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Heat networks have the potential to deliver up to 20% of heat to homes in the UK by 2050 and are able to deliver significant reductions in carbon emissions contributing substantially to the UK's 2050 net zero target. However, for many years the sector has been unregulated which means that some consumers of heat networks have been paying high prices for heating systems which may have been poorly constructed and which they do not understand. This analysis identifies three key problems that have arisen from a lack of regulation in the sector: higher prices for consumers, a lack of transparency and understanding of heat networks, and design and build problems, which have all served as barriers to realising low carbon heating in the UK. The recently enacted Energy Act 2023 will be analysed to determine the extent to which it will resolve these problems. [ABSTRACT FROM AUTHOR]

In the transactive energy (TE) paradigm, the devices of participative consumers, or prosumers, may be aggregated and employed to drive operational objectives at the network level. Home heating, ventilation and air‐conditioning (HVAC) systems in particular are well‐suited to modulate their behaviours based on both home thermal flexibility and requests from the utility grid. This paper develops a robust, hierarchical power dispatch scheme in the context of a residential distribution network. The formulation couples a unique, multiphase linear distribution optimal power flow (OPF) at the upper level with model predictive control (MPC)‐based HVAC fleet controllers at the lower level. The proposed approach is tested on nearly 2000 homes with a three‐phase distribution network in an intraday market setting, where two major applications are explored and analysed. [ABSTRACT FROM AUTHOR]

We simulated the energy performance of smart ventilation controls based on outdoor temperature in homes located in California climate regions, designed to comply with the 2016 Title 24, Part 6 California Energy Code prescriptive requirements. The smart controls shift ventilation rates in time, but ensure an annual occupant pollutant exposure equal to, or less than, what would be experienced in a home with a constant ventilation rate equal to the whole house target airflow in the ASHRAE Standard 62.2-2016. Annual simulations of previously developed prototype homes with validated ventilation models were conducted via co-simulation of EnergyPlus with CONTAM. Controller performance varied substantially by climate zone, airtightness and house prototype. Smart controls were generally ineffective in Climate Zone 1 (Arcata) due to its lack of a cooling season and low diurnal temperature swings. The most successful smart controls used parameters pre-calculated using an optimization routine. In order to better inform state energy policy, we also determined savings weighted by the amount of new home construction in each climate. The best controls averaged about one-third of ventilation-related energy savings that increased to about 48–55% when weighted. Annual average savings were about 650–700 kWh/year for the best controllers. The vast majority of site energy savings were for heating end-uses (>90% of total savings). Whole house ventilation rates increased between 0% and 42%, with typical increases in the 15–20% range. The best-performing control strategies shifted ventilation rates seasonally and modulated flows within each season. Peak concentrations during low ventilation times were kept below an exposure level of 3, well below the maximum of 5 required to avoid acute exposure issues. [ABSTRACT FROM AUTHOR]

Highlights • Data mining is introduced to reveal mechanical ventilation behavior patterns. • The analysis is based on the historical data from 10 Dutch dwellings. • Crucial factors affecting the mechanical ventilation behaviors are revealed. • Motivations behind the behaviors are identified and grouped. Abstract Occupant behaviors influence the energy consumption of dwelling mechanical ventilation systems significantly. There is still a lack of effective method to analyze the occupant behaviors in adjusting the mechanical ventilation systems in buildings. Therefore, this study proposes a data mining-based method to reveal the occupant behavior patterns and the motivations behind. A first derivative Gaussian filter-based approach is developed to detect when an occupant increases or decreases the mechanical ventilation flowrate without direct measurements. A logistic regression-based statistical analysis approach is developed to find the crucial factors influencing the behaviors of increasing and decreasing ventilation flowrate. A K-means clustering-based analysis approach is introduced to further find the motivations behind the behaviors. The proposed data mining-based method discovers the ventilation behaviors and the crucial factors influencing them successfully for the occupants from the 10 dwellings located in a Dutch community. The motivation patterns of the ventilation flowrate adjustment behaviors are further revealed based on the discovered crucial factors. The discovered insights are useful to provide more accurate assumptions and inputs for the mechanical ventilation system models. It is also helpful to generate tailored design, refurbishment and control strategies. [ABSTRACT FROM AUTHOR]

Poultry suffer from large temperature variations with traditional tunnel ventilation and wet-pad evaporative cooling (TV) system in continental climates, which negatively influences production performance, resulting in significant economic losses. An ideal ventilation system is desired for retrofitted and new poultry houses. A new ventilation (NV) system was designed to mitigate the air temperature variations and improve the uniformity in poultry houses located in continental climate regions. The evaporative cooling pads were installed on both sidewalls and exhaust fans were located on a gable wall in the NV system. The system could be operated in different modes for daytime and night time by automatically running or not running evaporative cooling according to indoor set-point temperature. The performance of the NV system was evaluated in comparison with a TV system by measuring the thermal environment and layer performance of two commercial poultry houses with different ventilation systems. The results showed that the NV system provided a cooler air environment than the TV system, and the maximum fluctuation in average air temperature was reduced to 1 °C vs. 6.1 °C in TV system. Based on temperature-humidity heat stress index (THI) values, compared to the TV system, the NV system reduced heat stress time across the building in horizontal and vertical planes. The egg production was higher in the NV system house than in the TV system house (20.3% vs 18.9%), and the mean bird's mass in NV system house was 21 g higher than in TV system house. • Evaporative cooling pads of new ventilation system were installed in commercial house. • The new ventilation system provided a cooler air environment than the traditional system. • The new ventilation (NV) system reduced temperature-humidity heat stress index values. • Egg production was higher in the NV house than in the traditional system (TV) house. • The mean bird mass was 21 g higher in the NV house than in the TV house. [ABSTRACT FROM AUTHOR]

