Types Of Heating Systems Research Articles

Model predictive controls for residential buildings with heat pumps: Experimentally validated archetypes to simplify the large-scale application

Exploiting the energy flexibility resulting from thermal loads management in buildings is one of the most promising solutions to contribute to the energy transition targets. To offer energy flexibility to the grid, the building should meet the requirements: (i) it needs electrically powered generation (e.g., through Heat Pumps) and (ii) advanced control techniques (e.g., Model Predictive Controls) must be implemented. In recent years, the scientific community has produced many studies demonstrating the potential of Model Predictive Controls combined with Heat Pumps to exploit energy flexibility in buildings. However, a large-scale deployment of such control techniques is still far off, both because of the not yet widespread use of Heat Pumps and the computational challenges involved in implementing them. The aim of this study is to contribute to the deployment of advanced control techniques for Heat Pumps systems in buildings by simplifying their implementation. At this aim, validated archetypes of Model Predictive Controls for Heat Pumps in residential buildings are proposed. The availability of archetypes can greatly facilitate the practical application of Model Predictive Control. In fact, they are adaptable to the characteristics of different buildings and Heat Pump installations and their structure is designed to have an acceptable trade-off between calculation time and prediction reliability. The archetypes cover three different types of heating systems: low temperature radiators without (i) and with (ii) integrated heat storage devices and (iii) underfloor heating system. All archetypes are applied to a real Heat Pump and validated through experimental campaigns. During the experimental test all the archetypes proved to be effective in controlling the real system and the results showed good reliability of the prediction model in the control (for all archetypes a Root Mean Square Error lower than 0.44 °C was obtained) and an optimizer success rate in Model Predictive Controls greater than 91 %. The archetypes proposed are provided as open-source tools that can be reused for similar cases to facilitate Model Predictive Controls implementation in heat pump systems.

Comparison of thermal comfort between different heating systems and adaptation to different indoor climates in winter.

Individual heating systems, such as the air-source heat pump (ASHP) air-conditioner or floor heating (FH), are usually used by people living in the hot summer and cold winter (HSCW) zone of China to heat indoor climates in the winter. However, little research has been conducted in the HSCW zone on the thermal comfort difference between indoor climates heated by ASHP air-conditioners and those heated by floor heating, as well as how occupants adapt to different indoor climates. We conducted a comparative field experiment in ASHP-heated and FH-heated apartments in Nanjing to investigate how different types of heating systems influence the thermal sensation of occupants, and we conducted a comparative field experiment in ASHP-heated office buildings and naturally ventilated teaching buildings in Shanghai to investigate how occupants adapt to different indoor thermal environments. Indoor environmental parameters and body surface temperatures were measured using instruments, and occupants' thermal sensation, activity level, and clothing were evaluated using the questionnaire. The results show that floor heating improves thermal comfort by raising foot temperature compared to the ASHP air-conditioner, and that occupants become acclimatized to different indoor climates by adjusting neutral operative temperature. According to the findings, there is no need to overheat the indoor environment in the HSCW zone because occupants can adapt to their experienced thermal environment and it is critical to maintain warm foot temperature in the cool/cold indoor environment.

The Effect of the Temperature Increase on Heat Demand Calculation for Building in the Polish Climatology

Heat demand calculation procedures for buildings are currently being conducted based on the Polish Standard grounded on the European Standard for heat losses methodology. Poland was divided into several climatic zones with given calculations and annual average external air temperature values. In each zone, the technical committee gives the temperature that must be considered. The data included in the Polish Standard preparation concern several years backwards. However, throughout the previous years, we have observed the tendency of the temperature to increase throughout the year, not only in Poland. The phenomenon provides scientists with the conclusion that the temperatures will continue to increase yearly. The low temperatures in the winter season will no longer occur. Therefore, it is necessary to analyse the possibility of lowering the heat demand calculation, including the actual prevailing temperature values. The study was conducted regarding possible economic benefits for the building users due to the lower temperature difference between the internal and external temperatures. Three types of heating systems were analysed. The calculations were conducted for air to water heat pump, pellet boiler and gas condensing boiler, proving that regarding the actual meteorological data, the average annual cost reduction will be in the range of 858 PLN to 1,035 PLN.

