September 18, References. To create this article, volunteer authors worked to edit and improve it over time. This article has been viewed 30, times. Learn more Being able to properly calculate fan power is important for many different applications, whether you are calculating the power of an industrial fan or a household fan.
When calculating this, you will be able to determine the power that a fan requires theoretically, but you must be aware that the actual power that the fan requires called brake horsepower will always be greater than what you calculated simply because no fan can achieve perfect efficiency.
Understand what fan power involves. Fan power measures exactly how much energy a fan must receive in order to be able to produce a specific amount of air flow. Fan power is a function of both air pressure and air flow and units of horsepower is typically the measure used. Measure the air pressure. This is measured in inches of water gauge iwg. This is the unit of measure which is used for various fan calculations.
The other end of the manometer must be placed at the end of the fan outlet. Now you simply measure the difference between the liquid height on both sides of the manometer in order to measure the total pressure. Measure the air speed. Now that you have the total pressure, you will have to measure the air speed in feet per second. For this you will need a vane anemometer. After you have done that, average all of those readings in order to accurately measure air speed.
The recommended amount of different velocity measurements is nine, according to the University of Connecticut. Measure the diameter. At this point, you must accurately measure the fan diameter in feet.
Relationship between CFM and RPM
When you have the diameter, divide it by 2 and square the result. After doing so, multiply it by 3. Determine the air flow. Now that you know the fan area it is time to multiply it by the air speed of the fan.
This will give you the air flow in CFM or cubic feet per minute. Determine the horsepower.Log In. Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
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Related Projects. Hi, I'm trying to get some help doing a rough estimate calculation of the volumetric flow through and induced draft fan on a balanced draft unit without doing a performance test. Is there a different equation I could use to determine a rough estimate of the vol.
I think motor eff is what you can use. Do you have the design calc for the fan? That should give you a good estimate for what the fan is rated for and what you should be seeing. If you are suspecting that the fan is not doing what it is supposed to, do a traverse across the outlet of the fan and see what is being pushed.
The efficiency in the above formula is fan efficiency. The equation doesn't know if you are driving the fan with motors, turbines or horses. I do not have have the design calc for the fan. The fan is performing as it should as it relates to pressure rise. What I am trying to do is plot the operating point on the fan curve live with the instrumentation that I have. The true problem is we suspect the fan is surging or in a rotating stall at certain operating points because the ductwork and structural steel is vibrating severely.
If I can plot the operating point live, I can determine how much it is surging.CFM \u0026 Air Flow
The fact is: There are UL standards that place limitations on ceiling fan manufacturers that prevent them making fans that spin too fast. These limitations for safety purposes and are meant to minimize the risk of injury should a person raise their hands or any other object into the path of the ceiling fan blades while the fan is in operation.
Imagine if some ceiling fan blades moved as fast as an airplane propeller and had blades like a machete! Well, UL standards prevent manufacturers from making such products The first basic limitation is that no residential ceiling fans are allowed to be installed such that the blades are less than 7 feet from the floor.
The second basic limitation has to do with the RPMs at which a fan can spin relative to the thickness of the blades. The concept is that thinner blades can cause more damage of laceration, so they are not allowed to spin as fast as those with thicker blades. The RPMs allowed for any residential ceiling fan that can be installed on a ceiling less than 10 feet high are restricted by UL based on the blade span and thickness of the blades see chart below.
No ceiling fan is allowed to be installed with the blades closer than 7 feet from the floor. These limitations are in place to minimize the risk of injury should a person raise their hands or any other object into the path of the fan blades while the fan is in operation. The amount of air that a ceiling fan produces is certainly affected by how fast is spins. Yet RPMs alone do not produce airflow.
The aerodynamics of the blades is every bit as important as the RPMs. If a fan has blades that are straight and flat, it doesn't matter how fast it spins, it's not going to generate much airflow. Take the same blades and give them a 15 degree pitch and the fan will move air, but the RPMs will be slower since the angled blades are now having to perform some work, which puts drag on the motor.SpeedFan is a program that monitors voltagesfan speeds and temperatures in computers with hardware monitor chips.
SpeedFan can even access S. SpeedFan can even change the FSB on some hardware but this should be considered a bonus feature. SpeedFan can access digital temperature sensors and can change fan speeds accordingly, thus reducing noise. It works with Windows 64 bit too. SpeedFan can access the temperature sensors available on your motherboard and on your nVidia video card. The most widely available temperatures are from the chipset, the CPU, the ambient and from the power circuitry.
Modern CPUs can report their own internal temperature. Multi-core CPUs are often able to report temperatures from each single core. SpeedFan can access those readings and report changes. More powerful hardware motherboards, CPUs, video cards and hard disks often requires more power.
More power leads to more heat to dissipate. A proper airflow inside the computer cabinet helps to keep temperatures low. Inside computers there are fans that create such an airflow. SpeedFan can report the speeds of each fan and it can even change their speed based on current temperatures.
This lowers noise and improves computer experience. SpeedFan can access the voltages reported by the hardware. This can help to identify odd issues with computers resetting under stress, for example. Please, note that SpeedFan reports the voltages according to the official documentation. Sometimes hardware manufacturers use custom circuitry. In the FAQ you can find further info on this topic.
Almost every hard disk can report a set of data about its own health and status. This is called S. Based on reported data, a hard disk failure can often be early detected. Hard disk temperature can be read too and it is useful to identify overheating components that could reduce your valuable data reliability. SpeedFan offers a unique feature called "In-depth online analysis" that compares your hard disk SMART data to a model derived from millions of reports. This helps to better identify when a specific hard disk is outside "normal" values.