In the design of residential developments, it has been common practice for façade sound insulation (to protect against outdoor noise) to be considered separately from the provisions for ventilation and for mitigating overheating. This fragmented approach has led to different designers making different, incompatible assumptions about the internal environmental quality conditions: the acoustic designer assumes that windows are closed to control external noise ingress, while the mechanical designer assumes that windows are open for ventilation or mitigating overheating. This leaves occupants with a choice between reasonable noise levels or thermal comfort, but not both. This problem is exacerbated by increased overheating risk in modern buildings and future climate scenarios. In response to this issue, the Association of Noise Consultants has produced the draft Acoustics Ventilation and Overheating Residential Design Guide – the 'AVO Guide'. The AVO guide recommends an approach to acoustic assessment that takes regard of the interdependence of provisions for external noise ingress, ventilation and overheating. This paper describes the context, background and content of the AVO Guide. There are references to passive attenuated options for ventilative cooling to help designers avoid simply specifying mechanical cooling.Practical application: This paper is entirely focused on the practical application of the guidance in the Association of Noise Consultants' Acoustics, Ventilation and Overheating Residential Design Guide. It describes the current practical problem that designers face, and the mistakes that are the common practice across the industry, of failing to integrate the design for noise with the ventilation strategy and provisions for overheating. It outlines how this can be achieved to enable better internal environmental quality conditions for occupants, supported by the current English Planning regime and professional good practice guidance available. [ABSTRACT FROM AUTHOR]

Abstract As energetic systems become more and more complex, it is necessary to develop strategies for analyzing the influence of the parameters as well as their couplings. This approach is even unavoidable when the optimization procedure is based on multi-criteria. In the present work, we propose an analysis strategy for multi-criteria optimization applied to inter-seasonal solar heat storage for residential building energy needs, including heating and domestic hot water. The modeling is based on simplified equations of the components, while keeping the main physical and coupling phenomena. A sensitivity study is applied to the corresponding energetic system in order to identify the most relevant parameters and couplings interacting on the various output objectives. Several simulations are performed to investigate a multi-objective optimization and various figure representations are presented to refine the analysis. Highlights • Dynamical system study including inter-seasonal and short-term energy storages. • System analysis to insure heating and domestic hot water demands. • Achievement of sensitivity analysis for parameters and coupling parameters. • Investigation of weighted multi-criteria optimization. • Implementation of combined analysis to promote a general efficient methodology. [ABSTRACT FROM AUTHOR]

Protecting the environment and maintaining the EU's competitiveness must be inextricably linked. From this perspective, the scope of present article may be seen as quite timely. Air pollution is the main environmental risk factor contributing to deterioration of the health of the population, and consequently influences the economic development of the state. The usage of hard fuels for the heating of local dwellings is one of the most important sources of local air pollution. The aim of this paper is to identify the relationship between the pollution caused by heating and the health of the population. The health status of the population was assessed using the potential years of life lost per 100,000 inhabitants. Data on the energy sources used for heating were taken from a survey of all dwellings in the Slovak Republic from the 2011 census of inhabitants, homes and apartments. To create clusters of similar municipalities in terms of the variables considered, we used the fuzzy cluster analysis for individual size-standard groups of municipalities. The map view of the fuzzy cluster analysis results confirmed the division of the Slovak Republic into two regions - the north, which showed more favorable results and the south, which showed negative findings. The membership function values of the first cluster indicate a significant positive spatial autocorrelation as measured by Moran's coefficient. A local Moran cluster map identified the areas of interest investigated below. [ABSTRACT FROM AUTHOR]

Home workers at the shoe industry in Semarang Regency mostly suffer from callus (84.8%), stiff shoulder (75.8%), and headache (72.2%). This study aims to analyze the physical environment of the house as a workplace with a work-related complaint on the shoe industry workers in Semarang regency. It was an observational research with cross sectional approach. The population were all the workers in the shoe industry, Semarang Regency. The Sample for the research 66 workers taken by proportional random sampling method. Data analysis used distribution frequency, Chi-Square test and logistic regression. The results showed that there were several physical environment variables of the house that have relation with the complaints due to work with the value of p ≤ 0.05 such as light intensity, house ventilation, and house temperature. Multivariate analysis showed work-related complaints were influenced by variables of lighting, temperature and ventilation jointly by 93.5% and the rest influenced by other factors. The conclusion of this study was the importance of maintaining the quality of the physical environment of the house as a workplace because it can affect the complaints due to work. Shoe industry home workers should pay attention to the intensity of light, ventilation, and the temperature of the house as a place of work. [ABSTRACT FROM AUTHOR]

Abstract While vertical farming can promote sustainable living and mitigate urban heat island, vegetation could worsen the cross natural ventilation due to additional drag force on air flow. This study aims to investigate the impact of vertical farming on ventilation performance that is important to the thermal comfort especially at tropical/subtropical cities. The Computational Fluid Dynamics (CFD) simulation was first validated against the wind tunnel experiment in the street canyon with tree planting. The vegetable was modelled as porous medium in CFD simulation. In the parametric study, six configurations of facades module were investigated with respect to the vegetable block ratio, arrangement, and vegetable species. The results indicate that the natural ventilation performance is highly affected by the block ratio of vegetable. When three forth of the façade is covered by vegetable, i.e. block ratio of 0.75, the natural ventilation of the façade is very limited, with minimum leeward wind speed of 0.2m/s for incoming air flow of 2.0m/s. For the façade with a block ratio of 0.5, half of incoming air flow, i.e. minimum wind speed of 1.0m/s, can reach the near field downstream of the façade to promote indoor thermal comfort. Therefore, in the design process of the vertical farming, the block ratio of vegetable should be carefully determined regarding the ventilation performance. Furthermore, the natural ventilation with the same block ratio of vegetable could also be improved by appropriately modifying the vegetable arrangement and vegetable species. This study provides important understandings on vertical farming to enable architects to make the evidence-based decision in the architectural design. [ABSTRACT FROM AUTHOR]

The article examines that a 2035 deadline for decarbonizing U.S. electricity would strand only several percentage of fossil capacity per years. Topics include reports that decarbonizing the electricity sector is critical for addressing climate change, particularly given the expected role of an expanded clean electricity system for home heating, transportation, and industry.

