Ceiling Fan Research Articles

Investigation of The Blade’s Sweep Size Effect On the Air Flow Field and The Energy Efficiency of the Ceiling Fan

The ceiling fan is the most economic device to cool the residential areas and as well as commercial areas. The ceiling fan plays vital role in thermal comfort for the people in those areas. Due to recent advancement in technologies ceiling fans are become energy efficient. This paper talks about the comparison of energy efficient and changes in flow field across the user perceiving annulus radius of three different sweep size of ceiling fan. Also suggesting user to select the ceiling fan based on their flow-field requirement. It explains the flexibility of blade design and its effect on flow field. This approach also talks about the power consumption and volumetric airflow for energy efficiency. Specifically, variation from 0.9m, 1.2m and 1.4m sweep size blades considered and compared. The flow field generated by the ceiling fans are captured by Reynolds Averaged Navier-Stokes (RANS) technique. All the tree different sweep size ceiling fans are analysed through CFD. The CFD results shows that the 1.4m sweep size blade fan gives more spread and energy efficient than other type of fans.

An integrated experimental and CFD analysis of ceiling-fan-integrated air conditioning system: Indoor air quality and air velocity

The Ceiling-Fan-Integrated-Air Conditioning (CFIAC) represents an innovative HVAC design, which involves directing supply air towards the vicinity of ceiling fans, facilitating the mixture and distribution of air within a room. By eliminating the need for terminal ductwork and diffusers, CFIAC offers an efficient cooling solution for occupants. This study employs experimental and CFD methodologies to assess various parameters, including airflow, air pollution, and temperature related to this system. Experimental tests were conducted in a controlled chamber, with the lowest inlet air velocity and the temperature, where supply air was projected from a high-sidewall vent directly towards a ceiling fan's centerline. Different operational conditions of the ceiling fan were examined (off, Level 2 and Level 4 downwards, and Upwards). Carbon dioxide (CO2), employed as a tracer gas, was released near a thermal manikin at three distinct locations within the chamber: the middle, lower left, and upper right, and the corresponding CO2 concentration distributions were evaluated. Additionally, air velocity measurements were collected and analyzed. The effectiveness of ventilation and potential health exposure was quantified using the age of air and intake fraction (IF) metrics. The findings indicate that operating the fan at Level 4 with downward airflow enhances air velocities and heat loss while reducing CO2 concentrations and age of air by an average of 14 % and 4 min, respectively. Moreover, the IF values for Level 4 operations, both downward and upward, were marginally lower compared to those recorded for Level 2 downward and fan-off scenarios, suggesting a decreased risk of cross-infection.

3D CFD simulation of room air temperature and velocity with ceiling fan and exhaust fan and the resulting thermal comfort

The integration of energy-efficient solutions remains an essential hurdle in the pursuit of sustainable and comfortable indoor settings. As building energy consumption continues to climb, there is an urgent need to implement methods that reduce environmental effects, and at the same time, maintain adequate thermal comfort for occupant well-being and productivity. Ceiling fans, a standard fixture in many indoor settings, have gained popularity for their ability to provide better air movement and temperature adjustment while using substantially less energy than standard HVAC systems. This work presents a 3D Computational Fluid Dynamics (CFD) investigation of thermal comfort that can be achieved with a ceiling fan and an exhaust fan. A 3D fan zone model available in ANSYS Fluent was used to model the ceiling fan, considering the ceiling fan as a solid disc. Numerical methodology has been validated by verifying the transient simulation results against the experimental data available in the literature. The work analyzes thermal comfort parameters - temperature and velocity - in a room with a typical ceiling fan or an exhaust fan available in India. The room temperature and velocity distribution are presented for different times of a day in summer for a warm and humid climatic zone in India. The results show that the thermal comfort obtained with the exhaust fan is better than that with the ceiling fan for the evening, night, and early morning.

The adoption of ceiling fans as an alternative cooling strategy to air-conditioning: what can we learn from building sustainability index certified homes?

