation layer is increased, the thermal performance of the enclosing structures has improved by 30%, which contributes to energy saving.

The Influence of the Properties of Thermal - Insulation Materials on the Thermomoist Indicators of a Building

One of the basic measures of energy efficiency in residential buildings is the reduction of heat and coolant pressure, when external structures - walls, ceilings - contain thermal insulation material, as a result of which heat and cold losses are reduced, as a result of air-and moisture permeability. Their number is largely determined by the climatic zone of the building, construction, sources of heat and cold, fuel and electricity prices in this region. In such practice, first of all, attention is paid to the problems of the optimal thickness of the thermal insulator, the installation location, since improper installation in the structure can cause water condensation, which will lead to partial wear of the structure, since the properties of reinforced-concrete layers will deteriorate. This concerns the peculiarities of carrying out thermal insulation works and their necessity both in under construction and in buildings in use. However, even in these conditions, when discussing the thermal effect of thermal insulation on structures, due attention is not paid to individual structures, especially walls, moisture problems. Consideration of insulators with more or less efficient energy and heat engineering characteristics, when it was found that there is a significant difference between their results and effects, aroused particular interest in the study of the problem. This is followed by a study of the influence of the presence of thermal insulation in the structure on the cold load required for cooling, revealed a pattern of cost changes in the case of insulating materials with more or less properties - foam.

Reed as a Thermal Insulation Material: Experimental Characterisation of the Physical and Thermal Properties

The building sector plays a significant role in reducing global energy use and carbon emissions. In the European Union (EU), the building stock represents 40% of total energy use and in which cooling and heating systems represent over 50%. Portugal is one of the EU countries where the consequences of energy poverty are most evident due to the families' financial inability to adequately climate their homes. The reasons are several, but they are mainly linked to buildings' poor passive thermal performance, resulting from inadequate adaptation to the climatic context and reduced thermal insulation. Thus, it is necessary to develop solutions to increase buildings’ thermal performance and reduce their potential environmental impact, which arises mainly from the significant use of active systems. In this sense, natural building materials are a promising solution, reducing energy use and carbon emissions related to buildings. This research studies the potential use of reed found in Portugal (Arundo donax) as a thermal insulation material. Its physical characterisation and the influence of geometry configuration on its thermal performance are evaluated. Its durability was studied too. Reed stalks were used to carry out the physical and durability tests. A reed board (150 x 150 mm) was built, and its thermal performance was tested in a hotbox. According to the results, the characteristics of reeds found in Portugal make it suitable to be used as a building material. Furthermore, regardless of the configuration studied, the reeds have a satisfactory thermal performance to be used as thermal insulation, under the requirements defined by Portuguese thermal regulation, Re ≥ 0.30 (m2.oC)/W. There is a trend to the mould growth in the reed, but only under favourable conditions. Additionally, considering the abundance of reed throughout the Portuguese territory, this is an eco-friendly and low-cost option that gathers all requirements to be more used in the construction market.

Improved Magnesium Cement for Durable Hemp Composite Boards

Hemp concrete is a well-known bio-based building material, but due to its relatively low compressive strength is mainly used as an insulation material with a load-bearing wooden frame. There are possibilities to expand hemp concrete application in construction by substituting traditional lime with magnesium cement. Magnesium oxychloride cement is a material already known for some time and nowadays used in building board production. Strength, lightweight, ease of use are advantages that highlight relatively new magnesium oxychloride type boards compared to traditional sheeting materials such as plywood, gypsum plasterboard and fibre-cement board. Therefore, similar parameters are thought to be reached by producing magnesium oxychloride hemp board. In this work, magnesium cement water resistance was studied and possibilities to improve it was examined by adding fly ash and nanosilica. Among the nanomaterials used in building materials, nanosilica has gained significant interest by performing a beneficial effect in improving the mechanical properties of concretes. In addition, due to its ultrafine size and high chemical reactivity, the performance of nanosilica is much better with a lower amount of admixture required. Results show that applied nanosilica slightly reduced the compressive strength of magnesium cement in a dry state, but at the same time significantly increased its water resistance. Hemp magnesium oxychloride cement board prototype samples were produced and demonstrate promising results for further manufacturing of hemp composite boards.

Physical Properties and Hygrothermal Behavior of Mycelium-Based Composites as Foam-Like Wall Insulation Material

This research aims to study mycelium-based composites (MBC) by assessing their performance as foam-like wall insulation material. Various substrates have been selected to get optimized performance of the composite. Results showed that a prolonged growing period arose a denser mycelium outer layer in MBC, which rendered better water resistance due to the hydrophobicity of mycelium. Thermal conductivity and mechanical properties are highly dependent on substrate choices than other parameters of MBC, which coincided with the literature. Additionally, influences of accelerated aging test and moisture buffer capacity of MBC were first studied in this research. The results indicated that MBC not only maintained good functional performance after the accelerated aging test (i.e. drying and wetting cycles) but also constituted good moisture buffer capacity. This means that MBC has key material essences to apply as internal wall insulation material and become one of the layers in vapor-permeable building envelope systems to passively regulate indoor relative humidity and thermal comfort.

Low density rigid polyurethane foam incorporated with renewable polyol as sustainable thermal insulation material

Palm olein-based polyol (PP) was used as a partial replacement for commercial sucrose/glycerine initiated polyether polyol (GP) for the production of low density rigid polyurethane foams (RPUFs). The hydroxyl value (OHV) of the GP was 380 mg KOH/g, whereas the OHV for PP was 360 mg KOH/g. The RPUFs were prepared by replacing the GP with PP up to 50 parts per hundred parts of polyols (pph). Characterisation of the RPUFs, including density, compressive strength and strain, cell morphology and thermal conductivity ( k-value), were conducted. The dimensional stability of the foams was also evaluated. The study showed improvement in the compressive strength and strain for palm-based RPUFs with the incorporation of up to 30 pph PP as compared to GP foams. The lowest k-value (0.0232 W/m.K) of RPUF with density below 30 kg/m3 was obtained with the incorporation of 10 pph PP. This was due to the smallest and uniform pore size distribution observed using SEM images. The dimensional stability of the RPUF prepared from PP was within the acceptable range. Thus, the RPUFs made from PP are potential candidates to be used as insulation for refrigerators, freezers and piping.

Bio-Based Products

Communicating the related environmental benefits of bio-based products to consumers represents a key component of their market uptake. In this regard, the use of ecolabels ISO 14024 Type I play a crucial role. This article identifies and analyzes different criteria proposed by ecolabels for conducting a sustainability assessment of bio-based products considering its entire lifecycle. A comparison of the selected criteria with existing indicators ruled out by the SDGs is proposed. Through expert consultation, the suitability of existing ecolabel criteria for bio-based products has been tested for four applications of biobased products: food packaging from PLA; biobased automotive components; bio-based mulch film; and bio-based insulation material.