University of Perugia, Italy
Industrial Engineering
Buildings’ thermal-energetic assessment and the relative proposal of new technical solutions applied to both summer and winter analyses has a strategic role in increasing the year-round performance of buildings. Buildings’ dynamic... more
Buildings’ thermal-energetic assessment and the relative proposal of new technical solutions applied to both summer and winter analyses has a strategic role in increasing the year-round performance of buildings.
Buildings’ dynamic analysis is by now a well-established procedure to study effective building energy performance given real climate considerations. Then in this work, a concise and effective methodology for analyzing buildings’ thermal performance in a dynamic environment is proposed and applied to different case studies, consisting of single-family residential buildings’ prototypes. This procedure is aimed to define different performance levels by proper non-dimensional indexes named thermal deviation indexes (TDI). These indexes values could express in a concise way buildings’ thermal behavior, different optimization strategies impact, sensitivity analysis results.
Buildings’ prototypes representing the case studies are three free-floating houses where the architectural shape role and the sensitivity of different envelope features are analyzed, also supported by experimental results regarding envelope properties measured on existing residential buildings in Italy. The three prototypes are respectively designed to optimize summer or winter energy performance or to represent the typical Italian house before and after energy efficiency regulation is implemented. To better define the important envelope parameters necessary to calibrate the numerical models, experimental activities are conducted. In particular, thermal insulation level and roof reflectance, characterized by means of spectrophotometrical measurements, are measured both in the case of an old traditional Italian building and in the case of a modern building.
The results of the dynamic analysis are expressed in terms of TDI values, to define buildings’ thermal performance with respect to the variation of all the considered architectural and envelope’s properties (i.e. architectural layout, mass and insulation, roof reflectance, Solar Heat Gain Coefficients of windows’ glasses, weather data) within a specific climatic context.
For validating the proposed method, the obtained TDI results are compared with those obtained from existing procedures. In particular, the TDI values are correlated to an adaptive comfort indicator, for verifying how much the TDI could be effective for evaluating free-running buildings thermal performance during both summer and winter.
Buildings’ dynamic analysis is by now a well-established procedure to study effective building energy performance given real climate considerations. Then in this work, a concise and effective methodology for analyzing buildings’ thermal performance in a dynamic environment is proposed and applied to different case studies, consisting of single-family residential buildings’ prototypes. This procedure is aimed to define different performance levels by proper non-dimensional indexes named thermal deviation indexes (TDI). These indexes values could express in a concise way buildings’ thermal behavior, different optimization strategies impact, sensitivity analysis results.
Buildings’ prototypes representing the case studies are three free-floating houses where the architectural shape role and the sensitivity of different envelope features are analyzed, also supported by experimental results regarding envelope properties measured on existing residential buildings in Italy. The three prototypes are respectively designed to optimize summer or winter energy performance or to represent the typical Italian house before and after energy efficiency regulation is implemented. To better define the important envelope parameters necessary to calibrate the numerical models, experimental activities are conducted. In particular, thermal insulation level and roof reflectance, characterized by means of spectrophotometrical measurements, are measured both in the case of an old traditional Italian building and in the case of a modern building.
The results of the dynamic analysis are expressed in terms of TDI values, to define buildings’ thermal performance with respect to the variation of all the considered architectural and envelope’s properties (i.e. architectural layout, mass and insulation, roof reflectance, Solar Heat Gain Coefficients of windows’ glasses, weather data) within a specific climatic context.
For validating the proposed method, the obtained TDI results are compared with those obtained from existing procedures. In particular, the TDI values are correlated to an adaptive comfort indicator, for verifying how much the TDI could be effective for evaluating free-running buildings thermal performance during both summer and winter.
Thermal and energy dynamic analysis of buildings is a well-established procedure to evaluate the effective building energy performance, considering real climate. The proposal of new technical solutions and innovative strategies to be... more
Thermal and energy dynamic analysis of buildings is a well-established procedure to evaluate the effective building energy performance, considering real climate. The proposal of new technical solutions and innovative strategies to be applied for both summer and winter period has a fundamental role also considering the IPCC suggestions and the EPBD European Directive implementation.