ABSTRACT Ceiling fans have been promoted as an alternative cooling technique to save energy, while their adoptions in the residential sector have yet to be investigated. This study analysed the adoption of ceiling fans in residential buildings and compared their energy-saving potential with that of air-conditioning in Building Sustainability Index (BASIX) certificated single (n = 268,558) in New South Wales, Australia, from 2011 to 2019. Four climate zones were classified according to heating and cooling hours via k-means, based on which predictive models for the relationship between cooling technologies and energy-saving levels were established via machine learning. Dwellers in the hot zone of New South Wales would be more likely to adopt ceiling fans. In the living rooms, dwellers could adopt ceiling fans alone, while in bedrooms, dwellers could adopt air-conditioning in addition to ceiling fans. This study provides empirical evidence on the adoption of ceiling fans in green buildings and helps to map out the low carbon solutions using alternative cooling in the residential sector.

15-Year Suicide Trends Using Media Reporting Methodology from the Tricity Region of Chandigarh: A Brief Analysis

Introduction: Suicide has become a societal crisis owing to the recent increasing trends globally. Of the total suicide deaths globally, two-thirds occur in the developing countries including India. The available data on suicide in India reflect a rate of 11% (according to the National Crime Records Bureau 2013) with the highest rates in older adult males and an increasing trend of suicide deaths in younger age groups. Much of the literature is from the southern part of India with a relatively sparse data from North India. Aim and Methodology: The aim was to examine the 15-year (2004-2019) trend of suicide (age and gender distribution, methods used, and reasons) in an urban city in North India. Information was collected from the leading newspapers (English, Hindi, and Punjabi) of the area. Duplication of information was avoided, and statistical analysis was done using SPSS version 20. Results: Fluctuations in the total number of suicide cases over the 15-year period were observed with nearly 63% of people committing suicide being younger than 30 years of age, of whom 53% were male. More females in the younger age group and more males in the older age group were suicide victims. Of all the methods used, hanging was the most common (70%), followed by consuming poisonous substance, jumping from height, shooting self, and stabbing in the descending order. A ceiling fan was used for hanging by 32% of victims who hanged themselves, of whom 65% were male. Among the cited reasons, stress/depression was experienced by 19% of victims. Discussion and Conclusion: The trends with respect to age distribution, gender, and method used that is reported in the current study are in line with the trends reported globally. The preventive measures, especially using technological advances in designing fans not suitable for tying noose around it, can be explored.

Analysis of Range and Speed Detection Using A Commercial RADAR module at 24GHz

In this work, the performance of OmniPreSense Module OPS243-C has been studied for range and speed detection, at 24 GHz, whose results are obtained using Fast Fourier Transform (FFT) commands using a MATLAB script and verified with the physical range of objects used. Four custom-made scenarios have been created, two using stationary objects namely a stand and a tripod for their range at two different distances, and two using moving objects, a person and a ceiling fan for their respective speed. A total of 10 observations for range detection are taken inside an anechoic chamber and reported with a range of percentage errors, which varies for objects and their range. The mean values of the tripod and stand range are detected at 4.06m and 0.42m, respectively, in scenario 1 whereas in scenario 2, the mean values of the tripod and stand range are found to be 2.56m and 1.53m, respectively. Thestandard deviations in these observations are found from 0.09 to 0.12 m for range detection. In scenario 3, the speed of a moving person is found to be varied from 2.0 m/s to -2.1 m/s for Inbound and Outbound directions from the module at a distance of 4.62 m. For scenario 4, a variation in the speed of the rotating fan is observed at the knob positions (0 to 4) from the OFF to ON condition of the fan and is found to be varied from 0.1 m/s to 4.9 m/s at different knob positions. In both scenarios 3 and 4, the speed data is found with a standard deviation less than 0.5 m/s from 10 observations. In this analysis, results confirm that the OPS243-C can detect stationary and moving objects successfully.

Exploring Information and Comfort Expectations Related to the Use of a Personal Ceiling Fan

Rising global temperatures have increased the need for research into human adaptability and comfort in buildings. To reduce comfort-related energy demands, low-energy-consumption alternatives for space cooling, such as personal environmental control systems (PECS), are being investigated. The implementation of PECS in office buildings is still underway, and little is known about how occupants’ expectations can influence their satisfaction with PECS and indoor environmental quality. This study examines the influence of tailored information and occupants’ comfort expectations on their thermal perceptions and satisfaction with a personal ceiling fan. Seventy-six participants completed an online questionnaire and attended a half-day session at 30 °C in a climate chamber in Germany. A manipulation technique to activate personal norms was used to test the influence of information on expectations. Results indicated higher reported thermal comfort in participants with more positive thermal expectations, regardless of their expectations of the building systems. These effects were largely moderated by personal norms, indicating the importance of activating normative motivations to increase thermal comfort. Occupants with negative expectations improved their perceptions of the fan when making personal adjustments to stay comfortable. However, this effect was not moderated by personal norms. Practical implications focus on manipulating occupants’ comfort expectations, e.g., by providing occupants with normative messages and individual control, to achieve greater comfort and acceptance of personal building controls in naturally ventilated buildings.