Highlights • China faces challenges to supply clean building heating services to its citizens. • All building heating solutions have a great potential. • The choice of building heating solutions in China is affected by spatial parameters. • It is essential to use spatial analysis to find proper building heating solutions. Abstract With continuing of urbanization, improving of life quality as well as combating against air pollution, China is facing comprehensive challenges to supply modern clean heating to a majority of its citizens. For space heating solutions, currently in urban areas of north China, coal based district heating is prevalent. In urban areas of south China, distributed heating solutions are used. In rural areas, de-centralized coal stoves and biomass stoves are still commonly used. As renewable building heating solution, ground source heat pumps are installed for large scale applications. Building floor areas heated by ground source heat pumps increased tremendously during past ten years. Air source heat pump is being promoted in north Chinese rural areas as part of coal to clean heating project. Solar water heater and electric water heater for domestic hot water supply is widely used in north China and gas water boiler is widely used in south China. A series of policies have encouraged clean fossil fuel district heating in north China. National development plans are also supporting and subsidizing renewable heating technology such as heat pumps. Different building heating technologies have their own advantages and disadvantages from techno-economic and environmental perspectives. The choice of building heating solutions for different geolocations of China is strongly affected by spatial parameters such as local climate condition, population distribution, natural resource availability etc. Therefore, a spatial data analysis method is essential to help stakeholders decide proper building heating solutions in different parts of China by key performance indicators reflecting lower primary energy use, economic affordability and lower environmental impact. [ABSTRACT FROM AUTHOR]

The passive cooling strategy adopted in the street space of Huizhou traditional dwellings boasts great ecological value. This paper probes into the influencing factors of passive cooling and the formation mechanism of these factors. It is concluded that sun-shading should be utilized and wind pressure ventilation should be suppressed in daytime to reduce the heat gain; the space interface should be utilized to boost the accumulation of cold; the thermal pressure ventilation at day should be combined with wind pressure ventilation at night to speed up radiation. Field test and analysis was adopted to probe into the influencing factors of these factors. The mutual influence between these factors helps to maintain a good thermal environment in the street space in summer. And the findings of this study may serve as guidelines for outdoor environment design of traditional residential buildings. [ABSTRACT FROM AUTHOR]

In North America, the majority of homes use forced‐air systems for heating and cooling. The proportion of time these systems operate, or runtime, has a significant impact on many building performance parameters. The recent adoption of smart thermostats in many North American homes presents a potential data source for runtime. Smart thermostat data collected from over 7000 homes were compared with nine other investigations and a runtime estimation method based on exterior temperature. The smart thermostat runtimes have a median of 18% across all homes, but show considerable variation between homes, even at constant exterior temperature conditions suggesting that factors besides climate (eg, system sizing, user operation) have a significant impact on runtime. Results from other investigations suggest that smart thermostat runtimes are consistent with other measurement approaches. The practical implications of runtime include the impact on central filtration performance. At low to average runtimes, the filter efficiency matters much less for effectiveness because the system does not run enough for a sufficient air volume to pass through the filter and have a substantial impact on particle concentrations. This work illustrates the importance of measuring runtime for a particular home, and the value of data obtained from smart thermostats. [ABSTRACT FROM AUTHOR]

Growing concern about the scale and extent of the gap between predicted and actual energy performance of new and retrofitted UK homes has led to a surge in the development of new tools and technologies trying to address the problem. A vital aspect of this work is to improve ease and accuracy of measuring in-use performance to better understand the extent of the gap and diagnose its causes. Existing approaches range from low cost but basic assessments allowing very limited diagnosis, to intensively instrumented experiments that provide detail but are expensive and highly disruptive, typically requiring the installation of specialist monitoring equipment and often vacating the house for several days. A key challenge in reducing the cost and difficulty of complex methods in occupied houses is to disaggregate space heating energy from that used for other uses without installing specialist monitoring equipment. This paper presents a low cost, non-invasive approach for doing so for a typical occupied UK home where space heating, hot water and cooking are provided by gas. The method, using dynamic pattern matching of total gas consumption measurements, typical of those provided by a smart meter, was tested by applying it to two occupied houses in the UK. The findings revealed that this method was successful in detecting heating patterns in the data and filtering out coinciding use. [ABSTRACT FROM AUTHOR]

Abstract Nowadays most retrofit decisions are based on reducing CO 2 / heating consumption. The aim of this study was to determine the reliability of three tools (RdSAP, SAP and IES) often used to predict these reductions. Three no-fines concrete (NFC) dwellings (C1, C2, and C3) with similar floor area and construction but different occupants were monitored. Key information about the thermal performance of the fabric; the behaviour of the occupants and the energy consumption was collected before and after 110 mm of external wall insulation (EWI) was added. The target was a 30% reduction on energy consumption due to the EWI. However, only C3 decreased it by 30% as expected, C2 only by 14% due to a subtle rebound effect and C1 actually increased consumption by 75%, due to rebound effect. Steady state tools (RdSAP and SAP) were found to be inaccurate in predicting the operational energy consumption of dwellings, only dynamic performance analysis software (IES) was suitable to carry out this type of prediction accurately. However, this type of software requires highly accurate and detailed information regarding: the baseline performance of the fabric, external weather conditions and, most importantly, accurate pre- and post- heating operational habits of the occupants. Few retrofitting projects have the resources and time to gather this information. Unless those are available, the retrofit decisions should be based in a different criteria, rather than using inaccurate SAP or RdSAP energy consumption predictions. The coefficient of heat loss of the fabric of a dwelling is independent of the occupants. SAP was found quick to calculate reasonable predictions of the coefficient, by using accurate fabric data, and to show the impact of different factors on the heat loss of the fabric. Therefore, it could be claimed that the coefficient of heat loss of the fabric is a suitable alternative criteria to make pre-retrofit decisions. [ABSTRACT FROM AUTHOR]

