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The Leaf Community is a unique blend of inspired qualified personnel where the preservation of the natural environment, renewable energy sources and worldwide R&D meets education, local culture and society. The Leaf Lab is an industrial building of a rectangular shape and a floor area of approximately 6,000 m 2 located in the Leaf Community, one of the very well‐established smart microgrids in Europe. The Leaf Lab is a near‐zero energy building, combining passive systems, energy‐efficient technologies, integrated monitoring and control, as well as renewable energy production. The number of residents in the Leaf House varies, as it accommodates both employees of the Loccioni Group and short‐term visitors of the Leaf Community. The apartments in the Leaf House are equipped with a touch display providing access to an energy management interface for observing indoor conditions and energy‐related data as well as managing the heating, ventilation and air conditioning; lights; and window shutters.

This chapter presents a comprehensive approach for evaluating the performance of one industrial and one residential smart/near‐zero energy building. The research activities performed and presented in this chapter target the estimation and evaluation of the performance gap between the design and operational phase of zero energy buildings. The steps are as follows: selection of the case study buildings; analysis of the buildings and their systems' design and an assessment of power and energy requirements through dynamic thermal simulation models; data collection while the buildings are in operation; and a comparison of the results of the buildings and the extraction of useful remarks and conclusions. The chapter analyzes the Leaf Lab's energy performance and compares modeling results with real‐time data. There is a systematic and continuous approach in establishing near‐zero energy targets, through research and innovation activities.

The 2030 climate and energy framework includes EU-wide targets and policy objectives for the period 2021–2030 of (1) at least 55% cuts in greenhouse gas emissions (from 1990 levels), (2) at least 32% share for renewable energy, and (3) at least 32.5% improvement in energy efficiency. In this context, the methodology of the cost-optimal level from the life-cycle cost approach has been applied to calculate the cost of renovating the existing building stock in Europe. The aim of this research is to analyze a pilot building using the cost-optimal methodology to determine the renovation measures that lead to the lowest life-cycle cost during the estimated economic life of the building. The case under study is an apartment building located in a mild Mediterranean climate (Castellon, SP). A package of 12 optimal solutions has been obtained to show the importance of the choice of the elements and systems for renovating building envelopes and how energy and economic aspects influence this choice. Simulations have shown that these packages of optimal solutions (different configurations for the building envelope, thermal bridges, airtightness and ventilation, and domestic hot water production systems) can provide savings in the primary energy consumption of up to 60%.

Summarization: Smart meters, one of the crucial enablers of the smart-grid concept and cornerstones in smart planning for cities, offer the opportunity for consumers to address their energy consumption effectively through timely and accurate data on their energy usage. However, previous studies have shown that smart meters may not lead to the desired energy savings unless actively used by households. To this end, the research presented in this paper investigates the penetration of smart meters at community level and explores how such a metering system can help people to understand and manage their energy use better. It examines the awareness about smart meters, looks into their presence in current accommodation and focuses on the views people have about smart meters. For this purpose, a questionnaire was prepared and distributed to a group of individuals residing in the wide area of Ancona province in Italy. Although the deployment of modern second-generation smart meters started in 2017 replacing the outdated smart meters massively installed in the 2000s, the results show low-to-moderate levels of awareness of modern smart meters among the respondents and a low presence of second-generation metering devices in their current accommodation. However, the general view expressed by the participants about smart meters is positive. The findings demonstrate that respondents are in need not only of a gauge that measures energy consumption but also of a tool that assists them to manage effectively their energy use. Παρουσιάστηκε στο: 3rd International conference on Smart and Sustainable Planning for Cities and Regions

The present paper describes a holistic energy efficient retrofit of low income multiple social housing located in Athens, Greece. A holistic analysis was conducted in order to determine the optimum retrofit plan that includes innovative and state of the art commercially available technologies, passive techniques as well as renewable energy sources, aiming to reduce its energy consumption and carbon footprint, improve indoor environmental conditions and be cost effective at the same time. An extensive experimental campaign including air leakage measurements, thermal imaging, energy consumption and indoor environmental quality measurements was conducted before and after the implementation of the retrofit. In addition, advanced building simulation, occupant surveys and socioeconomic analyses were performed in order to evaluate the impact of the retrofit and estimate specific performance indicators.

As we are nowadays experiencing a transition period for the energy demand, there is a clear movement of the European energy market towards a new field of efficiency including reliable and smart systems that will upgrade the improvement of Europe's economic and environmental health. To this end smart systems introduce innovative applications with multiple and interdisciplinary characteristics: safe integration of additional renewables, distribution to the network, efficient delivery systems and monitoring control through demand response in order to achieve zero energy targets. The integration of smart technologies requires a holistic approach that takes into account all aspects of sustainability. The implementation of highly efficient smart buildings is feasible through the integration of smart metering, renewable systems acting as generators/storage and energy management. The holistic system supports and fulfils demand load management and distribution network of future grids.. Moreover, the benefits of effective thermal and electrical storage are underlined as a crucial factor of smart systems and smart buildings. This paper highlights the principles of integrated design procedure and links the process with smart building technologies. Energy efficiency methodologies and innovative techniques applied at building level are presented. To this context current EU policy framework, trends and perspectives concerning integrated design as a supportive tool for zero energy concept are also provided.