Assessment of the Pollution Indices of Particulate Matter Trapped in Classroom Ceiling Fans in a Tertiary Institution in Southern Nigeria.

Assessment of the Pollution Indices of Particulate Matter Trapped in Classroom Ceiling Fans in a Tertiary Institution in Southern Nigeria.

Design and Evaluation of a Dust Filter for Ceiling Fans

Design and Evaluation of a Dust Filter for Ceiling Fans

Performance investigation on the ventilation systems of high-speed railway train depots in hot summer regions

As a place for the maintenance of high-speed trains, the current ventilation system in the train depot cannot meet comfort requirements according to the feedback from the inspection department. The poor thermal environment could seriously affect the physical health and work efficiency of staff. This study provides some basic data and design methods for improving the thermal environment in high-speed railway depots. Field studies were conducted in five different high-speed railway depots in hot summer regions of China, including the form and the operation of the ventilation system, the thermal and humid environment and the characteristics of the heat sources. According to the survey results, the maximum temperature in the depot can reach 41.2°C in summer. There is a clear vertical temperature stratification in the afternoon of the depot, and the maximum temperature difference between three working platforms can reach more than 4°C. The cooling effect of ventilation systems in depot was investigated and compared. The recommended ventilation mode is natural ventilation system + bottom mechanical air supply system + ceiling fan system, and it is recommended to combine the west window louvers with external sun shading to achieve the best cooling effect in high-speed railway depot.

Traumatic Head Injuries from Ceiling Fans at a Pediatric Level I Trauma Center in the United States

Background/Objective: Several studies describe traumatic head injuries caused by ceiling fans in Australia, the Middle East, and Malaysia. Some injuries required neurosurgical intervention, especially those caused by metallic ceiling fans. This study describes traumatic head injuries caused by ceiling fans at a single pediatric level 1 trauma center in the Southern USA. Methods: Medical records were retrospectively reviewed for patients under 18 years of age who presented with a traumatic injury to the head from a ceiling fan from January 1, 2008, through December 31, 2021. The cohort of patients meeting all inclusion criteria was identified by querying multiple free-text fields derived from the electronic medical record, followed by a manual record review. Results: Of 60 children treated for traumatic head injury from a ceiling fan, the median age was 5.7 years and 53% were female. Laceration was the most common injury (80%), followed by scalp swelling/hematoma (20%), contusion (8%), and skull fracture (7%). Two patients (3%) with intracranial hemorrhage and fracture underwent neurosurgery. One neurosurgical case involved a metal ceiling fan and the other involved an outdoor ceiling fan. Nearly half of the injuries involved bunk or loft beds (47%) and young children were often injured while being lifted up by a caregiver (18%). Conclusion: Although most pediatric traumatic head injuries from ceiling fans resulted in minor injuries, our center saw a similar proportion of cases with skull fractures to what has been reported in Australia (5%). The effects of fan construction and blade material on the severity of head injury may warrant further study. Understanding the most common mechanisms for these injuries may guide injury prevention efforts.

A clandestine affair – A case report

According to the witnesses, crime scene and inquest report, deceased is a 30 years old female, found dead lying on floor, in her apartment house along with a male, who was found hanging from a ceiling fan in the same room. The deceased body was brought to Mortuary, Osmania General Hospital at 04:00 PM on 28/01/2023 by the Investigation Officer and requested for postmortem examination under section 174 Criminal Procedure Code. The postmortem findings were an antemortem horizontally placed ligature mark at the level of thyroid cartilage in the front of neck, internally there was an inward fracture of tip of greater horn of hyoid bone on the right side with surrounding tissue contusion. There were some small crescent shaped abrasions noted on both sides of front of neck which were suggestive of nail marks. There was a contusion over the inner surface of the scalp. With meticulous crime scene investigation and post mortem examination and interpretation of the findings cause of death was given as “Ligature Strangulation”