Performance boost of a commercial air-to-air plate heat recovery unit by mesh-net insert; thermal-frictional, economic, and effectiveness-NTU analysis

This research proposes, tests, and comprehensively investigates the application of mesh-net to increase the efficiency of any air-to-air plate heat exchanger (mainly as a building heat recovery unit). The idea is tested through a commercial heat-recovery unit and all parameters including Nusselt number, pressure drop, friction factor, thermal performance factor, effectiveness, number of thermal units, pumping power and economical profitability are comprehensively investigated and reported with and without mesh-net insert. In economic evaluation the price of electricity and type of building heating system (resistance heater, heat pump and so on) are considered. In the maximum air flow rates, the overall heat transfer coefficient is enhanced from 24 to 36 W/m2K. Nusselt number increases up to 75 % depending on air flow rate. The economic results were found very interesting, and even by paying further fan power due to the higher pressure drop, the economic profitability is positive when the building heating system is resistance heater or heat pump with lower coefficient of performance. The profitability of the mesh net insert is higher for the region with higher electricity price. This means the gained recovered heat overcomes the further energy required for pumping power. Nonetheless, final decision making from pure economic viewpoint depends on the desired supply air flow rate, type of heating system and local price of electricity.

Internal Sales Management of Heating Materials and Heating Systems

Software - M3, Microsoft office dynamics 365 and Microsoft excel. The whole work deals with three types of categories HS (Heating System), PHS (Process Heating System) and HM (Heating Material). All these categories consist of many products. The heating system requires 3 to 6 weeks to be manufactured. The process heating material needs 3 months to be manufactured. The heating materials are usually kept ready for the orders. There are two types of sales- the field sales and the inside sales. The field sales take care of the getting orders from the customers. The inside sales takes care of the internal information of the customer, invoicing, and order confirmation. The inside sales also look after the payment process and order placement. Firstly, a PO is sent from the field sales regarding the customer and the order requested. As mentioned, customer master and financial based works are taken over by the inside sales. The customer master is used to check whether the customer is new or old, whether to accept the order and to also check whether payments can be made. All the information is uploaded in a M3 and Dynamics 365 software and an invoice is being created. The invoice is sent to the technical team. When the technical team confirms the order then the information is sent to the design team and the delivery date is finalized. Then the order is confirmed by the inside sales. The production is started after confirmation. There is a separate team for assembly. After confirmation the inside sales proceed with payment methods.

Life cycle assessment (LCA) and energy assessment of the production and use of windows in residential buildings

There is an observable scarcity of comprehensive research results comparing the environmental damage associated with both the production of windows and their subsequent operation. The environmental impact of the operation of windows depends on their thermal insulation parameters, and thus the amount of heat that must be generated to heat the building. The type of heating system and, above all, the type of fuel used to generate heat are also not without significance. Unfortunately, in Poland, a significant proportion of single-family houses operate on the fossil fuel heating system, including on coal and fuel oil. It is therefore important to present an environmental balance sheet of both the production and operation of windows for different variants of building heating. The purpose of the study was to determine: to what extent the manufacturing of windows of different construction and different insulation parameters affects the environment, to what extent does the negative environmental impact of the process of manufacturing with greater insulation compensate by the lower environmental impact related to savings on fuel (gas, coal, fuel oil) used to generate heat during the operation of windows. Three types of windows were selected for a detailed analysis: a triple-glazed aluminum construction, a double-glazed PVC construction and a triple-glazed PVC. The research results show that in the case of all impact categories, the greater environmental losses related to the improvement of the thermal insulation parameters of the windows at the production stage are fully compensated at the stage of their useful life, regardless of the type of fuel used to heat the buildings. Double-glazed PVC windows should be phased out of production due to significant environmental footprint associated with their operation.

