Ceiling Fan Research Articles

Optimized design of permanent magnet brushless DC motor for ceiling fan applications

The objective of this research to design a compact electrical motor for a ceiling fan to save more electric power. Presently, single phase induction motor is used for ceiling fan application. Losses generated by single phase induction are more and hence efficiency is lower. In addition, overload is not handled by single phase induction motor whereas DC models can handle a lot of overload quite easily. In induction motor, the rotor frequency is lesser than stator frequency i.e rotor frequency is slip times the stator frequency. AC induction motor uses capacitor in anyone of its phases to excite and rotate the machine, so it is larger in size. In this paper, the axial flux type of permanent magnet machine configuration is selected to propose the optimum design of ceiling fan machine. The proposed configuration has single stator and single rotor for the axial flux permanent magnet Brushless Direct current Motor (BLDC) machine. By using the magnet software, the analysis of proposed machine has been done in terms of various aspects such as the induced voltage, phase current and air gap flux density.

Ceiling-fan-integrated air conditioning: Airflow and temperature characteristics of a sidewall-supply jet interacting with a ceiling fan

Ceiling-Fan-Integrated Air Conditioning (CFIAC) is a proposed system that can greatly increase buildings' cooling efficiency. In it, terminal supply ducts and diffusers are replaced by vents/nozzles, jetting supply air toward ceiling fans that serve to mix and distribute it within the room. Because of the fans' air movement, the system provides comfort at higher room temperatures than in conventional commercial/institutional/retail HVAC. We have experimentally evaluated CFIAC in a test room. This paper covers the distributions of air-speed, temperature, and calculated comfort level throughout the room. Two subsequent papers report tests of human subject comfort and ventilation effectiveness in the same experimental conditions. The room's supply air emerged from a high-sidewall vent directed toward a ceiling fan on the jet centerline; we also tested this same jet on a fan located off to the side of the jet. Primary variables are: ceiling fan flow volumes in downward and upward directions, supply air volume, and room-vs-supply temperature difference. Velocity, turbulence, and temperature distributions are presented for vertical and horizontal transects of the room. The occupied zone is then evaluated for velocity and temperature non-uniformity, and for comfort as predicted by the ASHRAE Standard 55 elevated air speed method. We show that temperatures are well-mixed and uniform across the room for all of the fan-on configurations, for fans both within or out of the supply jet centerline. The ceiling fan flow dominates the CFIAC airflow, and even though non-uniform is capable of providing comfortable conditions throughout the occupied area of the room.

Dangerous Weather

Dangerous Weather Natalie Teal McAllister (bio) Jim wanted the ceiling fan and you wanted the window unit and Jim won until the baby was born. Jim won everything until the baby was born, and then the baby won everything thereafter. The baby had been born in August. The first night she was home neither the fan nor the window unit could keep up. She screamed and thrashed until Jim had her in just a diaper and you hovered over her and hoped she would cry herself to sleep because to touch her would surely have made the situation worse. Jim had central air installed within the week, but that was his idea, too. Thirty years later with the same unit outside, you should have known you were in trouble when you woke up to the sound of robins in the mulberry tree. In the still-dark morning, you can hear the last handful of crickets in the yard and a car on the main road three streets over. What you can’t hear is that air conditioner. ________ When you wake again the sun is up and even the birds are too hot to sing. It’s near 90 in the bedroom. You shuffle to the thermostat and let it confirm what you suspected. The dial reads closer to 85, but the bedroom is on the sun side of the house and stays warmer in every month of the year. You slide the knob as far to the left as it will go and wait for the machine to kick on. You tell yourself to give it five minutes. Be patient with the old thing. Two minutes later you slide into your flip flops and push open the back door. The unit is tucked into an odd corner of the house. Maybe it has been a few years since you’ve actually looked at it. You nudge the bottom of your flip flop into it. When that doesn’t work, you clap the palm of your hand against the metal grate. Then you do it again. The second time your hand comes up with a coat of rust and you give the unit up for dead. ________ You keep a collection of magnets on the refrigerator. Names of repair men and plumbing companies. People who want to sell you insurance. You peel off one for Randy Mr. Fix It. He picks up on the third ring. “Randy Mr. Fix It,” he says. “You break it, I fix it.” You tell him the situation with the unit. “Alright. I can fix that. Let me get you on the schedule.” You ask him what he means by schedule. “I mean yours isn’t the only one that’s broken.” You pull back the curtain on the back door and look over at your neighbor’s unit. As far as you can tell, it’s working. “The news said there’s an excessive heat warning,” you say. “That’s got to mean something.” You say it but you don’t believe it means anything to people like Randy. What else is this world but [End Page 156] a place where men can promise to care for you, to watch out for you, and never mean a second of it. Still you find the smallest part of your heart wants to believe otherwise. “I’m getting through them as fast as I can. I can try to get you in at 4:30. Last call of the day.” They said on TV it would be 110 by then. “If I get done sooner, I’ll get there sooner. I’ll do what I can.” “I could die in here before then,” you say. “That’s what they said.” He takes what feels like a full minute to answer. You spend that minute wondering—if you did die, when would they find you? Would it be come winter? Or would they notice when your mail piled up? What if you didn’t have much mail to speak of? Then it comes to you: it would be the overgrown lawn. That’s how they would know you were dead. “If I were you,” he says, “I...

