Belt Driven Air Compressor VS Direct Drive: 3 Main Differences

Belt Driven Air Compressor VS Direct Drive

The difference between a belt-driven and direct drive air compressor is that the belt-driven air compressor uses an external power source to power the compressor, whereas the direct drive uses an internal electric motor.

A direct drive air compressor has a lower starting torque than its belt-driven counterpart and has a higher efficiency rating. However, it will be more expensive than its belt-driven counterpart because of the additional costs associated with electrical components.

A Belt-driven air compressor is quieter because there's no mechanical noise from moving parts. The installation and repair are simple and easy.

A Comparison chart of Belt Driven Air Compressor and Direct Drive Air Compressor

​Belt Driven Air Compressor

​Direct Drive Air compressor





PSI upgrade facility

Not maintenance free

​Super performance

​High initial investment

​Low initial investment

Not fit for extreme temperature

Energy efficient


Silent operation


Maintenance free

No pressure adjustment facility

Low repair cost


Fit for extreme temperature

​High repair cost



​Ideal for Continuous Use



Highly Adaptable to Extremely Harsh Environments.

In cold weather the belt of the belt-driven air compressor becomes stiff and in hot weather it becomes loose. A belt-driven air compressor is not well suited for extreme temperatures. They work great only in moderate weather conditions or during mild weather.

This will not happen with a direct drive air compressor since they don’t have the belt. You can use it at any temperature.

Energy Efficient

Direct drive air compressors are found more power efficient compared to its counterpart. The direct-drive air compressor's crankshaft is directly connected to the engine instead of pulleys and belts to transmit power which reduces friction and therefore less amount of energy needed to run an air compressor. There is no chance of energy loss.

Let’s talk about belt-drop. When a belt is running, it can slip. This is called a belt drop. A belt drop happens when the tension from the drive roller loosens and the drive belt loses contact with the pulley. When this happens, energy loss happens.

Direct drive air compressors offer a smaller starting current and use a more efficient on-off valve than belt-driven models and this results in significant power savings.

Ideal for Continuous Use

Technologically more advanced direct drive air compressors are capable to produce compressed air efficiently for as long as you need.

Industrial-oriented direct drive air compressors are intended for especially heavy-duty work environments like big factories and industries.

When used in a garage or a shed, belt-driven air compressors are more common. More rarely, do serious DIYers choose belt-driven air compressors?

Maintenance Free

A belt-driven air compressor requires maintenance because belts wear out and need to be checked and changed periodically. A direct drive does not require maintenance. The only thing that will need to be changed is the oil.


High Repairing Cost

The mechanism of a direct-drive air compressor is much more complex than that of a regular belt-driven model. If it fails, there's no point in trying to repair the air compressor at home.

You will need to take it to a qualified repair specialist or bring it to a shop. Furthermore, the parts are also costly enough.


Direct drive air compressors use a shaft and rugged gears to turn the compressor's pump. The gears that turn the pump must be rugged to take the stresses of continuous operation. These gears make noise.


Pressure Adjustment Facility

Belt-driven air compressor gives you the facility to upgrade PSI (output pressure) just by replacing the pulley. To give an example, if your compressor currently has 80 PSI, you can increase its output pressure by as high as 100 by exchanging the pulley.

Thus, you can meet the demand for more powerful air tools at your worksite.

Less Noisy

In belt-driven models, the belt absorbs some of the noise and vibration resulting in silent operation. A direct drive means the motor turns the shaft that turns the compressor, so there are more moving parts and it makes noise.

To guarantee smooth operation, it is highly recommended to regularly lubricate the belt. You also have to inspect the tension of the belt periodically so that it does not break.

Low Initial Cost

Unlike direct vehicle air drive, belted drive air compressors are offered at a reasonable price. You don’t need to make a large initial fund investment.


Frequent Maintenance

Belt-driven air compressors require maintenance to keep them operating smoothly. A belt is a loop of rubber that is wrapped around a motor and it transports power from the motor to another machine.

When the belt starts to wear down from use, it can become loose and cause problems with the machine. If you don't maintain your belt-driven air compressor by replacing belts or tightening belts when they get loose, this will decrease the life of the compressor.

Which Is Better: Direct Drive or Belt Drive Compressor?

If you are looking for an economical way to power your shop’s machinery, then a direct drive air compressor may be just what you have been searching for!

The only downside is that they can cost more than belt-driven compressors. However, if you need something reliable with low maintenance costs, this could be it.

Belt-driven units are for those who need variable speed and have the less initial budget. They are also ideal for smaller shops where space is limited. They are easy to use, maintain, repair, and operate.

​Detail Information About Belt Driven Air Compressors

What is a Belt Driven Air Compressor?

Belt-driven air compressors are designed with a motor and a pump. A belt is stretched between the motors and the pump, used to transfer the power from the motor to the pump.

The belt-driven pulley turns the compression cylinder, with a set ratio of gearing that is determined by the desired input pressure, volume flow rate, and outlet pressure.

A flywheel system aids in the smooth running of the engine in order to keep it running continuously without interruption.

This allows for more efficient operation without much power losses through friction or other gear-driven machinery.

What is a Direct Drive Air Compressor?

A direct drive air compressor is a machine designed specifically to be connected directly to another piece of equipment such as a drill press, band saw, table saw, etc., without using any belts, pulleys, gears, chains, sprockets, clutches, or other mechanical devices.

How does a Belt driven air compressor function?

