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This data article contains eleven tables supporting the research article entitled: Cost-Optimal Design For Nearly Zero Energy Office Buildings Located In Warm Climates [1].The data explain the procedure of minimum energy performance requirements presented by the European Directive (EPBD) [2] to establish several variants of energy efficiency measures with the integration of renewable energy sources in order to reach nZEBs (nearly zero energy buildings) by 2020.This files include the application of comparative methodological framework and give the cost-optimal solutions for non-residential building located in Southern Italy. The data describe office sector in which direct the current European policies and investments [3,4].In particular, the localization of the building, geometrical features, thermal properties of the envelope and technical systems for HVAC are reported in the first sections. Energy efficiency measures related to orientation, walls, windows, heating, cooling, dhw and RES are given in the second part of the group; this data article provides 256 combinations for a financial and macroeconomic analysis.

Data are related to the multi-objective optimization process applied to the building materials to obtain high energy-efficient precast walls for cold climate. The methodology has been explained on the paper entitled “High performance precast external walls for cold climate by a multi criteria methodology” (Baglivo and Congedo, 2016) [1]. The modeFRONTIER rel.4.3 optimization tool has been used to evaluate the dynamic behaviour of the building components in accordance with the UNI EN ISO 13786:2008 and to obtain a multitude of high efficiency configurations. The results are divided into three categories thick, thin and ultra-thin precast walls, in accordance with their thicknesses. The input data are the building materials with their thermal properties, sustainability characteristics and the supply and installation costs. The output values of the simulations are adapted to the cold climate and based on thermal properties, costs and sustainability score. Several combinations of external precast walls have been shown as optimal for cold climate.

A concept of Air-Cooled Heat Pump (ACHP) coupled with a Horizontal Air-Ground Heat Exchanger (HAGHE), also called Horizontal Earth-To-Air Heat Exchanger (EAHX), has been proposed. The Air-Cooled Heat Pump is a system which transfers heat from outside source (air) to inside sink (water) and vice versa in summertime. The innovation is to provide a geothermal treatment of pre-heating/cooling of air before meeting the evaporator in winter or the condenser in summer of the heat pump. Besides, it is known that the variations of the ground temperature, respect to the external air one, are mitigated already in the first layers of the ground throughout the year, due to the high thermal inertia of the ground, letting the heat pump work with more mitigated conditions, improving the performances. The behaviour of HAGHE has been investigated by varying the length and the installation depth of the probes, the air flow rate and the ground thermal properties. All the combinations have been implemented using TRNSYS 17 software (Transient System Simulation Program) to obtain the outlet temperatures from HAGHE, resulting from the 54 configurations. The results are compared in terms of Coefficient of Performance (COP) in wintertime and Energy Efficiency Ratio (EER) in summertime between configurations with and without the coupling with HAGHE. In addition, two seasonal performance SCOP and SEER coefficients have been calculated considering, not only the inlet air temperatures into the Air-Cooled Heat Pump, but also their frequency of occurrence, the off-set external temperature (16 &deg, C), the nominal external temperature and heating and cooling loads.

The improvement of energy efficiency and the integration of renewable energy in buildings are key elements of current European policies. According to the recast of the Directive EPBD (Energy Performance of Buildings), Member States have to target nZEBs (nearly zero energy buildings) and minimum energy performance requirements within a cost-optimal framework by 2020. This study reports the comparative methodology reported in the EPBD, aimed at the establishment of cost-optimality in office buildings located in a warm climate. A number of energy efficiency measures have been selected and applied to the envelope and the systems of a virtual reference office building. Technical features and energy performance calculations have been assessed for the obtained configurations. Primary energy consumption and global costs have been derived to identify the cost-optimal configuration from a financial and macroeconomic analysis. The paper shows the suitability of the methodology to support the design of cost-effective energy efficient solutions in new office buildings. Results show technical variants selection able to a decrease primary energy consumption by 39% and CO2 emissions by 41% at the lowest cost. They also illustrate how to design cost-optimal nZEBs for a warm climate in compliance with EU (European Union) policies.

