scholarly journals Experimental Data and Simulations of Performance and Thermal Comfort in a Typical Mediterranean House

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3311
Author(s):  
Víctor Pérez-Andreu ◽  
Carolina Aparicio-Fernández ◽  
José-Luis Vivancos ◽  
Javier Cárcel-Carrasco
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Thermal Characterization ◽  
Energy Performance ◽  
Building Stock ◽  
Energy Demands ◽  
Dwelling House ◽  
Account Standard

The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.

scholarly journals Numerical Assessment of Zebra-Stripes-Based Strategies in Buildings Energy Performance: A Case Study under Tropical Climate

Biomimetics ◽  
2022 ◽  
Vol 7 (1) ◽  
pp. 14
Author(s):  
Miguel Chen Austin ◽  
Kevin Araque ◽  
Paola Palacios ◽  
Katherine Rodríguez Maure ◽  
Dafni Mora
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Natural Ventilation ◽  
Heat Dissipation ◽  
Energy Performance ◽  
Base Case ◽  
Energy Needs ◽  
Numerical Assessment ◽  
Lower Temperature

Urban growth has increased the risk of over-heating both in the microclimate and inside buildings, affecting thermal comfort and energy efficiency. That is why this research aims to evaluate the energy performance of buildings in terms of thermal comfort (operative temperature (OP) levels, satisfied hours of natural ventilation SHNV, thermal lag), and energy efficiency (roof heat gains and surface temperatures) in an urban area in Panama City, using superficial-heat-dissipation biomimetic strategies. Two case studies, a base case and a proposed case, were evaluated using the Designbuilder software through dynamic simulation. The proposed case is based on a combined biomimetic strategy; the reflective characteristics of the Saharan ant applied as a coating on the roofs through a segmented pattern such as the Zebra’s stripes (one section with coating, and another without). Results showed that the OP decreased from 8 to 10 °C for the entire urban zone throughout the year. A reduction of 3.13% corresponding to 8790 kWh per year was achieved for cooling energy consumption. A difference of 5 °C in external surface temperature was obtained, having a lower temperature in which the biomimetic strategy was applied. Besides, it was evidenced that a contrasted-reflectivity-stripes pitched roof performed better than a fully reflective roof. Thus, the functionality of Zebra stripes, together with the reflective characteristics of the Saharan ant, provide better performance for buildings’ thermal regulation and energy needs for cooling.

The Application of Computer Simulations on one Commercial Building to Improve Energy Performance

2010 ◽  
Vol 171-172 ◽  
pp. 364-367
Author(s):  
Jia Fang Song
Keyword(s):  
Thermal Comfort ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Energy Performance ◽  
Comfort Level ◽  
Commercial Building ◽  
Simulation Tools ◽  
Output Performance ◽  
Support Software

This paper introduces the application of the TAS simulation support software to determine the energy performance in between a full mechanical ventilated building than that of a hybrid ventilated-- combined mechanical and naturally ventilated (atrium area to be naturally ventilated) building. A modeled three-storey commercial office building will be used as the main subject of this analysis. To determine the thermal comfort level of the central atrium, Parameters will be set in such a way that the full height windows will be 100% open. Results will be then tabularized to determine and analysis the output of the simulation. Recommendations will be then given based on the output performance of the building. In Tropics, it’s very difficult to achieve better thermal comfort in a naturally ventilated building. With the help of these simulation tools we can find whether natural ventilation is possible in this tropical climate in terms of thermal comfort, ventilation system and energy demand.

scholarly journals Cooling Degree Models and Future Energy Demand in the Residential Sector. A Seven-Country Case Study

2021 ◽  
Vol 13 (5) ◽  
pp. 2987
Author(s):  
Raúl Castaño-Rosa ◽  
Roberto Barrella ◽  
Carmen Sánchez-Guevara ◽  
Ricardo Barbosa ◽  
Ioanna Kyprianou ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Demand ◽  
Energy Performance ◽  
Low Energy ◽  
Extreme Weather Events ◽  
Building Stock ◽  
Residential Sector ◽  
Adaptive Thermal Comfort