A 7 story social housing apartment building in Athens, Greece has been renovated following a holistic energy efficient retrofit process. The retrofit plan, resulting from tenant surveys, environmental parameters monitoring and extensive energy simulations, included commercially available technologies like insulation and energy efficient windows, innovative technologies like energy efficient lighting and smart coatings, passive techniques like night ventilation as well as RES, aiming to transform this inefficient building into a near zero energy one, achieving a reduction of the energy consumption and CO 2 emissions by 80% and significant improvement of thermal comfort conditions. An experimental campaign has been executed in order to measure and validate the energy savings and indoor comfort conditions before and after the retrofit. The results of this monitoring procedure are reported and analyzed. Measurements include air leakage and thermal imaging for determining leakage rate and heat loss through the building fabric, smart meters to record energy consumption and indoor and outdoor environmental measurements. The opinion of the occupants is taken into account through pre- and post-retrofit surveys.

The MedZEB (Mediterranean Zero Energy Building) approach aims at stimulating the market uptake of energy deep and beyond retrofitting of existing buildings of the Mediterranean. Its holistic nature implies the evaluation and integration of a range of relevant factors and the effective support to the retrofitting supply chain, also with the help of an ICT platform. Main concern of the approach are residential buildings within a framework dealing with High TRL levels and with already on the market technologies to be combined to create Med-specific cost-optimal Packages of technical Solutions, linked to a Voluntary Certification Scheme. The triggered creation of trust and information exchange will pave the way to new investments and strengthen the Med deep and beyond retrofitting network.

The role of the materials used in the urban fabric is highly important for the microclimate and the energy loads of the cities. This has led to the research and development of innovative solutions with advanced thermal and optical properties. Thermochromic coatings that are reflective in summertime and absorptive in wintertime can address the demand for lower surface temperatures and energy savings. The function, however, of thermochromic materials in outdoor spaces is complex as they degrade when interacting with solar radiation. Various techniques with UV absorbers and UV filters prove that ultraviolet radiation is not the only parameter that affects thermochromism. This study aims to go one step forward and investigate the factors that destroy the reversible thermochromic circle besides UV radiation. Combinations of UV and optical filters were used on thermochromic coatings applied on concrete tiles under accelerated aging conditions of a one-month period to isolate the parts of solar spectrum that cause the photodegradation. The measurements of reflectance and color prove that the use of UV filter did not improve significantly the dark phase of thermochromic effect, while at the white phase, SR was reduced by 5% and SRvis was reduced by 9.7% compared with the uncovered sample. Covering the sample with red filter, which cuts off wavelengths below 600nm, protects most efficiently the reversible color change of the thermochromic coating as the solar reflectance at the dark phase remains unaffected during the whole experimental period.

Energy efficiency, advanced controls and renewable energy systems for operating industrial, residential and tertiary sector buildings designed to be Near-Zero Energy are investigated to explore the performance gap. The analysis involves a comparison of energy dynamic and quasi-dynamic models with data from smart monitoring systems, indoor and outdoor environment measurements, power consumption and production data. Specific issues and conclusions have been drawn as the basis for addressing the performance gap between energy efficiency prediction in the design phase and measurements’ evaluation in operational phase.

Summarization: Commonly used materials in the construction of the building façades located in warm climates, often entrap a great amount of heat from the incoming solar radiation, leading to a respective thermal increase in the interior. The aim of the present study is to examine mineral-based coatings as a passive solar technique that contributes to buildings’ energy efficiency. A series of mineral based samples are developed and tested. Their thermal performance is estimated by infrared thermography and surface temperature measurements. Their optical properties are also measured while the energy efficiency is quantified using simulation techniques. The results revealed that renders based on hydraulic and/or hydrated lime with additions of calcium carbonate powder, as well as mineral paints comprised either of lime wash or silicate minerals can behave as cool coatings and contribute to a significant reduction of the cooling demand in warm climates. Παρουσιάστηκε στο: Solar Energy

The present paper is a review article aiming to present the actual state of the art on the development and the assessment of cool materials (i.e. materials with high solar reflectance and infrared emittance) for buildings and urban structures. The research in this field is roughly divided in four phases and includes the development and assessment of: (a) highly reflective and emissive light colored materials, (b) cool colored materials, i.e. colored materials with increased near infrared and thus overall solar reflectance compared to similarly colored conventional ones, (c) phase change materials and (d) dynamic cool materials. All major aspects related to each technology are described and the benefits and impacts of these materials at building, city and global scale are reported. The wide use of such materials can significantly contribute to the mitigation of the heat island effect and the improvement of urban environmental quality.