The recast of EU (European Union) Directive on EPBD (Energy Performance of Buildings) requires nZEBs (nearly zero energy buildings) as the building target from 2018 onwards and the establishment of cost-optimal levels of minimum energy performance requirements in buildings. This paper presents the results of the application of a methodology to identify cost-optimal levels in new residential buildings located in a warm climate. Mono-residential buildings have been considered as virtual reference buildings in this study. Different energy efficiency measures have been selected for the envelope and the systems. A combination of technical variants has been then applied to the reference case in order to obtain several configurations to be compared in terms of primary energy consumption and global costs. The cost-optimal solution is identified assessing technical features and energy performance. Standard and high efficiency buildings are analysed to show how the selected configuration allows a decrease of primary energy consumption and CO2 emissions at the lowest cost. Results are useful for comparison with other climates and building types. They also show the feasibility of the methodology to comply with EU requirements and to support the choice of economically efficient nZEBs solutions at the design stage.

Data are related to the numerical simulation performed in the study entitled “CFD modeling to evaluate the thermal performances of window frames in accordance with the ISO 10077” (Malvoni et al., 2016) [1].The paper focuses on the results from a two-dimensional numerical analysis for ten frame sections suggested by the ISO 10077-2 and performed using GAMBIT 2.2 and ANSYS FLUENT 14.5 CFD code.The dataset specifically includes information about the CFD setup and boundary conditions considered as the input values of the simulations.The trend of the isotherms points out the different impacts on the thermal behaviour of all sections with air solid material or ideal gas into the cavities. Keywords: CFD, Thermal break, Window, Frame, 10077, EPBD

Several technical combinations have been evaluated in order to design high energy performance buildings for the warm climate. The analysis has been developed in several steps, avoiding the use of HVAC systems. The methodological approach of this study is based on a sequential search technique and it is shown on the paper entitled “Envelope Design Optimization by Thermal Modeling of a Building in a Warm Climate” [1] . The Operative Air Temperature trends (TOP), for each combination, have been plotted through a dynamic simulation performed using the software TRNSYS 17 (a transient system simulation program, University of Wisconsin, Solar Energy Laboratory, USA, 2010). Starting from the simplest building configuration consisting of 9 rooms (equal-sized modules of 5 × 5 m2), the different building components are sequentially evaluated until the envelope design is optimized. The aim of this study is to perform a step-by-step simulation, simplifying as much as possible the model without making additional variables that can modify their performances. Walls, slab-on-ground floor, roof, shading and windows are among the simulated building components. The results are shown for each combination and evaluated for Brindisi, a city in southern Italy having 1083 degrees day, belonging to the national climatic zone C. The data show the trends of the TOP for each measure applied in the case study for a total of 17 combinations divided into eight steps.

Finding the most appropriate configuration of building components at the design stage can reduce energy consumption in new buildings. This study aims to optimize the design of the envelope of a new residential building located in a warm climate (southern Italy). The thermal behaviour of the building has been analysed to evaluate the indoor operative air temperature for several configurations. The building prototype has been modelled using the dynamic simulation software TRNSYS 17 (A transient system simulation program, University of Wisconsin, Solar Energy Laboratory, USA, 2010) using a sequential search technique. Starting from the simplest building configuration, the main evaluated components are: walls, slab-on-ground floor, roof, shading, windows and internal heat loads. For each of these components, different design options have been modelled and compared in terms of indoor thermal comfort. Comfort parameters have also been taken into account to evaluate users’ satisfaction with the optimized configurations. The study of the operative air temperature demonstrates that the absence of insulating layers in the ground floor ensures a lower internal temperature in summer. The paper shows how each component impacts the thermal behaviour of the whole building. It highlights the usefulness of the envelope design optimization that is characterized by high values of heat storage capacity, enabling internal temperature fluctuations to be kept under control, especially during summer.

