Humidity Control System Research Articles

Baby Room Temperature and Humidity Control System Using Fuzzy Logic

The health and comfort of infants are highly sensitive to room environmental factors, particularly temperature and humidity, which play a critical role in supporting their well-being. Managing these factors becomes complex due to constant fluctuations in ambient conditions, necessitating the use of advanced technology to ensure stability and adaptability. This study explores the application of fuzzy logic in designing a temperature and humidity control system for infant rooms, aiming to maintain an optimal environment for infant care. Fuzzy logic offers a robust approach for handling variability, enabling precise adjustments based on a set of predefined rules and inputs. The system operates by processing real-time input values of temperature and humidity and producing adaptive responses through control outputs, such as cooler, heater, and blower settings. These adjustments are determined by a series of if-then rules that interpret the input conditions to produce the necessary responses. Experimental testing and evaluation confirm that the fuzzy logic-based control system effectively maintains room temperature and humidity within the desired range. The results indicate that this approach can successfully sustain a stable and comfortable environment, underscoring its potential application in enhancing infant health and comfort through controlled indoor climate conditions.

Design and Application of Greenhouse Humidity Control System Based on Single-chip Microcomputer

Greenhouse planting is widely used, greenhouse humidity control automation has become people s urgent demand, automatic humidity control can reduce manual operation, improve management efficiency, and reduce operating costs through energy-saving means. In addition, such systems help to achieve a stable production environment, reduce the occurrence of pests and diseases, and improve the sustainability and economic efficiency of agricultural production. Referring to the design of greenhouse humidity control system in recent years, in view of the low degree of automation of greenhouse planting in China, a more reliable greenhouse humidity control system with AT89S51 single-chip microcomputer as the core was designed.

Implementation of Sugeno Fuzzy Logic Method as an Automatic Humidity and Moisture Control System in Terrarium

A terrarium is a mini ecosystem that requires precise humidity control to ensure plant growth and the survival of animals within it. However, manual humidity control is difficult to implement consistently, especially if the external environment changes. This problem can be overcome by implementing an automatic system based on Sugeno fuzzy logic. This research aims to design and implement an automatic system that is able to control terrarium humidity dynamically using a fuzzy logic approach. This system is designed using humidity sensor data as input which is then processed through Sugeno fuzzy logic to determine appropriate control actions. The method used involves modeling input humidity and temperature sensors, determining fuzzy rules, and defuzzification using the Sugeno method to regulate the automatic irrigation system in the terrarium. Tests were conducted under several different environmental conditions to measure the system's response to changes in humidity and temperature. The research results show that the system is able to maintain terrarium humidity within optimal limits with a low error rate. The system is able to adjust control actions in real-time, produce consistent calculations, and provide humidity stability despite external changes.

PLC Controlled Fuzzy Logic-Based Egg Hatching Machine

In response to the increasing food demand due to the growing global population, this study has designed a fully automated incubator machine based on a Programmable Logic Controller (PLC) to enhance efficiency in the egg production sector. To align with Industry 4.0 technologies, this machine controls temperature and humidity using fuzzy logic, one of the artificial intelligence methods. The incubator is capable of meeting the specific temperature and humidity needs for the incubation processes of various types of bird eggs. It has been tested under different conditions, and its performance has been examined in detail. The analysis results show that the fuzzy logic-based temperature and humidity control systems on the PLC successfully reached the set reference values and maintained them continuously and stably after initial fluctuations. In conclusion, the design and control of an automated incubation machine with a PLC-based fuzzy logic controller were successfully accomplished.

Design and Development of a Fuzzy Logic-Based Temperature and Humidity Control System for Cricket Breeding Enclosures

Cicadas are insects that can be cultivated in Indonesia. The most common species of cicadas cultivated in Indonesia are Gryllus bimaculatus and Acheta domesticus. Cicadas are commonly used as livestock feed, including ornamental chickens, poultry, and birds, because of their high protein content. Cicadas cultivation in Indonesia is still mostly done manually, both in the process of controlling the environmental conditions around the cage and in the process of breeding cicadas eggs. One of the problems that often occurs is the temperature and humidity in the cicadas cage are not stable. Therefore, this research aims to design a system that can control the temperature and humidity in the cicadas cage. This system applies the fuzzy logic method to control actuators that can regulate the duration of spraying and the level of lighting needed in the cicadas cage based on the fuzzy rules that have been made. The components used in this system include Arduino uno, DHT22 sensor, relay, AC light dimmer, mist maker, lamp, and fan. The results of this research show that the temperature and humidity control system in a cicadas cage using fuzzy logic method with a predetermined setpoint has been realized. The accuracy testing of the DHT22 sensor obtained an error of 1.55% and a temperature accuracy rate of 98.44% and humidity of 1.66% with an accuracy rate of 97.64%. Then, the testing of the comparison results on the system and fuzzy simulation with the matlab application obtained an accuracy percentage in the mist maker testing of 97.37% and in the lamp testing of 98.81%.