In this paper a synthetic but also exhaustive method for thermal dynamic analysis of buildings is proposed. It is based on performance levels assignment, defined by proper non-dimensional indexes (TDI, Thermal Deviation Index) that allow to express the building behavior and the sensitivity analysis results, in relationship to the climatic context.
The proposed methodology is then applied to different case studies consisting of numerical prototypes of free-running residential buildings to evaluate first the architectural shape role and then the sensitivity of different envelope features, characterized also by experimental measurements conducted on real Italian residential buildings. The prototypes are designed to optimize respectively summer or winter energy performance or to represent the typical Italian house before and after energy efficiency regulation coming into force. To better define some important parameters necessary to calibrate the numerical models, experimental activities are carried out. In particular, thermal insulation level and roof reflectance, characterized by means of spectrophotometrical measurements, are measured both in the case of an old traditional Italian building and in the case of a new one.
The results of the dynamic analysis, concerning all the considered variables (mass and insulation, roof reflectance, Solar Heat Gain Coefficients of glasses, weather data, etc.) are defined by TDI values that make it possible to evaluate and to compare the role of each element for defining the building thermal performance, also related to the specific climatic context.
The results obtained using the proposed method are also compared with those obtained from existing procedures. In particular the TDI values are correlated to an adaptive comfort indicator, for verifying how much the TDI could be effective for evaluating free-running buildings thermal performance during both summer and winter period.
In this paper a synthetic but also exhaustive method for thermal dynamic analysis of buildings is proposed. It is based on performance levels assignment, defined by proper non-dimensional indexes (TDI, Thermal Deviation Index) that allow to express the building behavior and the sensitivity analysis results, in relationship to the climatic context.
The proposed methodology is then applied to different case studies consisting of numerical prototypes of free-running residential buildings to evaluate first the architectural shape role and then the sensitivity of different envelope features, characterized also by experimental measurements conducted on real Italian residential buildings. The prototypes are designed to optimize respectively summer or winter energy performance or to represent the typical Italian house before and after energy efficiency regulation coming into force. To better define some important parameters necessary to calibrate the numerical models, experimental activities are carried out. In particular, thermal insulation level and roof reflectance, characterized by means of spectrophotometrical measurements, are measured both in the case of an old traditional Italian building and in the case of a new one.
The results of the dynamic analysis, concerning all the considered variables (mass and insulation, roof reflectance, Solar Heat Gain Coefficients of glasses, weather data, etc.) are defined by TDI values that make it possible to evaluate and to compare the role of each element for defining the building thermal performance, also related to the specific climatic context.
The results obtained using the proposed method are also compared with those obtained from existing procedures. In particular the TDI values are correlated to an adaptive comfort indicator, for verifying how much the TDI could be effective for evaluating free-running buildings thermal performance during both summer and winter period.
- by Anna Laura Pisello and +1
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Given the significant energy consumption imputable to buildings, the development of accurate models to predict building energy performance to understand their environmental impact has become a fundamental research issue. In this paper, a... more
Given the significant energy consumption imputable to buildings, the development of accurate models to
predict building energy performance to understand their environmental impact has become a fundamental
research issue. In this paper, a method for evaluating a building’s energy performance by
enlarging the assessment perspective from a single building to a network of buildings is proposed and
applied. The purpose of this research was to establish how a combined Inter-Building Effect (IBE) on
energy consumption could work and how it could condition buildings’ energy performance when there
are close spatial relationships among buildings. To examine this, a simulation of the energy performance
of a whole network of buildings represented by a realistic block of twenty single-family homes subject to
different climatological contexts was conducted. The results demonstrate that buildings can mutually
impact the energy dynamics of other buildings and that this effect varies by climatological context and by
season. The IBE analysis and the specific proposed methodology revealed energy requirement modeling
inaccuracies of up to 42% in summer (in Miami, FL) and up to 22% in winter (in Minneapolis, MN). These
findings demonstrate that in order to accurately predict the energy performance of a single building, the
IBE created by the spatial relationship with surrounding buildings should be considered.