The effect of floor material and construction solutions and the type of heating system on greenhouse gas (GHG) emissions – A case study

The paper deals with the issue of greenhouse gas emissions from heating a livestock building using various energy carriers. The purpose of the study was to calculate the emissions of some pollutants (total dust, CO, CO2, NOx, SOx, benzo(a)pyrene) resulting from the heating of the broiler house, using gaseous fuel, coal and fuel oil, in two variants of material and construction solutions of the floor. The scope of work included measurement of selected microclimate parameters, validation and calibration of the model, calculations and analysis of the obtained results. Continuous measurements of selected indoor and outdoor microclimate parameters, such as outdoor and indoor air temperature and relative humidity, floor temperature, wind speed and direction, solar radiation intensity, were conducted in the studied facility. The study used the numerical method of elementary balances to calculate energy demand in selected design variants. A geometric model was created, corresponding to the real dimensions. Based on the measurement data obtained, validation of the computational model was carried out. The obtained results of the numerical analysis were used to calculate selected indicators of greenhouse gas emissions from the studied building. Six calculation variants were assumed, in which different types of heat carriers were taken into account. The obtained results show that NOx emissions when heating the building with hard coal are 74% higher than when using gaseous fuel. Increasing the thermal resistance of the floor to 3.69 m2K·W-1, this reduced the annual energy demand by 56.1% for hard coal and by 15.8% when using fuel oil.

Overview of Solar Steam Devices from Materials and Structures.

The global shortage of freshwater supply has become an imminent problem. The high energy consumption of traditional desalination technology cannot meet the demand for sustainable energy development. Therefore, exploring new energy sources to obtain pure water has become one of the effective ways to solve the freshwater resource crisis. In recent years, solar steam technology which utilizes solar energy as the sole input source for photothermal conversion has shown to be sustainable, low-cost, and environmentally friendly, providing a viable low-carbon solution for freshwater supply. This review summarizes the latest developments in solar steam generators. The working principle of steam technology and the types of heating systems are described. The photothermal conversion mechanisms of different materials are illustrated. Emphasis is placed on describing strategies to optimize light absorption and improve steam efficiency from material properties to structural design. Finally, challenges in the development of solar steam devices are pointed out, aiming to provide new ideas for the development of solar steam devices and alleviate the shortage of freshwater resources.

Individual Factors that Affect the Perceived Thermal Comfort Condition during Heating Seasons

This paper investigated the effect of individual differences and the type of heating system on the perceived thermal comfort condition, neutral temperature, and thermal sensitivity in cold outdoor air conditions. Three types of individual factors, such as gender, temperament, and thermal past experience, were studied and compared in this paper. According to the results, temperament and thermal past experience directly influenced the occupants’ thermal preference and indirectly influenced the thermal sensation by affecting their clothing level. However, the effect size of such variations was negligible. The type of heating system had the most significant impact on the neutral temperature, with a mean difference of 2.8°C. Individual factors did not have a direct impact on the neutral temperature. However, thermal sensitivity was influenced by an individual’s temperament. Occupants with a cold temperament were more sensitive to the variation in the running mean outdoor temperature (Trm) than those with a warm temperament. When the results were compared with the predictions by the adaptive thermal heat balance (ATHB) and the predicted mean vote (PMV) models, it indicated that if the control condition over the heating system became limited, there would be no (i.e., very low) behavioral, physiological, and psychological adaptation. However, by creating an opportunity to control the heating system, thermal adaptation could be reached at a lower temperature under cold outdoor air conditions.

친환경 바이오연료를 사용하는 난방시스템 디자인설계 및 환경시험평가

Research and development for alternatives to fossil fuels such as coal and petroleum have progressed considerably worldwide. Among clean fuels, bio-diesel has been a representative fuel and it was used for the following advantages; renewable, ready to use with low fine dust emission and non-toxicity. But it is expensive and cause strain on local resources. In our study, to resolve these issues, we developed two types of heating systems by direct input of waste cooking oil, and the heating system was optimized through mechanical design and design process. In addition, we conducted an environmental test to evaluate the reliability and environmental characteristics of the developed device. Firstly, through the design modification of heat recirculation system, more efficient combustion for the complete combustion of bio-fuel(waste cooking oil), was possible. As for the heating system, two products (tube heating system, agricultural hot air blower) were optimized for management convenience, space utilization, and efficiency improvement by 6-step design. From the environmental test result, the combustion efficiency of the heating system was up to 99%, the average oxygen concentration was 8.3%, and the CO concentration was 7.9 ppm for a stable combustion, NOx was up to 67 ppm, and SOx was not detected.