Ultrahigh humidity-resistance ppb-level formaldehyde sensing at room temperature induced by fluorinated dipole based "umbrella" and "bridge"

Formaldehyde (HCHO) is a major indoor pollutant that is extremely harmful to human health even at ppb-level. Meanwhile, ppb-level HCHO is also a potential disease marker in the exhalation of patients with respiratory diseases. Higher humidity resistance and lower practical limit of detection (pLOD) both have to be pursued for practical HCHO sensors. In this work, by assembling indium oxide (In2O3) and fluorinated dipole modified reduced graphene oxide (rGO), we prepared a high-performance room temperature HCHO sensor (In2O3 @ATQ-rGO). Excellent sensing properties toward HCHO under visible illumination have been achieved, including ultra-low pLOD of 3 ppb and high humidity-resistance. By control experiments and density functional theory calculation, it is indicated that the introduced fluorinated dipoles act as not only an "umbrella" to improve the humidity resistance of the composite, but also a "bridge" to accelerate the electron transport, improving the sensitivity of the material. The significant practicality and reliability of the obtained sensors were verified by in-situ simulation experiments using a 3 m3 test chamber with a humidity control system and by detection of the simulated lung disease patient’s exhalation. This work provides an effective strategy of simultaneously achieving high humidity-resistance and low pLOD of room temperature formaldehyde sensing materials.

Implementation of the Fuzzy Logic Mamdani Method in the KUB Chicken Egg Incubator

Poultry farming plays an important role in rural Indonesia's economy, with increasing demand for poultry meat and protein-rich eggs. One of the main challenges for farmers is the limited production of chicken seeds and suboptimal egg incubation methods. Modern egg incubators offer a solution with higher ease and efficiency compared to traditional methods. However, existing machines on the market have weaknesses, such as less accurate temperature and humidity control, and less optimal power source switching. The use of fuzzy logic methods in egg incubators has proven to be more efficient than manual methods, with a hatching success rate of 100% for 10 eggs. Fuzzy logic-based egg incubators start hatching earlier and more on days 18 and 19, while manual methods begin on days 19 and 20. The automatic egg-turning process in fuzzy logic machines saves labor and reduces the risk of error. This research highlights the importance of using accurate sensors and optimal temperature and humidity control systems to improve the success rate of chicken egg hatching. Index Terms—poultry farming; egg hatching; temperature; humidity; fuzzy logic

Application of ZigBee Technology in Smart Soil Temperature and Humidity Control Systems

As global food security increasingly becomes a focus, challenges faced by Chinese agriculture are particularly prominent. This study introduces an intelligent monitoring and control system for soil temperature and humidity using ZigBee technology, aimed at enhancing agricultural production efficiency and crop yield. The system's core, equipped with an STC89C52 microcontroller and DHT11 temperature and humidity sensors, gathers data and wirelessly transmits it to a central control unit via ZigBee modules, which then automatically adjusts the agricultural production environment to ensure crops grow in the most ideal soil temperature and humidity conditions. Compared to traditional methods, this system achieves remote monitoring and precise control, providing an innovative solution for modern agricultural production. Experiments prove that the system not only improves control accuracy but also significantly enhances operational convenience and response speed, playing an important role in promoting the development of smart agriculture.