predict building energy performance to understand their environmental impact has become a fundamental
research issue. In this paper, a method for evaluating a building’s energy performance by
enlarging the assessment perspective from a single building to a network of buildings is proposed and
applied. The purpose of this research was to establish how a combined Inter-Building Effect (IBE) on
energy consumption could work and how it could condition buildings’ energy performance when there
are close spatial relationships among buildings. To examine this, a simulation of the energy performance
of a whole network of buildings represented by a realistic block of twenty single-family homes subject to
different climatological contexts was conducted. The results demonstrate that buildings can mutually
impact the energy dynamics of other buildings and that this effect varies by climatological context and by
season. The IBE analysis and the specific proposed methodology revealed energy requirement modeling
inaccuracies of up to 42% in summer (in Miami, FL) and up to 22% in winter (in Minneapolis, MN). These
findings demonstrate that in order to accurately predict the energy performance of a single building, the
IBE created by the spatial relationship with surrounding buildings should be considered.
Cool roofs represent an acknowledged, relatively simple and low cost strategy to reduce cooling energy demand of buildings and mitigate urban heat island phenomena. The purpose of this paper is to study the coupled passive-active effect... more
Cool roofs represent an acknowledged, relatively simple and low cost strategy to reduce cooling energy demand of buildings and mitigate urban heat island phenomena. The purpose of this paper is to study the coupled passive-active effect produced by such a technology , where the active effect consists of the cool roof capability to decrease the suction air temperature of heat pump external units, when these units are located over the roof. This “cooling” benefit produces an extra-increase of the energy performance of the heat pump in cooling mode, given that it produces the decrease of the temperature lift between the source and the output. In order to study this twofold effect, an industrial building with an office area located in Rome, Italy, was continuously monitored in summer 2012. The main results showed that the cool roof allows to decrease the roof overheating up to 20°C. The office indoor air temperature also decreased, even if the same set-point temperature was kept constant during the whole campaign. The energy requirement for cooling decreased by about 34%. In order to investigate the “active” contribution, suction air temperature was monitored and a new simple analytical model is proposed in order to estimate the cool roof active effect.
Dynamic simulation is used in new buildings and renovations with the purpose to predict their thermalenergy performance, typically assuming a standard use of the buildings. Even if the role of occupants’ behavior is widely acknowledged to... more
Dynamic simulation is used in new buildings and renovations with the purpose to predict their thermalenergy
performance, typically assuming a standard use of the buildings. Even if the role of occupants’
behavior is widely acknowledged to be a key factor influencing energy consumption in buildings, these
predictive models are not used to quantify specific benefits deriving from precise occupants’ actions. In
this work, a numerical–experimental campaign is carried out in a village of green buildings in central
Italy, where the most innovative and efficient technologies are already implemented and, therefore,
where further physical active or passive retrofits would not be cost-effective. This work demonstrates
that, through a sophisticated theoretical–experimental modeling of a residential village, a substantial further
energy saving is still to be achieved through zero-cost simple actions, i.e. human-based energy retrofits.
Ordinary actions of energy waste reduction are described within the physical model with the final
purpose to quantify the effect of occupancy operations considered at the same level of traditional physical
retrofit scenarios. The combination of these human-based energy retrofits produces an annual personal
primary energy saving of 239 kW h/person in the village, and a corresponding annual money saving of
84 €/person. This work shows that, when theoretical dynamic simulation models are performed in order
to investigate buildings’ thermal-energy behavior and predict the cost-benefit efficacy of common physical
energy retrofits, simple and effective human-based energy retrofits should be considered at the same
level of physical retrofits, and even before them, for their intrinsic technical and economical efficacy.
performance, typically assuming a standard use of the buildings. Even if the role of occupants’
behavior is widely acknowledged to be a key factor influencing energy consumption in buildings, these
predictive models are not used to quantify specific benefits deriving from precise occupants’ actions. In
this work, a numerical–experimental campaign is carried out in a village of green buildings in central
Italy, where the most innovative and efficient technologies are already implemented and, therefore,
where further physical active or passive retrofits would not be cost-effective. This work demonstrates
that, through a sophisticated theoretical–experimental modeling of a residential village, a substantial further
energy saving is still to be achieved through zero-cost simple actions, i.e. human-based energy retrofits.
