Search

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]

Abstract: According to the Energy Performance of Buildings Directive (EPBD) all new European buildings (residential, commercial, industrial, etc.) must since 2006 have an energy declaration based on the calculated energy performance of the building, including heating, ventilating, cooling and lighting systems. This energy declaration must refer to the primary energy or CO2 emissions. The European Organization for Standardization (CEN) has prepared a series of standards for energy performance calculations for buildings and systems. This paper presents related standards for heating systems. The relevant CEN-standards are presented and a sample calculation of energy performance is made for a small single family house, an office building and an industrial building in three different geographical locations: Stockholm, Brussels, and Venice. The additional heat losses from heating systems can be 10–20% of the building energy demand. The additional loss depends on the type of heat emitter, type of control, pump and boiler. [Copyright &y& Elsevier]

Abstract: HVAC (Heating, Ventilation and Air Conditioning) systems used for heating or cooling buildings, consume a considerable amount of energy. To optimize the energy consumption, the behavior of occupants must be changed. This can be achieved by providing information and suggestions to occupants. A first step is developing of a less expensive and non-invasive measurement system and metering of the electricity and heat consumed. Based on collected experimental data, it can identify the parameters of a thermal model of the house. The model obtained will be used to simulate different aspects that can help to reduce the energy consumption. This paper presents a simple solution for thermal modeling of a house which includes experimental identification of the model''s parameters. Such data are used to simulate the thermal behavior of the house and to obtain solutions to reduce energy consumption. In simulation, the control of the thermal system is performed using a model based predictive control algorithm. [Copyright &y& Elsevier]

Abstract: This paper presents an evaluation of energy-related and economic aspects of production of thermal energy to heat a family house with wood briquette. The object of the study was a detached house with an area of 247m2, situated in Olsztyn, in the north-east of Poland. The study lasted three years, from October 2006 to September 2009. The highest monthly consumption of wood briquette for thermal energy production: heating water for the central heating system and hot utility water production were recorded in January (1052–1333kg/month). The average annual briquette consumption ranged from 6.36 to 6.72t/year. With the mean lower heating value of briquette of 17.99GJ/t, the mean consumption of energy in the fuel ranged from 114 to 121GJ/year. The annual cost of heat production for a family house with briquette as fuel ranged from €572 to €651, during the 2006/2007 and 2008/2009 seasons, respectively. It would have been cheaper by €187–228year−1 to heat the house with seasoned willow chips, whereas using alternative fuels, such as hard coal (fraction 0.5–2.5cm) oak pellets, natural gas and heating oil would have increased the cost of heat production. If the last of those fuels had been used, it would have increased the cost 3.5-fold as compared with wood briquette. [ABSTRACT FROM AUTHOR]

Abstract: This paper analyzes the thermal and energy behaviour of apartments in three-story block buildings located along a NE-SW axis (azimuth=120°) in a temperate-cold climate (latitude: 36°57′; longitude: 64°27′) in the city of Santa Rosa, La Pampa, central Argentina. Four apartments had been monitored during May and June 2009. Three of them are located in Block 126. Two of these apartments face South: 15 and 23 on the SE end, ground and first floor, respectively; 18 faces N on the second floor. Finally apartment, 12 is located in Block 374, on the first floor, faces N and shows a carpentry-closed balcony. The purpose of this work is – to study the evolution of the indoor temperature in each apartment; to analyze energy consumption and comfort conditions; to study energy potential and energy intervention in order to reduce energy consumption; to analyze bioclimatic alternatives feasibility and the possibility to extrapolate results to all blocks. On the basis of the analysis of natural gas historical consumption records, results showed that regarding heating energy consumption during the period May–June, Apartment 12, facing N, with its only bedroom facing NW and its carpentry-closed, transparent glass balcony, presented a mean temperature of 21.2°C, using a halogen heater for 6h/day between 9pm and 2am (0.16kWh/day/m2). Apartment 15, on the SE end, first floor of the block consumed 22.5kWh/day (0.43kWh/day/m2) (mean temperature=22.2°C). Apartment 23, located on the second and top floor (on top of Apartment 15) with higher energy loss, consumed 28kWh/day (0.54kWh/day/m2) (mean temperature=23.7°C). Apartment 18, also on the second floor and facing N, located in the centre and with its only bedroom facing SE, consumed 18.8kWh/day (0.48kWh/day/m2) (mean temperature=22.3°C). Apartment 23, with higher thermal loss through its envelope, but with heat transfer from the apartment located below, is the one that showed the highest level of consumption/m2. Closing the balcony with carpentry produced an important reduction of energy consumption while reaching comfort conditions. The analysis of the experimental results allowed: (a) to determine through analysis of historical consumption of natural gas prior to the year 2009 that the owner lived under conditions of comfort, (b) to evaluate possible interventions in the building that would lead to saving heating energy. Thermal insulation of roof and envelope appears as the most feasible alternative whereas closing balconies constitute a very good design option in winter. [Copyright &y& Elsevier]

Abstract: A traditional Chinese heating system, the Chinese Kang, is used by 175 million people in detached houses in the rural regions of China, especially in Northeast China. This system utilizes biomass such as corn stalks, straw, corncob and energy plants as the heat sources. The objective of this paper is to establish a set of models to simulate the energy performance of the Kang heating system in one Chinese detached house. An experimental field study was carried out to collect practical parameters in a newly constructed Chinese detached house. The dynamic performance of the Kang heating system was simulated by using IDA-ICE 4.0 embedded with an empirical model built in the field study. The results show that the simulation can obtain good overall agreement with the field measurement results. It was confirmed that the Kang model created by IDA-ICE 4.0 is capable of simulating the performance of the Kang system and of calculating energy consumption in the detached house. Moreover, the result reveals that the thermal environment in the present Chinese detached house is still poor during the severe cold season if only the Kang system is used to heat the whole house. [ABSTRACT FROM AUTHOR]

Abstract: The energy performance of two bioclimatic buildings located in Santa Rosa city, a temperate semi-arid agricultural region of central Argentina, is analysed. The bioclimatic design included direct solar gain, thermal inertia, natural ventilation, thermal insulation, external shading, building orientation, and dwelling grouping. Each double-story building is aligned on an East–West axis and it has a compact shape with 350m2 of useful floor area (58m2/apartment). The solar collection area is around 18% of the apartment''s useful area on the ground floor and 14% on the upper floor. This paper describes the energy performance of the buildings during the period 2001–2008. The analysis includes: (a) the energy consumption (natural gas and electricity) during 2001–2007 (natural gas: annually, bimonthly; electricity: monthly); (b) the natural gas consumption and the thermal behaviour during the winters of year 2001 (between July 27 and August 3) and 2008 (between August 8 and 13); (c) the daily natural gas consumption and the thermal behaviour during 2001 and 2008 winters; (d) the comparison between the energy consumption for heating in bioclimatic and conventional buildings. The authors concluded that the results confirm the large potential of solar buildings design to reach significant levels of energy saving. The comparison of solar and conventional buildings in terms of natural gas consumption demonstrates the magnitude of such potential. [Copyright &y& Elsevier]