Energy Consumption For Space Heating Research Articles

Benchmarking building energy consumption for space heating using an empirical Bayesian approach with urban-scale energy model

Calibration of an urban-scale building energy model is crucial for advancing building energy efficiency codes and policies to reduce carbon dioxide emissions whereas the accuracy of the model is challenged by performance gaps resulting from sparse data and uncertainties in modeling. An empirical Bayesian (EB) approach, incorporated a probability-based mixed-effects energy model and Monte Carlo Markov chain simulation, was developed to predict and benchmark building energy use intensity (EUI) for space heating, using the metering data of 2020 stochastically sampled district heating substations from a municipal utility database. The limitations, implementations and performances of different modeling strategy, including EB as well as Maximum Likelihood Estimation (MLE), Maximum A Posteriori (MAP) and Fully Bayes (FB) were compared. The results show that EB strategy achieved superior prediction performance than other strategies on the novel test dataset. The preparation, calibration, and validation efforts for implementing the EB approach were demonstrated. The proposed methodology is recommended as a robust approach for benchmarking urban-scale building EUI, distinguished from other machine learning approaches by requiring fewer training samples, better interpreting uncertainties in the data used, and exhibiting superior generalization capabilities. The proposed methodology was successfully demonstrated through the urban-scale benchmarking of space heating EUI in Beijing.

Occupant-centric dynamic heating demand in residential buildings based on a temporal-spatial combined quantification method

The occupant-centric Part-Time-Local-Space heating mode holds paramount significance for the carbon neutralization of buildings in China. It ensures a harmonious match between heat supply and personal demand in both temporal and spatial dimensions, effectively reducing space heating consumption. However, current studies predominantly focus on the temporal-spatial heating demands of occupants at the room scale, but the zonal scale heating demands remain inadequately explored. Thus, we developed a temporal-spatial combined quantification method to analyze residents’ indoor movement characteristics. It aims to identify the localized subzones in a room where residents have prolonged stays, with spatial boundaries of subzones entirely defined based on high-resolution positioning data. Using this approach, we analyzed the temporal-spatial heating demands of four households under single- and multiple-resident scenarios in typical rooms. Furthermore, we discussed the differences in demand between different heating modes. Results revealed distinctive “local space” demand features in living room and “part time” demand features in dining room. The areas of sofa subzones generally occupied less than 15 % of a room (within 4 m2), and stay durations in dining-table subzones ranged from 0.3 h to 1.2 h. Considering the entire monitored rooms, residents occupied only 4.1–12.1 % in space with 10.7–47.9 % in time per day, highlighting the significant energy-saving potential of the occupant-centric Part-Time-Local-Space heating mode. This evaluation provides a reference for the design and implementation of personalized environmental control system.

Realized dynamic effect of retrofits on energy consumption in Soviet-era multi-apartment buildings

Retrofit programs for old and highly energy-inefficient housing stock from the Soviet era are widely believed to offer a rare win-win opportunity for mitigating climate change and addressing acute energy poverty issues in Eastern European urban neighborhoods. However, despite government subsidies and a push for greater energy efficiency, many people do not undertake retrofits. This raises the question: do these retrofits truly deliver the promised returns? This paper aims to examine the effects of retrofit programs on old Soviet-era multi-apartment buildings' realized dynamic energy savings in Lithuania by analyzing monthly energy bills. Our findings suggest that retrofits are associated with a 50% to 59% reduction in average space heating consumption across various post-retrofit periods. Additionally, retrofits have a short-term effect on electricity savings of 3% to 3.6%. However, our cost-benefit analysis indicates that the energy savings were not sufficiently large to cover the initial investment costs.

A Comparison of Programmed Controlled Existing System vs. Electric Resistive Heating for a University Building in Newfoundland

Buildings consume in excess of 30% of the total energy worldwide. In the Canadian context, commercial and institutional buildings contribute to around 14% of the overall energy usage, and space heating emerges as the predominant end-use category, constituting approximately 57% of this consumption. This underscores a considerable potential for energy savings in the realm of building energy consumption. This paper compares the energy consumption for space heating at the Core Science Facility (CSF) of the Memorial University of Newfoundland (MUN), Canada. The analysis contrasts the current system, utilizing hot water from fuel oil-fired boilers, with a proposed system suggesting the replacement of the oil-fired boiler with an electric resistive boiler, by employing a building energy model (BEM) created with the OpenStudio application. The findings indicate that beyond the anticipated enhancements in energy efficiency, a supplementary energy saving of approximately 7% is attainable through the proposed transition. Comparing the simulation outcomes with actual data reveals that the projected consumption from the Building Energy Model (BEM) is lower than the actual figures. This difference is attributed to the model’s development, which involved distinct considerations and assumptions compared to the actual conditions such as construction materials, building occupancy, infiltration and exfiltration, interconnected buildings, energy usage by equipment and lighting, HVAC system energy consumption, and transmission losses through piping which can significantly influence the building’s energy consumption.