Ordinary actions of energy waste reduction are described within the physical model with the final
purpose to quantify the effect of occupancy operations considered at the same level of traditional physical
retrofit scenarios. The combination of these human-based energy retrofits produces an annual personal
primary energy saving of 239 kW h/person in the village, and a corresponding annual money saving of
84 €/person. This work shows that, when theoretical dynamic simulation models are performed in order
to investigate buildings’ thermal-energy behavior and predict the cost-benefit efficacy of common physical
energy retrofits, simple and effective human-based energy retrofits should be considered at the same
level of physical retrofits, and even before them, for their intrinsic technical and economical efficacy.
Building modeling and energy performance assessment models have become fundamental tools for both designers and researchers. Spanning the boundary of single building analysis, the purpose of this paper is to investigate how buildings... more
Building modeling and energy performance assessment models have become fundamental tools for both designers and researchers. Spanning the boundary of single building analysis, the purpose of this paper is to investigate how buildings energy performance is influenced by Inter-Building Effects (IBE). Previous research has examined IBE impact on cooling and heating energy performance predictions across buildings, however, the impact of IBE on lighting, which may be substantial, has not been examined. We investigated this impact through coupled numerical and experimental analysis. We built upon and further validated the Inter-Building Effect approach through modeling the contribution of lighting energy use on IBE and through the use of empirical data for model calibration. We demonstrated that the energy use performance prediction deviations resulting from lighting IBE are greater than those from heating or cooling in a case study building and we described this expanded IBE calculation and assessment as IBEII. To further confirm the reliability of the findings, we replicated the analysis for four different building orientations and observed non-negligible primary energy requirement modeling errors irrespective of orientation. This demonstrates the critical need to include lighting in IBE calculations to more accurately model primary energy requirement for buildings in urban contexts.
In the last couple of decades cool roofs, i.e. roof surfaces exposed to solar radiation charac-terized by high solar reflectance (albedo) and thermal emittance, are being intensively stud-ied for their ability to reduce the roof... more
In the last couple of decades cool roofs, i.e. roof surfaces exposed to solar radiation charac-terized by high solar reflectance (albedo) and thermal emittance, are being intensively stud-ied for their ability to reduce the roof temperature, which leads to a lower heat transfer into the building. This acknowledged phenomenon produces better indoor thermal comfort condi-tions and reduced energy requirement for cooling, resulting in lower greenhouse gas emis-sions. Additionally, cool roofs are also studied and optimized for their larger scale effect as Urban Heat Island mitigation strategy in dense cities. In this perspective, several reflective coatings and materials were used for cool roof applications, e.g. light color paintings, roof tiles and waterproof membranes. Recent research developments were also focused on the analysis of natural and sustainable materials having these properties. In particular, stone ag-gregates were studied for their intrinsic cooling potential with varying grain size and stone typology. Roof covered by stone aggregates can be considered as a rigid frame porous mate-rial whose acoustic properties can lead to similar advantages to the thermal ones: (i) a small scale benefit, i.e. an increased sound reduction index of the roof with a consequent lower sound transfer into the building; (ii) a larger scale benefit, i.e. a reduction of the environmen-tal noise thanks to the increased sound absorption coefficient. This paper reports the results of the measurement campaigns of sound absorption and transmission loss carried out on dif-ferent samples of loose gravel with different grain size and thickness. To this aim, several experimental analyses by means of impedance tube according to the transfer function meth-od described in ISO 10534-2 were carried out. Several comparative considerations between acoustic and thermal-energy experimental results represent the object of this contribution, with the final purpose to optimize this roof typology for its twofold potential.