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In this paper, a novel direct load control (DLC) planning based on providing free energy credits to residential end-users for their heating, ventilation, and air conditioning load during demand response (DR) events is proposed. The obtained credit can then be used by the end-users during relatively higher price periods free-of-cost to enable them lowering their energy procurement costs. Furthermore, the resulting reduction in the total household energy consumption considerably decreases the critical load demands in power systems, which is of vital importance for load-serving entities in maintaining the balance between supply and demand during peak load periods. In this regard, the aforementioned energy credits-based incentive mechanism is proposed for end-users enrolled in the DLC-based DR program, as a new contribution to the existing literature, testing it in a stochastic day-ahead planning context. [ABSTRACT FROM AUTHOR]

Windows are extremely useful multi-function devices which provide views, ventilation and passive solar gain, a means of escape, security and daylight gain. However, they can have a negative impact on a home's energy efficiency, particularly when the window area is large, and play a significant role in determining the heating and cooling load of a building. It has been estimated that around 47% of the heat lost from building envelop occurs through windows. This paper summarizes the impact of the Low Carbon Homes Program in terms of future requirements and areas of future research for windows' performance and investigates new window technologies that could help to meet these requirements. [ABSTRACT FROM AUTHOR]

Abstract: Evaluating a building’s performance usually requires a high number of sensors especially if individual rooms are analyzed. This paper introduces a simple and scalable model-based virtual sensor that allows analysis of a buildings’ heat consumption down to room level using mainly simple temperature sensors. The approach is demonstrated with different sensor models for a case study of a building that contains a hybrid HVAC system and uses fossil and renewable energy-sources. The results show that, even with simple sensor models, reasonable estimations of rooms’ heat consumption are possible and that rooms with high heat consumption are identified. Further, the paper illustrates how virtual sensors for thermal comfort can support the decision making to identify the best ways to optimize building system efficiency while reducing the building monitoring cost. [Copyright &y& Elsevier]

Abstract: The performance of different HVAC systems varies when coupled with different buildings. This paper examines the relationship between building heating and cooling load and subsequent energy consumption with different HVAC systems. Two common HVAC systems in use throughout the UK office building stock, variable air volume (VAV) system and fan coil (FC) with dedicated outside air system, have been coupled with a typical narrow plan office building with and without daylight control and for both cellular and open plan. The results presented in this paper clearly indicate that it is not possible to form a reliable judgment about building energy performance based only on building heating and cooling loads. For the two investigated systems, variable air volume system and fan coil with dedicated outside air system, the difference between system demand and building demand varied from over −40% to almost +30% for cooling and between −20% and +15% for heating. If a heat recovery unit is used, the difference in heating performance is even greater, rising to −70%. [Copyright &y& Elsevier]

Abstract: Building energy regulations, also referred to as building energy codes, emerged in the 1970s as an essential tool for improving energy efficiency and minimising energy consumption in buildings. Basically they aim at setting minimum energy efficiency requirements to achieve energy efficient design in new buildings. This paper analyses the development of building energy codes concerning Heating, Ventilation and Air-Conditioning (HVAC) energy efficiency, along with their scope and compliance paths. The paper focuses on the synthesis of energy efficiency requirements on HVAC systems of non-residential buildings in different regulations. Critical issues for the development of prescriptive and performance regulatory paths for this type of systems in non-residential buildings are discussed in order to improve the understanding of HVAC energy efficiency topics and to provide policy makers with a menu of options to strengthen the HVAC section of building energy codes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mechanical Engineering / Strojniški Vestnik is the property of University of Ljubljana, Faculty of Mechanical Engineering, Journal of Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A green building is a structure that avoids or eliminates negative environmental impacts and generates environmental benefits through its design, construction, or functioning. The use of ecologically friendly building materials increases the quality of life. The overuse of electronic equipment hinders the achievement of the overall green aim, even if smart buildings are a beneficial stimulus for sustainability. Demand-side management and green building energy consumption prediction are connected and depend on accurate estimates of how much energy a facility will need. While several approaches have been offered for predicting energy use, each method has advantages and disadvantages, and there is always room for improvement. This paper suggests the Artificial Intelligence-based Energy Management Model (AI-EMM) in green building. Adaptable to human choices, it can act intelligently to increase user comfort, safety, and energy efficiency. One of the key components of the AI-EMM model is a universal infrared communication system and subsystems for smart user identification and monitoring of the internal and exterior surroundings. Long Short-Term Memory (LSTM) models are used to enhance energy consumption. A green building’s energy usage data is analysed using the suggested approach. For a better interior climate, studies examining the relationship between Heating, Ventilation, and Air Conditioning (HVAC) system should focus on airside design optimization. According to the findings, economic gains and environmentally sustainable building coexist harmoniously. A green or sustainable building is one whose structure and characteristics preserve or enhance the local environment. The experimental outcome of the AI-EMM achieved a high-performance ratio of 94.3%, less energy consumption ratio of 15.7%, accuracy ratio of 97.4%, energy management level of 95.7%, and prediction ratio of 97.1%.

