Energy-efficient Ventilation Research Articles

Energy efficient heating and ventilation of a factory hall by monitoring the indoor air climate

Background Different usage scenarios and design guidelines were considered when planning a factory building and its ventilation system. Accordingly, it often makes sense to analyze the actual operating conditions again during subsequent operations in order to optimally adapt the air supply to the respective conditions in terms of demand-responsive ventilation. The aim is to ensure good indoor air quality and thermal comfort while significantly reducing energy consumption. Methods For this purpose, in addition to the sensors in the building management system, approximately 120 wireless sensors were installed in the occupied areas to measure the air temperature, operating temperature, humidity, and CO2. In this way the spatial and temporal distributions of temperature, humidity, and CO2 in the hall were visualized and evaluated to reduce the volume flows of the ventilation systems. The recorded data and findings were used to optimize ventilation systems by gaining a deeper understanding of indoor air flow. Results As part of the investigation, a considerable reduction in the air volume flows and thus the required energy consumption of the air handling units was achieved while maintaining the same thermal comfort. It was shown that the temperature field and indoor air quality were not negatively affected by the change in the air volume flow over a wide range. Conclusions This was made possible by the well-designed ventilation system, which achieves a low-pulse, slightly stratified indoor airflow, and a structural envelope with very good thermal insulation.

Energy-efficient ventilation strategies at hospital front desks for minimizing infectious particle dispersion: Considering patient postures and airflow optimization

This research presents a novel examination of infectious particle dispersion at hospital front desks, analysing the impact of different patient postures on particle dynamics. It evaluates the efficacy of various ventilation strategies in mitigating particle spread within this high-risk area. Specifically, this study innovatively assesses particle dispersion associated with three common patient postures: upright standing, sitting in a wheelchair, and lying on a mobile bed. Results showed the baseline ventilation that considers the upright standing patient has the highest particles (34) adhered on the nurse. Particle adherence decreases with the sitting (29 particles) and lying postures (20 particles), underscoring the significant influence of human posture on particle distribution. The key contribution of this study is the identification of an optimized ventilation strategy which installs low-level wall-mounted air supply diffusers and ceiling-mounted exhaust grilles, as demonstrated in Case 3. This strategy effectively reduces particle deposition on the nurses and visitors by 52.9 % and 40 %, respectively. These findings advocate for practical infection control measures, like barriers between nurses and patients, to better protect healthcare workers. The study also suggests that future research should account for more crowded environments and occupant movement to better reflect real-world conditions at hospital front desks.

Artificial neural networks for predicting the performance of heat pumps with horizontal ground heat exchangers

A Ground Coupled Heat Pump (GCHP) is a highly energy efficient heating, ventilation, and air conditioning (HVAC) system that utilises the ground as the heat source when heating and as the heat sink when cooling. This paper investigates GCHP systems with horizontal Ground Heat Exchangers (GHEs) in the rural industry, exemplifying the technology for poultry (chicken) sheds in Australia. This investigation aims to provide an Artificial Neural Network (ANN) model that can be used for GCHP design at various locations with different climates. To this extent, a Transient System Simulation Tool (TRNSYS) model for a typical horizontal GHE applied in a rural farm was first verified. Using this model, over 700,000 hourly performance data items were obtained, covering over 80 different yearly loading patterns under three different climate conditions. The simulated performance data was then used to train the ANN. As a result, the trained ANN can predict the performance of GCHP systems with identical (multiple) GHEs even under climatic conditions (and locations) that have not been specifically trained for. Unlike other works, the newly introduced ANN model is accurate even with limited types of input data, with high accuracy (less than 5% error in most cases tested). This ANN model is 100 times computationally faster than TRNSYS simulations and 10,000 times faster than finite element models.