Surgical control over superior sagittal sinus injury due to metallic ceiling fan-blade injury

The most serious dural sinus accident following traumatic brain injury is superior sagittal sinus (SSS) injury. It is usually resulted from depressed skull fracture extends to the midline. We present a traumatic superior sagittal sinus injury triggered by the metal ceiling fan blade with its surgical management. Injuries of the SSS have an increased mortality rate in head injured patients. Metallic ceiling-fan head injury differs from the classic traumatic brain injury concerning the presentation, radiology, management, and outcomes.

What Hank Did Next

Hank Carlson, once a successful businessman and a well-respected member of his community, spent nearly two years in prison for check fraud. When he was caught, the community turned on him instantly, and his family suffered financially and socially as a result of his deeds.Carlson did his time grudgingly, believing himself to have been the scapegoat of a Justice Department that was overcompensating for the Enron debacle by punishing any businessperson who set a toe even slightly outside the law...even if, as Carlson imagines is true of him, they hadn't really hurt anybody. Now, Carlson is out of prison and working to repair the broken trust and relationships within his family. He has an okay job and new connections with people who don't know about his past. But when an investment banker offers Carlson a finance job, Carlson fears that accepting it would reveal what he'd done all over again, exposing himself and his family to more damage. And then a local teacher at the center of a scandal reaches out to Carlson for help and advice. What should Carlson do? Excerpt UVA-E-0434 May 13, 2020 What Hank Did Next Introduction Hank Carlson had known this moment—the moment he had been dreading for an entire year—would come sooner or later. Although he had spent the last several months trying to put his life back together, he knew his criminal past couldn't stay buried. Eventually, the ugly truth would find its way out again. His family had already suffered a huge blow that had threatened to tear it apart, and Carlson had already lost everything. Yet he didn't want to make things any worse. Carlson watched the ceiling fan rotate above his head. He knew all too well that bad things could be hidden in plain sight. His head tingled in a familiar way—a pain along his hairline that started when he was feeling anxious. Carlson had spent nearly two years in prison, serving a sentence for check fraud. Every morning in prison, he'd awoken with this familiar anxiety and the constant depression of knowing that this day would be just like the day before—filled with the darkness that accompanied his anger and shame about his crime. He hadn't deserved to be in prison; he wasn't a bad person. Back then, he'd always wanted to hide, to be concealed, but he'd come to learn that no secret ever stayed hidden for very long. . . .