The most distinctive properties of the HVAC systems are their large-scale nonlinear systems that contain large thermal inertia, time variability, nonlinear constraints, uncertain disturbance factors, multivariate systems and coupled properties for both temperature and humidity. This paper considers a novel control algorithm that could handle such intricate characteristics by using hybridization layers between the physical parameters' memory and the neural networks' weight, which is well-structured by the Takagi-Sugeno-Kang Fuzzy inference strategy. The application of nonlinear regression to the offline hybrid layers construction and online fine-tuning methods are conducted by using the Gauss-Newton Method in order to achieve fast tuning operation. The feedforward strategy is adopted, so as to boost the stability of the overall system in addition to increasing the control precision and its response speed. Moreover, the effects of disturbances and uncertainty are eradicated by online tuning. The tracking control goal takes full advantage of mature strategies regarding the predicted mean vote (PMV) to address high thermal inertia, to save energy and to tackle coupling problem. The proposed control performance results are analysed and compared to hybrid PID cascade control, where both strategies are tested individually and simultaneously through the use on the HVAC system. The obtained results showed that Feedforward Hybrid Layers Control (FHLC) led to effective advantages regarding optimal performance, adaptation, precision and robustness. Furthermore, adopted the adaptive structural control algorithm for FHLC to improve indoor thermal comfort, whereas the significant energy reduction is achieved. The prospective scope for future work is to expand the control structure for full building control by adding more controlled elements, such as lighting, ventilation, security, fire protection and other building appliances. [ABSTRACT FROM AUTHOR]

Highlights • The carbon intensity exhibits significant variations over time, which can be used in control. • Three single family houses of varying age are simulated, using historical input data from Denmark. • MPC can optimise according to energy use, power price, dynamic carbon intensity, or comfort, to improve the performance of heating. • Footprint-wise, energy- and carbon-optimising MPC were more desirable than price or comfort optimising MPC. • The average carbon intensity of the power consumed is a relevant performance metric for MPC. Abstract Around the world, electricity systems are transitioning towards renewable energy to meet humanity's climate change mitigation targets. However, in a pre-transition system, the carbon intensity of power exhibits strong variations over time, which calls for load shifting to times when its impact is lower. In this work, the case of heating in single-family houses is studied, using Model Predictive Control (MPC) to optimise multi-zone operation. Low inertia heating is used, and simulations are made upon three different insulation level using historical grid and climate data from Denmark. The results show that energy and CO 2 optimisation are relevant objectives for predictive control for lowering the carbon footprint of heating, while SPOT price optimisation is comparatively undesirable. However, benefits of energy optimisation were questioned, as a well-tuned PID control might have had similar performance. Nevertheless, gains from CO 2 optimisation in recent houses highlight the importance of considering the average carbon intensity of energy used, in addition to the amount of energy itself, when aiming to reduce the carbon footprint. [ABSTRACT FROM AUTHOR]

An intensive study on the heating temperature aimed to create a satisfying indoor condition that should meet the residents’ thermal requirements in accordance to their daily behavior pattern. Unlike urban residents who stay indoors for a long time, rural residents constantly live in a dynamic environment: they often leave their residences and get busy with numerous labor activities. Therefore, the thermal sensation questionnaire survey performed in a steady environment is not suitable for them. To study the rural heating temperature in a dynamic environment, a three-years field investigation was performed in South Liaoning province. During the investigation, a continuous tracking method was adopted to record the residents’ behavior; objective environmental parameters test and subjective thermal sensation surveys were rigorously recorded. The results indicate that the residents behavior pattern exerts an influence on the heating temperature by influencing the residents’ clothing insulation. Heating temperature in auxiliary rooms can be directly determined by the residents’ thermal sensation, with the reasonable value of 11   °C. The influence of residents’ behavior on clothing should be considered when determining heating temperature in the master bedroom, the reported value of which is 13   °C. The heating temperature obtained by the thermal sensation fuzzy comprehensive evaluation model in paper reflects the rural residents’ real-life requirements on thermal environment, and it provides a reference for designing rural residences. [ABSTRACT FROM AUTHOR]

New smart building technologies that offer continuous dynamic optimization of Heating, Ventilation, and Air Conditioning (HVAC) control hold promise to advance building operations for efficiency and grid response. These technologies use data from the control system to determine the analytically optimal setpoints, and then write back the optimal setpoints into the control system to minimize system energy consumption or costs. There are limited studies documenting field validations of these technologies. This paper presents the results from a long-term field evaluation of a model-predictive HVAC optimization system that installed in four commercial buildings. Energy savings analysis was conducted based on pre/post submetered energy use. Across the cohort of evaluation sites, HVAC savings following the implementation of the optimization system were mixed, ranging from 0–9%. Analysis of site operational data showed that occupant comfort was neither positively nor negatively impacted. Key technology adoption considerations and recommendations are summarized in the paper. The technology performs best when HVAC systems are in good working condition, and can be exercised to achieve the full range of its optimized setpoints–however it may not provide extensive additional savings over cases where best practice sequences of operation and reset strategies are already comprehensively implemented. [ABSTRACT FROM AUTHOR]

This paper provides an analysis of the relationships between dwelling, household and motivation, behaviour and perception characteristics and thermostatic radiator valve (TRV) settings in living rooms ( n  = 187) and bedrooms ( n  = 159) in UK social housing. The work capitalises on primary data from a socio-technical household survey undertaken in Plymouth, UK during 2015, which was coupled with building audit data. The mean reported TRV setpoint temperatures in the living rooms and bedrooms were 23.4 °C and 21.9 °C, implying that occupants prefer cooler conditions in bedrooms. There were systematic variations according to dwelling, household, and motivation, behaviour and perception characteristics. In general, the setpoint temperatures in individual rooms were higher than the whole house thermostat setpoint temperature, implying that there may be a misunderstanding of the role of TRVs in the home heating system. The research could enable social housing providers, the government and commercial organisations to target energy efficiency measures (i.e. thermal upgrades) and social interventions (i.e. behaviour change) at those dwellings and households where their impact may be most beneficial. The results presented could also be used to improve the assumptions of zonal heating behaviour in energy models, which could result in more realistic predictions of the heating demands of social housing. [ABSTRACT FROM AUTHOR]