Thermoelectric active window frame: Constructive integration and preheating analysis

Building heating and cooling systems using thermoelectricity appear to be a feasible alternative, as it presents several features including versatility and high reliance. While most applications of thermoelectricity in buildings are found in wall systems, window integration shows excellent potential for enhancing the thermal performance of buildings at the façade level, compensating heat losses that take place in windows. Combining energy efficient ventilation with heat recovery leads to a significant reduction of the required energy, keeping desired comfort conditions inside buildings. Thus, the following study presents the design of an active window frame with an integrated thermoelectric system, attaining two functions: pre-heating the supply air, while simultaneously recovering the waste heat energy from exhaust air. Two full-scale prototypes were built, each featuring a different airflow pattern, and preliminary tests for heating mode were carried out under laboratory conditions. The results revealed a similar performance comparing both prototypes, achieving a COP ranging 1.56 to 2.71 for prototype A, while prototype B ranged from 1.62 to 2.65. The results showcase superior heating efficiency compared to a previous experiments conducted by the research group, where a maximum COP of 1.91 was achieved. From a building perspective, wider adoption of thermoelectricity applied to thermal conditioning is hindered by lack of suitable products for architectural integration. Therefore, the system's innovation stems from optimized design, integrated construction, and industrialized production, enhancing energy efficiency in buildings via a compact façade integrated system without space compromise.

Effectiveness of biological drying for citric acid dewatered sludge: Evaluating the impact of energy-efficient ventilation strategies

The effectiveness of dehydration and utilization processes for citric acid dewatered sludge is hampered by its high concentrations of polysaccharides, proteins, and water-binding properties of microbial extracellular polymers (EPS). This research explores the efficacy and mechanisms involved in extracting water from this type of sludge using biological drying technology, with varying rates of ventilation. Especially pertinent was the use of low ventilation rates as control variables. Our results suggest that a scheduled intermittent ventilation at lower rates allows for the most efficient removal of water, achieving a rate of 41.71 % within eight days, according to the zero-order kinetic model. Remarkably, the peak temperature registered was 60 °C, reaching this threshold in just 0.1 days and maintaining high temperatures for approximately 5.9 days. Component analysis of organic matter illustrated a preferential degradation process for lipids under these ventilation conditions which is pivotal for releasing and transforming bound water for efficient extraction, as well as facilitating the breakdown of easily hydrolysable materials. Further, polysaccharide/protein (EPS) decomposition contributed to water removal, though less significantly. The periodic ventilation strategy allowed for the maximum cumulative temperature to be sustained, demonstrating superior efficiency in harnessing bio-generated heat (82.77 % for water evaporation), resulting in dry sludge suitable for self-sustained combustion at relatively low cost ($26.61/t). Highlighted by this study is the considerable potential of energy-efficient ventilation methods in the biological drying treatment of citric acid fermented sludge and similar industrial waste materials.

Heat removal and ventilation limitations of the solar chimney attached with a built enclosure: Correlations of thermal Rayleigh numbers, port arrangements and discrete heating elements

For energy efficient ventilation and low carbon design, solar chimney has been extensively applied on buildings. In the present work, three representative solar chimneys were introduced, i.e., Model 1 with top-horizontal outlet, Model 2 with upper-vertical outlet and Model 3 with middle-vertical outlet. Updraft ventilation from the built enclosure to the outlet and heat transfer from the absorber to the fluid by heat convection were numerically and theoretically investigated, and their limitations and correlations with governing parameters were also discussed. Streamlines and heatlines were used to visualize transport paths of air and heat respectively. Reverse flow could not be observed in the solar chimney channels of Model 2 and Model 3; Therefore, total volume flow rate induced by the solar chimneys Model 2 and Model 3 and convection heat transfer rate of the absorber increases positively with thermal Rayleigh numbers (Ra). Model 2 chimney produces greater thermal buoyancy than that by Model 3, and its air flow rate is higher than that of Model 3. Generally, volume flow rate induced in Model 1 is higher than those of Model 2 and Model 3 as Ra is no more than 2.5 × 106, and simultaneously, convection heat transfer rate Nusselt number (Nu) is also greater than those of Model 2 and Model 3. When Ra exceeded 2.5 × 106, reverse air flow was intensified further, Nu of Model 1 started to decline. The three models with discrete heat sources could induce more air from indoor than that respective model without discrete heat sources. The maximum increment rate is obtained by the Model 1 solar chimney with discrete heat sources, then Model 2 and the least done by Model 3. Their power relationships between Nu and Ra, V*and Ra are regressed respectively. The dependence of volume flow rate on broad thermal Rayleigh numbers covering all the three flow regimes showed that there were linear correlations between discrete numerical volume flow rates and the scaling predictions, except in Model 1 for high Ra (exceeding critical value 9.0 × 105), where volume flow rate was remarkably reduced due to reverse air flow. This research could provide useful theoretical information for applying small sized vertical solar chimneys attached to the building sidewall to effectively reduce built energy consumption.