Airflow pattern induced by ceiling fan under different rotation speeds and blowing directions

Ceiling fans have been widely used as effective cooling and air mixing method for building environment conditioning. Understanding its airflow characteristics can be helpful to utilize ceiling fan or integrate it with background air conditioning system. However, the airflow induced by ceiling fan has different flow patterns under different rotating speeds and blowing directions. To date, it is still challenging to capture those complicated airflow fields in room scale. In this study, the airflow pattern induced by a ceiling fan was measured with a new technology, quad-view colour sequence particle streak velocimetry. A series of isothermal experiments were conducted under five rotation speed levels with downward and upward blowing directions in a room-size (4 m × 2.5 m × 3 m) chamber. Based on comprehensive three-dimensional three-component vector measurement results, the average velocity, turbulence intensity and vorticity on the middle section were calculated and used to analyse airflow patterns induced by ceiling fan. The results show that the blowing direction of the fan determines the indoor airflow pattern. When blowing downward, the flow will cause high diversion between jet core under the fan blades and surrounding region. While for upward blowing, the air speed in lower part of the room is much lower but pretty uniform. The detailed measured airflow fields can serve as reference for ceiling fan design and operation.

Design and Fabrication of Fleixible Ceiling Fan

Ceiling fan serve a dual purpose of warming or cooling air and more over is economically cheaper than AC and so it is worthy of study. Efficiency of ceiling fans depends upon RPM [rotations per minute], the height from the ceiling fan design. In our research, we would be considering the height from the ceiling and the CFM [Cubic feet per minute] of the fan to find its efficiency and as a result findings the most efficient height from the ceiling and CFM. There are two stages of experimentation we have done to get the expected results. Firstly, the height of the rod of ceiling fan is kept constant and wind speed readings are obtained by changing the area around the fan where wind blows. Secondly, for different heights of the rod again the above procedure is repeated. So we have fabricated the flexible ceiling fan rod according to the fans which we have taken for testing which are 3 blade, 4 blade, 4 blade with smaller blade size and have fabricated a flexible rod according to its weight and the air circulation. This can be altered in 3 steps according to the room size

Design and Implementation of a Wi-Fi- based Ceiling Fan Regulator System

Design and Implementation of a Wi-Fi- based Ceiling Fan Regulator System

A Call for Preventing Suicide by Hanging from Ceiling Fans: An Interdisciplinary Research Agenda.

Hanging is a common method of suicide in several countries. Even as global suicide rates decrease, there is no evidence of suicides by hanging declining. There is limited research by type of hanging, and only a few papers present suicide by hanging from ceiling fans. Our paper proposes a research agenda that will: specify the size of the problem of hanging by ceiling fan (Stage 1: Surveillance), use standard engineering product development processes to modify ceiling fans for reducing their lethal capacity (Stage 2: Design Testing and Redevelopment), and examine the resulting beta- and release-build fans for safety and potential to reduce suicide in community samples (Stage 3: Evaluation).

Effectiveness of free running passive cooling strategies for indoor thermal environments: Example from a two-storey corner terrace house in Malaysia

The widespread use of air-conditioning to achieve indoor cooling of residential buildings has caused increased electricity consumption. Effective passive cooling strategies, such as natural ventilation, are important for reducing energy consumption. Field measurements of thermal performance for a corner terrace house in Kuala Lumpur were conducted to clarify the effectiveness of free running (FR) ventilation as a passive cooling strategy with configurations: without ventilation, full ventilation, day ventilation, and night ventilation. Measurements were conducted for all bedrooms and a family area on the first floor. For comparison, a mixed mode (MM) consisting of FR, ventilation with a ceiling fan, and cooling with an air-conditioner, which represents the actual conditions of this house, was measured in the living and dining area on the ground floor. Operative temperature was compared with the predicted temperature using an adaptive thermal comfort equation (ACE) under relevant international standards. The mean indoor temperature under FR was approximately 27~37 °C, and 27~33 °C in MM. Full ventilation and day ventilation recorded better correlation between outdoor and indoor temperature compared with no ventilation and night ventilation. Furthermore, compared with the ACE for a hot-humid climate, MM ventilation resulted in an operative temperature 58% less than the acceptable comfort temperature; thus, it performed better and was closer to international standards than was FR ventilation, which resulted in an operative temperature of 27% less than the acceptable comfort temperature. FR was not adequate to provide comfortable conditions without assistance from MM.