Upgrading the thermal insulation of UK houses to improve wintertime energy efficiency raises concerns about potential summertime overheating risk. To address these concerns, experiments were conducted in a pair of thermally matched, solid walled houses, located in the UK. One of the pair was retrofitted with internal wall insulation, while the other remained uninsulated; both houses were monitored for four weeks during the summer of 2015. Operative temperatures in the living room and main bedroom were observed to be higher in the internally insulated house in comparison to the uninsulated house. The houses were again monitored for a further three weeks with a simple overheating mitigation strategy applied consisting of night ventilation and shading using internal blinds. The data were normalised for variations in external weather conditions using a linear regression model, with the exponentially-weighted outdoor running mean air temperature as the predictor variable of indoor operative temperature. The results showed that the mitigation strategy was effective at reducing the internal temperature in the internally insulated house to a level similar to that observed in the uninsulated house. The marginal increase in overheating risk should not be considered a barrier to the uptake of IWI in this type of house and location, at this time. Shading devices and secure noise attenuating vents for existing dwellings may be needed as part of a package of refurbishment in the future. It could become a requirement within the Building Regulations [1] to reduce overheating risk when retrofitting existing homes. [ABSTRACT FROM AUTHOR]

This paper focuses on the potential of a solar installation combining air-conditioning, heating and Domestic Hot Water (DHW) production processes intended for mass use in building sector in Morocco. The objective is to measure the relevance of the investment in such systems through a technico-economic assessment and a risk analysis based on classic economic choice criteria. Then, a sensitivity study was conducted to analyze the impact of the major characteristics of a solar plant project (amount of investment, operation cost, solar sunshine, etc.) on the decision-making in various environments to conclude the technical feasibility and economic viability of these systems under Moroccan conditions. Parametric studies including the solar collectors’ technology and field area in addition to the storage tank volume were carried out to design the solar plant and to ensure its optimization in dynamic mode operation. The major finding of this work is that incrementing the collector’s field area to 30 m 2 optimizes the thermal efficiency of the solar plant, and the electric booster consumption is reduced. Furthermore, it would be advantageous to use a number of collectors of 14 (a total surface of 22 m 2 to satisfy) the cooling, heating and hot water needs over the year since the overall system solar fraction remain above 55% when the optimum parameters are considered. The results indicated also that solar cooling systems in hot climates are an attractive option to increase energy savings and to mitigate CO 2 emissions. In addition, the solar contribution has increased from 605 kW h to 705 kW h in winter and summer periods, respectively, while the auxiliary consumption has achieved 1450 kW h, 1875 kW h and 2300 kW h for Agadir, Tangier and Ben Guerir, respectively. However, according to the economic assessment, the high solar plant cost is a main barrier facing their implementation in Morocco. Several recommendations were drawn from the profitability study to identify the sensitive points and to consider avenues for improvement with a view to future industrialization of the combined solar thermal installation in Morocco. [ABSTRACT FROM AUTHOR]

Living in cold conditions poses a risk to health, in particular to low-income, fuel-poor households. Improving the energy efficiency of the housing stock may bring multiple positive health gains through improved indoor temperatures and reduced fuel consumption. This study used a multilevel interrupted time-series approach to evaluate a policy-led energy-performance investment programme. Long-term monitoring data were collected for intervention and control households at baseline (n = 99) and follow-up (n = 88), creating a dataset with 15,771 data points for a series of daily-averaged hydrothermal outcome variables. The study found that the intervention raised indoor air temperature by on average 0.84 K as compared with control households, thereby bringing the majority of indoor temperature measurements within the ‘healthy’ comfort zone of 18-24°C, while average daily gas usage dropped by 37%. External wall insulation was the most effective measure to increase indoor air temperature. The greatest increases were found in the evening and at night, in the bedroom, and in British steel-framed buildings. No evidence was found that the intervention substantially increased indoor relative humidity levels when accompanied by mechanical ventilation. The study concludes that the multilevel interrupted time-series approach offers a useful model for evaluating housing improvement programmes. [ABSTRACT FROM AUTHOR]

Within the European context, most of the current residential building stock does not fulfil minimum thermal requirements and needs to be refurbished urgently. Quantitative internal infrared thermography can provide valuable information about the in-situ thermal transmittance of existing buildings for their future refurbishment. This paper aims to establish how operating conditions and thermophysical properties might affect the accuracy of the measured U -value using this technique. To assess the most influential operating conditions, one experimental room with a heavy single leaf-wall was chosen to develop the research in quasi steady-state conditions, with a wide temperature difference range (3.8 < Δ T  < 21   °C). A statistical analysis demonstrated that the variance in thermal transmittance could mainly be predicted by changes in the outer air temperature. To analyze the impact of the thermophysical properties, specifically the heat capacity per unit of area, four unoccupied residential buildings with heavy multi-leaf walls were tested (6 < Δ T  < 10   °C). The results mainly showed that the quantitative internal infrared thermography method is more accurate in heavy multi-leaf walls with high kappa values, reaching maximum deviations of 0.20%. [ABSTRACT FROM AUTHOR]

Abstract: This paper reviews studies of the relationships between ventilation rates (VRs) in homes and occupant health, primarily respiratory health. Five cross‐sectional studies, seven case‐control studies, and eight intervention studies met inclusion criteria. Nearly all studies controlled for a range of potential confounders and most intervention studies included placebo conditions. Just over half of studies reported one or more statistically significant (SS) health benefits of increased VRs. Wheeze was most clearly associated with VR. No health outcomes had SS associations with VRs in the majority of statistical tests. Most studies that reported SS health benefits from increased VRs also had additional health outcomes that did not improve with increased VRs. Overall, the number of SS improvements in health with increased VRs exceeded the anticipated chance improvements by approximately a factor of seven. The magnitude of the improvements in health outcomes with increased VRs ranged from 20% to several‐fold improvements. In summary, the available research indicates a tendency for improvements in respiratory health with increased home VRs; however, health benefits do not occur consistently and other exposure control measures should be used together with ventilation. The research did not enable identification of a threshold VR below which adverse health effects occur. [ABSTRACT FROM AUTHOR]