Cold Climate Challenges: Analysis of Heat Recovery Efficiency in Ventilation Systems

As building energy consumption gains ever-increasing attention worldwide, the focus on addressing it through the examination and optimization of efficient heat recovery solutions continues to intensify. With well-insulated and airtight buildings, the proportion of heating needs attributed to ventilation is growing, leading to the widespread integration and optimization of heat recovery solutions in mechanical ventilation systems. Heat recovery in ventilation is a highly efficient strategy for reducing heat losses and conserving energy. This study involves the investigation of a ventilation unit installed in an apartment situated in Riga, Latvia, as a practical examination of heat recovery system efficiency within the Latvian climate conditions, representing a cold climate region. The objective of this study was to examine the heat recovery efficiency of the ventilation system in the Latvian climate with variable outdoor and exhaust air parameters, given that the dry heat recovery efficiency is different from the actual heat recovery efficiency. The ventilation unit was equipped with a plate heat exchanger at an airflow rate of 105 m3/h. To evaluate heat recovery efficiency, extensive measurements of air temperature and relative humidity were conducted. The collected data was analyzed, employing statistical regression analysis to ensure measurement reliability and assess correlations. The findings indicated a strong correlation between variables such as heat content, moisture content, and sensible air parameters. It was observed that the actual heat recovery efficiency was 6% higher than the calculated dry efficiency, emphasizing the importance of considering real-world conditions in heat recovery assessments. Additionally, regression analysis demonstrated a positive linear correlation with a coefficient of 0.77, highlighting the dependency between actual measurements and the theoretical model. These quantitative outcomes provide essential insights for optimizing heat recovery systems and enhancing energy-efficient ventilation practices, especially in cold climate environments. Moreover, this study highlights the strong correlation between variables such as heat content, moisture content, and sensible air parameters. Findings offer essential insights for optimizing heat recovery systems and enhancing energy-efficient ventilation practices, especially in cold climate environments.

Investigating the influence of outdoor temperature variations on fire-induced smoke behavior in an atrium-type underground metro station using hybrid ventilation systems

Underground metro systems are expanding rapidly worldwide, necessitating research on energy-efficient ventilation systems, fire safety, and smoke control. This study investigates the optimisation of hybrid mechanical-natural ventilation for smoke control in complex metro stations. Full-scale winter/summer experiments and numerical simulations examined a double-deck atrium-type station. Results demonstrate the atrium fires are more significantly impacted by outdoor temperature variations versus concourse/platform fires, with a 70 K versus 30 K temperature rise above the fire respectively. The heat of the gathered high-temperature smoke inside the atrium can reach up to 900 K under a 5 MW train fire energy release. The dimensionless Archimedes number (Ar) defines the ratio of thermal buoyancy to gravitational forces. Cold exterior winter air (Ar<1) entering via the atrium ceiling openings restricted vertical smoke diffusion, enabling enhanced lateral propagation. With rising outdoor temperatures from −20 °C to 10 °C (Ar<1), the natural smoke extraction efficiency increased from 0 to 18 %, coupled with vertical airflow velocities accelerating from −3.5 m/s to 1.5 m/s. When outdoor temperatures were between 10 °C and 40 °C (Ar>1), airflow velocity only changed slightly. Empirical models predict internal temperature profiles as a function of external meteorology. The findings provide crucial engineering insights into integrating weather data and adaptable ventilation protocols for scenario-based smoke prevention/mitigation. Further work should examine seasonal variations beyond the tested -20‒40 °C range. Overall, considering outdoor climate effects allows 30 % optimisation of hybrid ventilation systems for fire safety in underground metro stations. This study promotes technological advances in energy-efficient transport infrastructure resilience.