The intensity and duration of hot weather and the number of extreme weather events, such as heatwaves, are increasing, leading to a growing need for space cooling energy demand. Together with the building stock’s low energy performance, this phenomenon may also increase households’ energy consumption. On the other hand, the low level of ownership of cooling equipment can cause low energy consumption, leading to a lack of indoor thermal comfort and several health-related problems, yet increasing the risk of energy poverty in summer. Understanding future temperature variations and the associated impacts on building cooling demand will allow mitigating future issues related to a warmer climate. In this respect, this paper analyses the effects of change in temperatures in the residential sector cooling demand in 2050 for a case study of nineteen cities across seven countries: Cyprus, Finland, Greece, Israel, Portugal, Slovakia, and Spain, by estimating cooling degree days and hours (CDD and CDH). CDD and CDH are calculated using both fixed and adaptive thermal comfort temperature thresholds for 2020 and 2050, understanding their strengths and weaknesses to assess the effects of warmer temperatures. Results suggest a noticeable average increase in CDD and CDH values, up to double, by using both thresholds for 2050, with a particular interest in northern countries where structural modifications in the building stock and occupants’ behavior should be anticipated. Furthermore, the use of the adaptive thermal comfort threshold shows that the projected temperature increases for 2050 might affect people’s capability to adapt their comfort band (i.e., indoor habitability) as temperatures would be higher than the maximum admissible values for people’s comfort and health.

scholarly journals ASSESSMENT OF ENERGY PERFORMANCE GAP OF AN OFFICE BUILDING

2021 ◽  
Vol 13 (0) ◽  
pp. 1-6
Author(s):  
Rasa Džiugaitė-Tumėnienė ◽  
Domas Madeikis
Keyword(s):  
Energy Efficiency ◽  
Energy Demand ◽  
Internal Heat ◽  
Energy Performance ◽  
Energy Model ◽  
Indoor Climate ◽  
Performance Gap ◽  
Protection Measures ◽  
Climate Parameters

The high share of global energy costs to create an indoor climate has been of increasing interest to the global community for several decades and is increasingly the focus of policy. This paper analyses the energy performance gap between actual energy consumption and energy demand obtained during the dynamic energy simulation and building certification. To identify the energy performance gap, an existing office of energy efficiency class B was selected as a case study. The simulation program IDA Indoor Climate and Energy was used to create a dynamic energy model, based on the designed documentation and the actual indoor climate parameters recorded by the building management system. The results of the case study showed that the accuracy and reliability of the results presented by the dynamic energy model of the building directly depend on the assumptions. The correct values of the internal heat gains, indoor climate parameters, human behavior, air quality levels at different times of the day and season, HVAC system operation parameters and operation modes, specific fan powers of ventilation systems, the seasonal energy efficiency of cooling equipment and characteristics of sun protection measures have to be selected.

scholarly journals Application of Urban Scale Energy Modelling and Multi-Objective Optimization Techniques for Building Energy Renovation at District Scale

2021 ◽  
Vol 13 (20) ◽  
pp. 11554
Author(s):  
Fahad Haneef ◽  
Giovanni Pernigotto ◽  
Andrea Gasparella ◽  
Jérôme Henri Kämpf
Keyword(s):  
Energy Efficiency ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Optimization Techniques ◽  
Multi Objective Optimization ◽  
Building Stock ◽  
Energy Efficiency Measures ◽  
Multi Objective ◽  
Efficiency Measures

Nearly-zero energy buildings are now a standard for new constructions. However, the real challenge for a decarbonized society relies in the renovation of the existing building stock, selecting energy efficiency measures considering not only the energy performance but also the economic and sustainability ones. Even if the literature is full of examples coupling building energy simulation with multi-objective optimization for the identification of the best measures, the adoption of such approaches is still limited for district and urban scale simulation, often because of lack of complete data inputs and high computational requirements. In this research, a new methodology is proposed, combining the detailed geometric characterization of urban simulation tools with the simplification provided by “building archetype” modeling, in order to ensure the development of robust models for the multi-objective optimization of retrofit interventions at district scale. Using CitySim as an urban scale energy modeling tool, a residential district built in the 1990s in Bolzano, Italy, was studied. Different sets of renovation measures for the building envelope and three objectives —i.e., energy, economic and sustainability performances, were compared. Despite energy savings from 29 to 46%, energy efficiency measures applied just to the building envelope were found insufficient to meet the carbon neutrality goals without interventions to the system, in particular considering mechanical ventilation with heat recovery. Furthermore, public subsidization has been revealed to be necessary, since none of the proposed measures is able to pay back the initial investment for this case study.