Investigation of the performance of mock-target IR thermography for indoor air temperature measurements under transient conditions

Mock Target IR Thermography for indoor air temperature measurement has been proven as an effective methodology for steady-state conditions. This method uses vertical poles of known emissivity placed in a space to measure air temperature by employing IR thermography. Compared to thermocouple / point-by-point measurement, this technique allows obtaining air temperature values in a continuous line. Several poles can be installed in a space ensuring the collection of a large amount of air temperature data entries by taking a single IR image, whereas measurements in large spaces with hundreds of thermocouples would require complicated wiring and data collection hardware. However, for this approach to be more widely considered, such measurement techniques should be adaptable for transient conditions as well, as air temperature can fluctuate and change due to external climatic conditions, occupancy or faults in HVAC equipment. This work aims to investigate if IR Thermography which was only tested in steady-state conditions can be applied to conditions of transient variation of indoor air temperature. For this purpose, measurements under lab conditions and numerical analysis with the use of finite element modelling (FEM) were performed. Specifically, measurements were carried out by using both Mock Target IR thermography and thermocouples, to investigate the precision of IR-obtained transient data. The experiments were conducted in the environmental chamber under controlled conditions. Three types of heating systems (underfloor heating, radiator heating, and ventilation heating) were investigated to ensure that the method is tested under conditions of different heat-emitting devices, as well as different convection and radiation ratios. Validated numerical models were developed using the FEM Multiphysics approach, to extend the scope of the assessment under various conditions and to observe the difference between the mock target pole temperature and air temperature. It was concluded that the mock target IR Thermography performance was accurate for the case of transient air temperature, as well as for different rates of temperature change, with an average temperature deviation of 0.4 [%] according to the experimental measurements and 1.74 [%] based on the numerical simulations.

Operational and embodied emissions associated with urban neighbourhood densification strategies

Urban densification increases the number of people living in urban areas and is hypothesized to be a more efficient use of available land than urban sprawl. The objective of this study was to quantify the operational and embodied emissions created as a result of densification. A ‘Business as usual’ and a ‘Concentrated’ densification strategy were investigated. When densifying at the neighbourhood level, existing buildings can either be replaced or extended to accommodate the additional inhabitants. The densification strategies were applied to two reference urban design neighbourhoods in Switzerland. The ‘Typical’ approach assumed that all the buildings were demolished and rebuilt and the ‘Preserve-existing’ approach involved the extension of existing buildings as much as possible. Construction material choice and modification of the built form were the sources of embodied emissions considered for each strategy. Urban building energy modelling was used to calculate the emissions incurred by heating the buildings and the embodied emissions were calculated using building standards. The operational performance was simulated assuming both a gas boiler and an electric heat pump to determine the influence of the heating system type on the operational emissions. This study found that savings of approximately 30% in embodied emissions can be achieved by extending the existing building stock rather than rebuilding. However, these savings represent a relatively small percentage of the total emissions incurred throughout a building’s lifetime and the savings further diminish in the concentrated densification strategies.

Effect of physical, environmental, and social factors on prediction of building energy consumption for public buildings based on real-world big data

In practical operations, various static and dynamic parameters affect the prediction of building energy. In this study, seven modes were constructed based on the Extra-Trees algorithm to investigate the impacts of 19 factors involving physical, environmental, and social aspects on the specific energy consumption. The analysis is supported by data obtained from 110 public buildings over one year in Shenzhen, China. The results indicate that considering more factors significantly improves the prediction accuracy. Factor importance analysis shows that building type is the most significant factor, followed by ambient temperature, month, structure, floor area, and rent price. The external wall material is the least significant factor, followed by the type of heating system and subdistrict population. At least the top 8 most important factors must be provided to maintain an accuracy above 80%. Furthermore, the sensitivity analysis indicates that the SECs of comprehensive and office buildings demonstrate opposite variation trends to floor area; for rent price and distance from central business district, the SECs of comprehensive building show inverse and positive change trends, respectively, but the SECs of office remain almost unchanged. In addition, buildings with internal insulation can lead to more SEC in such climate.

