Energy Consumption For Space Heating Research Articles

Demand side digitalisation: A methodology using heat cost allocators and energy meters to secure low-temperature operations in existing buildings connected to district heating networks

With regard to the green transition toward 4th generation district heating (4GDH), a critical element is ensuring low operating temperatures in networks. This can help leverage the technical and economic potential of connecting renewable energy sources and recovering excess local heat. Poorly controlled and operated heating systems in existing building stocks limit the possibility of lowering the operating temperatures of district heating networks. Hence, digitalising the demand side can afford new opportunities for building services by monitoring heating systems and improving operations to secure the expected comfort in existing buildings with lower temperatures. Accordingly, this study investigated the innovative use and integration of data from heat cost allocators, district heating energy meters, and temperature sensors to improve space heating system operations. Based on the measurements, the methodology focused on identifying the critical flat in the building with the highest heat demand and calculating the minimum possible operating temperature. Five Danish multi-family buildings were considered as case studies in the investigations, highlighting good agreement between the new weather-compensated control curve and the measurements. Almost 75% of the total space heating consumption was distributed under outdoor temperatures exceeding 0 °C in 2021, whereas only 0.5% was associated with the lowest outdoor temperature of −9 °C. This clearly suggests that design conditions rarely occur during the typical operation of systems and that the radiators are oversized and suitable for operation at low temperatures for most of the heating season. Notably, it was documented that supply temperatures of 48–53 °C were sufficient to secure the expected comfort at an outdoor temperature of 0 °C, without any extensive energy renovation in the buildings.

Residential Building Construction Techniques and the Potential for Energy Efficiency in Central Asia: Example from High-Altitude Rural Settlement in Kyrgyzstan

Building construction in rural Kyrgyzstan is heavily dominated by earthen buildings. Old and inappropriate residential building structures contribute significantly to high domestic space heating energy consumption. Therefore, it is necessary to understand the relevant building construction techniques. However, the scant information on Kyrgyz building techniques, especially for high-altitude rural settlements, was the prime motivation to perform the presented study. The key objective of the study is to investigate residential building construction techniques in high-altitude rural Kyrgyzstan, and this was to be achieved by house visits during field trips, literature review, and pilot interviews with local people. The analysis enabled the detailed identification of individual building envelopes as well as predominant building materials to be recorded. Based on the assessment, a housing profile was created that represents the typical characteristics of traditional rural Kyrgyz houses. Furthermore, the study demonstrates the potential for energy savings in rural Kyrgyz houses of 50–70%. However, local conditions prevent people from making improvements to all domestic energy efficiency parameters simultaneously. Therefore, the study developed a ‘sequential roadmap’ to reduce domestic space heating demand in different phases based on simulation studies. Existing low-income rural Kyrgyz habitations can use the presented roadmap to reduce domestic space heating demand sequentially to overcome financial barriers and, therefore, contribute to establishing sustainable buildings in Kyrgyzstan. These results may be partially replicated in other Central Asian rural communities depending on their location and building characteristics.

Comparative Economic and Experimental Assessment of Air Source Heat Pump and Gas-fired boiler: A Case Study from Turkey

Since sustainability has become a major concern in the construction industry, making economically efficient investment decisions in energy conservation are needed to minimize energy consumption for space heating and cooling. Although Air-Source Heat Pump (ASHP) systems are used to meet buildings’ heating and cooling demands worldwide, high initial setup costs limit the widespread use of these systems. This paper presents comparative assessment of ASHP system versus conventional gas-fired boiler system for a real commercial building with a floor area of 2500 m2 in Istanbul, Turkey. The key performance variable, Coefficient of Performance (COP), of the ASHP system was experimentally evaluated. The experimental results revealed that the system’s COP ranged from 3.22 to 4.32, while the outside temperature ranged from 4.8 to 18.6 °C and the supply water temperature ranged from 32.2 to 36.2 °C. Moreover, the economic analysis results showed that despite the high initial cost, ASHP systems are cost competitive against gas-fired boiler in Turkey. ASHP system could reduce the present value of total Life-Cycle Cost (LCC) by up to 26.4% (47,865 USD) compared to the conventional gas-fired boiler system because it can dramatically reduce the energy consumption per year