Evaluation of the ventilation mode in an ISO class 6 electronic cleanroom by the AHP-entropy weight method

As ISO Class 6 electronic cleanrooms are required to meet stringent environmental control standards during production, an energy-efficient ventilation mode is required to maintain an appropriate thermal and humidity environment and a comfortable workplace. However, the optimum air supply distribution to ensure thermal comfort, energy efficiency and cleanliness is unclear. Therefore, numerical simulations were carried out to determine the workspace satisfaction, energy utilization coefficient satisfaction and contaminant-removal satisfaction with FFU-clean bench coverage(C) ranging from 25% to 100%. We use the AHP-entropy weight method to evaluate four different ventilation modes for different cleanroom design targets, and then select suitable ventilation modes to meet them. The results show that in the core work area, the temperature difference, relative humidity difference and air velocity difference increase with increasing coverage. Furthermore, when the C = 25%, the priority of thermal comfort and cleanliness of employees is satisfied. Moreover, when C = 50%, high energy efficiency of the ventilation system is achieved. The AHP-entropy weight method evaluation system provides a theoretical basis for the selection of cleanroom ventilation design solutions.

Multi-objective optimization of a CO2/H2O capture-based ventilation and air conditioning system

Developing energy-efficient ventilation and air-conditioning (VAC) strategies is pivotal for achieving green buildings’ triple merits of high indoor air quality (IAQ), low CO2 emission, and low energy consumption. While adsorption-based carbon capture technologies show promising potential in improving IAQ and reducing AC energy consumption by directly removing excess CO2/H2O and recirculating post-captured air in buildings, current studies lack in-depth investigation into simultaneously maximizing CO2 removal capacity and minimizing AC energy consumption. This trade-off, hindering the broad application of this technology, is rendered by the intricate interplay between indoor conditions, system configuration, and more importantly, the adsorbent materials. To circumvent this trade-off, this study proposes an NSGA-II-based multi-objective optimization model on a solar-driven CO2/H2O capture-based VAC system for optimizing its techno-energetic performances. This analysis maps the green buildings’ merits into five constrained objectives and fully optimizes them by considering a wide spectrum of decision parameters. This analysis automatically optimized the trade-off between conflicting objectives for both studied adsorbents to various extents. While maintaining the same IAQ level, a 74% and 59% improvement in maximal captured CO2 mass can be achieved for Mg-MOF-74 and Zeolite13X. Compared with Mg-MOF-74, Zeolites 13X performed 55% worse in maximal CO2 removal, but 82% better in maximal energy-saving potential due to higher cyclability, stability, and lower specific energy consumption. Additionally, the proposed multi-objective optimization framework could be applied to other adsorbent materials and capture methods to guide the optimal design of CO2/H2O capture-based VAC systems for green building development.