Improvement of Human Thermal Comfort by Optimizing the Airflow Induced by a Ceiling Fan

The purpose of this study is to investigate the relationship between the greenhouse effect and the overuse of electricity and energy under a sustainable environment. The goal is to investigate the airflow that is induced by ceiling fans, by measuring human body temperature. In the simulation model, the thermal plume phenomenon is observed in the indoor environment. By changing the ceiling fan parameters, the influence of the airflow is investigated by practical measurement of human body temperature. The indoor convective heat transfer is enhanced by installing a ceiling fan, which affects the whole body thermal sensation (WBTS). Different scenarios are reviewed by adjusting the fan speed in the simulation model, so that the distribution of human body temperature can be determined. By modeling the blade plane of the ceiling fan, the airflow characteristics can be determined by making the simulation model rotate in order to assess the thermal comfort characteristics. As the ceiling fan generates circulation within the domain, the thermal comfort is significantly enhanced. By keeping a reasonable thermal comfort level, a higher room temperature or a higher heat load is allowed so that a sustainable environment can be maintained without affecting the indoor thermal comfort or the efficiency of energy usage.

Multi-objective optimization model predictive dispatch precooling and ceiling fans in office buildings under different summer weather conditions

In summer, a ceiling fan has a tremendous potential to cool rooms, resulting in energy saving and a peak load reduction. During the critical peak pricing (CPP) period of the electricity, one method to attain substantial energy cost saving is to turn off the heating, ventilating and air conditioning (HVAC) system, but this may result in overheating. Fortunately, precooling and ceiling fans can be used to reduce the feeling of hot sensation. Therefore, the best control strategy for an HVAC system and ceiling fans is to maximize energy cost saving without much thermal comfort sacrifice. This paper presents a multi-objective optimization model predictive control (MO-MPC) of precooling temperature setpoint and ceiling fan speed. The proposed MO-MPC integrates an optimization engine, Dakota, and a detailed energy simulation tool, EnergyPlus, to determine the optimal control strategies considering the energy cost and thermal comfort simultaneously. A sub-program of substituting EnergyPlus with decision tree regression models for building climate prediction is deployed. If the calculation time is too long to achieve real-time control, this sub-program can be adopted to accelerate the calculation. In this study, the proposed MO-MPC framework is applied to a small and large building in four different cities with different CPPs. For a summer day, compared with the baseline cases of no precooling and no ceiling fan, the optimal strategies for the small building achieve energy cost savings between 10.3% and 33.3% and a peak power load decrease from 44.0% to 51.9%. Without precooling but with a ceiling fan control, on a particular summer day, for the large building case in Shanghai, 7.4% energy saving is achieved. The optimal control of the precooling temperature and ceiling fans result in a 14.4% energy cost saving. By using the decision tree regression models instead of EnergyPlus, the calculation time of the big office reduces from about 10 hours 40 minutes to 24.4 minutes.

The effects of using ceiling fans on human thermal comfort in a three-dimensional room with centralized heating including an occupant

PurposeThe purpose of this study is to analyze the effect of using a ceiling fan with central heating system in the winter on thermal comfort and heat transfer rate in a three-dimensional numerically.Design/methodology/approachThe geometry had certain dimensions, and an occupant was modeled to be in the room. In models which were used, the flow was turbulent, and turbulence models were used for simulating turbulence. Between all the models, k-ε model had best matching.FindingsResults show that using the ceiling fan during the winter had an efficient and considerable effect on improving the thermal comfort and energy saving inside buildings. By the use of ceiling fan, the effective room temperature has increased by 2.5°C. Furthermore, results show that by using ceiling fan in the winter, the predicted mean vote and the predicted percentage dissatisfied indexes improved. At the end, the case Room 11-0.05-15 with temperature of 87°C for radiator and normal fan velocity of o.25m/s were the optimal model that caused the complete thermal comfort and reduced energy consumption up to 28 per cent.Originality/valueIn the present study, the effects of using the ceiling fans on human comfort condition and heat transfer field during the winter (heating system) are studied. Following are the goals for all models: getting the appropriate temperature for radiator so that thermal comfort condition can be applied at the height of 75 cm of the room, velocity for fan so that air speed can be 0.25m/s at the height of 2 m or lower of the room and position to place the fan.