This work presents the study of two innovative solar water heating systems, integrated on the facades and the roof of a social house building. One of the systems combines collector and storage tank in a single unit, called Integrated Collector Storage solar water heater; the other one comprises a photovoltaic and a thermal collector known as Hybrid Photovoltaic/Thermal device, in which the produced energy support both thermal and electrical needs. The analysis has considered the integration of the studied solar systems on building's envelope, investigating the effect of these systems in terms of building's thermal load along with their capacity to cover the hot water and electrical needs. The energy behavior of the building, as well as the energy output of the solar systems are investigated through simulation analysis for two cities (Nicosia, Cyprus and Athens, Greece) and three orientation modes (South, East and West). The results show that, after the interventions, the energy demands of the building for space heating and cooling are decreased at about 10%, while the hot water and electrical demands are covered up to 80 and 50%, respectively. The energy contribution of the respective solar systems with regard to the buildings’ energy demand is evaluated through Life Cycle Assessment; the respective analysis allows the evaluation of the environmental impacts during the entire life cycle of the considered systems. [ABSTRACT FROM AUTHOR]

A large fraction of the global population relies on the inefficient combustion of solid fuels for cooking and home heating, resulting in household exposure to combustion byproducts. In the southwestern United States, unhealthy air quality has been observed in some homes that use solid fuels as a primary source of heat on the Navajo Nation. In order to better understand how home heating fuel choice can influence indoor air quality in this region, we used recently developed low-cost electrochemical sensors to measure carbon monoxide (CO) air mole fractions continuously inside and outside 41 homes in two communities on the Navajo Nation. Using low-cost sensors in this study, which don't require extensive training to operate, enabled collaboration with local Diné College students and faculty in the planning and implementation of home deployments. Households used natural gas, propane, pellets, wood, and/or coal for heating. We developed quantification methods that included uncertainty estimation for Alphasense CO-B4 sensors, for measurements both inside and outside homes. CO concentrations elevated above background were observed in homes in each heating fuel group, but the highest hourly concentrations were observed in wood and coal burning homes, some of which exceeded World Health Organization Guidelines on both an hourly and eight-hourly basis. In order to probe the many factors that can influence indoor pollutant concentrations, we developed and implemented methods that employ CO emission and decay time periods observed in homes during everyday activities to estimate air exchange rates as well as CO emission rates on the basis of a given well-mixed volume of air. The air quality measurement tools and methods demonstrated in this study can be readily extended to indoor air quality studies in other communities around the world to inform how home heating and cooking practices are influencing indoor air quality during normal daily activities. [ABSTRACT FROM AUTHOR]

An area less than 5.5% of Egyptian territory is where most of Egypt's population lives. A narrow strip of land forms the Nile Valley and Delta sector. The National Project for Desert Hinterlands is one of the urban projects targeting rehabilitation of the poor in alternative villages in the near desert to stop urban sprawl over agricultural land and decrease congestion in the old habitats. Low cost energy efficient houses are the aim of the architect in similar projects taking in consideration the high electricity consumption of Egypt's residential sector. Based on a literature review, this paper presents a proposal for designing desert dwellings that accommodate the hot dry climate by incorporating passive elements and using stabilized earth blocks as a local building material. Furthermore, simulation is used to test alternative proposals. The results show that an underground constructed house with a sunken courtyard incorporating an Earth to Air Heat Exchanger System (EAHE) can reduce between 42- 72% of energy consumption used to achieve thermal comfort compared to contemporary desert housing projects. [ABSTRACT FROM AUTHOR]

This paper presented a novel analytical method for the performance evaluation of various rural houses space heating systems and determination of the most appropriate system type, on the basis of Analytic Hierarchy Process (AHP) and Fuzzy Comprehensive Evaluation (FCE) methods. To initiate the system performance evaluation, a number of parametrical indexes, including three primary indexes namely, social benefit, environmental benefit and economic benefit, and nine secondary indexes namely, room temperature qualified rate, heating system reliability, smoke concentration, SO 2 concentration, NO x concentration, energy consumption, initial investment, operational costs and policy incentives, were developed by running a dedicated specialists' questionnaire. These indexes were then applied to the performance assessment of the selected five rural houses space heating systems, i.e., hybrid solar/biomass boiler, biomass boiler, air source heat pump, hybrid solar/electrical heating and coal-fired boiler. As a result, the weights of different indexes for the five systems were determined using the AHP method and consequently, the priority order of the five systems was listed using FCE. The modelling results indicated that among the five selected systems, solar/biomass heating system presented the best performance, followed by the biomass boiler type, air source heat pump type, solar/electrical heating type, and coal-fired boiler type. The novelty of the research lies in the combined use of the AHP and FCE methods for solving the complex multi-factors inclusive equations. This combination can overcome the AHP's shortfall in subjective selection of the indicators, and meanwhile, prevent the FCE's drawback of ignoring the weights of the indexes, thus providing a realistic and effective method for selection of the best performing rural house space heating system. Wide deployment of research outcomes can help improve the living standard of the residents staying in wide range of rural areas in China and thus harvest greater social, environmental and economic benefits subsequently. [ABSTRACT FROM AUTHOR]

Currently, the 4th Generation District Heating (4GDH) is an attractive topic in the energy field as it concerns a sustainable and efficient means of delivering heat to houses. The 4GDH concept is characterised by low temperatures, low heat distribution losses, renewable and excess energy utilisation, as well as high efficiency. As a result of implementing the 4GDH concept, existing district heating systems (DHS) are undergoing massive improvement. The barriers faced by existing DHS over the course of the transition process towards the 4th generation are reviewed in the paper; the methodology for the evaluation of the DHS transition process towards the 4th generation is also presented. This methodology allows to assess the transition process dynamics, as well as helps to focus on DHS characteristics, which need to be improved. A large-scale DHS in Tallinn (Estonia) was analysed with the help of the proposed methodology. Supply and return temperatures, the share of renewable energy, and network conditions demonstrated the highest potential for improvement and had the most notable impact on the Tallinn DHS transition process. [ABSTRACT FROM AUTHOR]

One of the possibilities for an efficient use of electrical energy for heating is to apply a certain temperature schedule for heating of the room. In case of optimization using the criteria of minimum electric energy consumption, the time it takes to reach a set temperature increases, and in time-optimal control, the electric energy consumption increases. This article proposes fuzzy control of the heating in a household room in accordance with the energy consumption, response time and accuracy, which is performed within an admissible range specified by the thermal comfort in the home. [ABSTRACT FROM AUTHOR]