PANDEMIC: Occupancy driven predictive ventilation control to minimize energy consumption and infection risk

During the SARS-CoV-2 (COVID-19) pandemic, governments around the world have formulated policies requiring ventilation systems to operate at a higher outdoor fresh air flow rate for a sufficient time, which has led to a sharp increase in building energy consumption. Therefore, it is necessary to identify an energy-efficient ventilation strategy to reduce the risk of infection. In this study, we developed an occupant-number-based model predictive control (OBMPC) algorithm for building ventilation systems. First, we collected the occupancy and Heating, ventilation, and air conditioning system (HVAC) data from March to July 2021. Then, four different models (Auto regression moving average-based multilayer perceptron (ARMA_MLP), Recurrent neural networks (RNN), Long short-term memory networks (LSTM), and Nonhomogeneous Markov with change points detection (NH_Markov)) were used to predict the number of room occupants from 15 min to 24 h ahead with an interval output. We found that each model could predict the number of occupants with 85 % accuracy using a one-person offset. The accuracy of 15 min of the ahead prediction could reach 95 % with a one-person offset, but none of them could track abrupt changes. The occupancy prediction results were used to calculate the ventilation demand using the Wells-Riley equation, and the upper bound can maintain an infection risk lower than 2 % for 93 % of the day. This OBMPC model could reduce the coil load by 52.44 % and shift the peak load by 3 h up to 5 kW compared with 24 × 7 h full outdoor air (OA) system when people wear masks in the space. The occupancy prediction uncertainty could cause a 9 % to 26 % difference in demand ventilation, a 0.3 °C to 2.4 °C difference in zone temperature, a 28.5 % to 44.5 % difference in outdoor airflow rate, and a 10.7 % to 28.2 % difference in coil load.

Optimization of the air distribution system in motor vehicle cabin using computational fluid dynamics

The paper presents the application of CFD software for simulating the conditions that prevail inside the air distributor of the vehicle's ventilation system with the aim of increasing the efficiency of the distributor. The simulation results were validated based on the experimental data found in the literature. Based on the results of the simulation, the geometry of the distributor was optimized with the aim of reducing the pressure drop through the ventilation system. It was found that optimizing the distributor geometry to some extent can provide a more energy efficient ventilation system.

Parametric Performance Analysis of the Cooling Potential of Earth-to-Air Heat Exchangers in Hot and Humid Climates

Earth-to-air heat exchangers (EAHEs) are widely used to reduce the indoor temperature and associated cooling energy demand of buildings. This study investigated the potential reduction in indoor temperatures via energy-efficient ventilation through EAHEs in an existing architectural campus building (ACB) with an energy-efficient renovated building envelope in the hot and humid climate of Karachi, Pakistan. The building information modeling (BIM) program Autodesk Revit was used to develop a virtual ACB BIM model. An EnergyPlus parametric analysis of the ACB BIM model in DesignBuilder facilitated quantification of the influences of operating parameters such as pipe installation depth and pipe diameter for EAHEs with similar total pipe lengths and air-exchange rates on the performance of the EAHEs during the cooling season. A 3 m deep and 0.1 m diameter pipe layout in open space significantly reduces indoor temperature via a specific duct layout in an exemplary ACB. The results show that a pipe diameter above 0.1 m is unsuitable because of the reduction in convective heat transfer due to the increase in the pipe’s surface area and the decrease in pressure in the pipe. The findings of this study can be used to improve the indoor thermal comfort of buildings in climates with comparable properties.

Use of membrane energy exchanger in ventilation: Odour sensory measurement

Membrane energy exchanger (MEE) for a new generation of energy efficient heating, ventilation and air conditioning (HVAC) systems has attracted wide attention. As MEE has been increasingly employed, extensive studies of heat and moisture transfer features have been carried out. Nevertheless, odour transfer through MEE, which may cause odour nuisance and complaints regarding indoor environment, is seldom studied. For most applications of MEE in ventilation, MEE is presumed to be able to prevent the pollutants transfer including volatile organic compounds (VOCs) and odours, despite a lack of clear scientific evidence. This study measured the potential odour transport through an MEE by using an odour sensation panel. The sensory measurement shows the percentage of dissatisfied could reach 84% for the odour source of waffle mix powder in extract air. In comparison, the percentage of dissatisfied is 5% when there is no odour source. The sensory air acceptability, odour intensity and hedonic tone for the supply air using MEE are assessed by a panel for different odour sources in the extract air. The findings of this study indicate that the odours generated from, such as cooking and cleaning in kitchens and in bathrooms, are likely to be undesirably transferred to the supply air through the tested polypropylene membrane exchanger, which may lead to a poor perception of the indoor environment. It may be particularly important to pay attention to the odour transfer through MEE when the odours originate from a kitchen. More studies for different membranes are recommended in the future.