Belt Driven Air Compressor

A belt-driven air compressor is like a car. The belt connects the engine to the pulley which in turn sends power to the wheels. The belt in a belt-driven air compressor is connected between two pulleys, one of which attaches to the motor and one of which attaches to the air tank.

The belt-driven air compressor is more efficient than a screw-type compressor because it has no corners in which friction can occur.

A belt-driven air compressor is a machine that uses a rotating driveshaft, belt, and pulley system to compress air. The driveshaft is connected to the motor which powers the belt and pulley system.

When the driveshaft rotates it pulls on the belt, which in turn rotates the pulleys. Rotation of one pulley results in rotation of an opposite pulley so power is transmitted from one to the other without any direct contact being made.

What are The Components of Belt Driven Air Compressor?

The belt-driven air compressor has a compression part, an expansion part, and a pump. The compression part is the reciprocating piston; it is connected to the crankshaft which converts rotary motion into linear motion and vice versa.

The expansion part is the process of cooling heated air back down to its previous state by expanding it and reducing its pressure. This occurs in the power cylinder, which houses a fixed volume for this purpose.

In simple, Belt, pulley, crank, and air seal are the four primary components that compose an air compressor.

Belt: What it is and how does it work?

An air compressor belt is a long, rubberized belt that connects two pulley wheels placed in opposite directions. Its function is to transfer rotational energy from one wheel to the other.

In other words, the air compressor belt transfers power from the engine to the crankshaft pulley, powering the piston and crankshaft that drives the intake and exhaust valves in an engine.

Now the belt squeezes an airtight chamber and forces air into the vacuum created by a piston. This process then creates power that can be used for various applications like powering machinery, tools, and pneumatic equipment.

Pulley: The pulley's job and what's in the pulley

Let’s understand what are pulleys first. Pulleys are a type of lever used in mechanical engineering to increase the force exerted on an object. The pulley consists of a wheel or a rope wrapped around a wheel with a groove.

As the wheel moves, the rope moves through this groove, pulling objects attached to it. One pulley is commonly used in conjunction with other pulleys to deploy larger amounts of force onto an object.

The pulley in an air compressor functions to transmit the drive energy to the drive shaft. The pulley is typically made of steel and has a groove around it. This groove is used to guide the belt, which will transmit the power from the engine through the pulley, then into the shaft that will turn, causing compression.

With a pulley, there are two forces: tension and compression. Tension is what is needed to pull an object down. Compression is gravity pulling an object up.

Crank: How the Crank Works and Where It Is Located?

In the air compressor pump, the crank is a rotating member that transmits linear forces to the piston.

In addition, as the crank rotates about an axis it can cause a change in the position of a lever arm due to its momentary angular acceleration. The crank also acts as a direct mechanical linkage between the piston rod and the cylinder wall.

The air compressor crank is a mechanical device that converts rotational mechanical energy into kinetic energy. It is located in the center of the crankcase and is made up of a shaft, a piston, and connecting rod.

Air Seal: What It Does and Why It's Important?

The air seal is a critical component of a compressor because it seals the gap between the piston and cylinder so that compressed air does not escape. The air seal prevents contaminants from entering the machine and also reduces friction on the machine's moving parts.

What Are the Types of Belt Driven Air Compressors?

There are three types of belt-driven air compressors that offer different benefits for different types of needs.

The first type is the single-stage compressor which is the most common type.

The second type is the two-stage or two-speed compressor which has a high speed for constant use, and a low speed for intermittent use.

The third type is the multi-stage compressor which has even more stages than the two-stage.

​Why Do Some Air Compressors Have Belts?

The belt enables the compressor to more easily transfer power from the machine to the pump. A belt drive is used to transfer power from a moving engine to the pump and other machinery in the air compressor.

The belt will allow for smoother and more efficient transmission of power; this is especially true for engines that do not produce a lot of power. This type of drive is often found on small stationary compressors where there may not be enough room for an electrical coupling, such as those found on light industrial units.

What Type of Compressor is Belt driven?

Air compressors over a 5-gallon air tank are found either in direct drive or belt drive. Belt-driven air compressors are more often used in garages and workshops. Sometimes serious DIYers also go for belt-driven air compressor

Industrial-oriented direct drive air compressors are also available on the market, but they are more expensive and intended for especially heavy-duty work environments like big factories and industries.

Where to Use Belt Driven Air Compressor?

Belt-driven industrial air compressors are used in many industries including food processing, pharmaceuticals, chemical manufacturing, electronics assembly, automotive repair, construction, plumbing, HVAC (heating, ventilation, and air conditioning), fire protection, agriculture, mining, oilfield services, etc.

A belt-driven air compressor is perfect for a field that requires a constant operation. A belt drive system can have more efficient power transfer from the engine to the compressor without being reliant on the energy of the engine itself, leading to increased efficiency.

Belt drives can also be an asset in fields that require high static pressure because they provide a greater torque output on the crankshaft due to the increased time of engagement, which lends them to a more efficient, albeit less powerful, form of compression.


In conclusion, both of these air compressors have pros and cons. If you are looking for a less expensive option, the belt-driven compressor may be for you. However, if you need something that is more energy efficient, then the direct-driven compressor might be right for you.

Both air compressors have their advantages and disadvantages. The belt-driven compressor is less expensive but requires maintenance, while the direct-driven compressor consumes less energy but emits much noise.

Read Also: Maintenance Guide Of Industrial Air Compressor, Industrial Air Compressor Brands

 Watch Video on Belt Driven Air Compressor VS Direct Drive

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