Energy characterization of buildings in polar climate: Case study of Gabriel de Castilla Antarctic station

In this paper, we present the energy characterization of two habitable modules at the Spanish station “Gabriel de Castilla”, located on Deception Island, Antarctica. The analysis includes profiles of energy consumption for space heating and domestic hot water, as well as indoor air conditions, which were all recorded during one month of Antarctic summer. Additionally, the measurement of walls’ transmittance and air infiltrations, together with thermography analysis, enabled evaluating the conservation state of the buildings’ envelope. Upon analyzing all this data, it is evident that there is potential to enhance the design of future modules, improving the thermal comfort while significantly reducing the energy consumption. This will contribute to decrease the logistics and environmental impacts of these research stations, crucial considerations in human activity on the Antarctic continent.

Experimental Investigations on the Thermal Characteristics of Domestic Convectors

Better understanding of local thermal characteristics of domestic convectors could play a crucial role in reducing energy consumption for space heating and decarbonizing the economy. The current study evaluates the impact of varying water inlet temperature and flowrate on the local surface temperature of domestic convectors through extensive empirical investigations. Experiments are performed using a custom-made test-rig featuring a 400 mm × 600 mm Type 11 convector within a large and well-ventilated environment, minimizing the thermal influence of the surrounding space on the thermal behavior of the convector. Infrared thermography (IR) is used to acquire local surface temperature data for further analysis. Based on the results obtained, it has been observed that the inlet water temperature has a negligible effect on thermal characteristics of the convector while increasing the flowrate substantially decreases the time required for the convector to reach maximum surface temperature. Based on the numerical data, an analytical model for average surface temperature has been developed using multiple variable regression analysis, demonstrating a prediction accuracy of >90% compared with the experimental data. A detailed understanding of the heating behavior exhibited by domestic convectors has led to a better understanding of the local thermal characteristics, while the prediction model can be used to develop machine learning algorithms to install better flow control techniques for efficient space heating.

Over- and underconsumption of residential heating: Analyzing occupant impacts on performance gaps between calculated and actual heating demand

Previous research estimates that building physics and occupant practices equally contribute to the explanation of variations in residential heating consumption. However, the so-called performance gap, where calculated heating demand diverge from actual heating consumption, indicates that the relation between occupant practices and building physics vary across energy efficiency of the building. In this paper, using data from 2019 to 2021, we investigate such interactions 1) by comparing the calculated heating demand with actual energy consumption for residential space heating and domestic hot water (DHW) across energy performance certificates (A to G), and 2) by investigating variations in over- and underconsumption (deviance from calculated to actual) across socio-economic characteristics of households. In line with previous studies, we find that households living in energy inefficient houses tend to have lower heating demand than expected. Moreover, we find that lower-income households and households living in rural area has less overconsumption, indicating that they have more frugal heating practices.

Realizing the load shifting potential of residential space heating - A field study on the control input for thermostatic control of indoor air temperature

Economic model predictive control (MPC) of residential space heating utilizes indoor air temperature fluctuations and thermal mass for load shifting of space heating consumption and it can be used for various demand response purposes in district heating systems. A field experiment imitating the behaviour of an MPC has previously been carried out in three residential buildings in Aalborg, Denmark. Here, digital radiator thermostats were used, and it was found that the load shifting period was cut short when using the temperature measurement embedded in the thermostat as control input for the MPC. Therefore, the field study reported in this paper investigated whether using indoor air temperature sensors as control input for the thermostat improved the realisation of the load shifting. The field study took place in a single-family house in Aarhus, Denmark, and tested the load shifting potential when controlling with either the temperature sensor embedded in the thermostat or an offset between the radiator thermostat setpoint and an indoor air temperature sensor measurement. The study indicates that the use of indoor air temperature measurements as thermostat control input will provide longer periods of loading and unloading the building, thereby increasing the total load shifting potential of the heating consumption.