Calibration of building energy simulation model for a mechanically ventilated livestock facility

To enhance the productivity of livestock facilities, maintaining a comfortable indoor environment is necessary, as livestock are sensitive to indoor temperature and livestock excrement generates numerous pollutants. In most livestock facilities, the ventilation system represents a large proportion of the indoor environment. Therefore, an energy-efficient ventilation control system, which considers the performance of the ventilation fan and outdoor air conditions, is increasingly in demand. In this study, we developed a building energy simulation model for ventilation control system in a livestock facility. In addition, a polynomial equation for the part-load-factor according to the part-load-ratio was developed to calibrate the fan energy consumption. The indoor temperature prediction performance was calibrated by optimising the infiltration rate and equipment load variables. The proposed building energy simulation model is expected to contribute to energy reduction and productivity improvement of the livestock by determining the optimum fan operation schedule through simulation analysis of various factors. • A whole-building energy model for livestock facility was developed. • PLF model was applied in the energy model and showed high prediction performance. • High prediction performance for air temperature was secured by input optimization. • Daily model update better represents trend of indoor air temperature than weekly update.

Application Possibilities of the Off-Grid HVAC System Operation Solution for Temporary Shelters in the Latvian Climate Conditions

Abstract Temporary shelters are extensively used by emergency services (rescue, disaster relief, military response) and other end-users requiring temporary mobile power solutions for different purposes (event organization, vacation homes, summer camps, etc.). The Covid-19 pandemics resulted in an increase of motor homes worldwide sales. When temporary shelter connection to power grid is impossible, the off-grid liquid fossil fuel generator can be used for electricity generation. Since the liquid fuel supply is often limited, the stock of fuel requires storage that may pose an explosion risk. Quickly installable and energy-efficient ventilation / cooling system with heat recovery is essential to ensure adequate air hygiene and occupants’ comfort in temporary structure. This paper presents a mobile modular electric energy generating unit with photovoltaic (PV) panels for providing temporary shelters (tents) in Latvian climate conditions with heating, ventilation, and air conditioning (HVAC). All calculations were performed using the computer model developed with TRNSYS tool and based on real data from mobile modular energy unit for spring, summer and autumn 2020 and winter 2021. The results show that mobile modular energy unit can be successfully applied for off-grid HVAC system operation of temporary shelters in the Latvian climate conditions.

Influence of climate change on the energy performance assessment of NZEB houses

The Energy Performance of Buildings (EPB) regulations aim to reduce primary energy use and carbon dioxide emissions of buildings, which are the result of creating a comfortable and healthy indoor environment. In this study, the influence of climate change on the regulatory EPB calculation results is analysed for the Flanders region in Belgium. The results of the analysis may be used by authorities to better define nearly zero energy building (NZEB) requirements today. Meteonorm has been used to simulate future climate change based on IPCC scenarios and urban heat island effect. These future climates have been implemented in a Revit-and Excel-based tool that calculates the stochastic variation of energy performance for six different dwelling typologies, based on the semi-steady state energy use calculation method applied in the regional rating method. Four different packages of measures to achieve NZEB performance (thermal insulation, energy efficient ventilation, renewable energy technologies,…) have been considered. The results for primary energy use, overheating indicator and net energy use for heating and cooling have been analysed. As may be expected, climate change is found to lead to an increase in overheating risk, an increase in cooling energy use, and a decrease in heating energy use in the analysed dwellings. Since in most cases the decrease in heating energy use outweighs the increase in cooling energy use, the total primary energy use decreases in most cases for the 2050 future climate.