Flow-through moisture meter for measuring grain moisture as part of an automated grain moisture control system

The methods of increasing the accuracy and efficiency of the production process, as well as ensuring high quality of final products in the grain processing industry, are investigated. It is shown that to solve the problem of insufficient quality control of grain materials, an automated system for monitoring the properties and characteristics of bulk granular materials is necessary. The features of the construction of automatic and automated systems for monitoring the properties and characteristics of bulk granular materials are considered. Measurement methods and control devices of the main technological parameters used in the management of grain processing facilities are briefly described. It is proposed to include a flow moisture meter in the automated grain moisture control system. The physical properties of grain and grain materials, measurement conditions and instrumentation for grain moisture control are analyzed. The use of devices based on the dielkometric method in the subsystem of an automated process control system is discussed. The application of intelligent sensors of a measuring system with a complex multilevel hierarchy is described. The structure of the interconnection of measuring devices for intellectual support of humidification processes and quality control of the studied materials is given. A functional diagram and metrological characteristics of a prototype grain moisture monitoring device, a flow moisture meter, are presented. The metrological characteristics of this device meet the requirements of the grain processing industry and allow it to be used as part of a humidity control system

Quantitative evaluation of the impact of indoor relative humidity on deposition of aerosols generated during tooth grinding in a real-world clinical setting.

Exposure to aerosol particles generated from tooth grinding has a negative impact on the health of dental personnel. The aim of this study was to quantitatively analyze the impact of indoor relative humidity (IRH) on the deposition of these suspended particles in a well-controlled dental environment. In this study, a humidity control system was employed to effectively regulate and maintain indoor relative humidity (IRH). A novel computer-assisted numerical control system was developed to pre-treat the molar specimens, and accurately simulate clinical tooth grinding procedures. Each procedure was performed in triplicate, with an online real-time particle counter (ORPC; TR-8301, TongrenCo.) measuring aerosol production. All testing devices were controlled remotely. The data obtained were statistically analyzed using descriptive statistics and non-parametric tests (Kruskal-Wallis/ Dunn's post hoc test with Bonferroni correction, p < 0.05). The findings showed that with increasing IRH, the maximum peak concentration of aerosol particles decreased by 397% from 6.51 × 107 particles/m3 at 30% to 1.64 × 107 particles/m3 at 80%. The Kruskal-Wallis test results indicated a statistically significant effect of IRH on the aerosol increment (p < 0.05). Increasing the IRH level can effectively promote the deposition of aerosol particles, with a return to baseline within 15min after reaching 60% or above. Our study suggested that maintaining IRH above 70% during the cleaning process, allowing natural recovery to ambient humidity levels within 15min after cleaning, and taking basic precautions, may lead to an adequate reduction in the possible health risks of aerosol contamination.

Experimental investigation of a mixed desiccant solution of potassium formate and ionic liquid

Liquid desiccant technology is a promising energy-efficient alternative to conventional temperature and humidity control systems. In the quest to identify the optimal fluid for liquid desiccant systems, alternative desiccant solutions have been explored in terms of their feasibility and compatibility in dehumidification systems. This study proposes and characterises a new type of less expensive mixture of potassium formate (HCO2K) and 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]). This novel desiccant solution was investigated in terms of corrosiveness to metals, moisture absorption and desorption ability, cost-effectiveness compared to conventional desiccant solutions. The corrosiveness of desiccant solutions to copper-nickel, copper and steel was tested at room temperature and at 60 °C. Experiments were conducted in a climatic chamber with temperatures of 25–31 °C and relative humidities of 80–90% for the absorption process and temperatures of 50–70 °C and relative humidities of 20–30% for the desorption process to assess the moisture absorption and desorption capacities and mass fraction variations of the desiccant solutions. The mixed desiccant of HCO2K/[EMIM][OAc] in the ratio 60/10% wt. showed a moisture absorption capacity of 0.146 gH2O/gsol (compared to 0.18 gH2O/gsol for aqueous lithium chloride at 33.3% wt.) for a temperature and relative humidity of the climatic chamber of 25 °C and 90%, respectively. Its low corrosiveness, good moisture absorption and desorption capacity and higher cost-effectiveness make it a promising alternative to conventional desiccants, such as aqueous solutions of lithium chloride.

Design an Automatic Condenser in Swallow Bird House

This design is a system development carried out by swallow breeders in stabilizing the temperature and humidity of swallow houses. This design uses the principles of the Internet of Things (IoT), which will monitor temperature and humidity through internet media. This design aims to make a temperature and humidity control system in the swallow house automatically and find out the level of accuracy of temperature and humidity readings in the design made. This design uses a Wemos D1 Mini Board microcontroller that controls components such as DHT22 sensors, DS18B20 sensors and relays. The result of this design can control the condenser automatically, when the temperature and humidity are above the standard temperature, it will turn on the condenser automatically.