Detailed assessment of hybrid ventilation control system in a mixed-mode building in cold climate

This paper investigates a hybrid ventilation control method for a mixed-mode office landscape in a cold climate, i.e. Norway. The mixed-mode building utilizes a hybrid ventilation system that combines natural ventilation through automatic window opening with a balanced mechanical ventilation system controlled by demand control ventilation (DCV) method. For natural ventilation, the windows consist of two parts: the upper part which is openable and the lower part that is not openable and equipped with external solar shading. From a control point of view, the article elaborates a control algorithm for the proposed hybrid ventilation based on various parameters including outdoor air temperature, indoor air temperature, CO2 level, maximum air change per hour (ACH), operation schedules, and heating/cooling setpoints. The simulation results obtained from the hybrid ventilation and mechanical ventilation cases are compared based on thermal comfort, CO2 level, and energy savings. The primary results show that the proposed hybrid ventilation control method can satisfy the thermal comfort and CO2 level requirements while reducing the energy use for fan and ventilation cooling by approximately 55% and 45%, respectively. While the impact on energy consumption for space and ventilation heating is negligible.

A study on the impact of residents' energy usage behavior on heating energy consumption based on smart meter data and surveys

This study aimed to identify the factors that influence heating energy consumption in residential apartments using smart meter data and surveys. It emphasized the significance of residents' behavior as a key variable. The analysis considered physical and behavioral factors, including external factors, building characteristics, resident demographics, and residents' heating energy consumption behavior. Based on these factors, a model for heating energy consumption was developed. Moreover, the study found that residents' heating energy consumption behavior had a strong explanatory power in both space heating and hot water energy consumption models. Therefore, to achieve accurate prediction and evaluation of energy consumption in the residential sector, future research should thoroughly consider resident characteristics and energy use behavior, taking into account different types of final energy. Furthermore, it is crucial to comprehensively consider residents' characteristics when developing energy-saving policies for buildings, as this will lead to meaningful outcomes.

Evaluating Reduction in Thermal Energy Consumption across Renovated Buildings in Latvia and Lithuania

Currently, the optimization of thermal energy consumption in buildings is considered a suitable alternative in the construction of new buildings, as a result of which the overall energy efficiency of the building increases. Thus, this study examined the efficiency and efficacy of different building renovation packages conducted across several buildings in Latvia and in Lithuania (across a larger building stock). In the first section of this study, 13 multi-apartment residential houses with 3 building renovation packages have been investigated in the city of Daugavpils, Latvia, in order to determine the actual reduction in heat energy consumption across each of the renovation implementation packages. The study findings indicate that changes in Latvian building regulations regarding insulation thickness did not significantly impact thermal energy consumption in fully renovated buildings. However, the combination of facade renovations, upgraded heating systems, and improved ventilation systems resulted in substantial energy savings, with an average reduction of 50.59% in thermal energy consumption for space heating across the reviewed multi-apartment residential building stock. In the following section of this study, the impact of the Energy Performance of Buildings Directive (EPBD) on building energy efficiency in Lithuania has been examined. The results show that over a 10-year period in the 2000s, Lithuanian building stock experienced a 20% increase in energy efficiency, followed by an additional 6.3% increase between 2010 and 2016. The mandatory requirement for renovated buildings to achieve a minimum energy efficiency class has resulted in significant reductions in energy consumption for heating purposes. The findings underscore the effectiveness of building renovation packages and the EPBD regulations in enhancing energy efficiency and promoting sustainable building practices. The importance of heat metering, consideration of indoor air temperature, and the need to address indoor air quality during renovations were also highlighted.

About the effect of tailored energy feedback on space heating consumption and indoor air temperature in social housing buildings: An experimental investigation

Providing the occupants with tailored feedback on their energy consumptions can be an effective method to help the users to adopt energy-efficient behaviours. However, in specific contexts such as the social housing, this may be challenging, due to the peculiarities and the economic constraints of the end-users, which make them vulnerable and needing a proper design of the information. Nevertheless, there is a lack of detailed studies in the literature analysing the effects of personalized energy feedback on the space heating consumption and the indoor air temperatures in the social housing sector. This paper aims to evaluate the effects on space heating consumption and indoor air temperature of a personalized feedback campaign delivered in three social housing buildings consisting of 27 apartments in Mediterranean climate. To this end, a personalized feedback campaign was designed and developed, providing for the use of disaggregated energy consumption indicators to show the location of excessive thermal energy consumptions. The daily thermal energy consumptions, as well as the indoor air temperatures of the single dwellings, were monitored daily for over four heating seasons and their variations were analysed before and after the implementation of the personalized feedback. A saving in normalized natural gas consumption of the buildings was found on average equal to −14,8% after the feedback campaign, with no significant variations in the indoor air temperatures. However, some critical issues have been highlighted in the response of individual end-users to the feedback provided. A greater propensity of the occupants to regulate the indoor air temperature through the thermostatic radiator valves in the unoccupied rooms of the house was also observed after the occurrence of the feedback campaign.