scholarly journals Factors affecting the deep renovation of a single-family building – a case study

2021 ◽  
Vol 246 ◽  
pp. 05004
Author(s):  
Triinu Bergmann ◽  
Aime Ruus ◽  
Kristo Kalbe ◽  
Mihkel Kiviste ◽  
Jiri Tintera
Keyword(s):  
Energy Efficiency ◽  
Performance Indicator ◽  
Energy Performance ◽  
Resource Efficiency ◽  
Final Decision ◽  
Air Leakage ◽  
Single Family ◽  
Building Stock ◽  
Thermal Transmittance ◽  
Family Building

The Energy Performance of Buildings Directive (EPBD) of the EU states that Each Member State shall establish a long-term renovation strategy to support the renovation of building stock into a highly energy efficient and decarbonised building stock by 2050. The motive for the study was the dissatisfaction of inhabitants of a single-family building about the heating costs and thermal discomfort. In this study both the emotional and resource efficiency aspects were considered. The structures and technical systems of the studied small dwelling are typical of representing single-family buildings of the Estonian building stock. The initial purpose was to improve the energy efficiency of a building while preserving the existing load bearing structures as much as possible. The research questions were: 1) what the situation before the renovation was, 2) what solutions can be used, 3) making decisions, whether to renovate or demolish. Calculations were carried out – the thermal transmittance of the envelope structures was calculated based on the construction information, and the linear thermal transmittance of geometrical thermal bridges was calculated by using the software Therm. Field tests performed - the thermography and the air leakage of the building was found by standard blower-door test. Specific air leakage rate qE50=11.1 m3/(hm2) was estimated. A renovation solution was offered considering the need for extra insulation and airtightness. The dwelling energy performance indicator was reduced from the existing 279 kWh/(m2y) to 136 kWh/(m2y). For significant energy efficiency improvement deep renovation measures must be used and the question was whether it is rational. Before making the final decision, several aspects have to be considered: 1) emotional – the demolition or renovation of somebody’s home, 2) environmental aspects and resource-efficiency – the possibilities of the reuse of materials.

scholarly journals Urban energy performance calculation based on EPBD standards. GIS4ENER tool

2020 ◽  
Author(s):  
Gema Hernandez-Moral ◽  
◽  
Víctor Iván Serna-Gonzalez ◽  
Francisco Javier Miguel Herrero ◽  
César Valmaseda-Tranque
Keyword(s):  
Energy Demand ◽  
Planning Process ◽  
Energy Performance ◽  
Local Scale ◽  
Decision Makers ◽  
Energy Planning ◽  
Strong Impact ◽  
Building Stock ◽  
Urban Energy ◽  
Performance Calculation

Climate change will have a strong impact on urban settings, which will also represent one of the major challenges (world’s urban population is expected to double by 2050, EU buildings consume 40% final energy and generate 36% CO2 emissions). A plethora of initiatives address this challenge by stressing the underlying necessity of thinking globally but acting locally. This entails the inclusion of a varied set of decision-makers acting at different scales and needing robust, comprehensive and comparable information that can support them in their energy planning process. To this end, this paper presents the GIS4ENER tool to support energy planners at different scales by proposing a bottom-up approach towards the calculation of energy demand and consumption at local scale that can be aggregated to support other decision-making scales. It is based on three main pillars: the exploitation of publicly available data (such as Open Street Maps, Building Stock Observatory or TABULA), the implementation of standardised methods to calculate energy (in particular the ISO52000 family) and the use of Geographic Information Systems to represent and facilitate the understanding of results, and their aggregation. The paper presents the context, main differences with other approaches and results of the tool in Osimo (IT).

