**To calculate the free air delivery of a compressor, you need to know the volume of free air it can produce per unit of time and the pressure it can generate.**

A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. Free air delivery (FAD) is a measure of a compressor’s ability to deliver a given volume of air at a given pressure. It is usually expressed in cubic feet per minute (CFM) or liters per second (l/s).

To calculate the FAD of a compressor, you need to know the following factors:

- The compressor’s pressure ratio
- Its volumetric efficiency, and
- The displacement of the compressor

The pressure ratio is the ratio of the discharge pressure to the suction pressure. It is usually given as a percentage.

Volumetric efficiency is a measure of how well the compressor can compress the air. It is usually given as a percentage.

The displacement is the volume of air that the compressor can move in a single stroke. It is usually given in cubic feet per minute (CFM) or liters per second (l/s).

To calculate the FAD, multiply the pressure ratio by the volumetric efficiency and the displacement.

For example, let’s say you have a compressor with a pressure ratio of 80%, a volumetric efficiency of 85%, and a displacement of 100 CFM. The FAD would be:

FAD = 80% x 85% x 100 cfm

FAD = 68 cfm

## How To Calculate Free Air Delivery (FAD) Of A Compressor?

**To calculate the free air delivery (FAD) of a compressor, you will need to know the compressor’s displacement and the speed at which it is operating.**

If you’re in the market for an air compressor, one of the first things you need to know is the free air delivery rate or FAD. The FAD is a measure of how much-compressed air the compressor can generate per minute, and is expressed in liters per minute (L/min). In this article, we’ll show you how to calculate the FAD of a compressor so you can make an informed decision when purchasing an air compressor.

To calculate the FAD of a compressor, you’ll need the following information:

- The compressor’s flow rate (in CFM)
- The compressor’s discharge pressure (in PSI)
- The compressor’s efficiency (in percent)

Once you have this information, you can calculate the FAD using the following formula:

FAD = (CFM x PSI) / (100 x Efficiency)

For example, let’s say you have a compressor with a flow rate of 100 CFM, a discharge pressure of 125 PSI, and an efficiency of 80%. Plugging those numbers into the formula, we get:

FAD = (100 x 125) / (100 x 80)

FAD = 12,500 / 8,000

FAD = 1.56 L/min

This means that the compressor can generate 1.56 liters of compressed air per minute.

Now that you know how to calculate the FAD of a compressor, you’ll be able to make an informed decision when purchasing an air compressor.

## How Does FAD Vary With Compressor Speed?

**FAD varies with compressor speed because the faster the compressor speed, the greater the volume of air that is moved and the higher the pressures that are achieved.**

There are many factors that affect the performance of a compressor, including speed. The faster the compressor runs, the greater the volume of air that is drawn in and compressed. However, the efficiency of the compressor decreases as the speed increases. This is due to the increased friction and heat that is generated as the compressor parts move faster.

The compressed air volume per unit of time is known as the Free Air Delivery (FAD). This is a measure of the compressor’s output and is usually expressed in cubic feet per minute (CFM). The FAD will vary with the speed of the compressor, with faster speeds resulting in increased output. However, the efficiency of the compressor will decrease as the speed increases, so the overall energy consumption will also increase.

Operating a compressor at the highest possible speed may not always be the most efficient option. In some cases, it may be more efficient to run the compressor at a lower speed and use a larger tank to store the compressed air. This will reduce the overall energy consumption and also minimize the wear and tear on the compressor parts.

## How Does FAD Vary With Compressor Discharge Pressure?

**FAD is directly proportional to compressor discharge pressure.**

FAD (free air delivery) is the volume of air that a compressor can produce at a given pressure. The higher the discharge pressure, the lower the FAD. This is because the compressor is working harder to achieve the higher pressure, and therefore can’t produce as much air.

This relationship is important to understand when selecting a compressor for a particular application. If you need a lot of air at high pressure, you’ll need to choose a compressor with a high FAD. However, if you only need a small amount of air at low pressure, you can choose a compressor with a lower FAD.

To calculate the FAD of a compressor, you’ll need to know the compressor’s displacement and the pressure it’s operating at. The displacement is the volume of air that the compressor can move in a single stroke. The pressure is the amount of force that the compressor is exerting on the air.

To calculate FAD, divide the displacement by the pressure. For example, if a compressor has a displacement of 100 liters and operates at a pressure of 10 atmospheres, the FAD would be 10 liters.

Keep in mind that the pressure and displacement of a compressor can vary depending on the model and manufacturer. Always consult the manufacturer’s specifications to be sure.

## How Does FAD Vary With Compressor Inlet Temperature?

**FAD is directly proportional to the compressor inlet temperature. **As the compressor inlet temperature decreases, the volumetric flow rate of the air passing through the compressor also decreases.

This is due to the fact that cold air is denser than warm air. As the density of the air decreases, the compressor must work harder to maintain the same airflow. The result is an increase in power consumption and a decrease in efficiency.

## How Does FAD Vary With Compressor Outlet Temperature?

**FAD is lower at higher compressor outlet temperatures. **FAD is a function of many factors, but compressor outlet temperature is one of the most important. Here’s a quick rundown of how it works:

As the temperature of the compressor outlet increases, the FAD must increase to maintain a given volumetric flow rate. This is due to the fact that the density of the air decreases as the temperature increases. In order to maintain the same mass flow rate, more air must be moved.

The relationship between FAD and compressor outlet temperature is not linear. When the temperature is increased by a certain amount, the required FAD will increase by a larger amount. This is because the density of the air decreases exponentially with increasing temperature.

As the compressor outlet temperature increases, the FAD will increase. However, there is a limit to how much the FAD can increase. This is because the air can only be compressed so much before it reaches the point of saturation. At this point, further increases in temperature will not result in further increases in FAD.

### FAQ

#### How Does FAD Vary With Compressor Volumetric Efficiency?

#### How Does FAD Vary With Compressor Isentropic Efficiency?

The FAD of a compressor varies with its isentropic efficiency according to the following equation:

FAD = (1 – isentropic efficiency) x (compressor power)

So, if a compressor has a higher isentropic efficiency, the FAD will be lower.

#### How Does FAD Vary With Gas Density?

#### How Does FAD Vary With Gas Viscosity?

#### How Does FAD Vary With Gas Compressibility Factor?

### Conclusion

There is no definitive answer to this question as there are a number of factors that can affect the free air delivery of a compressor. However, a good rule of thumb is to multiply the compressor’s flow rate by its pressure ratio. This will give you an approximate estimate of the free air delivery.

If you’re still unclear on how to calculate free air delivery of a compressor, please leave a comment below and I’ll be happy to help.