A comparison of building system parameters between affordable and market-rate housing in New York City

Low-income households in the United States experience higher than average energy burdens (defined as the proportion of household income spent on energy utilities), and many of these households struggle to simultaneously pay for rent, energy, and basic household necessities. The analysis presented here examines whether the underlying characteristics of buildings and their energy systems could contribute to this disparity for affordable housing residents in New York City. It combines an energy audit dataset of 7,328 multifamily buildings with a database of properties receiving local, state, or federal housing subsidies. The results of this analysis indicate that the building-level installed equipment in large (greater than 50,000 square feet) affordable housing buildings in New York City is more efficient than that in market-rate buildings, but this trend largely disappears when considering overall building characteristics, such as location, size, or age. Significant differences in the types of systems installed in affordable and market-rate housing are also observed, as well as the types of energy efficiency recommendations made by energy auditors. However, these latter data were not normalized by building system characteristics, as that analysis is much more difficult to interpret for categorical data such as heating system type. These findings indicate that retrofit policies and building performance standards focused on affordable housing will likely need to account for underlying differences in building characteristics between affordable and market-rate housing to achieve intended impacts.

Risk Assessment of Household Gas Heaters in Tehran During an Earthquake Crisis by Using the Fuzzy FMEA Model

Background: A variety of gas heaters are used in residential, administrative, and commercial buildings in Iran. Home packages (HP) and central heating boiler rooms (CHBRs) are among the most common types of heating systems that can be damaged during earthquakes and, thus, harm the building and the residents. Methods: By doing a survey and an interview in 50 residential buildings in District 16 of Tehran, the risks of these facilities were assessed during earthquakes from the viewpoint of the residents. To do the risk assessment, the failure mode and effects analysis (FMEA) model in the fuzzy space were applied. To analyze the risk priority number (RPN), defuzzification and the center of gravity method were used. Based on the results, 11 indicators were identified and evaluated for each system. Results: The mean RPNs obtained for both systems were almost equal (the difference was about 2%). Thus, no definitive superiority can be presumed for HP or CHBR when earthquakes happen. The major difference in the risk of each system can be separately evaluated based on the conditions of each building, confidence about the quality of installation, connections, pipe materials, electric wire corrosion, etc. Conclusion: It is suggested that the risks of CHBR and HP during earthquakes are the same, and some issues such as design, economy, and technical issues play a greater role in contractors’ selection of the system.

Air Quality in a Large City in the Baikal Natural Territory: the Social Dimension (a Case Study of Ulan-Ude)

In this article, we propose a new approach to the development of measures to reduce the negative impact of pollutant emissions from stationary sources. For the first time, a systematic approach was applied to the development of measures to reduce the negative impact of emissions into the atmosphere for a large city in the Baikal Natural Territory (a case study of Ulan-Ude). The use of a systematic approach helped us to achieve the following outcomes: to develop a geographic information system with sources of emissions into the air of Ulan-Ude (GIS “Air of Ulan-Ude”); to identify natural factors of atmospheric air pollution in Ulan-Ude; to develop registers of stationary sources of emissions; to assess the impact of air pollution on public health; to carry out a sociological survey using questionnaires; to propose suitable technical solutions to reduce the emissions. The research methodology involved the concept of sustainable development, in terms of preserving living conditions for future generations of mankind. The institutional approach was also used to study the environmental situation from the perspective of the interaction of social institutions. A sociological study of private households in the context of financial and environmental aspects of heat supply for different types of heating systems led us to the conclusion that the problem of pollutant emissions by households is related to the standard of living and the availability of green fuel. The following measures were proposed to improve the quality of atmospheric air. The functional zoning of residential areas for industrial and housing development should take into account climatic, natural, and technogenic factors affecting the redistribution of pollutants in the surface layer of the atmosphere. The authorities should assist in connecting residential buildings to central heating. State support for the transition to clean fuels (gas, electricity, smokeless fuel, etc.) through subsidies, partial compensations, and other incentive programs. State support for the development of small-scale power generation and alternative energy; raising public awareness of the need to reduce emissions into the atmosphere.