BIOCLIMATIC OPTIMIZATION: SKYLIGHT GROUND FLOOR NEW BUILDING, UDLA PARK TORRE II

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Mauro Cepeda ◽  
Santiago Morales F. ◽  
Viviana Cabrera
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Natural Ventilation ◽  
Air Flow ◽  
Internal Flow ◽  
Effective Area ◽  
Academic Environment ◽  
Minimum Area ◽  
Ground Floor ◽  
Beneficial Effects

When high thermal comfort and energy efficiency are provided in an academic environment many beneficial effects on student’s comfort, performance, productivity, and health are shown. The research provides a parametric airflow evaluation of a skylight in a ground floor of new educational building assuming a variation of 4 stages with eight scenarios for the admissions office. By means of the bioclimatic analysis, Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) indices, the best internal airflow performance for the study area applying natural ventilation is achieved with the air flow optimization. A minimum area of 1.79 m has been established for extraction and movement of the internal flow, both with the natural extraction louvers system measuring 12 inches by 60 inches and the 18 inches by 60 inches, they work properly. However, the 18 inches by 60 inches system has better effectiveness as it has fewer louver units to be placed, is more homogeneous, avoids turbulence and provides better air extraction. In addition, by having fewer louver units distributed along the length of the skylight, it will allow the operation to be more controlled during the operation of the building. The use of 8 louvers of those proportions, with an individual effective area of 0.23 m and a total of 1.84 m was recommended in accordance with the results obtained.

Energy Saving Policies for Housing Based on Wrong Assumptions?

2014 ◽  
Vol 39 (2) ◽  
pp. 78-83
Author(s):  
Henk Visscher ◽  
Dasa Majcen ◽  
Laure Itard
Keyword(s):  
Energy Saving ◽  
Energy Demand ◽  
Energy Use ◽  
Housing Stock ◽  
Energy Performance ◽  
Research Projects ◽  
Building Stock ◽  
Energy Saving Potential ◽  
Energy Performance Of Buildings ◽  
New Buildings

The energy saving potential of the building stock is large and considered to be the most cost efficient to contribute to the CO2 reduction ambitions. Severe governmental policies steering on reducing the energy use seem essential to stimulate and enforce the improvement of the energy performance of buildings with a focus on reducing the heating and cooling energy demand. In Europe the Energy Performance of Buildings Directive is a driving force for member states to develop and strengthen energy performance regulations for new buildings and energy certificates for the building stock. The goals are to build net zero energy new buildings in 2020 and to reach a neutral energy situation in the whole stock by 2050. More and more research projects deliver insight that the expected impact of stricter regulations for newly built houses is limited and the actual effects of energy savings through housing renovations stay behind the expectations. Theoretical energy use calculated on base of the design standard for new houses and assessment standards for Energy Performance Certificates of existing dwellings differ largely from the measured actual energy use. The paper uses the findings of some Post Occupancy Evaluation research projects. Is the energy saving potential of the housing stock smaller than expected and should we therefore change the policies?

Semantic Data-Driven Models to Improve Energy Efficiency in Buildings and Cities

2021 ◽  
pp. 515-539
Author(s):  
Álvaro Sicilia ◽  
Gonçal Costa ◽  
Leandro Madrazo
Keyword(s):  
Energy Efficiency ◽  
Holistic Approach ◽  
Energy Performance ◽  
Building Stock ◽  
Semantic Web Technologies ◽  
Improve Energy Efficiency ◽  
Semantic Data ◽  
Multiple Data ◽  
Efficiency Measures ◽  
Multiple Domains

The assessment of building energy performance requires data from multiple domains (energy, architecture, planning, economy) and scales (building, district, city) to be processed with a diversity of applications used by experts from various fields. In order to properly assess the performance of the building stock, and to develop and apply the most effective energy efficiency measures, it is necessary to adopt a comprehensive, holistic approach. In this chapter, three research projects are presented which apply Semantic Web technologies to create energy data models from multiple data sources and domains in order to support decision making in energy efficient building renovation projects: SEMANCO, OptEEmAL, and OPTIMUS. A final reflection on the results achieved in these projects and their links to ongoing research on digital twins is presented.

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