Energy and Water Monitoring for a Large Social Housing Intervention in Northern Italy

In recent years, the awareness of the problem of the performance gap and rebound effect extends the interest in assessing the real operation of buildings, in assessing how buildings match users' needs once they are occupied, and in understanding how occupants' behavior affects the actual building performance. The paper discusses the case study and presents the results of a monitoring campaign of 2 years of occupancy of a large social housing intervention recently built near Milan, for a total of 152 flats. Data about the thermal energy consumption for heating and cooling, the domestic hot and cold water use, and the occupants' intervention on controlling devices are assessed and presented. The case study is representative of the actual design and construction of high-performing multi-family buildings in Italy. All the buildings are class A rated, very highly insulated, and ventilated with centralized mechanical ventilation systems with thermodynamic heat recovery. Centralized water-to-water heat pumps supply hot and refrigerated water for heating and cooling and domestic hot water as well. A building monitoring system is installed, able to track energy and water consumption, factors influencing the energy consumption not related to the building characteristics (weather data, operational setting) as well as the overall building performance data. The results show unexpected high energy and water consumption and moreover a large variability of the energy and water consumption pattern among the dwellings and between the years due to the significant influence of the occupants' behavior and habits

Energy-optimized versus cost-optimized design of high-performing dwellings: The case of multifamily buildings

Living in multi-family buildings is very common in Italy and it is important to optimize the design strategies to minimize the energy demand of these buildings and their related operational costs. This is particularly important for low-income tenants, and is pursued by many social housing developments where a good energy performance design is reached. In this work, a simulation-based optimization methodology that combines the use of TRNSYS® with GenOpt® is applied in order to minimize two objective functions - the annual primary energy demand and the operational energy cost - in different system technology scenarios, and verify the differences between energy-optimized design and cost-optimized design in a northern Italy climate. The study is performed on a typical floor of a real multi-family building for social housing. The envelope optimization demonstrates a potential reduction of the energy demand and cost for heating and cooling of more than 35%. The relationship between optimal solutions, system technology scenarios and optimization objectives is deeply analyzed. It is possible to find a set design solutions that are optimal in all the analyzed scenarios. This provides a set of design alternatives that are close to the environmental optimum and are able to reduce the low-income tenants vulnerability

Building monitoring system in a large social housing intervention in Northern Italy

Within the framework of the well-known problem of the performance gap, the paper demonstrates how a building monitoring system is able to provide feedback data instrumental to address the ongoing management issues of multi-family buildings in social housing: the need to have a good understanding of what works and what does not in building operation, the need of bills controlling and allocation of individual costs between the occupants, the facility and energy management requirements including the understanding of occupant’s behavior. It adopts a case study approach, discussing the case of a large environmentally friendly social housing intervention consisting in 323 flats, in which a building monitoring system was installed

A Simulation-Based Optimization Method for the Integrative Design of the Building Envelope

AbstractAn effective design of green buildings requires a process of optimization to meet all the sustainability goals through an integrative design approach. The research focuses on the development of a replicable methodology for the optimization of the building features that affects specifically the energy demand and indoor comfort conditions.Optimal design solutions are found following two steps: minimization of the total energy demand for heating, cooling and lighting coupling TRNSYS®, a dynamic simulation software, and GenOpt®, a Generic optimization program; a post-processing analysis considering thermal and visual comfort aspects. This optimization methodology was conducted on a school classroom case-study

Influence of envelope design in the optimization of the energy performance of a multi-family building

In Europe, the recast of the Directive on the Energy Performance of Building and the consequent Zero Energy Buildings objective that has to be reached for all new buildings by 2020, lead designers to re-think building design as a complex optimization problem aimed at identifying the most effective strategies to improve building performance.These strategies can help reducing not only the climate change effect, but also the risk of energy poverty for low-income households. This work is intended to apply a simulation-based optimization methodology for optimizingthe energy performance of a multi-family building for social housing. The method combines the use of TRNSYS® withGenOpt®. A typical floor of a real case study was modeled and the impacts of the variation of several design parameters on the heating and cooling demand wereassessed.The optimization lead to reduce the primary energy demand of a floor by 36%. The resulted differences in performance and energy rating between flats were analyzed

Influence of envelope design in the optimization of the operational energy costs of a multi-family building

The international efforts for improving energy efficiency in buildings and reducing their environmental impact also constitute a challenge for working against the risk of energy poverty. The work aims to test a methodology for optimizing the operational costs of the different flats of a multi-family building for social housing. The method combines the use of TRNSYS building energy simulation program with GenOpt Generic Optimization program in a so-called simulation-based optimization method. A typical floor of a real case study building was modeled and the energy costs for heating and cooling due to the variation of design variables related to the building envelope was studied. The optimization led to reduce the total operational costs of the flats by the range 17%-23%. The different share of heating, cooling, ventilation and DHW in the total operational costs was studied and resulted differences in energy rating and costs between flats were analyzed

Measuring the sustainability through a life cycle perspective: the case of Sunslice, a ZEB for high density urban environment

The ecological optimization of construction and disposal of nearly zero-energy buildings is the crucial step for the future. In order to confront the main challenges of the building sector, limited resources as well as the energy-efficiency and a sustainable building stock, a life cycle view is required. The life cycle perspective draws boundaries to include all phases of the building lifetime - materials, construction, use (including operating energy), replacement, end of life - and allows a representative characterization of cumulative environmental impacts over the life of the building. Coupling an LCA model in SimaPro with a detailed energy simulation model carried out with EnergyPlus, it is possible to adopt a comprehensive approach that focuses on the the impact of a set of Sunslice technical features: a dry reversible construction system with an aluminium structure, an eco-efficient envelope, passive design strategies, photovoltaic power generatio

Measuring the sustainability through a life cycle perspective: the case of Sunslice, a ZEB for high density urban environment

The ecological optimization of construction and disposal of nearly zero-energy buildings is the crucial step for the future. In order to confront the main challenges of the building sector, limited resources as well as the energy-efficiency and a sustainable building stock, a life cycle view is required. The life cycle perspective draws boundaries to include all phases of the building lifetime – materials, construction, use (including operating energy), replacement, end of life - and allows a representative characterization of cumulative environmental impacts over the life of the building. Coupling an LCA model in SimaPro with a detailed energy simulation model carried out with EnergyPlus, it is possible to adopt a comprehensive approach that focuses on the the impact of a set of Sunslice technical features: a dry reversible construction system with an aluminium structure, an eco-efficient envelope, passive design strategies, photovoltaic power generation