Numerical simulation of cooling performance of radiant ceiling system interacting with a ceiling fan

Numerical simulation of cooling performance of radiant ceiling system interacting with a ceiling fan

Electric Throwing Wheel from Repurposed Bucket, Ceiling Fan Motor, and Sewing Machine Regulator for Pottery Demonstration

The cost of electric potters’ throwing wheel keeps soaring high even when throwing yet a course that firmly exists and is valued in the ceramic production process besides other forming techniques in art/design schools. The challenge herewith is the need to look for cheaper alternative electric throwing wheels through local fabrication to alleviate the impending high cost of imported ones and the general scarcity of potter’s wheels for demonstration in a simple ceramic studio setting by improvising available materials. The experimental-based methodology was deployed by sourcing and assembling the required components – an electric potter's wheel using a sewing machine regulator, iron bucket and basin, German plywood ½ inch, 1inch screw nails, bolts, and nuts, and 3 pin plug head. The principles of the ‘development cycle’ and the ‘rotational kinetic energy (RKE’ were adopted. The results of the study revealed that: the electric has the capacity speed of 200rovulation per minute (rpm) sufficient to center a-2kg of a well-prepared mass of leather hard clay - 50 rpm cylinders and bowls of various heights and widths up to 6" (height) and 5" (width) are viable; the repurposing of the conventional functions of the water bucket and fan the provision of air into an electric throwing wheel was successful. In conclusion, the study showed some success. The recommendations of the study include thus: further improvement as the focus of this one (project) is primarily to proffer a concept even though the topic is relevant to both product and service design; adoption of improvisation through repurposing for the mass construction of wheels as an alternative to the costly imported ones should be encouraged.

Sensorless Single-Switch PFC Converter Fed Brushless Direct Current Motor Ceiling Fan

This work deals with the reduction in total harmo-nics distortion, power input, and a supply power factor correction (PFC) of permanent-magnet brushless direct-current motor (PMBLDCM) ceiling fan (CF) to get reduced bills for the consumers. To address these supply power-quality issues in the existing PMBLDCM-CF, a single-stage, single-switch boost-flyback power-factor-correction-converter (S4BF-PFCC) is employed at the front-end. The front-end PFCC is designed in discontinuous conduction mode, which offers inherent supply PFC. The high-frequency-transformer (HFT) auxiliary-voltage is utilized as a feedback to get the controlled PFCC voltage output (VDC), and with this controlled VDC, CF speed is controlled. This method eliminates the required DC-link sensor or sensing circuitry. Moreover, the back-EMF sensorless-control is used to eliminate the Hall sensors and their auxiliary supply. The speed control with a variable output voltage of front-end PFCC allows an inverter to work at a commutation frequency, which offers low switching losses and improves CF efficiency. This CF system is modelled and simulated in MATLAB/Simulink. Its simulation and test results are compared to validate the design. The supply current harmonics distortion of CF meets the IEC standard 61000-3-2.

Enhancement of Power-Quality in a BLDC Ceiling-Fan Powered by Unity-Power-Factor Zeta Converter

This paper presents a permanent magnet brushless direct current motor (PMBLDCM) ceiling-fan (CF) that operates on AC mains with a unity power factor (UPF). An AC-DC power-factor-corrected converter (PFCC) performs in discontinuous-conduction mode (DCM) to facilitate various merits such as an inherent UPF, reduced passive components size, stable operation, and required voltage control. The PMBLDCM ceiling fan speed is controlled by a smooth change in converter voltage output, and it helps to operate a voltage source inverter (VSI) at a fundamental frequency with low switching losses. This control maximizes efficiency of a ceiling fan. The THD (Total Harmonics Distortion) of a supply-current is reduced with a wide range of speed control and supply voltage fluctuations. A prototype of it is developed to validate the design and control. Its performance is compared with a conventional PMBLDCM ceiling fan. Test results are shown to verify the design of PFCC. The power quality indices (PQI) at input supply are meeting the IEC61000-3-2 standard.