A Numerical Investigation of the Influence of Humid Environments on the Thermal Performance of a Phase Change Thermal Storage Cooling System in Buildings

Phase change thermal energy storage (PCTES) technology has garnered significant attention in addressing thermal management challenges in building HVAC systems. However, the cooling performance of PCTES systems in humid scenarios remains unexplored, which is crucial in subtropical regions, high-humidity underground areas, and densely populated spaces. Taking the mine refuge chamber (MRC) as an example, this study focuses on a passive temperature and humidity control system by employing cold storage phase change plates (PCPs) for 96 h. First, an improved and simplified full-scale numerical model including PCPs and MRC parts is established. Then, the model is validated through the experimental results and solved using a numerical method. Finally, the influence of various factors within the system is investigated and an optimization method involving batch operation is proposed. The results indicate that (1) within 40 h, the use of cold storage PCPs leads to an indoor temperature reduction of 4.8 °C and a 7% decrease in relative humidity; (2) the PCPs show asynchronous states in sensible and latent heat transfer rates; (3) for every 50 additional PCPs, the average indoor temperature increases by 0.6 °C and the relative humidity decreases by 1.5%; (4) implementing batch operation of PCPs ensures that the indoor Heat Index drops by 10 °C, which is vital for human survival. The findings will play a crucial role in the global expansion and application (including geographical and functional aspects) of phase change thermal storage technology.

Effect of late spring frosts on the growth and development of garden strawberry

The paper presents the results of research for 2022–2023, as well as the analysis of the effect of prolonged negative late spring temperatures on garden strawberry on May 8-12, 2023. The research was aimed at evaluating garden strawberry varieties for a complex of economically valuable characteristics after exposure to prolonged late spring frosts on May 8–12, 2023. Objects of study included 14 garden strawberry varieties of foreign selection: NF 421, ‘Festivalnaya romashka’, ‘Florida Festival’, ‘Verona’, ‘Dely’, ‘Joli’, ‘Senga Sengana’ (k), ‘Sweetheart’, ‘Syria’, ‘Cabot’, ‘Elianni’, ‘Malvina’ and 2 varieties selected by the Institute: ‘Zvezdochka’ (k), ‘Zhanna’. The plants were planted on May 6, 2022, the survival rate accounted for 100%. The research was conducted in the Research Institute of Horticulture and Medicinal Plants “Zhigulyovskie sady” (Samara, Russia) on the collection variety plot in accordance with the generally accepted program and methodology of varietal study of fruit, berry and nut crops. The analysis of weather conditions for 2022–2023 was performed using the data of the Volga Department for Hydrometeorology and Environmental Monitoring (UGMS), with additional data obtained from the temperature and humidity control system located on the test plot in Malaya Tsarevshchina, Krasnoyarsky District, Samara Oblast. The varieties ‘Verona’, ‘Zvezdochka’ (k), ‘Cabot’, ‘Sweetheart’, ‘Festivalnaya Romashka’, and ‘Malvina’ demonstrated the highest resistance to late spring frosts according to the complex of characteristics. The main part of the varieties had 28-33% damage to flowers and buds. The highest damage figure was revealed in the variety of the average maturity period NF 421 and the early variety ‘Zvezdochka’ (k). The late variety ‘Malvina’ did not suffer from frost.The lowest degree of fruit deformation was observed in the varieties ‘Sweetheart’, ‘Zvezdochka’ (k), and ‘Malvina’. The greatest degree of freezing after exposure to low temperatures on May 8-12 was observed in the varieties ‘Dely’, ‘Joli’, ‘Florida Festival’ and ‘Elianni’. The best adaptive capacity according to the results of overall plant condition for the period 2022-2023 was shown by the varieties ‘Verona’, ‘Zvezdochka’ (k), ‘Senga Sengana’ (k), ‘Cabot’, ‘Sweetheart’, ‘Syria’. The highest average berry weight was recorded in NF 421 (19.5 g/bush). The highest productivity was observed in later ripening varieties – ‘Malvina’ (261.4 g/bush) and ‘Cabot’ (241.0 g/ bush), as well as in the control variety ‘Seng Sengana’ (k) (197.1 g/bush). The lowest indicators were reported in ‘Dely’ (50.1 g/bush) and ‘Florida Festival’ (29.0 g/bush). The genotype was revealed to influence the resistance to low late spring temperatures and recovery ability of plants after late spring frosts.