Assessing drivers of residential energy consumption in Turkey: 2000–2018

The residential sector, which represents one-third of global energy consumption and 40 % of CO2 emissions, has recently gained more attention with the long-term ambitious climate targets. The right pathway can be tracked by unveiling energy efficiency potential in residential buildings. This study aims to understand the reasons behind the increase in Turkish residential energy consumption and conduct a quantitative analysis to calculate the contribution of energy efficiency improvements to reduce energy consumption in Turkey between 2000 and 2018 using the decomposition analysis methodology Logarithmic Mean Divisia Index-I. Results show that the increase in population and wealth leads to a rise in residential energy consumption by 4.95 mtoe and 9.01 mtoe, respectively. The milder climatic conditions have resulted in a 2.25 mtoe reduction in space heating energy consumption. Energy efficiency resulted in a saving of 9.16 mtoe energy during the analysis period. Improvements in space heating made the most significant contribution to energy savings. Because of the increased ownership rates of dishwashers and washing machines, the only end-use -where energy intensity did not improve- is seen as domestic hot water. The analysis also revealed that the Energy Efficiency Law and its secondary legislation have significantly accelerated energy efficiency improvements. The methods employed in this study can simply be adapted to any country to enlighten the policymakers in choosing the best policy options.

Investigation of Thermal Energy Accumulation Using Soil Layer for Buildings’ Energy Efficiency

The cold climate countries require high energy consumption for buildings’ heating. According to EU directives and national law, buildings’ energy efficiency is increasing due to higher investment in the sector. Primary energy consumption for space heating still comprises a large part of global energy consumption. It is essential to develop technological solutions and innovations to reduce energy consumption by using newer, smarter, more natural energy generation and accumulation. The soil layer could be used as a natural material for thermal energy accumulation. The soil’s temperature is higher than atmospheric air in the heating season and is lower in the non-heating season. Underground buildings placed in a soil medium could use less thermal energy for buildings’ heating and cooling during its life cycle. The impact of the wind is eliminated in this underground building case. As the soil temperature rises, the difference in temperature of the building’s inside air and the soil decreases. This means that the heat loss into the soil generates the conditions acting against the heat loss. However, heat spreads further and dissipates in the surrounding soil medium. The analysis of this research results showed that the savings in energy could reach 28 percent in the case of the underground building. Heat loss to the soil could be treated as the charge of the soil by thermal energy. The charging by heat and heat dissipation in the soil was researched experimentally. The dependence of the intensity of the charge on time was analysed and presented in this paper also.

Thermal performance of building prototype with different cool roof structures in composite climate

ABSTRACT In the domestic sector, buildings contribute to about 55% of the total energy consumption for space heating and cooling. In this study, an experiment was carried out using a square shape building prototype made up of laminated plywood with Reinforced Cement Concrete (RCC) roof. Surface treatment of four types of reflective paints was applied on the RCC roof slab. Their performance was monitored in the summer season (April and May). Based on the peak temperature of interior and exterior roof layers, several important parameters, such as temperature, indoor thermal amplitude, time lag, decrement factor, thermal damping, thermal performance index, peak degree hours and thermal performance of each roof slab, were analysed. The application of cool roofs (CR-1, CR-2, CR-3, and CR-4) shows a significant reduction in indoor temperature (2.1°C–3.2°C), and indoor thermal amplitude (16.10%–27.94%) compared to a standard RCC roof. The drops in peak temperature of exterior and interior roof layers were 4.8°C–6.8°C and 3.9°C–6.3°C, respectively. A significant improvement was achieved in time lag and decrement factor (3–4 h more than the reinforced concrete roof), with energy savings varying from 10.58% to 13.73%.