The outdoor low temperature fresh air can be used as a free cold source to eliminate waste heat for the building interior zones during the transition season and winter. This paper takes a project in Hunan as an example, and the project building interior zones is 25m×7m×3.9m(L×W×H). Using Fluent software to simulate the temperature field and velocity field both the interior and exterior zones of the engineering offices. The simulation results show that using the displacement ventilation system to take the outdoor air into inner rooms not only cooling but also improving the air quality and adding comfort. According to the simulation results and outdoor air dry bulb temperature and enthalpy values, the h - d diagram is divided into three air conditioning conditions (summer, winter, transition season), and three different operation adjustment methods have been proposed corresponding to each air conditioning condition, which will reduce the energy consumption of air conditioning system. [ABSTRACT FROM AUTHOR]

This paper aimed to evaluate the applicability of adiabatic humidification in the heating, ventilation, and air conditioning (HVAC) systems of semiconductor cleanrooms. Accurate temperature and humidity control are essential in semiconductor cleanrooms and high energy consumption steam humidification is commonly used. Therefore, we propose an adiabatic humidification system employing a pressurized water atomizer to reduce the energy consumption. The annual energy consumption of three different HVAC systems were analyzed to evaluate the applicability of adiabatic humidification. The studied cases were as follows: (1) CASE 1: a make-up air unit (MAU) with a steam humidifier, a dry cooling coil (DCC), and a fan filter unit (FFU); (2) CASE 2: a MAU with the pressurized water atomizer, a DCC, and a FFU; and (3) CASE 3: a MAU, a DCC, and a FFU, and the pressurized water atomizer installed in the return duct. The energy saving potential of adiabatic humidification over steam humidification has been proved, with savings of 8% and 23% in CASE 2 and CASE 3 compared to CASE 1, respectively. Furthermore, the pressurized water atomizer installed in the return duct exhibits greater energy saving effect than when installed in the MAU. [ABSTRACT FROM AUTHOR]

In a central heating, ventilation, and air conditioning (HVAC) system, the set-points for several local control loops have a significant influence on the overall energy performance of the system. Real-time optimization (RtOpt) of those set-points has therefore been widely studied. However, due to the nonlinear dynamics of the HVAC system as well as the constraints associated with the system operation, real-time optimization always suffers from a heavy on-line computational load when those set-points are optimized simultaneously. To overcome this problem, multiplexed real-time optimization (MRtOpt) has been developed, which optimizes only one set-point at a time but with a faster optimization frequency. Because frequently resetting the set-points introduces artificial disturbances into the local control loops and may deteriorate the system stability, this paper presents a study to enhance the system stability of the multiplexed real-time optimization by integrating a degree of freedom (DOF) based set-point reset to renew the set-points instead of the conventional step-change set-point reset. The control performance of the integrated strategy was investigated using case studies. The results showed that around 10% of the energy saving was achieved by the proposed method compared with a method without real-time optimization. When compared with the conventional real-time optimization method, the proposed method resulted in around 70% computational load reduction, and over 26% reduction in the tracking errors of the local control loops. [ABSTRACT FROM AUTHOR]