Detailed visualization of radioactive hotspots inside the unit 1 reactor building of the Fukushima Daiichi Nuclear Power Station using an integrated Radiation Imaging System mounted on a Mecanum wheel robot

ABSTRACT In the decommissioning of the Fukushima Daiichi Nuclear Power Station, understanding the distribution of radioactive substances and dose-equivalent rates is crucial to develop detailed decontamination plans and minimize worker exposure. In this study, we remotely visualized radioactive hotspots and dose-equivalent rate distribution in Unit 1 reactor building of the station using a Mecanum wheel robot equipped with a Compton camera, simultaneous localization and mapping device, and survey meter. We successfully visualized high-concentration radioactive hotspots on the U-shaped piping of the drywell humidity control system and the atmospheric control piping in the ceiling in front of the transverse in-core probe room. Furthermore, the hotspot location was identified in three dimensions using the Compton camera used to analyze the atmospheric control piping. By simultaneously analyzing the dose-equivalent rate data acquired by the survey meter and the hotspot locations visualized by the Compton camera, it was confirmed that the hotspots caused elevated dose-equivalent rates in the surrounding area. In the future, if this robotic system is used in unexplored areas, such as the upper floors of reactor buildings, it can provide information about the locations of radioactive hotspots and the distribution of dose-equivalent rates.

A Calibration Facility for Hot-Wire Anemometers in Extremely Low Speed with Air Temperature and Humidity Variable and Controllable

Aimed at addressing the difficult problems existing in extremely low speed calibration facilities for hot-wire anemometers, where calibration accuracy is often insufficient and vulnerable to the contamination from temperature and humidity discrepancies between the calibration environment and the application environment, a calibration rig with a velocity range from 0.10 m/s to 1.0 m/s, an air temperature range from ambient temperature to 60 °C, and a humidity range from 20%RH to 80%RH was designed, developed, and constructed. The overall layout arrangement and the mechanical structure of the facility are illustrated. The master control system, the motion control system, the temperature and humidity control system are designed, tested and adjusted. The adjustment results are demonstrated and discussed. The analysis of the results reveals that the maximum velocity control error is 0.000989 m/s, satisfying the design target of 0.003 m/s; the corresponding maximum relative error is 0.241%, which is less than the design target of 0.4%; the maximum temperature control error is 0.9 °C, meeting the design target accuracy of 1 °C; the maximum humidity control error is 2.9%RH, which is below the design target of 4%RH. When the facility is applied to the calibration of a hot-wire anemometer, the maximum error of the fitting curves in modified King’s law is 0.02236 m/s, while that in Van der Hegge Zijnen’s formula is 0.023217 m/s, both of which satisfy the design target accuracy of 0.03 m/s. The maximum relative errors of fitting curves using the two formulas are 5.214% and 8.527%, respectively. Analysis of calibration data reveals that the discrepancy in temperature and humidity between application site and calibration site may bring errors that can reach up to 1.2676% per unit relative humidity discrepancy, and 5.672% per degree Celsius of temperature deviation, respectively.

Chiral Reticular Chemistry: A Tailored Approach Crafting Highly Porous and Hydrolytically Robust Metal-Organic Frameworks for Intelligent Humidity Control.

Control of humidity within confined spaces is critical for maintaining air quality and human well-being, with implications for environments ranging from international space stations and pharmacies to granaries and cultural relic preservation sites. However, existing techniques rely on energy-intensive electrically driven equipment or complex temperature and humidity control (THC) systems, resulting in imprecision and inconvenience. The development of innovative techniques and materials capable of simultaneously meeting the stringent requirements of practical applications holds the key to creating intelligent and energy-efficient humidity control devices. In this study, we introduce chiral reticular chemistry as a tailored synthetic approach, targeting a highly porous hea topological framework characterized by intrinsic interpenetrating pore architecture. This groundbreaking design successfully circumvents the traditional compromise between the pore volume and hydrolytic stability. Our metal-organic framework (MOF) exhibits an extraordinary working capacity, setting a new record at 1.35 g g-1 within the relative humidity (RH) range of 40-60%, without exhibiting hysteresis. Consequently, it emerges as a state-of-the-art candidate for intelligent humidity regulation within confined spaces. Utilizing single-crystal X-ray measurements and molecular simulations, we unequivocally elucidate the mechanism of water clustering and pore filling, underscoring the pivotal role of the linker functionality in governing the water seeding process. Our findings represent a significant advancement in the field, paving the way for the development of highly efficient humidity control technologies and offering promising solutions for diverse real-world scenarios.

