Energy Performance and Indoor Comfort of a 1930s Italian School Building: a Case Study

In the line of pursuing better energy efficiency in human activities that would result in a more sustainable utilization of resources, the building sector plays a relevant role, being responsible for almost 40% of both energy consumption and the release of pollutant substances in the atmosphere. For this purpose, techniques aimed at improving the energy performances of buildings’ envelopes are of paramount importance. Among them, green roofs are becoming increasingly popular due to their capability of reducing the (electric) energy needs for (summer) climatization of buildings, hence also positively affecting the indoor comfort levels for the occupants. Clearly, reliable tools for the modelling of these envelope components are needed, requiring the availability of suitable field data. Starting with the results of a case study designed to estimate how the adoption of green roofs on a Sicilian building could positively affect its energy performance, this paper shows the impact of this technology on indoor comfort and energy consumption, as well as on the reduction of direct and indirect CO2 emissions related to the climatization of the building. Specifically, the ceiling surface temperatures of some rooms located underneath six different types of green roofs were monitored. Subsequently, the obtained data were used as input for one of the most widely used simulation models, i.e., EnergyPlus, to evaluate the indoor comfort levels and the achievable energy demand savings of the building involved. From these field analyses, green roofs were shown to contribute to the mitigation of the indoor air temperatures, thus producing an improvement of the comfort conditions, especially in summer conditions, despite some worsening during transition periods seeming to arise.

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Measured and Simulated Energy Use in a Secondary School Building in Sweden—A Case Study of Validation, Airing, and Occupancy Behaviour

Energies ◽

10.3390/en13092325 ◽

2020 ◽

Vol 13 (9) ◽

pp. 2325 ◽

Cited By ~ 3

Author(s):

Jessika Steen Englund ◽

Mathias Cehlin ◽

Jan Akander ◽

Bahram Moshfegh

Keyword(s):

Secondary School ◽

Energy Use ◽

Field Measurements ◽

Energy Performance ◽

Hot Water ◽

Space Heating ◽

School Building ◽

Efficiency Measures ◽

The 1960S

In this case study, the energy performance of a secondary school building from the 1960s in Gävle, Sweden, was modelled in the building energy simulation (BES) tool IDA ICE version 4.8 prior to major renovation planning. The objectives of the study were to validate the BES model during both occupied and unoccupied periods, investigate how to model airing and varying occupancy behaviour, and finally investigate energy use to identify potential energy-efficiency measures. The BES model was validated by using field measurements and evidence-based input. Thermal bridges, infiltration, mechanical ventilation, domestic hot water circulation losses, and space heating power were calculated and measured. A backcasting method was developed to model heat losses due to airing, opening windows and doors, and other occupancy behaviour through regression analysis between daily heat power and outdoor temperature. Validation results show good agreement: 3.4% discrepancy between space heating measurements and simulations during an unoccupied week. Corresponding monthly discrepancy varied between 5.5% and 10.6% during three months with occupants. Annual simulation indicates that the best potential renovation measures are changing to efficient windows, improved envelope airtightness, new controls of the HVAC system, and increased external wall thermal insulation.

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Improving building envelope performance with respect to thermal, sound insulation, and lighting: a case study

Building Acoustics ◽

10.1177/1351010x19877280 ◽

2019 ◽

Vol 26 (4) ◽

pp. 243-262

Author(s):

Shahryar Habibi

Keyword(s):

Energy Performance ◽

Building Envelope ◽

Sound Insulation ◽

Indoor Environmental Quality ◽

The Novel ◽

Existing Building ◽

Energy Retrofit ◽

Overall Evaluation ◽

Indoor Comfort

This study concerns an overall evaluation of building envelopes, for what concerns the energy, acoustic and lighting performances. It combines different topics of energy and indoor comfort, with the aim to improve the livability of an existing building (a social housing) by means of a comprehensive retrofit of their envelopes. The novel contribution of this study is to apply some methods for energy retrofit of a building envelope in such a way that objectives are achieved within the state-of-the-art combination simulation, optimization approaches, and equations describing the calculations of sound insulation in buildings. The results showed that properties of building envelope like the value of transmittance of the glass window and thermal properties of materials have an impact on indoor environmental quality and energy performance.