Influence of heating systems on indoor air quality and sick building syndrome (a case study in Qom, Iran)

Sick building syndrome (SBS) is an outcome of poor indoor air quality (IAQ) that can affect human health and performance. Heating system (HS) types are a factor of indoor air emission. The present study was conducted to evaluate the effect of the HS on IAQ and SBS in residential buildings. The air pollutant levels were monitored in the heating-season and non-heating-season. The SBS questionnaire was completed for each non-smoking people (22-50 years). People with respiratory diseases such as asthma and bronchitis were excluded. Results implied that pollutants concentrations and SBS symptoms were strongly influenced by HS type (P- value < 0.05). Tiredness, dry-throat, and dry-eyes were the commonest reported SBS symptoms. The open-fireplace users had more complain about dry throat (33%) and tiredness (33%) compared to other symptoms. The maximum prevalence of SBS symptoms observed for the use of the open-fireplace, gas-heater, and water circulating system was 40, 27, and 10%, respectively. In 33% of the study population, these symptoms are alleviated when individuals left the buildings. Nausea was the only reported symptom in the homes with the water circulating system. The findings of the present study provide helpful data that can be considered to develop a strategy for increasing public health.

Simplified data-driven models for model predictive control of residential buildings

Owing to recent advancements in Internet of Things technologies, data-driven model predictive control (MPC) has received significant research interest as a promising strategy to optimize building operation. As the MPC performance relies on the model prediction accuracy, complex building prediction models have been used in MPC applications, despite their high computational cost for optimization. This study examines whether linear-form prediction models are reliable to support the MPC of residential buildings equipped with single types of heating systems. This study developed linear-form models, namely an autoregressive with exogenous inputs (ARX) for predicting the indoor temperature and threshold-piecewise models for the return and supply water temperatures. The MPC performance on the basis of the linear models was evaluated under varying prediction horizons and weights associated with objective attributes. A case study of a residential unit through the simulated virtual building showed that the proposed models achieved the high goodness-of fit values greater than 0.9. The resulting MPC framework achieved heating energy savings up to approximately 12% relative to a simple on/off thermostat or reduction of comfort violation magnitude less than 0.5 °C. The influences of weight and prediction horizon on MPC performance were also investigated.

A Review of the Power Battery Thermal Management System with Different Cooling, Heating and Coupling System

The battery thermal management system is a key skill that has been widely used in power battery cooling and preheating. It can ensure that the power battery operates safely and stably at a suitable temperature. In this article, we summarize mainly summarizes the current situation for the research on the thermal management system of power battery, comprehensively compares and analyzes four kinds of cooling systems including air cooling, liquid cooling, phase-change materials and heat pipe, two types of heating systems including internal heating and external heating, and the corresponding characteristics of the coupled system in no less than two ways. It is found that liquid cooling system and its heating system, phase-change material cooling system and it is heating system, heat pipe cooling system, coupling cooling system and its heating system have great research prospects, it also provides a certain reference for future research directions.

Use of AI Algorithms in Different Building Typologies for Energy Efficiency towards Smart Buildings

Buildings’ heating and cooling systems account for an important part of total energy consumption. The EU’s directives and engagements motivate building owners and relevant stakeholders in the energy and construction sectors towards net zero energy buildings by maximizing the use of renewable energy sources, ICT, and automation systems. However, the high costs of investment for the renovation of buildings, in situ use of renewable energy production, and installation of expensive ICT infrastructure and automation systems in small–medium range buildings are the main obstacles for the wide adoption of EU building directives in small- and medium-range buildings. On the other hand, the concept of sharing computational and data storage resources among various buildings can be an alternative approach to achieving smart buildings and smart cities where the main control power resides on a server. Unlike other studies that focus on the implementation of AI techniques in a building or separated buildings with local processing resources and data storage, in this work a corporate server was employed to control the heating systems in three building typologies and to examine the potential benefits of controlling existing buildings in a unified energy-savings platform. The key finding of this work is that the AI algorithms incorporated into the proposed system achieved significant energy savings in the order of 20–40% regardless of building typology, building functionality, and type of heating system, despite the COVID-19 measures for frequent ventilation of the buildings, even in cases with older-type heating systems.