A Bayesian approach with urban-scale energy model to calibrate building energy consumption for space heating: A case study of application in Beijing

Urban-scale energy model can be a crucial tool for evaluating and in turn propelling the implementation of energy efficiency and low carbon programs for buildings and cites. A variety of disputes on integrity and correctness lie in basic statistical data of China's building energy use. Inadequate information and performance gap caused by input uncertainties are the common obstacles to produce reliable energy modelling results. This paper develops a bottom-up approach to depict energy use intensity (EUI) for space heating of building in the urban level accurately, even if the data resource is inadequate and imprecise or the data are influenced by uncertain issues. A hybrid probability model is developed and the model parameters are calibrated by Bayesian inference and Markov Chain Monte Carlo simulation using data set of meter reading from 2062 stochastic-sampled heating substations in Beijing. Preparation and simulation efforts of using this energy model are discussed, following this framework and adjusting according to local climate conditions, typological building characteristics and morphological urban-scale parameters. The results show that the approach is reliable and efficient to calibrate parameters in building energy models. The urban-scale benchmarks of EUI for space heating in Beijing is successfully performed to demonstrate the proposed methodology.

A Review on Energy-Sustainable Design and Operation of Greenhouses for Plant/Crop Production in Cold Regions

HighlightsIn cold regions, the immense energy consumption for space heating of greenhouses is a significant problem.Energy-efficient measures have been presented for conventional and nonconventional design aspects.Renewable resources have considerable potential to be used in greenhouses.Abstract. The energy consumption of greenhouses in cold regions, especially for space heating, is immense and therefore economically unbearable. The main objective of this article is to provide a comprehensive review of state-of-the-art energy-saving strategies for the design and operation of greenhouses in cold regions. The review covers conventional functions (lighting, air quality and temperature control, and irrigation), nonconventional functions (thermal insulation, thermal energy storage, and utilization of ground-source and renewable energy), and numerical modelling of the energy-performance of greenhouses. For each of these topics, pertinent plant science is provided and performance assessments are presented. The findings from this review conclude that hybrid lighting (LED with high-pressure sodium lamps) and proper scheduling result in the best combination of energy efficiency and plant yield. However, further studies are still required in this field. Keywords: Cold regions, Energy-efficiency, Greenhouse, Sustainability.

Tendencies of Adapting Building Materials and Constructive Solutions to the Present Climate Changes

Abstract The changes occurred on the climate are a reality that produces changes within the socio-economic environment. Climate change is largely due to greenhouse gas emissions generated by human, domestic and economic activities. In this climate, the constructive solutions of buildings must take into account climate changes and meet new requirements. In this context, building materials must improve and correspond to the new paradigm so as to fulfill their basic role, namely: - creating an indoor climate corresponding to the hygienic-sanitary and thermal, - comfort requirements in residential and socio-cultural buildings, - ensuring the necessary indoor climate for carrying out economic activities reducing, as much as possible, the energy consumption for space heating.

Experimental investigation on the effects of phase change material and different ventilation modes on the thermal storage, space heating and energy consumption characteristics of ventilated mortar blocks

Radiant heating floor integrated with micro encapsulated phase change material (PCM) can significantly increase the thermal storage capacity, and inside air channels can enhance the heat release flexibility. In this study, the impacts of micro encapsulated phase change material and ventilation on the thermal and energy characteristics of mortar blocks were experimentally investigated by a scaled system. Several mortar blocks with different amount of PCM were made, and the space heating performance and heating energy consumption were measured and analyzed under the same temperature-based control strategy. It is found out that when the mass ratio of PCM is 8.7%, the required heating time is increased by 78.5% and the thermal storage capacity is increased by 80.3% as compared to pure mortar block. Ventilation can further increase the energy consumption by more than 22.7%. Besides, by shifting the ventilation mode, the space heating and cooling rate can be flexibly adjusted, which is essential for the flexible operation of the new heating system. The concern of the maximum and reasonable weight percentage of the micro encapsulated PCM is also proposed and discussed.