Thermal responses in temporarily occupied space in the summer: Spatial-temporal synergetic alliesthesia using a ceiling fan

Although temporal and spatial alliesthesia have been widely studied in recent decades, their synergistic impact on occupant perceptions have received less attention. One reason for this is that prior to the concept of temporarily occupied space (TOS), real-world application circumstances were not clearly defined. TOS were defined as air-conditioned indoor facilities where the majority of people spend shorter than a set time period, such as banks, fast-food restaurants and train station waiting spaces (about 40 min). In this study, thermal responses based on the spatial-temporal synergetic alliesthesia were investigated. According to the association of human physiological parameters with thermal perception responses, a thermal sensation model was developed. Reasonable indoor design temperatures to achieve energy-efficient comfort were determined. Chamber tests were performed on acclimatized human volunteers to determine spatial-temporal synergetic alliesthesia. Besides, an actual building was used for transient energy consumption simulations. For this study, a TOS with a non-adjustable ceiling fan (0.85 m/s, 128 rpm, 17.2 W) setting was used. The results showed that 27 °C and 55%RH are the best HVAC control target settings for the air-conditioned TOS with ceiling fans. It has the potential to save 34% of energy (26.8 kWh/m2·yr) while maintaining the thermal comfort of the human body. The high-accuracy thermal sensation model for spatial-temporal synergetic alliesthesia demonstrated good agreement with experimental data that were not used in the regression development. TOS can be used as a real-world example of the spatial-temporal synergetic alliesthesia. The findings of this study are useful for promoting and applying alliesthesia in the field of buildings, as well as for energy-saving thermal comfort.

Zephyr

So many years spent learning how to talk to the wind, and I’m still sitting underneath a ceiling fan, my left eye watering, my parti-words littered out in little paper squares along the desk. I talked, but the only reply I could get was my own voice thrown back, echoed like the zephyr I was always chasing somewhere in the outskirts: I wanted to open a way station for monarchs, its milkweed itinerant and raucous. Or I played the first strains of Appalachian Spring and let those notes fill me with their epic persuasion, belated and in love still with all the zigzag currents who never even knew I was there.

Effect of passive and active ventilation on malaria mosquito house entry and human comfort: an experimental study in rural Gambia.

Rural houses in sub-Saharan Africa are typically hot and allow malaria mosquitoes inside. We assessed whether passive or active ventilation can reduce house entry of malaria mosquitoes and cool a bedroom at night in rural Gambia. Two identical experimental houses were used: one ventilated and one unventilated (control). We evaluated the impact of (i) passive ventilation (solar chimney) and (ii) active ventilation (ceiling fan) on the number of mosquitoes collected indoors and environmental parameters (temperature, humidity, CO2, evaporation). Although the solar chimney did not reduce entry of Anopheles gambiae sensu lato, the ceiling fan reduced house entry by 91% compared with the control house. There were no differences in indoor nightly temperature, humidity or CO2 between intervention and control houses in either experiment. The solar chimney did not improve human comfort assessed using psychrometric analysis. While the ceiling fan improved human comfort pre-midnight, in the morning it was too cool compared with the control house, although this could be remedied through provision of blankets. Further improvements to the design of the solar chimney are needed. High air velocity in the ceiling fan house probably reduced mosquito house entry by preventing mosquito flight. Improved ventilation in houses may reduce malaria transmission.

Comfort and Economic Viability of Personal Ceiling Fans Assisted by Night Ventilation in a Renovated Office Building

An expected increase in the use of air conditioning by 2050 will significantly increase electricity demand and come at a cost to the environment. Implementing passive cooling strategies and focusing on personal environmental control systems (PECSs) could help to address this issue. While numerous studies have investigated the positive impact of PECSs on thermal comfort and energy savings, their overall economic benefit has been poorly addressed. We present an economic evaluation of personal fans for an office building in Germany. Building performance simulation was used to compare passive and active cooling concepts, and sensitivity analysis was performed for different climate scenarios. A cost-benefit analysis was carried out, including an assessment of investment and operating costs and the monetary value of relative performance. The transferability of comfort and productivity into costs is the novelty of this paper. The results showed that by supplementing night ventilation with personal fans, discomfort hours could be reduced by up to 50%. However, the initial investment of the fan is not compensated by savings in productivity losses compared to night ventilation alone. A reduction in the cost of the technology could help to economically offset the investment. The results contribute to the literature on the economic evaluation of a PECS by proposing a framework to motivate its implementation in buildings.