Pietro Stefanizzi

Experimental Investigation on Lightweight and Lime Stabilized Earth Composites

An experimental investigation on different clay-based plasters with straw (lightweight plaster) and lime (stabilized plaster) was carried out. The aim of the study was to increase the knowledge on earthen materials in terms of final performance in building applications. In the first part of the study different thermal and hygric parameters were measured: thermal conductivity, specific heat capacity, sorption capacity, water vapour permeability. Furthermore, in order to test the suitability of the unfired clay as mortar, an analysis on the mechanical strengths was carried out, measuring the compressive and the bending strength. The results show, on one hand, that when straw is added to the basic mixture a significant improvement of the sorption capacity occurs, while, the addition of lime enhances the thermal properties. On the other hand, no significant improvement of mechanical strengths can be appreciated when using these additives. Nomenclature

Straw Based Materials for Building Retrofitting and Energy Efficiency

This work aimed to measure the hygrothermal properties of some different straw-based mix that could be used as building materials (panels or bricks). Straw is used to improve the hygrothermal performances of the final products. Several mix were produced adding different percentages of straw. Two types of fibers were used: wheat straw and bean straw. The results indicated that increasing the percentages of straw greater effects on the change of thermal properties can be appreciated. Furthermore the results also reveal that the specimen produced by water glass and straw, without binder, has the highest values of hygric properties and thermal insulation.

Soil Based Building Materials for Energy Efficiency

A descriptive analysis and some definitions of clays are provided at the beginning of the chapter; after that the most common earthen materials are introduced. A list of the most common worldwide building techniques and physical parameters is provided. The main building regulations are reported in a brief summary.At the end of the chapter, according to the main important studies, hygrothermal and physical performances of earthen building materials are discussed.

Visual and energy performance of glazed office buildings in Mediterranean climate

The present study is aimed at analyzing to which extent the type of window glazings affects the energy performance and the indoor comfort of buildings in Mediterranean climate. An office building located in Bari, southern Italy, was assumed as a case study due to its largely transparent envelope. Different glazings were applied to the building: a reflective window, a solar control window with low-E properties and an electrochromic window. The proposed solutions were compared with the existing windows, supposed to be ordinary clear double glazings. Thermal simulations, daylight analysis and economic evaluations were carried out to obtain an all-comprehensive view of the issue, involving energy parameters and comfort indicators. Reports pointed out that on an annual basis the main cost is entailed by cooling needs. The electrochromic window reduces the annual electricity demand for air conditioning by 17%, but its installation costs were found to be not sustainable with reference to the envelope life span. The low-E solar control window succeeds in ensuring the best thermal comfort indoors and in reducing the cost of air-conditioning by nearly 15%, as well as performing slightly better than the reflective glass in terms of electricity demand for lighting.

Fundamental Parameters of Heat and Moisture Transfer for Energy Efficiency in Buildings

Heat and moisture transfer in a room is critical for the indoor comfort.This first chapter introduces the basic concepts of heat and moisture transfer in buildings, dealing with the main theoretic fundamentals.It focuses on the most common parameters, used to analyze heat and moisture transfer in buildings.Furthermore this section takes into account a numerical model to calculate the simultaneous heat and moisture transfer in building materials.It is demonstrated that both the microstructure and physical parameters, e.g. density and porosity, may influence greatly the hygrothermal behaviour of the building materials. This is the reason why this chapter also gives prominence to the porous materials.