Projecting the impacts of housing on temperature-related mortality in London during typical future years

Climate change means the UK will experience warmer winters and hotter summers in the future. Concurrent energy efficiency improvements to housing may modify indoor exposures to heat or cold, while population aging may increase susceptibility to temperature-related mortality. We estimate heat and cold mortality and energy consumption in London for typical (non-extreme) future climates, given projected changes in population and housing. Building physics models are used to simulate summertime and wintertime indoor temperatures and space heating energy consumption of London dwellings for ‘baseline’ (2005–2014) and future (2030s, 2050s) periods using data from the English Housing Survey, historical weather data, and projected future weather data with temperatures representative of ‘typical’ years. Linking to population projections, we calculate future heat and cold attributable mortality and energy consumption with demolition, construction, and alternative scenarios of energy efficiency retrofit. At current retrofit rates, around 168–174 annual cold-related deaths per million population would typically be avoided by the 2050s, or 261–269 deaths per million under ambitious retrofit rates. Annual heat deaths would typically increase by 1 per million per year under the current retrofit rate, and 12–13 per million under ambitious rates without population adaptation to heat. During typical future summers, an estimated 38–73% of heat-related deaths can be avoided using external shutters on windows, with their effectiveness lower during hotter weather. Despite warmer winters, ambitious retrofit rates are necessary to reduce typical annual energy consumption for heating below baseline levels, assuming no improvement in heating system efficiencies. Concerns over future overheating in energy efficient housing are valid but increases in heat attributable mortality during typical and hot (but not extreme) summers are more than offset by significant reductions in cold mortality and easily mitigated using passive measures. More ambitious retrofit rates are critical to reduce energy consumption and offer co-benefits for reducing cold-related mortality.

Linking energy efficiency indicators with policy evaluation – A combined top-down and bottom-up analysis of space heating consumption in residential buildings

This paper studies the factors underlying the evolution of the energy consumption for space heating in residential buildings by linking top-down analysis, based on meso-indicators, and bottom-up analysis, based on policy evaluations. The top-down analysis (i.e. the perspective from energy statistics) allows one to separate the change in total energy use into activity level, societal factors and energy efficiency gains. The explanatory power of the resulting meso-(statistical) indicators is often limited, if the underlying factors are not examined (e.g. changes in heating levels and patterns, weather effects, cost of energy and policies regarding insulation and heating system standards). We overcome most of these drawbacks by conducting a bottom-up analysis (i.e the perspective from single policy measures), which enables us to discern the contribution of energy efficiency policies to the changes observed with the meso-analysis. We focus on space heating consumption in the residential sectors for Germany and Switzerland. A major aim of this analysis is to show the contribution of energy efficiency policies (such as thermal building regulation, subsidy programmes, fiscal measures etc.) towards the changes in this indicator. The results show that the progress in energy efficiency (both autonomous and policy induced) in both countries had the greatest effect (-776 PJ for Germany, −42 PJ for Switzerland) regarding the change in energy consumption for space heating in the period from 2000 to 2016. However, the impacts of “technical and comfort” rebounds (+436 PJ for Germany, N/A for Switzerland) and other developments such as societal changes (+316 PJ for Germany, +35.5 PJ for Switzerland) were found to compensate for a significant part of the energy efficiency gains. In both countries, it was possible to link physical energy efficiency indicators to policy evaluation, but limitations were also identified which are primarily related to data gaps.

Research on residential thermal environment differences in relation to transition and heating periods in Beijing

In Beijing, municipal central heating is normally scheduled from 15 November each year and energy consumption for space heating is growing rapidly. This field study aimed to investigate residential thermal environment and its effects on subjective thermal responses and behavior adjustments in cold climate. The investigation was conducted in 12 apartment houses in six communities in Beijing from October to December 2019, involving both transition period before the space heating and heating period after the space heating. Indoor environmental parameters were collected by self-recording instruments, while heating equipment, subjective evaluations and adaptive behaviors were obtained though paper questionnaires. The results demonstrated that average air temperature in bedrooms of transition period was 19.5 ± 1.3 °C, significantly lower than 22.9 ± 1.9 °C in heating period. Moreover, there are large variations in indoor thermal environments among the heating systems/equipment. During heating, the interior air in houses was overheated (>24 °C) and low humidity(<30%) for 28.2% and 40.6% of the time respectively, especially above 30% of physical data measured were in prefer-warmer comfort zone, resulting in energy consumption waste and thermal discomfort. Although some of the indoor climate distributions in the transition period were out of the comfort zone, the residents reported that indoor thermal environment was still acceptable through adaptive behavior adjustment. This paper could be beneficial to the design and operation of reasonable heating temperature for both building energy saving and thermal comfort.