In electric buses, the heating, ventilation and air conditioning (HVAC) system is responsible for up to 50% of the energy consumption, thereby significantly affecting the efficiency. It is therefore necessary to identify improved thermal settings for the bus cabin to minimize the energy consumption, while guaranteeing good thermal comfort. To achieve this goal, this paper presents the results of climatic measurements in an electric bus in Berlin, Germany. These measurements were performed for outer temperatures between 5.3 °C and 7.8 °C and four cabin temperature settings. During the measurements, several climatic parameters and the energy consumption were measured, whereas the thermal comfort (TC) was evaluated via 71 passengers' surveys. The results show that the climatic conditions in the bus vary greatly depending on the position (up to 3 K difference in mean air temperature) and height (up to 8 K/m temperature-to-height ratio). Additionally, the surveys show that the mean value of the thermal comfort parameter TC is minimized to a value of 0.15 (corresponding to "comfortable" thermal perception) for a set temperature of 21 °C, whereas the thermal conditions are perceived as acceptable even with heating off. [ABSTRACT FROM AUTHOR]

Buildings account for large part of global energy consumption. Besides energy consumed due to normal operation, a large amount of energy can be wasted due to faults in buildings subsystems. Fault detection and diagnostics techniques aim to identify faults and prevent energy waste, but are often difficult to apply in practice. Data-driven methods, in particular, require an adequate amount of fault-free training data, which is rarely available. In this paper, we propose a method for anomaly detection that exploits consensus among multiple identical components. Even if some of the components are faulty, their aggregate behaviour is overall correct, and it can be used to train a data-driven model. We test our method on variable-air-volume units in an existing building, executing two experiments grouping the components according to ventilation unit, and according to room type. The two experiments identified the same set of anomalous components, i.e., their behaviour was different from the rest of the group in both cases, and this suggests that the anomaly was not due to wrong group assignment. The proposed method shows the potential of exploiting consensus among multiple identical systems to detect anomalous ones. [ABSTRACT FROM AUTHOR]

Reinforcement learning has emerged as a potentially disruptive technology for control and optimization of HVAC systems. A reinforcement learning agent takes actions, which can be direct HVAC actuator commands or setpoints for control loops in building automation systems. The actions are taken to optimize one or more targets, such as indoor air quality, energy consumption and energy cost. The agent receives feedback from the HVAC systems to quantify how well these targets have been achieved. The feedback is captured by a reward function designed by the developer of the reinforcement learning agent. A few reviews have focused on the reward aspect of reinforcement learning applications for HVAC. However, there is a lack of reviews that assess how the actions of the reinforcement learning agent have been formulated, and how this impacts the possibilities to achieve various optimization targets in single zone or multi-zone buildings. The aim of this review is to identify the action formulations in the literature and to assess how the choice of formulation impacts the level of abstraction at which the HVAC systems are considered. Our methodology involves a search string in the Web of Science database and a list of selection criteria applied to each article in the search results. For each selected article, a three-tier categorization of the selected articles has been performed. Firstly, the applicability of the approach to buildings with one or more zones is considered. Secondly, the articles are categorized by the type of action taken by the agent, such as a binary, discrete or continuous action. Thirdly, the articles are categorized by the aspects of the indoor environment being controlled, namely temperature, humidity or air quality. The main result of the review is this three-tier categorization that reveals the community's emphasis on specific HVAC applications, as well as the readiness to interface the reinforcement learning solutions to HVAC systems. The article concludes with a discussion of trends in the field as well as challenges that require further research. [ABSTRACT FROM AUTHOR]

Abstract: Heating Ventilation and Air Conditioning (HVAC) system energy consumption on average accounts for 40% of an industrial sites total energy consumption. Studies have indicated that 20 – 30% energy savings are achievable by recommissioning Air Handling Units (AHUs) in HVAC systems to rectify faulty operation. Studies have also demonstrated that on-going commissioning of building systems for optimum efficiency can yield savings of an average of over 20% of total energy cost. Automated Fault Detection and Diagnosis (AFDD) is a process concerned with automating the detection of faults and their causes in physical systems. AFDD can be used to assist the commissioning process at multiple stages. This paper outlines the development of an AFDD tool for AHUs using expert rules. It outlines the results of the alpha testing phase of the tool on 18 AHUs across four commercial & industrial sites with over €104,000 annual energy savings detected by the AFDD tool. [Copyright &y& Elsevier]