Urban Heat Island refers to the temperature increase in urban areas compared to rural settings, exacerbating the energy consumption of buildings for cooling. The use of highly reflective materials in buildings and urban structures reduces the absorbed solar radiation and contributes to mitigate heat island. This paper presents the results of a study aiming to measure and analyze the solar spectral properties and the thermal performance of 5 color thin layer asphalt samples in comparison to a sample of conventional black asphalt. Computational fluid dynamics (CFD) simulation is used for evaluating the thermal and energy impact of applying the samples in outdoor spaces (roads). The spectrophotometric measurements showed that the colored thin layer asphalt samples are characterized by higher values of solar reflectance compared to the conventional asphalt, which is mainly due to their high near infrared solar reflectance. From the statistical analysis of the surface temperatures it was found that all the colored thin layer asphalt samples demonstrate lower surface temperatures compared to conventional asphalt. The maximum temperature difference recorded was for the off-white sample and was equal to 12 °C. The CFD simulation results show that surface and air temperatures are decreased when applying the color thin layer sample.

High-spatial resolution multispectral satellite images collected over the metropolitan Athens area in Greece were used to generate (a) a shortwave albedo map depicting the albedo spatial variations across the metropolitan area, (b) a fractional vegetation cover map showing the spatial distribution of urban vegetation and (c) a daytime and night-time land surface temperature (LST) map depicting the spatial variations of the surface temperature across the city. From LST maps, cooling and heating regions were identified and analysed to reveal relationships between surface heat islands and urban surface characteristics. Based on the data acquired with the use of satellite images and in order to better define the heat island problem and the mitigation measures that need to be taken, the most common building and paving materials used in the urban fabric of Athens were examined. Their optical properties were measured using a UV/VIS/NIR spectrophotometer fitted with an integrating sphere, an emissometer and their...

The present study reports the development and comparative testing of thermochromic coating to be used in buildings and urban structures. Experimental results from an extensive comparative analysis of the thermal and physical behaviour of thermochromic, highly reflective (cool), and common coatings are reported and analyzed. The surface temperature was monitored on 24 h basis from August to mid-September 2007. It was revealing that the temperature of thermochromic coatings was lower than cool and common coatings. Measurements of spectral reflectance indicated that the thermochromic coatings at the colored phase (below the transition temperature of 30 °C) are energy-absorbing while at the colorless phase (above the transition temperature of 30 °C) are energy-reflecting. The data obtained was used for the calculation of solar reflectance. The results showed that the solar reflectance of the thermochromic samples was significally higher compared to the cool and common ones. A 10-day period test was also performed showing the impact of solar radiation on thermochromism. The comparative results demonstrate that the use of thermochromic coatings can both contribute to energy savings in buildings, providing a thermally comfortable indoor environment, while can contribute highly to improve the urban microclimate.

The present work focusses on the investigation of the correlation between occupancy, energy performance of the building as well as the quality of the indoor environment in terms of the thermal and air quality aspects. In this respect 3 different types of rooms (use and occupancy), situated in a building of the National University of Singapore campus, were selected. The building is equipped with an advanced BMS system capable of assessing the energy performance, the thermal behaviour and the air quality of all sections, thus providing guidelines towards a zero energy performance maintaining an acceptable indoor environment. The results indicate that strong correlation between energy consumption and occupancy is identified while the levels of illuminance do not seem to be strongly influenced by the amount of people. The indoor concentration of CO2 which is related to human exhalation, found to be high especially during the class hours. This is attributed to the insufficient performance of the mechanical ventilation central system which cannot be adjusted accordingly.

Δημοσίευση σε επιστημονικό περιοδικό Summarization: This paper describes recent research on the prediction of the performance of light pipes and the ways to optimise their design, in order to house artificial lighting, able to supplement daylight in a space. The research has resulted in an algorithm, for the easy and quick calculation of the interior illuminance provided by light pipes, and in a procedure for the calculation of the power of the necessary artificial lighting (light emitting diodes [LEDs]) and the energy savings for lighting, due to the daylight provided by the light pipes and the daylight linked controls of the LEDs. Παρουσιάστηκε στο: International Journal of Sustainable Energy

Δημοσίευση σε επιστημονικό περιοδικό Summarization: Rejection of solar gains is the aim of passive cooling strategies in any type of building and any climatic region. The extent of cool materials’ applicability depends on the external climatic conditions and internal heat gains. The aim of the present paper is to analyse the contribution of an innovative cool fluorocarbon coating in the reduction of energy demand for cooling when applied in an industrial building with increased heat gains under temperate climatic conditions. The material is tested using accelerated weathering procedures and its optical properties, i.e. solar reflectance and infrared emmitance are measured. There is an increase of 120% of the roof's albedo by the application of cool material. Regarding the heating and cooling loads there was a decrease of 73% for cooling while there was a minor heating penalty of 5%. Παρουσιάστηκε στο: Energy and Buildings