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Green Wall Design Approach Towards Energy Performance and Indoor Comfort Improvement: A Case Study in Athens

Sustainability ◽

10.3390/su12093772 ◽

2020 ◽

Vol 12 (9) ◽

pp. 3772

Author(s):

Margarita-Niki Assimakopoulos ◽

Rosa Francesca De Masi ◽

Filippo de Rossi ◽

Dimitra Papadaki ◽

Silvia Ruggiero

Keyword(s):

Energy Performance ◽

Building Envelope ◽

Design Approach ◽

Single Family ◽

Sustainable Improvement ◽

Energy Needs ◽

Living Wall ◽

Building Level ◽

Indoor Comfort

In the 21st century, sustainable development is high on the international agenda, with the implementation of green walls contributing significantly to achieving environmental and social benefits, mainly in the frame of sustainable improvement of the building sector. The installation of a greening system can provide engineered solutions for stormwater management and climate change mitigation at both the urban and building level. This facilitates improving indoor comfort conditions and reducing energy needs. In order to improve the features of products and to facilitate the implementation of a proper technical standard, this paper proposes a critical bibliographic analysis of more recent scientific works. Moreover, by means of a numerical model of an existing single-family apartment, placed in the Mediterranean climate zone, a building envelope refurbishment with a living wall is carried out. A parametric analysis provides evidence for the application of different plants’ types and insulation materials. The results are analyzed considering the energy needs, the thermo-hygrometric comfort, and the outdoor surface temperature variation of the building envelope, emphasizing that a multi-criteria design approach is needed for green vertical systems. The paper provides data and an approach useful for designers and researchers in the evaluation and optimization of the performance of greening systems.

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Indoor Climate Performance in a Renovated School Building

Energies ◽

10.3390/en14102827 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2827

Author(s):

Pavla Mocová ◽

Jitka Mohelníková

Keyword(s):

Indoor Environment ◽

Natural Ventilation ◽

Carbon Dioxide Concentration ◽

Heating System ◽

Climatic Conditions ◽

School Building ◽

Ventilation Strategy ◽

Indoor Climate ◽

Microbiological Testing ◽

Indoor Comfort

Indoor climate comfort is important for school buildings. Nowadays, this is a topical problem, especially in renovated buildings. Poorly ventilated school classrooms create improper conditions for classrooms. A post-occupancy study was performed in a school building in temperate climatic conditions. The evaluation was based on the results of long-term monitoring of the natural ventilation strategy and measurements of the carbon dioxide concentration in the school classroom’s indoor environment. The monitoring was carried out in an old school building that was constructed in the 1970s and compared to testing carried out in the same school classroom after the building was renovated in 2016. Surprisingly, the renovated classroom had a significantly higher concentration of CO2. It was found that this was due to the regulation of the heating system and the new airtight windows. The occupants of the renovated classroom have a maintained thermal comfort, but natural ventilation is rather neglected. A controlled ventilation strategy and installation of heat recovery units are recommended to solve these problems with the classroom’s indoor environment. Microbiological testing of the surfaces in school classrooms also shows the importance of fresh air and solar radiation access for indoor comfort.

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Neighborhood Energy Modeling and Monitoring: A Case Study

Energies ◽

10.3390/en14123716 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3716

Author(s):

Francesco Causone ◽

Rossano Scoccia ◽

Martina Pelle ◽

Paola Colombo ◽

Mario Motta ◽

...