We have developed a spatiotemporal heating control algorithm for use in homes. This system utilises a combination of relatively low-tech hardware interfaced with electric heating systems and a smartphone interface to this hardware, and a central server that progressively learns users' room-specific presence profiles and thermal preferences. This paper describes the associated spatiotemporal heating control algorithm, its evaluation utilising the dynamic building performance simulation software EnergyPlus, and a longitudinal deployment of the algorithm controlling a quasi-autonomous spatiotemporal home heating system in three domestic homes. In this we focus on the prediction of occupants' presence and preferred set-point temperature as well as on the calculation of optimum start time and the utilisation of user-scheduled absences; this for two comfort strategies: to maximise comfort and to minimise discomfort. The former aims to deliver conditions equating to a ‘neutral’ thermal sensation, whereas the latter targets a ‘slightly cool’ sensation with corresponding heating energy savings. Simulation results confirmed that the algorithm functions as intended and that it is capable of reducing energy demand by a factor of seven compared with EnergyStar recommended settings for programmable thermostats. Field study results align with these findings and highlight the possibility to reduce energy under the minimise discomfort strategy without compromising on occupants' thermal comfort. [ABSTRACT FROM AUTHOR]

The present work aims at presenting the development of a performance-based model of a water-to-air variable capacity ground-source heat pump. The main challenge is to apply the recommended control strategy to vary the speed of the compressor for each mode of operation and to be able to switch from one mode to the other. A series of verification tests tend to confirm that the speed control strategy has been correctly implemented. The proposed model is used in annual simulations of a residential system equipped with a variable capacity ground-source heat pump. In this case, the seasonal performance factor (SPF = ratio of the annual energy requirement for heating, cooling and domestic hot water (DHW) over the annual total energy consumption) is 3.64. The corresponding value for a conventional system composed of a fixed capacity heat pump operating in on-off mode and a separate electric DHW tank is 2.60. [ABSTRACT FROM AUTHOR]

In France, 40% of buildings are heated with electrical devices causing high peak load in winter. In this context, advanced control systems could improve buildings energy management. More specifically, optimal strategies have been developed using a dynamic programming method in order to shift heating load, taking advantage of the building thermal mass. However, this optimization method is computationally intensive and can hardly be applied to real-time control. Statistical techniques can be used to derive near-optimal laws from the optimal control results. These rule extraction techniques model the relationship between explanatory variables and a response variable. This paper investigates the use of Beta regression model. This regression-based strategy was able to mimic the general characteristics of the optimization results with a small mean bias error (−6%) and greatly reduce computational effort (150 times faster). Given its simple mathematical formulation, it could be implemented in real-time building systems control. [ABSTRACT FROM AUTHOR]

The design and analysis of community-scale energy systems and incentives is a non-trivial task. The challenge of such undertakings is the well-documented uncertainty of building occupant behaviours. This is especially true in the residential sector, where occupants are given more freedom of activity compared to work environments. Further complicating matters is the dearth of available measured data. Building performance simulation tools are one approach to community energy analysis, however such tools often lack realistic models for occupant-driven demands, such as appliance and lighting (AL) loads. For community-scale analysis, such AL models must also be able to capture the temporal and inter-dwelling variation to achieve realistic estimates of aggregate electrical demand. This work adapts the existing Centre for Renewable Energy Systems Technology (CREST) residential energy model to simulate Canadian residential AL demands. The focus of the analysis is to determine if the daily, seasonal, and inter-dwelling variation of AL demands estimated by the CREST model is realistic. An in-sample validation is conducted on the model using 22 high-resolution measured AL demand profiles from dwellings located in Ottawa, Canada. The adapted CREST model is shown to broadly capture the variation of AL demand variations observed in the measured data, however seasonal variation in daily AL demand behaviour was found to be under-estimated by the model. The average and variance of daily load factors was found to be similar between measured and modelled. The model was found to under-predict the daily coincidence factors of aggregated demands, although the variance of coincident factors was shown to be similar between measured and modelled. A stochastic baseload input developed for this work was found to improve estimates of the magnitude and variation of both baseload and peak demands. [ABSTRACT FROM AUTHOR]

Occupant behaviour is a key variable affecting the amount of energy used in homes. The understanding, interface and interaction with heating controls hold the potential to influence how heating is operated and, in turn, how much energy is consumed. A study is presented to test a series of hypotheses that the design of the home-heating interface can positively influence the achievement of home-heating goals, if it is specifically designed to communicate a user mental model (UMM) of how the system functions. This would encourage appropriate inhabitant behaviour. The experiment involved 20 pairs of participants matched by age, gender and home-heating experience. The participants were asked to attain a series of home-heating goals using an accelerated home-heating simulator. The impact of specific design features of a novel interface design was compared with an interface offering a traditional home-heating system experience. The evidence confirms that design features contributed to differences in UMMs, intentional behaviour and goal achievement. A mental model approach to design can be used as a means of putting users 'in control' of their heating system to enable them to fulfil their home-heating goals better. [ABSTRACT FROM AUTHOR]

When considering interior insulation of historic, multi-storey buildings with solid masonry walls, it is important to focus on two important factors: How big is the building segment to which it can be applied, and what is the significance of how the multi-dimensional geometry of these façade walls is considered in the assessment of the heat saving potential. The findings show that a large proportion of Danish multi-storey dwellings with solid masonry walls, high energy consumption, and uniform characteristics were found to originate from the period 1851–1930. This segment accounts for 25% of all multi-storey apartments in Denmark. It was investigated, which relative reduction of the average thermal transmittance could be obtained by interior insulation when simulated in different dimensions, degrees of insulation and thickness. The analysis showed that partial insulation of the spandrels below windows on the 2nd/3rd highest storeys accounted for up to 40% of the average thermal transmittance reduction achievable by fully insulating inside walls, while covering 17% of the space needed in the full insulation strategy. Furthermore, the analysis showed an underestimation of average thermal transmittance by 2-dimensional compared to 3-dimensional simulation by up to 57%, indicating that 3-dimensional analysis is needed to obtain realistic results. [ABSTRACT FROM AUTHOR]