Evaluation of Serrano Pepper Crops Growth under Controlled Conditions of Vapor Pressure Deficit in a Pilot-Scale Hydroponic Greenhouse

Controlled Environment Agriculture (CEA) has become an important field of study in recent years. The objective of this research is to evaluate the growth rate of the serrano pepper crop under controlled conditions of vapor pressure deficit in a pilot-scale hydroponic greenhouse. The controlled conditions were generated with the development of a control system composed of a non-mixed crossflow heat exchanger for internal temperature and a humidification system for internal humidity control. The comparison of variables and the growth rate of the crop was carried out in a controlled and a timed greenhouse. The best growth rate for serrano pepper cultivation was obtained under the following conditions: between 4.14 and 5.42 kPa with 0.251 and 0.225 cm/day in the controlled greenhouse. The results show that it is possible to obtain higher crop growth rates by controlling the vapor pressure deficit in a pilot-scale hydroponic greenhouse, using a heat exchanger for temperature control and a humidification control system. Controlling vapor pressure deficit can be a useful tool for agriculture in CEA.

Temperature and Humidity Control System With Long Range in Mushroom Barn Using Fuzzy Logic

Room temperature and humidity are parameters required for quality mushroom growth. To get the appropriate and stable temperature and humidity values, a control system is needed. This test aims to create a temperature and humidity control system using IoT-based fuzzy logic implementation. This temperature and humidity control system, uses the main components of DHT22 sensors, NodeMCU ESP32, Arduino nano and Lora. The transmitter is placed in the mushroom barn. The transmitter control system stabilizes the temperature and humidity in the barn using a predetermined fuzzy method. After that, the data processed at the transmitter will be sent to the receiver via Lora communication. At the receiver, the device is placed in the mushroom farmer's house, which will capture the data sent by the transmitter. This recognition system has a good level of accuracy against the DHT22 sensor and Hygrometer, which has a difference of 1℃ or a difference of 2.08%. In contrast, for humidity, it has a total difference of 16% or 97.61%. When testing using fuzzy logic, the resulting temperature and humidity are stable, and the predetermined fuzzy logic carries out watering.

Updating subsystem-level fault-symptom relationships for Temperature and Humidity Control Systems with redundant functions

As we aim for deep space exploration, supporting vital systems, such as the Temperature and Humidity Control System (THCS) in the Environmental Control and Life Support System (ECLSS), through timely onboard fault detection and diagnosis becomes paramount for mission success. Many existing fault diagnosis approaches assume that the function that models the relationship between faults and associated symptoms (fault-symptom relationships) will remain constant throughout the THCS’ lifetime. Therefore, many of these diagnosis methods are not robust enough to automatically account for changes in fault-symptom relationships as a result of changes in the habitat (e.g., system reconfiguration). The work highlighted here is on (i) surveying existing work on adaptable fault diagnosis methods and (ii) showcasing a real-life case study, in which we identified the need for an automatically adaptable fault diagnosis method. The case study focuses on a reconfigured terrestrial THCS analog, the Heating, Ventilation, and Air Conditioning (HVAC) system, where the original fault-symptom relationship is revealed to be no longer accurate. We then apply current adaptable fault-symptom relationship generation methods, such as Model-Based Dependability Analysis (MBDA) methods and data-driven causal discovery methods. Through this analysis, we detail our procedure in (i) identifying relevant fault-free system information, such as redundancy, to revise fault-symptom relationships used in fault diagnosis and (ii) evaluating the fault diagnosis performance in a THCS with the original and revised fault-symptom relationship. Our contribution lies in identifying the shortcomings of current methods and pinpointing future steps in creating an adaptable fault diagnosis framework. We found that although the MBDA methods can automatically generate fault-symptom relationships given system flow information and fault mode of components, they also required manual revision of the aforementioned information to create fault-symptom relationships that reflect redundancies. On the other hand, we concluded that the causal discovery methods can detect fault-free system information, such as redundancies, that may help us revise fault-symptom relationships, but suspect variables that contribute to redundancies may have to be hand-picked.