Keyword(s):

High Performance ◽

High Efficiency ◽

Early Stage ◽

Energy Performance ◽

Monitoring Plan ◽

Performance Targets ◽

Carrier Energy ◽

Zero Carbon ◽

Energy Grid

Cities and nations worldwide are pledging to energy and carbon neutral objectives that imply a huge contribution from buildings. High-performance targets, either zero energy or zero carbon, are typically difficult to be reached by single buildings, but groups of properly-managed buildings might reach these ambitious goals. For this purpose we need tools and experiences to model, monitor, manage and optimize buildings and their neighborhood-level systems. The paper describes the activities pursued for the deployment of an advanced energy management system for a multi-carrier energy grid of an existing neighborhood in the area of Milan. The activities included: (i) development of a detailed monitoring plan, (ii) deployment of the monitoring plan, (iii) development of a virtual model of the neighborhood and simulation of the energy performance. Comparisons against early-stage energy monitoring data proved promising and the generation system showed high efficiency (EER equal to 5.84), to be further exploited.

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Decision-Making Processes in Controlling Exposure to Sunlight Supported by Simulation Tools: A Case Study in Warm Weather

Energies ◽

10.3390/en14144100 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4100

Author(s):

Mariana Huskinson ◽

Antonio Galiano-Garrigós ◽

Ángel Benigno González-Avilés ◽

M. Isabel Pérez-Millán

Keyword(s):

Decision Making ◽

Global Analysis ◽

Energy Performance ◽

Information Modeling ◽

The European Union ◽

Evaluation Tool ◽

Simulation Tools ◽

Building Information ◽

The Impact

Improving the energy performance of existing buildings is one of the main strategies defined by the European Union to reduce global energy costs. Amongst the actions to be carried out in buildings to achieve this objective is working with passive measures adapted to each type of climate. To assist designers in the process of finding appropriate solutions for each building and location, different tools have been developed and since the implementation of building information modeling (BIM), it has been possible to perform an analysis of a building’s life cycle from an energy perspective and other types of analysis such as a comfort analysis. In the case of Spain, the first BIM environment tool has been implemented that deals with the global analysis of a building’s behavior and serves as an alternative to previous methods characterized by their lack of both flexibility and information offered to designers. This paper evaluates and compares the official Spanish energy performance evaluation tool (Cypetherm) released in 2018 using a case study involving the installation of sunlight control devices as part of a building refurbishment. It is intended to determine how databases and simplifications affect the designer’s decision-making. Additionally, the yielded energy results are complemented by a comfort analysis to explore the impact of these improvements from a users’ wellbeing viewpoint. At the end of the process the yielded results still confirm that the simulation remains far from reality and that simulation tools can indeed influence the decision-making process.

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Mapping the energy poverty: a case study based on the Energy Performance Certificates in the city of Bologna

Energy and Buildings ◽

10.1016/j.enbuild.2021.110718 ◽

2021 ◽

pp. 110718

Author(s):

Kristian Fabbri ◽

Jacopo Gaspari

Keyword(s):

Energy Performance ◽

Energy Poverty ◽

The City

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UNDERSTANDING THE EMBEDDED CARBON CHALLENGES OF BUILDING SERVICE SYSTEMS

Proceedings of the Design Society ◽

10.1017/pds.2021.589 ◽

2021 ◽

Vol 1 ◽

pp. 3279-3288

Author(s):

Maria Hein ◽

Darren Anthony Jones ◽

Claudia Margot Eckert

Keyword(s):

Energy Use ◽

Cooling System ◽

Current System ◽

Energy Performance ◽

Service Systems ◽

Carbon Footprints ◽

Embodied Carbon ◽

Study Results ◽

Operational Energy

AbstractEnergy consumed in buildings is a main contributor to CO2 emissions, there is therefore a need to improve the energy performance of buildings, particularly commercial buildings whereby building service systems are often substantially over-designed due to the application of excess margins during the design process.The cooling system of an NHS Hospital was studied and modelled in order to identify if the system was overdesigned, and to quantify the oversizing impact on the system operational and embodied carbon footprints. Looking at the operational energy use and environmental performance of the current system as well as an alternative optimised system through appropriate modelling and calculation, the case study results indicate significant environmental impacts are caused by the oversizing of cooling system.The study also established that it is currently more difficult to obtain an estimate of the embodied carbon footprint of building service systems. It is therefore the responsibility of the machine builders to provide information and data relating to the embodied carbon of their products, which in the longer term, this is likely to become a standard industry requirement.

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