This study demonstrates how it is possible to increase the performances of an air-cooled heat pump by the use of Horizontal Air-Ground Heat Exchanger (HAGHE); the analysis has been carried out varying the air flow rate and heat conductivity of the ground. For a warm climate, the air treatment using HAGHE involves an improvement of the Energy Efficiency Ratio (EER) of the heat pump for the entire summertime. About the wintertime, the coefficient of performance (COP) results improved from November to February, but it is possible to install a by-pass to permit to the heat pump to work at the best conditions.

Daylight access and indoor thermal comfort are key issues for high design level of sustainable buildings. In fact, daylight provides energy savings and visual comfort condition that can foster higher productivity and performance. This paper proposes a case study of sizing of daylight devices for zenith light. It enables the decision-making process of the designer to reach high levels of daylight factor. The proposed method is shown with an example of application. For the case study, a room in south of Italy, 24 different solar tunnels configurations and 12 cases with different number of skylights have been evaluated.

This paper proposes an integrated rehabilitation project of an abandoned farmhouse in a rural area in Southern Italy. The building underwent a functional recovery to become a tourist accommodation. The use of natural materials can reduce energy consumption and carbon footprints considering environmental sustainability aspects. A proper selection of interventions targeted for the specific warm climate has led to benefits for heating, cooling and lighting in the interior spaces. The project also includes the integration of hydraulic facilities and landscaping, such as planting hedges, green barriers and native trees.

This work presents the performances of an Air-Cooled Heat Pump combined with Horizontal Air Ground Heat Exchanger. The Horizontal Air Ground Heat Exchanger has been used not for the direct ventilation of the room, but for the treatment of the outside air flux of an Air-Cooled Heat Pump; consequently, the heat pump works with colder and warmer air than outside one in summer and winter, respectively. The results are exposed in terms of the Coefficient of Performance and Energy Efficiency Ratio of the Air-Cooled Heat Pump.

The recast of the energy performance of buildings directive (EPBD) describes a comparative methodological framework to promote energy efficiency and establish minimum energy performance requirements in buildings at the lowest costs. The aim of the cost-optimal methodology is to foster the achievement of nearly zero energy buildings (nZEBs), the new target for all new buildings by 2020, characterized by a high performance with a low energy requirement almost covered by renewable sources. The paper presents the results of the application of the cost-optimal methodology in two existing buildings located in the Mediterranean area. These buildings are a kindergarten and a nursery school that differ in construction period, materials and systems. Several combinations of measures have been applied to derive cost-effective efficient solutions for retrofitting. The cost-optimal level has been identified for each building and the best performing solutions have been selected considering both a financial and a macroeconomic analysis. The results illustrate the suitability of the methodology to assess cost-optimality and energy efficiency in school building refurbishment. The research shows the variants providing the most cost-effective balance between costs and energy saving. The cost-optimal solution reduces primary energy consumption by 85% and gas emissions by 82%–83% in each reference building.

The main goal of the EPBD (Energy Performance Buildings Directive) is the improvement of the energy performance of the European buildings. The internal comfort is critically dependent on the envelope that plays a key role in the thermal balance of the entire building. In particular, the windows are one of the most critical elements in terms of solar gains, heat losses and thermal bridges; therefore, the design of high efficiency frames is requested, both in cold and warm climate, but with different peculiarity. The UNI EN ISO 10077-2 provides a methodology to evaluate the frame thermal behaviour and it proposes the criteria to validate the numerical model. This paper presents a two-dimensional numerical method for the thermal behaviour evaluation of the frame sections using GAMBIT 2.2 and ANSYS FLUENT 14.5 CFD code. The results have been validated in accordance with the UNI EN ISO 10077-2. The standard ISO replaces the air gas with a fictitious material “air solid” into the cavities. Besides the simulation carried out with ideal gas entails higher internal surface temperature than the air solid case. Therefore, the standard ISO imposes preventive computational conditions. The proposed numerical method can be implemented for several frame profiles with different features in terms of geometry and materials, representing a valid support in the design of new high thermal performance frames.

