Reliability Analysis and Economic Evaluation of Thermal Reflective Insulators

High-performance thermal insulators allow a dramatic reduction in the thickness of coatings, thanks to their low thermal conductivity. This study provides an overview about thermal insulation materials, with regards to heat reflective insulators in particular. Then, the numerical investigation method adopted to compute the thermal resistance associated with reflective insulators is introduced. This method has been used in turn to check the accuracy of the declared, measured performance of different, heat-reflective materials on the market. Many manufacturers of reflective insulators were available to provide information and a good agreement between the declared and expected thermal resistance has been found. The choice of a non-experimental approach is meant to check the validity of an already performed test on a reflective insulator using a predictive approach instead of standard, additional testing. Then, the insulation of five typical walls at three different sites in Italy has been simulated, showing that most of heat-reflective materials cannot achieve the maximum required transmittance. Interstitial condensation is likely to occur in specific cases, also because of the aluminum layers inside. The economic analyses showed comparable costs for both heat reflective and traditional insulators, and their cost effectiveness needs to be evaluated case by case

A proof of the Hamiltonian Thom isotopy Lemma

In this note we present a complete proof of the fact that all the submanifolds of a one parameter family of compact symplectic submanifolds inside a compact symplectic manifold are Hamiltonian isotopic

A proof of the Hamiltonian Thom Isotopy Lemma

In this note we present a complete proof of the fact that all the submanifolds of a one parameter family of compact symplectic submanifolds inside a compact symplectic manifold are Hamiltonian isotopic.Comment: arXiv admin note: substantial text overlap with arXiv:2212.1027

Optimal Regulation Criteria for Building Heating System by Using Lumped Dynamic Models

Abstract Energy efficiency of buildings has gained an important role with respect to possible energy saving policy measures, mainly for space heating demand which represents the dominant energy end-use. The present contribution addresses the problem of estimating building heating energy consumptions by using numerical models able to simulate the dynamic interaction between the building and the heating system. A dynamic numerical code in the Engineering Equation Solver (EES) is developed to simulate both building and heating system and the influence of heating system regulation criteria on different parameters (mainly energy saving and internal comfort) is investigated in an optimization perspective

Thermal bridge correction in energy refurbishing of civil existing buildings according to European minimum energy targets by 2020:pratical application to one case study,

The actual effort in Europe is refurbishing old buildings, improving their energy performances according to Kyoto protocol 20-20-20 (down 20% CO2 emissions, down 20% energy need increase of 20% renewable energies by 2020 ) and next Paris 2015 conference on climate Changes. Insulation is the first goal to achieve. In urban contest often is not possible to increase wall thickness with insulation covering because of the limited available distances among buildings and property border reasons. A possible technique of insulation is to fill the cavity wall air layer which is present in many existing buildings with granular isolated material. This type of work doesn\u2019t improves thermal performance on thermal bridges with risk of mould grow. The purpose of the present paper is to study the optimal thickness and length of the correction to apply on the thermal bridge. A 2d model has been built to study the thermal behaviour of the complex structure. The paper presents the result of the study conducted by the author on the influence of thermal bridges in the case insulation in existing buildings in the inner part of the peripheral wall and the possible practical application in case, of thin existing layers available, for correction in accordance with the new targets of the European decree of minimum requirements in refurbished buildings by 2020. It is shown the importance of the extension of the thermal correction overlapping the insulation in the cavity rather than its thicknes

Test per Tecnici Competenti in Acustica

Il presente testo \ue8 rivolto a tutti coloro, professionisti e non, che frequentano per la prima volta il campo dell\u2019acustica. Sotto forma di quiz teorici e numerici viene proposto un percorso di formazione ed approfondimento dei concetti chiave della disciplina, anche in funzione dell'esame da sostenere per diventare Tecnici Competenti in Acustica ai sensi del Decreto Legislativo n. 42 del 17/02/2017. Partendo dagli aspetti introduttivi di base, si prosegue con le tre principali tematiche: acustica ambientale, degli edifici e della sicurezza sul lavoro, con particolare attenzione alla legislazione e alla normativa vigenti. L'acustica ambientale \ue8 finalizzata alla riduzione dell'inquinamento acustico nell'ambiente esterno e alla valutazione dell'impatto acustico di nuove opere infrastrutturali o edilizie. L'acustica edilizia si occupa di garantire un adeguato isolamento degli edifici dal rumore proveniente da o diretto verso l'esterno ed altri edifici confinanti, nonch\ue9 dal rumore di origine impiantistica, oltre che di assicurare una corretta distribuzione del suono all'interno di ambienti caratterizzati da particolari destinazioni d'uso, quali l'ascolto della musica e della parola. L'acustica relativa alla valutazione del rischio rumore negli ambienti lavorativi \ue8 finalizzata alla salvaguardia dei lavoratori occupati in attivit\ue0 caratterizzate da una significativa esposizione al rumore. I test sono prodotti dal lavoro di squadra di autori provenienti dall\u2019ambito accademico e professionale, con esperienza nel campo della formazione e dell\u2019aggiornamento. Ci\uf2 ha permesso di dare un taglio estremamente applicativo al libro, senza rinunciare alle nozioni teoriche di base. Le soluzioni sono presentate in entrambe le forme tabellata e ragionata, con lo svolgimento degli esercizi e numerosi spunti di riflessione ed approfondimento sulle tematiche pi\uf9 rilevanti nel campo dell\u2019acustica. Si ringraziano fin d'ora quanti, studenti o professionisti, dopo aver letto il presente manuale, effettueranno apprezzamenti, consigli di miglioramento o critiche costruttive, anche segnalando eventuali sviste o errori. Gli interessati sono invitati a mettersi in contatto con gli autori in modo tale che le osservazioni possano essere prese in considerazione in caso di riedizione o di ampliamento dell'opera

Energy Audit of a \u201860 Residential Building Served by a Steam Heating System

The present paper deals with an energy audit of a residential building served by two central systems for heating and domestic hot water production respectively. The heating service is obtained by a low pressure and natural circulation steam system. These types of plants show lots of problems: low energy efficiency due to the high operating temperatures and to the poor insulation of pipes, lack of comfort within the building units due to the high inertia and to the inefficiency of the regulation. In order to calculate the energy performance of the building, a model based on the UNI/TS 11300 standards and validated on the basis of the real consumption has been used. The current building state has been simulated and different actions to improve energy performance have been examined. For each of them, using cost-benefit analysis, the simple payback time has been rated

L'incidenza del coefficiente medio globale di scambio termico per trasmissione nelle ristrutturazioni importanti di primo e secondo livello alla luce del DM 26/06/2015

Vengono presentate alcune considerazioni circa l'applicazione del recente DM 26/06/2015 riguardante i requisiti minimi da rispettare in materia di risparmio energetico nell'edilizia. In particolare vengono discusse, con riferimento alle ristrutturazioni importanti di primo e secondo livello, le problematiche riscontrate e le possibili soluzioni pratiche per il rispetto dei limiti imposti sul coefficiente medio globale di scambio termico per trasmissione H'T. Dall'analisi di alcuni semplici casi di studio, si deduce che i limiti imposti sono spesso di difficile applicazione nelle ristrutturazioni degli edifici esistenti