Energy performance measurement, monitoring and control for buildings of public organizations: Standardized practises compliant with the ISO 50001 and ISO 50006

Abstract The International Standards ISO 50001 and ISO 50006 can be easily transferred to organizations, which outputs consist of tangible products. However, it is equally important to build an energy management system tailored to public organizations, whose outputs are often immaterial goods and in which buildings highly affect the overall energy performances. Commonly, energy performances of buildings are assessed by comparison with sector-based benchmarks, whilst monitoring and control practises are often overlooked. Under these premises, this paper aims at proposing a common framework for an energy management system tailored to public organizations in which buildings play a pivotal role in targeting energy performance improvement. The proposed energy management system also relies on the effective exploitation of monitoring and control tools to promptly identify deviations from the expected energy performance values and to evaluate improvements over time

Sensitivity analysis for room thermal response

The sensitivity theory is a suitable approach for assessing the room thermal response. It results in the 'sensitivity coefficients' (SCs) which, as derived here, evaluate the variation of the thermal load due to a fluctuation in a given design parameter around its nominal value. In this paper the general method is presented and a number of SCs are derived to evaluate the sensitivity of the building energy demand to the window surface area, to the overall transmittance and mass thermal capacity of a given wall, and to other structural data

Assessment of thermal discomfortin non-uniformly heated enclosures: Two indices in the time-space domain

In this paper two indices are proposed to assess the thermal discomfort in not-uniformly heated enclosures in the time-space domain. The discussion of some meaningful cases reveals that living spaces are subject to significant non-uniform radiant heat fields, resulting in thermal discomfort. In order to quantify such effects, the concept of 'uniform equivalent temperature' is invoked. This allows two indices i+ and i− to be developed for assessing the thermal discomfort in intensity and duration. Such indices have a clear physical meaning and therefore may provide substantial help in detecting causes and/or locations of thermal unpleasantness. On this basis a necessary but not sufficient condition for thermal comfort is stated in the form: i+ = i− = 0, to be sought everywhere within the room. Further examples illustrate the value of the procedure in thermal comfort conscious design

Application of the Complex Network Theory in Urban Environments. A Case Study in Catania

Abstract Cities are responsible for the 70% of the world's energy demand and represent the largest source of GHG emissions. The constant growth of cities encourages towards the configuration of urban energy plans in order to make urban areas more sustainable places. In this direction, Decentralized Energy Systems (DES) play an important role in order to improve the efficiency in urban energy consumptions. However, the decentralization of urban energy systems requires a comprehensive evaluation of the energy interactions that can occur among consumers. To this aim, proper mathematical models need to be defined in order to take into account how those interactions occur. In this paper, a mathematical procedure based on the complex network theory is introduced and tested to a neighborhood within the city of Catania

Local Production and Storage in Positive Energy Districts: The Energy Sharing Perspective

In response to the Positive Energy District transition, this paper proposes an energy tool for the modeling of energy sharing configurations among buildings equipped with energy production systems and distributive storages. The model is targeted for urban planners and energy policymakers and gives insights into the role of buildings in fostering the achievement of net-zero energy balances in districts when virtual or physical peer-to-peer configurations are established in the area. A real urban district is considered as a case study and the energy performances are measured against properly defined Key Performance Indicators. Results confirm the strategic role played by energy sharing among buildings in achieving self-sufficient and carbon-neutral areas. In particular, the insertion of storages allows not only for higher self-sufficiency of the area (by facilitating the coupling of production and demand) but also for higher distribution rates among buildings. However, photovoltaic insertion and storages should be appropriately balanced since it has been observed that at increasing the number of production and storage systems, the distribution is reduced in favor of autonomy, thus limiting the usefulness of an interconnected local distribution grid

Multi-sector mitigation strategies at the neighbourhood scale

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On the effect of the aspect ratio on the mixed convection in a vertical cylindrical cavity with rotating inner wall

The thermal fluidynamic behaviour of a variety of fluids filling either vertical cylinders or vertical annuli under external conditions giving rise to natural convective motions has been thoroughly investigated, both experimentally and numerically, because of the several possible engineering applications that can be well approximated and described by these kinds of configurations. This study aims at investing through a numerical analysis the mixed convection arising inside cavities formed between two horizontal adiabatic disks and two isothermally and differentially heated vertical cylindrical walls, one of which is rotating. Previous studies reported and discussed the role played by both the Rayleigh number the Reynolds number for the case of the rotation of either the inner or the external wall and for a specified geometry of the cavity. The focus of the present study is to analyse the role played by the aspect ratio, A=H/(Re-Ri), for the case of rotating inner cylinder. It is reported that this role is particular relevant with respect to the flow structures established within the cavity and, as a consequence, also with respect to the Nusselt number

application of a mapping tool to plan energy saving at a neighborhood scale

Abstract This study proposes the application of a model for the evaluation of the overall energy demand of existing urban neighborhoods, which can be useful when planning energy enhancement strategies at urban scale. The application of this model can be interconnected with the use of a GIS software tool, thus providing the opportunity to perform the energy mapping of city neighborhoods. In the proposed model, the overall energy demand of existing urban neighborhoods is evaluated by considering the three most energy intensive sectors: buildings, transport and urban lighting. However, in this paper the application of the model is only focused on the assessment of the energy demand in the building sector. The proposed methodology is applied to a neighborhood of the municipality of Catania in Southern Italy. The preliminary results are reported in this study: first, the existing energy consumption for space heating and electric appliances is assessed, then the effectiveness of a series of energy-saving strategies is considered, thus providing a tool to implement effective energy planning policies at urban scale

uhi effects and strategies to improve outdoor thermal comfort in dense and old neighbourhoods

Abstract Modelling techniques have received growing attention as a tool to investigate the thermal comfort within a city, on the basis of which decision makers can set-up appropriate mitigation strategies. This research aims at studying the effectiveness of strategies for reducing the urban heat island-associated effects in dense and old neighborhoods considering, in particular, green roofs, cool roofs, cool pavements, green areas and urban renewal actions. Computer simulation was selected as the major methodology in this research; ENVI-met software was used under different scenarios for a case study consisting in an old neighborhood in the city of Avola. The investigation focused on evaluating the efficacy of each strategy for a condition corresponding to a typical summer heat wave. The results highlight that the cool pavements allow relevant improvements at the height of 1.50 m, with a temperature decrease up 1.15°C, whereas the other scenarios, given the relatively high density of the buildings, are able to improve outdoor conditions only at higher elevations. Reported results represent a guideline for the choice of UHI mitigation method that can help stakeholders involved in new urban assessment of old neighborhoods in Mediterranean climate