Shepherd Chemical invests in the Vosges

Research related to personal comfort systems is growing due to their potential to increase an individual’s satisfaction with indoor environmental conditions and energy efficiency. At moderately high indoor temperatures, the use of ceiling fans can be a low-energy cooling strategy to enhance comfort in a working environment. This paper studies the performance of a personal ceiling fan and its influence on occupants’ satisfaction with the indoor environment, focusing on the effects of personal control, previous experience with fans, variations on participants’ activity level and air coming from different directions. In a laboratory study, 41 participants from two age groups were exposed to six different ceiling fan configurations either in sitting or standing positions, with and without control over the ceiling fan speed, and under two thermal conditions (balanced order of in total 24 conditions). Results showed that participants’ thermal comfort at indoor temperatures of 28 °C and 31 °C was fulfilled when they used the personal ceiling fan, independent of the direction of the supplied air coming from above. The possibility to control the fan speed showed a significant influence on the thermal perception of participants at a slightly higher activity level compared to fully sedentary. The influence of previous experiences with fans had a positive effect on the rating of the analyzed ceiling fan and thermal comfort. The positive acceptance of personal ceiling fans encourages its use in retrofitted office buildings to increase thermal comfort and motivate energy savings.

Gulf Coast plants open, and new ones are planned

Research related to personal comfort systems is growing due to their potential to increase an individual’s satisfaction with indoor environmental conditions and energy efficiency. At moderately high indoor temperatures, the use of ceiling fans can be a low-energy cooling strategy to enhance comfort in a working environment. This paper studies the performance of a personal ceiling fan and its influence on occupants’ satisfaction with the indoor environment, focusing on the effects of personal control, previous experience with fans, variations on participants’ activity level and air coming from different directions. In a laboratory study, 41 participants from two age groups were exposed to six different ceiling fan configurations either in sitting or standing positions, with and without control over the ceiling fan speed, and under two thermal conditions (balanced order of in total 24 conditions). Results showed that participants’ thermal comfort at indoor temperatures of 28 °C and 31 °C was fulfilled when they used the personal ceiling fan, independent of the direction of the supplied air coming from above. The possibility to control the fan speed showed a significant influence on the thermal perception of participants at a slightly higher activity level compared to fully sedentary. The influence of previous experiences with fans had a positive effect on the rating of the analyzed ceiling fan and thermal comfort. The positive acceptance of personal ceiling fans encourages its use in retrofitted office buildings to increase thermal comfort and motivate energy savings.

Process for reducing the total acid number in refinery feedstocks

Research related to personal comfort systems is growing due to their potential to increase an individual’s satisfaction with indoor environmental conditions and energy efficiency. At moderately high indoor temperatures, the use of ceiling fans can be a low-energy cooling strategy to enhance comfort in a working environment. This paper studies the performance of a personal ceiling fan and its influence on occupants’ satisfaction with the indoor environment, focusing on the effects of personal control, previous experience with fans, variations on participants’ activity level and air coming from different directions. In a laboratory study, 41 participants from two age groups were exposed to six different ceiling fan configurations either in sitting or standing positions, with and without control over the ceiling fan speed, and under two thermal conditions (balanced order of in total 24 conditions). Results showed that participants’ thermal comfort at indoor temperatures of 28 °C and 31 °C was fulfilled when they used the personal ceiling fan, independent of the direction of the supplied air coming from above. The possibility to control the fan speed showed a significant influence on the thermal perception of participants at a slightly higher activity level compared to fully sedentary. The influence of previous experiences with fans had a positive effect on the rating of the analyzed ceiling fan and thermal comfort. The positive acceptance of personal ceiling fans encourages its use in retrofitted office buildings to increase thermal comfort and motivate energy savings.