Abstract: A retrofit study was conducted in an unoccupied manufactured house to investigate the impacts of airtightening on ventilation rates and energy consumption. This paper describes the retrofits and the results of the pre- and post-retrofit assessment of building airtightness, ventilation, and energy use. Building envelope and air distribution systems airtightness were measured using fan pressurization. Air change rates were measured continuously using the tracer gas decay technique. Energy consumption associated with heating and cooling was monitored through measurement of gas consumption by the forced-air furnace for heating and electricity use by the air-conditioning system for cooling. The results of the study show that the retrofits reduced building envelope leakage by about 18% and duct leakage by about 80%. The reduction in the house infiltration rates depended on weather conditions and the manner in which the heating and cooling system was controlled, but in general these rates were reduced by about one third. The energy consumption of the house for heating and cooling was reduced by only about 10%, which is relatively small but not totally unexpected given that infiltration only accounts for a portion of the heating and cooling load. [Copyright &y& Elsevier]

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

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

Abstract: In this paper, we propose a vision-based system for human detection and activity analysis in indoor environment. The developed presence sensor is based on video analysis, using a static camera. Composed of three main steps, the first one consists in change detection using a background model updated at different levels to manage the most common variations of the environment. Second, a moving objects tracking, based on interest points, is performed. Third, in order to know the nature of the various objects that could be present in the scene, multiple cascades of boosted classifiers are used. The validation protocol, defined by the industrial partners involved in the CAPTHOM project focusing among other things on “Energy Management in Building”, is then detailed. Three applications integrated into the CAPTHOM project illustrate how the developed system can help in collecting useful information for the building management system. Occupancy detection and people counting as well as activity characterization and 3D location extend to a wide variety of buildings technology research areas such as human-centered environmental control including heating adjustment and demand-controlled ventilation, but also security and energy efficient buildings. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a detailed meta-analysis of end and primary energy use for heating, cooling and ventilation of 11 low-energy non-residential buildings and one residential building in Germany that belong to the EnOB research program launched by the German Federal Ministry for Economy. In particular, the analysis emphasizes the substantial impact of auxiliary energy use on the efficiency of heating and cooling performance. The investigated buildings employ environmental energy sources and sinks – such as the ground, ground water, rainwater and the ambient air – in combination with thermo-active building systems. These concepts are promising approaches for slashing the primary energy use of buildings without violating occupant thermal comfort. A limited primary energy use of about 100kWhprim/(m2 neta) as a target for the complete building service technology (HVAC and lighting) was postulated for all buildings presented. With respect to this premise, a comprehensive long-term monitoring in high time resolution was carried out over the course of two to five years, with an accompanying commissioning of the building performance. Measurements include the energy use for heating, cooling, and ventilation, as well as the auxiliary equipment, the performance of the environmental heat source and sink, and local climatic site conditions. [Copyright &y& Elsevier]

Abstract: Axiomatic design (AD) is a theory that helps to develop new design objects and allows one to evaluate the quality of designs. The aim of this paper is to apply this theory to the design of heat ventilation and air-conditioning (HVAC) systems and to come to conclusions about the design quality of some specific applications. The focus is the comfort and energy consumption in commercial buildings in South European climates. The discussion contains a brief description of variable air volume (VAV) systems and dedicated outdoor air systems (DOAS) with terminal units, such as fan-coils, induction units and chilled ceilings. Occasionally, the DOAS design should include over-cooled outdoor air in order to ensure an extra cooling means. According to the AD''s first axiom, ideal systems are independent or decoupled. Our conclusion is that VAV and DOAS with induction units are coupled designs, and on the other end, DOAS with fan-coils or chilled ceilings are decoupled designs. In addition, over-cooling outdoor air (OA) flow couples the OA flow with the indoor heat removable needs. [Copyright &y& Elsevier]

Building simulation is increasingly being used in energy performance and indoor climate analysis and heating, ventilation and air conditioning systems design. Simulation requires hourly weather data. In this study Estonian climate was analysed to construct a test reference year for heating and cooling energy calculations and simulations according to a new standard, ISO15927-4. The selection was made on the basis of temperature, humidity, and global solar radiation and wind speed recordings at six weather stations over a period of 31 years, from 1970 to 2000. The constructed test reference year contains typical months from a number of different years. The average number of heating degree-days was calculated from data at six locations. The test reference year has many applications, including energy consumption and energy performance certificate calculations according to the directive about energy performance in buildings. [ABSTRACT FROM AUTHOR]