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Abstract The goal of this paper is to evaluate the advantages achieved through the adoption of low impact energy saving strategies for an independent natural gas fired boiler heating system in a recently built residential building in Rome. For this purpose, an existing apartment was selected as a case study and dynamically simulated in TRNSYS with which the model was validated. Low impact retrofit solutions and heating system management were considered as possible solutions to achieve energy savings. The chosen retrofit solutions consist of envelope elements replacements and building automation controls improvement while heating system management depends on occupants' behavior. Overall, 36 scenarios were considered, starting from the combination of 3 comfort temperature set-points, 2 insulation levels for transparent components, 2 types of zone comfort set-point control with 3 dead-band temperatures. Each case is evaluated in terms of energy results and economic results. The simulation results provide energy savings up to 44% when windows are replaced lowering their transmittance nearby 32%. The choice of a proportional control for zone temperature set-point compared to a simple on-off control guarantee energy saving up to 39% when temperature set-point is low (19 °C) and controls dead-band is 0.5 °C. The effect of different temperature control dead-bands is higher when proportional controls are adopted (up to 40% passing from 2 to 0.5 °C dead-band for 19 °C set-point). Energy consumption reductions up to 63% are achieved if the indoor temperature set-point is lowered 2 °C, underlining the importance of occupants' behavior. At last, an analysis on socio-economic impacts was performed, based on the results of a previous study focused on the externality costs due to pollutants emissions. Highlights • Energy advantages achieved through the adoption of low impact energy saving strategies for an independent gas fired boiler were evaluated. • An existing apartment of a modern residential building in Rome was selected and dynamically simulated in TRNSYS. • 36 energy saving scenarios were considered. • Each case was evaluated in terms of energy and economic results. • An analysis on socio-economic impacts was performed, based on the externality costs due to pollutants emissions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hierarchical approach for automatic layout of an underfloor heating system is proposed. • The routing problem is formulated as a shortest path problem in a proper routing graph. • An order relation is defined to separate the intersecting paths. • A depth-first layout algorithm based on recursion is developed to solve the coverage path planning problem. The layout of an underfloor heating system determines its heating performance. Conventionally, the design is completed by qualified experts using professional software, but this method is inefficient and heavily relies on the experts' previous experience. This paper proposes a hierarchical approach for the automatic design of underfloor heating systems aimed at residential buildings, and the underfloor heating layout problem is decomposed into a routing problem and coverage path planning problem. First, the routing problem is formulated as a shortest path problem in an appropriate routing graph and solved to provide the routing of pipes for further coverage. Subsequently, a depth-first layout algorithm is developed to recursively simplify the coverage path planning problem to obtain the basic rectangle layout, achieving uniform coverage of the given layout zone. Simulation results on two houses show that, unlike one popular commercial platform, the proposed approach generated feasible solutions in all 13 test instances. The new method improved the minimum temperature, average temperature, average percentage of nodes greater than 30 °C, and total energy efficiency by 3.18 °C, 0.79 °C, 3.23%, and 4.19%, respectively, with a lower variance on average. These improvements lead to a higher coverage rate, more even thermal distribution, and stronger robustness under flexible parameter selection. [ABSTRACT FROM AUTHOR]

This paper proposes a novel approach in order to accurately calculate the savings due to heat metering. The approach is based on a detailed dynamic simulation of building-plant systems. The building is geometrically modelled in Google Sketchup and linked to the TRNSYS environment, including an extremely detailed model for the simulation of building thermo-physical behavior. All the models are validated using the data provided by the occupants. The model allows one to evaluate the yearly energy demand, energy supplied by radiators, heat gains, etc. A specific case study is developed for a residential building located in Naples (South Italy). The developed model is used to calculate the building energy demand for 3 scenarios: centralized heating system not equipped with heat metering; centralized heating system with thermostatic valves and not equipped with heat metering; centralized heating system with thermostatic valves and equipped with heat metering. Results show that in case of centralized heating systems equipped with thermostatic valves and heat metering devices, thermal energy savings up to 64% can be reached mainly when the system operates for many hours per day, leading to discounted pay back periods lower than 4 years. • Dynamic analysis of energy performance of building adopting thermostatic valves. • Dynamical analysis of heat metering devices for a residential building. • Dynamic analysis of building energy performance. • Thermostatic valves and heat metering devices are able to reduce by 64% building thermal energy demand. [ABSTRACT FROM AUTHOR]