Why do people turn down the heat? Applying behavioural theories to assess reductions in space heating and energy consumption in Europe

Reducing heating-related energy consumption is vital in Europe, where it accounts for a significant portion of domestic energy usage. We studied the factors that influence reduced heating-related consumption by using three theoretical frameworks: the Theory of Planned Behaviour, the Value Belief Norm theory, and the Prototype Willingness Model. Our sample consisted of 3098 people from 29 European countries. We conducted a confirmatory factor analysis to verify whether our observed variables measure our latent factors, followed by a structural equation model that incorporated these three behavioural models. We find that perceived behavioural control, subjective norms and attitudes (as part of the Theory of Planned Behaviour) are significant predictors of intent to reduce consumption. However, perceived behavioural control was not statistically significantly associated with behaviour. Environmental concern had a more significant influence on attitudes towards energy reduction than bill consciousness. Attitude was additionally significantly associated with fear of losing comfort and energy knowledge. Moreover, personal moral norms (as part of Value Belief Norm Theory) and willingness (as part of the Prototype Willingness Model) contributed to explaining the intent to reduce consumption, while willingness was also associated with behaviour.

The indoor environmental quality and energy savings potential of room ventilation units compared to exhaust-only ventilation systems in France

Humidity-controlled mechanical exhaust ventilation (RH-MEV) has been widely used in France for over 35 years, demonstrating high durability and robustness. This exhaust-only ventilation strategy is widely used as an energy-saving measure, replacing constant mechanical exhaust ventilation (Constant-MEV) systems in residential buildings. It demonstrates energy savings due to the restricted airflows, but as a downside, the building’s indoor air quality (IAQ) often deteriorates. Moreover, it is impossible to recover heat with exhaust-only ventilation systems, which means that energy consumption for space heating is still quite significant and cold supply air temperatures are frequently introduced to the heated spaces. Room ventilation units (RVUs) with heat recovery represent an alternative ventilation solution allowing simple installation through the façade and providing fresh outdoor air and exhaust ventilation to each room. This study investigates these units’ energy saving potential and indoor environmental quality performance as an alternative solution to centralized exhaust-only ventilation systems. The dynamic simulations were performed for a reference residential building under various French climatic conditions for a heating season. The three ventilation strategies investigated were Constant-MEV, RH-MEV and room-based ventilation with RVUs. The results demonstrated 61–85% savings in space heating demand with the RVUs, compared to Constant-MEV under all climatic conditions. Compared to RH-MEV, the RVUs saved 44–75% energy for space heating while the CO2 concentration and relative humidity levels were decreased due to RVUs’ constant air exchange rate. In all cases, RVUs provided considerably higher supply air temperatures due to the implemented heat recovery, which can potentially improve indoor thermal comfort.

Assessment of space heating consumption efficiency based on a household survey in the hot summer and cold winter climate zone in China

Space heating demand in the hot summer and cold winter (HSCW) climate zone in China has increased rapidly over the past decade. It poses significant challenges for China's electricity supply infrastructure and building decarbonization. This study aims to understand the relative energy efficiency of household space heating and identify potential opportunities to reduce electricity usage at the household level. A stochastic frontier analysis approach is used to quantify the energy efficiency of households' space heating by forming an efficient frontier (minimum requirement of consumption given the characteristics of the household) and by comparing all households against that frontier. The results indicate that the average household space heating efficiency is 0.69. This indicates that households in the HSCW area have the ability to reduce their heating electricity consumption by 31% while still keeping the current level of indoor thermal comfort in the winter. The level of building energy efficiency standards (BEES) is the key factor influencing the space heating savings potential. Thus, Policy choices should focus on revising and optimizing superior BEES, and accelerating energy efficiency retrofits of existing residential buildings in this region.

A Review on Trombe Wall Technology Feasibility and Applications

The current global energy challenges require strategies to increase energy-independence across regions and individual countries in order to facilitate and foster the utilization of passive energy sources. As such, solar energy utilization for covering and offsetting building heating loads is a sustainable way to reduce energy consumption (electricity, gas etc.) for space heating. Trombe wall technology is a passive building solar heating system that can be modified and applied to mild and cold regions. This work presents a review of Trombe wall system’s feasibility and applications across different climatic regions. Trombe wall systems are applicable as a secondary space heating source in mid-sunshine and cold regions. However, a number of design and structural aspects must be thoroughly considered, including the incorporation of PCMs, and the integration of PV/BIPV elements and other performance-improving aspects to enhance the system’s thermal performance and output. The findings of this work can be used in potential future assessments of the Trombe wall system’s technology in different climatic regions.