Low-Energy Architecture for Sustainable Neighborhoods

Nowadays, energy consumption in buildings is one of the fundamental drivers to control greenhouse gas emissions and environmental impact. In fact, the air quality of urban environments can cause two main phenomena in metropolitan areas: urban heat island and climate changes. The aim of this work is to showcase how different building variables can impact the residential building’s space heating and cooling energy consumption. Buildings energy-related variables can be fundamental viewpoints to improve the energy performance of neighborhoods, especially in future urban planning. This work examines four neighborhoods in the city of Turin (IT): Arquata, Crocetta, Sacchi, and Olympic Village characterized by different morphologies and building typologies. In each neighborhood, residential building was grouped according to orientations and construction periods. A sensitivity analysis was applied by analysing six building variables: infiltration rate, window-to-wall ratio, and windows, walls, roofs, and floor thermal transmittances. The energy consumption for space heating and cooling of residential buildings and local climate conditions were investigated using CitySim Pro tool and ENVI-met. The challenge of this work is to identify the building variables that most influence energy consumption and to understand how to promote high-energy efficiency neighborhoods: the goal is to identify the “ideal” urban form with low consumption and good comfort conditions in outdoor urban environments. The results of this work show a significant connection between the energy consumption and the six analyzed building variables; however, this relationship also depends on the shape and orientation of the neighborhood.

On the real performance of groundwater heat pumps: Experimental evidence from a residential district

• Heat pump is a key clean energy technology for residential buildings. • Monitoring and data analysis is key to optimize system integration and operation. • Real performance of groundwater multipurpose heat pumps is lower than expected. • Improvements to the heat pumps design and control logic are proposed and validated. • Systematic approach for system data collection and analysis is needed. Heat pumps are among the most promising technologies driving energy transitions towards the carbon reduction objectives. Their use is being particularly encouraged in the residential sector, where the heating and cooling uses account for the larger energy demand. However, their real performance often does not correspond to designers’ expectations, leading to higher running energy costs than expected, and the reasons should be primarily investigated by means of large data collection and analysis. This paper reports the results of a long-term monitoring campaign of a multipurpose groundwater heat pump system for a district of multifamily buildings in Italy. The survey includes data on thermal energy consumption for space heating, domestic hot water, space cooling and electricity consumption of the groundwater heat pumps taken between 2017 and 2018. It was shown that the performance of the installed groundwater heat pumps was significantly lower (up to 60%) than expected. Some defined strategies, mainly related to the system control logic, were demonstrated to be able to significantly increase the system performance, highlighting the need for improvements in integrated design and control strategies since the early design phase and for continuous monitoring in operation to optimise the system integration in real contexts.

Evaluation of Urban-Scale Building Energy-Use Models and Tools—Application for the City of Fribourg, Switzerland

Building energy-use models and tools can simulate and represent the distribution of energy consumption of buildings located in an urban area. The aim of these models is to simulate the energy performance of buildings at multiple temporal and spatial scales, taking into account both the building shape and the surrounding urban context. This paper investigates existing models by simulating the hourly space heating consumption of residential buildings in an urban environment. Existing bottom-up urban-energy models were applied to the city of Fribourg in order to evaluate the accuracy and flexibility of energy simulations. Two common energy-use models—a machine learning model and a GIS-based engineering model—were compared and evaluated against anonymized monitoring data. The study shows that the simulations were quite precise with an annual mean absolute percentage error of 12.8 and 19.3% for the machine learning and the GIS-based engineering model, respectively, on residential buildings built in different periods of construction. Moreover, a sensitivity analysis using the Morris method was carried out on the GIS-based engineering model in order to assess the impact of input variables on space heating consumption and to identify possible optimization opportunities of the existing model.