This study presents the results of research on heat loss from various types of residential buildings through ventilation systems. Experimental research was done to analyse the effectiveness of ventilation systems of different types and determine the parameters of air discharged via the ventilation ducts. A model of heat loss from the discharge of exhaust air outside through air ducts has since been developed. Experiments were conducted on three experimental systems of building ventilation: gravitational, mechanical, and supply-exhaust ventilation systems with heat recovery. The proposed model dependencies were used to chart the daily fluctuations of the optimum multiplicity of air exchange for precise control of the parameters of mechanical ventilation systems in residential buildings. This study proves that natural ventilation in residential buildings fulfils its function only by increasing the air flow into the building, and that this incurs significant heat loss from buildings during the heating season. [ABSTRACT FROM AUTHOR]

Five houses with attached garages were tested for contaminant transport into the living space. Sulphur hexafluoride tracer gas was intentionally released periodically in the garage, and concentrations were measured in air samples taken from various points within the living space, garage, and ancillary spaces. Progressive interventions, including passive/mechanical ventilation, and air/duct sealing were implemented to evaluate their impact on contaminant transport. Quantification of the contaminant transport and the effectiveness of the interventions were evaluated using the ratio of maximum sulphur hexafluoride concentration detected in the living space relative to the garage. Air sealing was effective only in some cases, and appears to be most applicable for sites without HVAC equipment located in the garage. Mechanical exhaust ventilation was effective to some degree at all sites, and was the only reliable method at sites with HVAC equipment in the garage. Although no interventions completely eliminated the transport of tracer gas into the living space, continuous mechanical exhaust ventilation was able to consistently reduce concentrations in the living space. The largest evaluated exhaust flow rate (290 CFM, 8.2 m3/min) resulted in living space concentrations less than 1% of that reached in the garage, and the smallest evaluated flow rate (50 CFM, 1.4 m3/min) reduced it to that level in 3 of the 5 houses. [ABSTRACT FROM AUTHOR]

The National Institute of Standards and Technology constructed the Net-Zero Energy Residential Test Facility to support the development and adoption of cost-effective net-zero energy designs and technologies. In support of indoor air quality goals, contaminant source control approaches were implemented that minimized the use of products containing urea-formaldehyde resin and utilized products with relatively low volatile organic compound emissions. Indoor and outdoor concentrations of formaldehyde and acetaldehyde were approximately measured monthly for 15 months. Independent emission measurements of formaldehyde were made in a small chamber system to determine the emission rates from samples of the wood flooring, plywood, and wood cabinetry taken from the house. Blower door tests were performed to determine the leakage area of the exterior envelope, the interior floors, and transfer grilles between floors. Real-time formaldehyde concentration and energy measurements were used to verify the indoor concentrations and energy predictions of a coupled CONTAM-EnergyPlus model of the house. The verified model was then used to evaluate the impacts of different outdoor air ventilation rates on indoor concentrations and energy. The current work demonstrates the need for consideration of source control options during product selection and the provision of mechanical ventilation, especially in homes with relatively airtight envelopes. [ABSTRACT FROM PUBLISHER]

Solar heat pump systems (SHPs) have been investigated for several decades and have been proven to increase the share of renewable energy and reduce electric energy demand in residential heating applications. Many review articles have been published on the subject, however literature discussing the techno-economics of different solar technologies (thermal, photovoltaic and hybrid thermal/photovoltaic) in combination with heat pumps is lacking, and thus to directly compare the merits of different SHPs is not an easy task. The objectives of this study are: a) review the different system boundaries and the main performance indicators used for assessing energetic and economic performances; b) review techno-economic studies in the literature and identify which studies give enough information and are compatible enough for making an economic inter-comparison; c) present an economic inter-comparison based on the identified systems. The results show that there is a lack of studies including an economic assessment of solar photovoltaic and heat pump systems. Additionally, there are no consistent boundaries or approaches to the study structures, making comparisons between systems difficult. In conclusion, a standardized or broadly accepted definition of technical and economic performance for SHPs is needed. Despite this, the study has shown that there are clear trends for decreasing payback times for SHPs, both solar thermal (ST) and photovoltaic (PV), with decreasing heating degree-days and with increasing solar resource. [ABSTRACT FROM AUTHOR]

Circulation pumps are mechanical devices, which are used to create the overpressure required for the transportation of a heat-transfer medium in heating technology as well as in other related technologies. In a circulation pump the mechanical energy generated by the drive machine - an electric motor - is transformed to hydraulic energy, which consists of kinetic and static energy. In the pipeline of a heating system circulation pumps represent a source of hydraulic energy (positive differential pressure), which is consumed to transport the heat-transfer medium. During the flow, the heat-transfer medium puts up resistance to the so-called passive resistors, which consist of pressure losses from friction in the pipes and pressure losses due to local resistance. In this article the authors describe the research, which is based on a case study. They analyze the effect of a circulation pumps on the investments and operating costs in a residential building. Different types of circulation pumps, ranging from the most unfavorable to the optimal, were selected. [ABSTRACT FROM AUTHOR]

This article provides general information about the air pollution in the Skopje valley, its geographical, climatic and meteorological conditions, that contribute to high concentrations of PM10 and PM2,5 in the city, especially during the heating season. The measuring network shows that PM10 concentrations in all measuring point in the city of Skopje is drastically above the limit of 50μg/m3, with accident reaching value up to 1000μg/m3. Part of this research is done by conducting a survey on 5044 households in 17 municipalities of the Skopje plan region, with analysis of the type of system they use for heating the household, the surface area of the object they live in, the part of the object they heat during the winter (heating season), the fuel they use or source of energy for heating and the amount of fuel for one heating season. The analysis of the type of wood fuels used within a the region of Skopje include proportional (percentage) breakdown of the typical types of wood (oak, spruce, pine, etc) and nature of equipment in use (age), maintenance patterns and frequency of wood, the emission factor for PM10 is calculated and proposed that can be used in further TIER1 calculations. [ABSTRACT FROM AUTHOR]