Trombe Wall System’s Thermal Energy Output Analysis at a Factory Building

Solar energy utilization for covering and offsetting the heating loads of buildings, is a sustainable way to reduce energy consumption (electricity, gas, etc.) for space heating. As such, a Trombe wall technology is a classic passive solar heating system used in buildings, that can be modified and applied to cold climate regions. This work presents a case study on a Trombe wall’s application in relation to its thermal energy output for space heating purposes at a factory building in central Latvia. The solar radiation and temperature measurements were carried out throughout the months of June to October. The results show that the examined wall has a monthly energy yield of 120 to 290 kWh, suggesting that Trombe wall systems are applicable as a secondary space heating source in cold climate regions such as northern Europe, however, a number of design and structural aspects have to be thoroughly considered.

Wave analysis method for air humidity assisted sorption thermal battery: A new perspective

Sorption thermal battery has attracted burgeoning attention which is considered as a promising method to reduce energy consumption for space heating. Sorption “reaction wave” model could be used to find the criteria for stable output. However, mechanism of sorption process evolution in reactor is still unclear since the method cannot derive more reaction details. The paper initially proposes a comprehensive wave analysis method which could bring more insights of sorption thermal battery from a heat and mass transfer perspective. The wave parameters are analysed and orthogonal experiments are then carried out. Results indicate that solid sorbents with type I and V isotherms have the advantage of stable heat supply. Air velocity and inlet relative humidity have the most significant influence on the output parameters. Besides, response surface methodology is adopted to evaluate the critical parameters, e.g., relative humidity, flow rate, temperature of inlet air. The optimal system energy storage density could reach 191.7 kWh·m−3 when sorption reactor length is 0.178 m and the relative humidity is 70 % using zeolite 13X as sorbents. Therefore, the proposed wave analysis method is expected to become a potential solution which would guide sorbent selection and reactor design for sorption thermal battery.

Experimental Study of the Model Predictive Control for a Residential Split Air Conditioner

Buildings consume 60% of the total building energy consumption for space heating and cooling purposes, and even more with inefficient and outdated air-conditioners (AC) - which are most common in developing countries. Although there are already conventional control strategies like ON/OFF control and PID in practice, their performance worsens once the building’s complexity increases and they cannot cope-up with the stochastic nature of the inside and outside environment. So one of the most efficient and preferred control strategies in complex systems like a building would be model predictive control (MPC). This study uses MPC to predict and control a 1.5 tonne inverter-based air conditioner. A cascaded control strategy - including various control methods, i.e., hysteresis, bang-bang, MPC, and an adaptive MPC, is implemented over the inbuilt thermostat-based control. MPC minimizes the setpoint tracking error and optimizes real-time thermal comfort by generating optimal temperature setpoints. An automated hardware setup is developed using Arduino Mega-2560, Raspberry Pi 3 B+ model, calibrated temperature, and humidity sensors that set the optimal setpoints to the air-conditioner via an infrared remote controller. Both MPC and adaptive MPC are able to maintain thermal comfort strictly within the desirable range, i.e., ±0.5 PMV throughout the experimental day, with thermal comfort hours of 24 hrs. and 23.67 hrs., respectively. On the contrary, with regular thermostat-based control, the thermal comfort is not maintained at any manually set temperature setpoint. With an adaptive MPC, energy saving of more than 7.06% is achieved as compared to the air-conditioner’s regular operation, running at a constant 24∘C - that is taken as the baseline for this study.

Identifying the influence of user behaviour on building energy consumption based on model-based analysis of in-situ monitoring data

This study carries out a comprehensive comparison between design and monitoring results in a building located in Innsbruck, Austria, with the focus on the user influence as an important part of a fault detection strategy. The space heating consumption shows a difference from the design (of 11 kWh/(m2a)), with an excess of 22 kWh/(m2a) in 2019 and 28 kWh/(m2a) in 2020. Contrarily, monitored energy consumption for domestic hot water and appliances are lower than the design. Electricity consumption for mechanical ventilation and photovoltaic production are similar to the design. A fault detection and diagnosis analysis is carried out at building and room level (apartments and common rooms), studying the correlation between the energy consumption and temperature of the corresponding space. Several methods are tested to identify the rooms with non-standard behaviour with respect to window ventilation, setpoint temperature and a combination of them and their influence on the space heating demand. The analysis assesses an influence of the occupants behaviour (in terms of higher window ventilation and setpoint temperature) of 20–32% on the space heating demand, which does not entirely justify the high mismatch between measured and design values. Combinations of known, likely and possible causes for the higher monitored space heating are investigated and show the upper and lower bound of user behaviour and building deficiencies.