# Quick Answer: How Is Fan Efficiency Calculated?

## What is static efficiency of fan?

Static efficiency is a ratio of the fan power output to the power supplied to the fan.

It can be found by multiplying the Mechanical efficiency by the ratio of the fan static pres- sure to the fan total pressure.

SP Static pressure is the measure of the potential energy of the airstream..

## How do I calculate RPM?

How to Calculate Motor RPM. To calculate RPM for an AC induction motor, you multiply the frequency in Hertz (Hz) by 60 — for the number of seconds in a minute — by two for the negative and positive pulses in a cycle. You then divide by the number of poles the motor has: (Hz x 60 x 2) / number of poles = no-load RPM.

## How can I increase my fan efficiency?

That means, if fan rotation speed is reduced by 10%, the fan power will reduce 27%. The most efficient way to reduce fan energy use in variable flow is to reduce fan rotation speed, which can be most efficiently achieved with frequency controlled electric motors.

## How is HP Fan calculated?

P = (Q x p)/(229 x ) or.P = (Q x PF)/(33,000 x ) or.P = (Q x Pw)/(6356 x ) Where: P = Power, hp. Q = Flow Rate, cfm. p = Pressure, lb/in2 Pf = Pressure, lb/ft2 Pw = Water Gauge, Inches. = Efficiency coefficient.

## How static pressure of a fan is measured?

Static Pressure is rated in inches water gauge (inWG) or the metric equivalent, millimeters water gauge (mmWG). 1 inWG = 25.4 x mmWG. Standard air has a density of . 075 lb/ft3 and is based on a temperature of 70°F and 29.92″ Hg barometric pressure (sea level).

## How is fan motor power calculated?

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. In order to find the horsepower, multiply the air flow by the total pressure and divide the result by 6356.

## What is the efficiency of a fan?

Fan total efficiency is calculated using total pressure. Static efficiency is calculated using only static pressure. Positive static pressure is created as a fan moves air through a system. Negative static pressure is what all other components in the airflow path create as they resist air movement.

## What is the power of fan?

Power Consumption of a Ceiling FanSpeedAtomberg Ceiling FansOrdinary Ceiling FanSpeed 16 Watts16 WattsSpeed 210 Watts27 WattsSpeed 314 Watts45 WattsSpeed 419 Watts55 Watts1 more row•Aug 4, 2017

## What is the rpm of a fan?

Customers looking at fan speed should check the fans RPM (Rotations per minute of the blades). The standard 1200 mm (48) fan, runs at 300/350 RPM while the Hi-Speed fan runs at 380/390 RPM or so. Ideally, a ceiling fan should be about 7-9 feet off the ground.

## Is a higher CFM better?

CFM Meaning (Cubic Feet per Minute) Well, a fan’s airflow is measured in CFM or cubic feet per minute. … Generally, the higher the CFM rating, the better. However, when dealing with hardware obstructions, static pressure can be more efficient with less CFM.