Winter air infiltration induced by combined buoyancy and wind forces in large-space buildings

Excessive winter air infiltration causes high energy consumption for space heating and unsatisfactory indoor environment in large-space buildings, which has not been fully considered in the design and operation stages. This study proposes a simplified method to predict winter air infiltration rate in large-space buildings induced by combined buoyancy and wind forces. The method is based on a theoretical model of indoor space and a CFD simulation of outdoor wind. Compared with a full-scale indoor-outdoor CFD model, the simplified method predicts the air infiltration rate with an average absolute deviation of 5.4% (max: 11.0%). The simplified method is then utilized to discuss the differences between winter air infiltration and natural ventilation in large-space buildings. The average indoor-outdoor temperature difference is only 2.2~4.8 ​K in the natural ventilation condition, while that reaches 10.3~31.6 ​K in the space heating condition. The effective opening area in the natural ventilation condition is 3.5~3.9 times of that in the space heating condition. Therefore, the dominant driven force of buoyancy in the space heating condition results in little possibility of solution multiplicity for winter air infiltration, which ensures the validity of the proposed method.

A Bayesian Approach with Urban-Scale Energy Model to Calibrate Building Energy Consumption for Space Heating: A Case Study of Application in Beijing

A Bayesian Approach with Urban-Scale Energy Model to Calibrate Building Energy Consumption for Space Heating: A Case Study of Application in Beijing

Dynamic Approach to Evaluate the Effect of Reducing District Heating Temperature on Indoor Thermal Comfort

To reduce energy consumption for space heating, a coordinated action on energy supply, building fabric and occupant behavior is required to realize sustainable improvements. A reduction in district heating supply temperature is an interesting option to allow the incorporation of renewable energy sources and reduce distribution losses, but its impact on the final users must be considered. This aspect is especially critical as most European countries feature an old building stock, with poor insulation and heating systems designed for high-temperature operation. In this study, a complete methodology is devised to evaluate the effect of district heating temperature reduction on the end users by modeling all the stages of the system, from the primary heat exchanger to the indoor environment. A dynamic energy performance engine, based on EN ISO 52016-1:2017 standard and completed with a heat exchanger model, is implemented, and its outputs are used to calculate thermal comfort indicators throughout the heating season. As a practical application, the method is used to evaluate different scenarios resulting from the reduction of primary supply temperature of a second-generation district heating network in Northern Italy. Several building typologies dating back to different periods are considered, in the conservative assumption of radiator heating. The results of the simulations show that the most severe discomfort situations are experienced in buildings built before 1990, but in recent buildings the amount of discomfort occurrences can be high because of the poor output of radiators when working at very low temperatures. Among the possible measures that could help the transition, actions on the primary side, on the installed power and on the building fabric are considered. The investigation method requires a limited amount of input data and is applicable to different scales, from the individual building to entire urban areas lined up for renovation.

Energy saving potential for space heating in Chinese airport terminals: The impact of air infiltration

Airport terminals are key infrastructures with rapid development, which have a high level of energy consumption, especially for space heating in cold climate zones. In this study, large-scale field investigations from 2012 to 2019 into the space heating performance were conducted in eighteen Chinese airports terminals. It is indicated that severe air infiltration (air change rate: 0.06–0.56 h−1) is almost the most significant factor influencing space heating (18%–71% of total heat loss). A simplified model of airport terminals is then established and validated to evaluate the energy saving potential of reducing air infiltration. The airtightness of airport terminals can be quantified by the field investigated parameters, i.e., the discharge coefficients of the roof (cr: 1 × 10−5–1 × 10−3) and the gates (c: 0.25–0.55). Improving the airtightness and using the radiant floor in airport terminals can achieve an average reduction of annual heating demand by 84%. Thus, reducing air infiltration provides a feasible approach towards the goal of “zero energy for space heating” in airport terminals. This study sheds light on the current situation of high energy consumption for space heating in airport terminals and provides guidelines for both design and operation.