Nowadays, the design of Zero Energy Buildings requires a technology of light multi-layered walls and the envelope represents a key element to reach high level of thermal behaviour and indoor comfort. This paper illustrates a method based on a multi-criteria analysis for the design of energy-efficient precast walls in the cold climate. It encourages the use of eco-friendly building materials and local materials, in accordance with the directions of the Building Sustainable Protocols, like LEED and Itaca. The designed methodology involves the use of MatLab rel.7.0 for the computational procedure and the modeFRONTIER rel.4.3 optimization tool to evaluate the dynamic behaviour of the building components and to obtain a multitude of high efficiency configurations. The optimization has been performed in terms of steady thermal transmittance, periodic thermal transmittance, decrement factor, time shift, areal heat capacity, thermal admittance, surface mass, thickness, supply and installation costs and eco-friendly score. Furthermore, hygro-thermal and acoustic check have been evaluated for three walls, selected between the most efficient. The walls present no interstitial condensation. The results highlights that it is possible to rich high efficiency precast walls also by thin and ultra-thin thicknesses.

Energy consumption in new buildings can be reduced at the design stage. This study optimizes the ventilation system design of a new residential building located in a warm climate (Southern Italy). Different system options of horizontal air-ground heat exchangers (HAGHEs), also called earth-to-air heat exchangers (EAHX), have been considered to search for the optimal configuration. The thermal behaviour of the obtained configurations has been modelled by the dynamic simulation software TRNSYS 17. The pipe numbers, the air flow rate, and the soil thermal conductivity are among the simulated building components. For each of them, different design options have been analysed to study how each parameter impacts the building thermal behaviour in winter and summer. The operative air temperature (TOP) has been evaluated inside the building prototype to investigate the indoor comfort. The paper demonstrates that HAGHEs permit to assure a suitable indoor climatization if the building envelope is optimized for a warm area. These conditions require high values of heat storage capacity to keep under control the internal temperature fluctuations, especially in summer. The paper confirms the importance of geothermal systems and design optimization to increase energy savings.

The data given in the following paper are related to input and output information of the paper entitled Design method of high performance precast external walls for warm climate by multi-objective optimization analysis by Baglivo et al. [1]. Previous studies demonstrate that the superficial mass and the internal areal heat capacity are necessary to reach the best performances for the envelope of the Zero Energy Buildings located in a warm climate [2–4]. The results show that it is possible to achieve high performance precast walls also with light and ultra-thin solutions. A multi-criteria optimization has been performed in terms of steady and dynamic thermal behavior, eco sustainability score and costs. The modeFRONTIER optimization tool, with the use of computational procedures developed in Matlab, has been used to assess the thermal dynamics of building components. A large set of the best configurations of precast external walls for warm climate with their physical and thermal properties have been reported in the data article.

The European policy framework is focused on reducing energy consumption in the building sector. The recast of Energy Performance of Buildings (EPBD) Directive establishes that minimum energy performance requirements have to be set to achieve cost-optimal levels. A methodology is developed to assess energy and cost effectiveness in new buildings located in the Mediterranean area. Several energy efficiency technical variants are applied to a multi residential reference building selected as a representative model of the national building stock. Primary energy consumption and global costs are evaluated in a number of configurations to derive the cost-optimal solution. The paper shows how economical high efficient buildings can be obtained at a design stage for a warm climate. The selected configuration decreases primary energy consumption by 90% and CO 2 emissions by 88% with respect to the baseline building. Results appear useful for comparison with other climates and building types. The paper also points out that the methodology is suitable to guide and support the choice of cost effective energy efficiency measures in compliance with EU requirements.

