Retrofit strategies applied to a tertiary building assisted by

Energy Procedia, 2015

This paper describes an integrated passive design approach to reduce the heating demand for an existing tertiary building through an improved thermal envelope design and high efficiency windows. The numerical optimization has been performed dynamically by means of TRNSYS simulation tool. The model here treated is aimed at the determination of the thermal demand with reference to a tertiary building in Italy, which it is supposed to be located in two different climatic zones, i.e., Bologna and Rome. The final part of the paper deals with the investment costs analysis, applied to each retrofitting scenario: it has been demonstrated that the simple payback period results to be strongly affected by the climatic zone of the building location and by the national policies of fiscal incentives.

The construction sector is responsible for high levels of energy consumption and for environmental impacts during the life cycle of a building all over the world. Therefore, sustainability has become an inherent topic in building design, in response to the stringency of natural resources and to performance. A way to design sustainable buildings is taking advantage of the available natural resources on site to reduce the needs for artificial conditioning. Requirements of performance have become more restrictive and existing buildings must conform to them. This is possible through a retrofit process which improves their performance to comply with actual requirements, besides improving the comfort of their occupants. Most of the developed procedures for retrofitting analysis take into account only energy consumption and emission of pollutants. The aim of this paper is to demonstrate a procedure to help designers and decision makers on choosing the best retrofit strategy considering energy consumption, thermal comfort and the cost-benefit of these strategies. A computational model of a building located at the State University of Campinas was developed to simulate different passive strategies and the results obtained are presented in an easy-to-use chart as part of the procedure.

Indoor and Built Environment, 2018

Upgrading the energy efficiency of existing buildings is a well-known issue around the globe. Given the very low renewal rate of the building stock, thermal retrofit of the existing buildings seems to be a good solution to improve the environmental performance of the building sector. Several studies have acknowledged the lack of knowledge, experience and best-practice examples as barriers in thermal retrofit of existing buildings. Therefore, this study has focused on developing recommendations on the most effective and feasible retrofitting techniques for existing buildings and performing financial analysis of initial investment vs return based on the quantitative results of the energy modelling. Thermal comfort modelling software FirstRate5 has been used to simulate the annual heating and cooling energy consumption of nine benchmark buildings through a range of retrofitting techniques. Dwellings of varying construction materials including weatherboard, cavity brick and brick veneer have been simulated to improve accuracy. Examining seven different thermal retrofitting options in this study, it has become apparent that there is significant heating and cooling energy reduction, with payback period of less than three years, by implementing two options of the examined retrofitting cases to existing residential dwellings.

Energies, 2021

Retrofitting heritage buildings for energy efficiency is not always easy where cultural values are highly concerned, which requires an integrated approach. This paper aims to assess the potential of applying passive retrofitting scenarios to enhance indoor thermal comfort of heritage buildings in North Africa, as a hot climate, little attention has been paid to retrofit built heritage in that climate. A mixed-mode ventilation residential building in Cairo, Egypt, was selected as a case study. The study combines field measurements and observations with energy simulations. A simulation model was created and calibrated on the basis of monitored data in the reference building, and the thermal comfort range was evaluated. Sets of passive retrofitting scenarios were proposed. The results (based on the ASHRAE-55-2020 adaptive comfort model at 90% acceptability limits) showed that the annual thermal comfort in the reference building is very low, i.e., 31.4%. The application of hybrid passive retrofitting scenarios significantly impacts indoor thermal comfort in the reference building, where annual comfort hours of up to 66% can be achieved. The originality of this work lies in identifying the most effective energy measures to improve indoor thermal comfort that are optimal from a conservation point of view. The findings contribute to set a comprehensive retrofitting tool that avoids potential risks for the conservation of residential heritage buildings in hot climates.

Energies

The building sector greatly contributes to energy consumption and Greenhouse Gas emissions, relating to the whole building life cycle. Boasting a huge building heritage of historical and architectural value, Europe faces challenging retrofit perspectives, as the potential for high energy efficiency has to be exploited while preserving the buildings’ original characteristics. The present work aims to feature the influence of a passive strategy on a heritage building in a mild climate. As historical its façade cannot be modified, its large glazing areas involve multiple issues, such as an increase in the heating (QH) and cooling (QC) energy demands and the risk of thermal discomfort. Thus, window replacement was proposed for retrofitting. A dynamic simulation model in TRNSYS was validated with experimental data collected by the continuous monitoring of walls of different thicknesses and orientations. Solutions from replacement with Double Glazing Units (DGUs) with improved thermal ins...