Study of mixed convection in closed enclosure with a ceiling fan

This paper presents a numerical study of heat transfer by convection in a square cavity. The vertical walls of the cavity are differentially heated and the horizontal ones are considered adiabatic. A fan is placed in the middle of the cavity and releases a jet down. Numerical simulation was performed using the lattice Boltzmann method to show the flow patterns and the heat flux depending on the Rayleigh number (thermal convection intensity) and the Reynolds number (fan-driven flow intensity). A parametric study was performed presenting the influence of Reynolds number (20 ≤ Re ≤ 500), Rayleigh number (10 ≤ Ra ≤ 106) and the fan position (0.2 ≤ HF ≤ 0.8). In forced convection mode, the flow structure has been mapped according to the position and the power of the fan. Three structures have emerged: two symmetrical cells, four symmetrical cells and asymmetrical structure. It has been observed that the heat transfer rate increases with the rise of Reynolds number and the reduction of the distance of the fan position from the ceiling. For the latter one, an unfavorable evolution of Nusselt number is observed for Ra > 104.

Design of Ceiling Fan Regulator Knob

Design of Ceiling Fan Regulator Knob

An enemy hides in the ceiling; pediatric traumatic brain injury caused by metallic ceiling fan: Case series and literature review

Purpose: We report a series of 29 pediatric patients who sustained head injuries due to metallic ceiling fans. They all were admitted to the Emergency Department of Neurosurgery Teaching Hospital in Baghdad, Iraq, during January 2015 to January 2017.Results: Pediatric ceiling fan head injuries are characterized by four traits which distinguish them from other types of head injuries; 1- Most of them were because of climbing on or jumping from furniture between the ages of two and five. 2- Most of them sustained compound depressed skull fracture which associated with intracranial lesions and pneumocephalus. 3- The most common indication for surgical intervention was because of dirty wound which mixed with hairs. 4- These variables were statistically significantly correlated with the outcome: Level of consciousness, neurologic deficit, fracture site (occipital fracture had worse outcome), intracranial hemorrhage and surgery.Conclusion: Pediatric metallic ceiling fan head injury should be seen as a distinct type of head injury because it has special presentations, managements, and outcomes. In addition, we should start applying preventive methods to minimize its occurrence.

Measurement of airflow pattern induced by ceiling fan with quad-view colour sequence particle streak velocimetry

Ceiling fans have been widely used for a long time as an effective cooling equipment to create a sustainable indoor environment. However, it is rather difficult for the current measuring techniques to capture such a complicated airflow field in a whole-room scale. In this study, a novel large-scale airflow measurement technology, quad-view colour sequence particle streak velocimetry (CSPSV), is developed and applied to measure the airflow induced by a ceiling fan in a 4 m × 2.5 m × 3 m chamber. Four cameras were used in the new method, two at the higher position measuring airflow near the ceiling while the other two at the lower position measuring airflow near the floor, to capture the room-scale flow field. After reconstructing the vectors from each camera pair, the airflow vectors are merged to fill the blind zone near the ceiling and floor. Based on the three-dimensional three-component vector field measurement data, the averaged velocity vector, turbulence intensity, and vorticity were calculated and the airflow patterns were analyzed. The results indicate that the quad-view CSPSV method provides a more comprehensive measurement in room-size complex air movements such as ceiling fan airflow. Six pattern zones can be identified for a typical ceiling-fan-induced airflow. The flow under ceiling fan swirls along its path with the same rotation direction of fan blades with the core shrinking gradually and becoming diluted by the surrounding air. This study provides a new velocimetry method for room-sized complex airflow and a better understanding of ceiling fan airflow pattern.