Taking into account the global environmental problems, there is the urgent need to reduce energy consumption and the greenhouse gas emissions in the construction sector. Environmental awareness can be achieved through the extensive application of precast systems in buildings construction. A multi-criteria analysis has been used to obtain energy-efficient precast walls for Zero Energy Building in warm climate focusing on eco-friendly building materials. The modeFRONTIER optimization tool, with the use of computational procedures developed in Matlab, has been used to assess the thermal dynamics of building components. The optimization has been carried out in terms of steady thermal transmittance, periodic thermal transmittance, decrement factor, time shift, areal heat capacity, thermal admittance, surface mass, small thickness, eco sustainability score, light-weight and costs. The best sequences of layers show repetitive features: high surface mass for the first layer (internal side), followed by eco-friendly insulating materials for the middle layer and common insulating materials for the outer layer. The results illustrate that it is possible to obtain high performance precast multi-layered walls also with light and thin solutions; in particular, the superficial mass and the internal areal heat capacity have an important role to obtain the best performance in the warm climate.

Given the recent worldwide environmental issues, there is a need to reduce the energy consumption and the greenhouse gas emissions of the building sector, keeping in mind the whole life cycle assessment of construction materials. Determining the sustainability of the products is complex, and the presence of one or more “eco” features does not necessarily make it “eco” in its entirety. The ITACA Protocol for environmental sustainability promotes the use of recycled, renewable and locally sourced materials. A multi-criteria analysis has been carried out in order to identify high energy efficiency external walls for ZEBs in the Mediterranean climate, privileging eco-friendly building materials. The modeFRONTIER optimization tool, by the use of calculation procedures developed in Matlab, was used to evaluate the dynamic performance of building components. The optimization was performed in terms of steady thermal transmittance, periodic thermal transmittance, decrement factor, time shift, areal heat capacity, thermal admittance, surface mass, thickness and ITACA score. A method for the design of new low-cost residential buildings will be defined; in particular, the final aim is to determine not a single optimal solution, but a set of possible external wall configurations among which the designer can choose the proper solution for his application, according to the Pareto front of the multi-criteria problem. The results underline that, in a warm climate, the best sequences of layers are with high surface mass for the first layer (internal side), followed by common insulating materials for the middle layer and eco-friendly insulating materials for the outer layer.

\{ZEBs\} in Europe adopt a technology of light multi-layered walls by using structural materials with low density, thermal isolation, wide thickness, low specific weight, low mass accumulation, to achieve very low steady thermal transmittance. These techniques work toward bringing down winter heating costs. In the Mediterranean area, the thermal overload is irreversible when radiation is not controlled and the free supply of heat indoors is mismanaged. The characteristics of multi-layered walls do not yield typical passive heating system benefits because there are not large surfaces with thermal accumulation mass that are capable of storing heat when necessary, and discharge it once the effect of solar radiation is exhausted. A multi-objective analysis is key to obtaining several types of high energetic efficiency external walls for \{ZEBs\} in the Mediterranean climate, through the combination of various materials. The analysis is carried out in terms of steady thermal transmittance, periodic thermal transmittance, decrement factor, time shift, areal heat capacity, thermal admittance, surface mass, thickness. The results show that the superficial mass of the external wall has important to obtain the best performance in the warm climate. It is possible to reach high performance in the summertime also by lighter and thinner walls.

The data reported in this article refers to input and output information related to the research articles entitled Assessment of cost-optimality and technical solutions in high performance multi-residential buildings in the Mediterranean area by Zacà et al. (Assessment of cost-optimality and technical solutions in high performance multi-residential buildings in the Mediterranean area, in press.) and related to the research article Cost-optimal analysis and technical comparison between standard and high efficient mono residential buildings in a warm climate by Baglivo et al. (Energy, 2015, 10.1016/j.energy.2015.02.062, in press).