Risks to children from inhalation of aerosolized aqueous manganese emitted from ultrasonic humidifiers can be greater than for corresponding ingestion

The essential trace element manganese (Mn) can cause neurotoxicity with inhalation acknowledged as a more severe health and cognition threat than ingestion. Methods: Over a range of aqueous Mn concentrations present in tap water, this research characterizes exposures and risks for adults and 0.25, 1, 2.5, and 6 yr old children who ingest the water and inhale respirable particles produced by a room-sized ultrasonic humidifier filled with the same water. Aqueous Mn concentrations evaluated included 50 µg/L USEPA esthetic guideline, 80 µg/L WHO infant guideline, and 120 µg/L Canadian regulatory level. Airborne-particle-bound Mn concentrations were generated for water filling an ultrasonic humidifier under four realistic room conditions (33 m3 small or 72 m3 large) with varying ventilation rates from 0.2/h -1.5/h. Average daily doses (ADD) and reference intake doses were calculated for ingestion and 8-h inhalation of humidified air. Hazard quotients (HQ) compared the intake doses and reference doses. Multi-path particle dosimetry (MPPD) model quantified the particle deposition and deposited dose in children's and adults’ respiratory tracts. Results: At only 11 µg/L Mn, the resulting humidified air Mn exceeds USEPA's reference concentration of 0.05 µg/m3 Mn in small room with low, energy-efficient ventilation. Inhalation ADD are 2 magnitudes lower than ingestion ADD for identical water Mn concentrations and daily exposure frequency. Even so, ingestion HQs are approximately 0.2 but inhalation risk is significant (HQ>1) for children and adults when breathing Mn-humidified air under most small room conditions at 50, 80 or 120 µg/L Mn. MPPD model indicates inhaled Mn deposits in head and pulmonary regions, with greater Mn dose deposits in children than adults. Conclusion: Inhalation of Mn-particles produced from ultrasonic humidifiers can pose greater risks than ingestion at the same water concentration, especially for children. Aqueous Mn concentration and room size influence risks. Limiting manganese exposures and setting regulations requires consideration of both ingestion and inhalation of water.

THERMODYNAMIC ANALYSIS OF WIND CATCHER WITH COOLING PADS USING SSG REYNOLDS STRESS TURBULENCE MODEL.

With increase in energy requirement, the researchers are looking for energy efficient passive ventilation techniques. The current design concept is based on environment sustainability and use of renewable energy sources is preferred over conventional energy sources. The current research investigates the wind catcher design with cooling pads using techniques of Computational Fluid Dynamics. The CAD model of wind catcher is designed using Creo design software and CFD analysis is conducted using ANSYS CFX software. The CFD analysis is directed at different air inlet velocities and SSG Reynolds stress turbulence model under steady state thermal conditions for both side open design and singe side open designs. The cooling pads have successfully reduced temperature up to 1.65 degrees for single side opening and 2.86 degrees for double side opening design. Maximum air flow rate is achieved with higher air inlet velocities for both design types.

Improving the Energy Efficiency of Buildings Based on Fluid Dynamics Models: A Critical Review

The built environment is the global sector with the greatest energy use and greenhouse gas emissions. As a result, building energy savings can make a major contribution to tackling the current energy and climate change crises. Fluid dynamics models have long supported the understanding and optimization of building energy systems and have been responsible for many important technological breakthroughs. As Covid-19 is continuing to spread around the world, fluid dynamics models are proving to be more essential than ever for exploring airborne transmission of the coronavirus indoors in order to develop energy-efficient and healthy ventilation actions against Covid-19 risks. The purpose of this paper is to review the most important and influential fluid dynamics models that have contributed to improving building energy efficiency. A detailed, yet understandable description of each model’s background, physical setup, and equations is provided. The main ingredients, theoretical interpretations, assumptions, application ranges, and robustness of the models are discussed. Models are reviewed with comprehensive, although not exhaustive, publications in the literature. The review concludes by outlining open questions and future perspectives of simulation models in building energy research.