Such data contains the hard disk temperature too. Hard disk temperatures are positively correlated to hard disk failures.
This is the reason why these information are so important. Reliable access to RAID controllers requires support from hardware manufacturers. This is something that is being worked on. SpeedFan 4. It adds support for a lot of new hardware. Bug fixes and more, as always. This version took quite a long time to see the light because of many things that happened. New versions will now appear more often. An article has been added to describe the long awaited new Advanced Fan Control method.
You can find it here. How fan speed changing works.Before installing the H the server was quiet, fans ran very low. Nothing else changed except the addition of the second PCI card.
Is this normal? Is there anything I can do reduce the fan RPM? Go to Solution. I am considering this matter closed. I spoke with Dell support through chat, turns out this server was still eligible for support. They suggested at first that it was a temperature issue, which is obviously was not as the environment has not changed for this server in over a year. I'm not sure if it was moving the card that did the trick or the fact that I had to power down the system to move it, but I was able to get all the fans even the PSU fans down to a sane level.
Just so there's no confusion, here are the commands I used:. I found that 0x2c is around 6K RPM and fairly quiet but still allows adequate airflow to cool the system. I've already put far too many hours into trying to fix this, so I'm going to live with running these two commands in a cron on reboot. Yes, they have to be run every time the system is power cycled.
View solution in original post. This is somewhat helpful, but it doesn't work on theI assume a different HEX sequence would though. The post I linked had the last hex value as 0x46 which I figured was a value for the fan speed. I slowly reduced it until I had the fans running around rpm. I either need the raw values to control those fans OR the raw values to completely disable the " third-party PCIe card cooling response ".
I am experiencing the same issue.
I updated to the latest BIOS 6. Browse Community. Turn on suggestions. Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. Showing results for. Search instead for. Did you mean:. R 2nd PERC causes high fan rpm. All forum topics Previous Topic Next Topic. Accepted Solutions.Background The FD fan supplied air for a boiler and was driven by a steam turbine through a speed-reducing gearbox as shown Figure 1. Refinery personnel reported high vibration several days after replacing the fan roller bearings.
In an attempt to reduce the vibration, a second set of replacement bearings was installed; however, the vibration remained high. Initial vibration data were acquired with a hand-held analyzer.
However, other factors can cause vibration problems, as described in the reference paper1. Therefore, the refinery requested that more detailed testing be performed before attempting to field balance the FD fan.
Industrial Fans and Blowers | ID Fan | FD Fan | Blower Fans | Thermodyne
The test procedure included the following steps:. First, a simple wire-frame model was created from basic dimensions of the FD fan. The undeformed representation of the bearing housings, bearing pedestals, and concrete foundation is shown in Figure 2 as dashed lines. While operating the unit at constant speed and load, a tri-axial accelerometer was moved to 18 different locations to measure vibration in three orthogonal directions.
Phase angles were determined from a stationary reference accelerometer. The highest vibration occurred at the top of the bearing housings in the horizontal direction. Figure 2 shows the rocking motion in which both ends air inlet and coupling were moving in-phase. Vibration on the concrete foundation was 3 - 4 mils p-p, which was also considered excessive. However, no significant separation was found between bearing housings, pedestals, and concrete foundation.
Therefore, looseness was ruled out as a possible cause of the high vibration. This demonstrated that the vibration was not caused by aerodynamic forces. Both bearings still had approximately the same level of vibration, which pointed to a static unbalance condition of the fan impeller and not coupling unbalance.
Fan Inspection During the inspection, five balance weights of various sizes were found already welded around the periphery of the fan impeller. This indicates previous trouble balancing the fan. The fan impeller was covered with a thin layer of dirt, so it was difficult to tell if a balance weight had possibly come loose.
How to set custom fan speed on a Windows 10 PC
No obvious signs of damage were found, and no foreign objects were found inside the fan housing. The amount of dirt would have been similar before and after the bearing replacements.ID fan Induced Draft Fan basically pulls out flue gas from the furnace of boiler.
It is located between dust precipitators ESPs and Chimney. It handles air at normal temperature. Normally both fans are used in thermal power plant. FD fan is used to draw the air from atmosphere to boiler that will create positive pressure inside the boiler.
But ID fan is used to evacuate the flue gas from boiler to atmosphere via ESP ,chimney and that will create negative pressure inside the boiler In a balanced draft boiler you actually have both F. D fan. D stands for Induced draft Fan whereas F. D stands for Force Draft fan. FD fan Forced Draft Fan supplies the required air into the furnace for combustion of fuel. D handles air at normal temperature.
More info: The ID fan serves two functions: 1. Create a negative pressure in the furnace compared to outer pressure. After the furnace the flue gases cool, especially when they pass various cleaning processes, so they may not reach the height in the atmosphere where they are distributed, and stay condensed above the plant site and nearby area. FD Fan pushes the air into the system. FD Fans are normally direct driven fans.
ID Fan pulls the air out of system. ID Fans for high temperature flue gases are belt driven fans. Post New Answer. If the rated speed of a d. Shunt motor is r. How you calculating the 30 Hp 3 phase AC motor of power what size of cable is used for this motor?
The principle of switching circuits for different types of batteries in application of storage systems. Answers were Sorted based on User's Feedback what is the difference between id fans and fd fans. Is This Answer Correct?
ID fans also reduce the excess air, by this increasing efficiency. Less lost heat Is This Answer Correct? More Electrical Engineering Interview Questions.
T and L. T Cables?