The study investigates the potential of coupling natural ventilation and thermal storage systems to improve hygrothermal comfort and reduce energy consumption during summer season in an existing building in the Mediterranean. It aims at bridging the knowledge gap between designers, researchers and building scientists, fostering a multidisciplinary approach and promoting numerical simulation of the energy performance of buildings within architectural professional practice. The study analyses the interaction between six natural ventilation systems (single sided ventilation through facade openings; cross ventilation through facade openings, inlet wind tower, thermal chimney, evaporative cool tower, earth pipes) and with two thermal storage typology (heavy and medium-light) within four strategic Italian location (Rome, Naples, Messina and Catania). For each interaction we perform a numerical dynamic simulation of indoor comfort, indoor air quality and energy consumption during the summe...

Around 30% of the European building stock was built before 1950, when no regulations about energy efficiency were in force. Since only a small part of them has been renovated by now, the energy performance of this building stock is on average quite poor, resulting in a significant impact on the energy balance of European countries, as confirmed by data published by ISTAT (Italian National Statistical Institute). However, energy retrofit in historic edifices is a quite demanding issue as any intervention must take into account the need to preserve existing building materials and appearances while also allowing reversibility and low invasiveness. As an example, in these buildings it is not possible to apply an ETICS (External Thermal Insulation Composite System), since this would alter the historic and architectural value of the façade. On the other hand, internal insulation would have the drawback of reducing the net useful floor area, which also implies a loss of economic value. Moreover, internal insulation may induce overheating risks and mold formation. In this paper, all these issues are investigated with reference to an existing historic building located in southern Italy, showing that a retrofit strategy aimed at energy savings and cost-effectiveness is still possible if suitable materials and solutions are adopted.

2015 IEEE International Conference on Industrial Engineering and Engineering Management (IEEM), 2015

In order to reduce energetic consumption, buildings may be retrofitted by covering them with an insulation envelope composed of rectangular parameterizable panels. In such scenario different envelopes configurations are possible to cover the same building. Thus, a crucial aspect of the retrofit is to select, among potential solutions, those ones providing good thermal performance at reasonable cost. In this paper are discussed which characteristics are part of a panels-made envelope, how to compute their performance and associated cost, and a bicriteria function evaluating the envelope. We compute thermal and cost estimations with respect to the spatial positioning of panels configuring the layout. The aim of our contribution is to assist architects in their decision-making process. Conception and implementation of the thermal retrofit are then supported by our estimations.

Journal of Cleaner Production, 2018

Building retrofits are often motivated by the desire to improve the energy efficiency of a building. However, environmental burdens associated with additional materials used to accomplish energy efficiency are not usually taken into account. Life-cycle assessment (LCA) and life-cycle cost assessment (LCCA) approaches have been extensively applied to analyze building environmental impacts and costs. However, LCA and LCCA are time-consuming and resource-intensive and are usually performed in late design stages when significant reduction in total life-cycle impacts is costly to achieve. The aim of this article is to present an integrated, streamlined LCA-LCCA approach to building retrofits to provide feedback on environmental impacts and costs at early-design stage decisions. We propose a framework that fully integrates a streamlined embodied LCA, statistical-based operational energy, and cost models. This approach incorporates uncertainty to address the lack of information in early design stages by using the building attribute to impact algorithm approach, which includes structured under-specification and probabilistic triage. An automated process enables several scenarios to be assessed and compared as a means of better informing designers of the relative environmental impact of materials and dimensioning choices. It is demonstrated that by selecting very few attributes and then comparing several options, robust retrofit decisions can be made in early-design stages, thereby promoting a reduction in environmental impacts and costs. 1 Introduction Building retrofits can promote a significant reduction in the environmental load and operating costs of the European building stock (European Comission, 2012). The European Commission established a long-term objective of decreasing the CO2-emission levels for the building sector by 88-91%, compared to 1990 levels, to be implemented by 2050. In order to achieve this target, which is also a prerequisite for meeting other EU economic and climate goals, the EU

Energy Procedia, 2014

With the adoption of the recast EPBD in 2010, EU Member States faced new tough challenges, moving towards new and retrofitted nearly-zero energy buildings by 2020 and the application of a cost-optimal methodology for setting minimum requirements for both the envelope and the technical systems. Attention often is focused on building envelope technologies however nowadays technical systems can be a powerful instrumental factor in achieving high levels of energy efficiency. Thermal systems producing heating and cooling have higher investment costs but it is possible to demonstrate that in a long term they are cost effective related with traditional high efficient technologies. Refurbishment and energy retrofitting in residential buildings is frequently approached with standard and traditional technologies preventing the penetration of different but already consolidated solutions. The paper shows the technical and economical comparison between three technical systems (gas boiler, ASHP and GSHP) as option to replace an oil boiler after a whole refurbishment of an apartment residential building in Milan, Italy. The retrofitting of the envelope was standard nevertheless the most innovative choice was on thermal system.