How To Choose the Right Size Air Compressor for Your Job
Air compressors are also known as pneumatic compressors. They are a great tool for powering air tools. This is true in many settings, such as construction sites or home repair jobs.
Using low-quality equipment can lead to injury. Therefore, it is essential to check the capacity of the air compressor to ensure safety.
When choosing an air compressor, make sure it is the right size for your air-powered devices. Ensure it can meet or exceed the highest air pressure and air delivery requirements.
Your compressed air drill needs 5 CFM at 90 PSI. To meet these requirements, you must choose a pneumatic compressor with a capacity of 7.5 CFM at 90 PSI.
Examining the components that influence a compressor’s efficiency will help you determine the ideal size for your organization.
What Factors Affect Air Compressor Performance?
It may surprise you, but the power of an air compressor does not depend solely on its size. Other factors, such as air pressure, air delivery, and design, also affect its effectiveness.
Additional process details and considerations below.
How To Find the Right Air Compressor Size
Note the CFM requirements of your tools. Select a model that is 10-20% above this requirement. This will ensure you pick the right size air compressor.
Next, find a compressor with a large enough tank to power your tools for extended periods. Usually, 35-75 Litres will suffice. Finally, pick the smallest possible model that meets these requirements to simplify transport and storage.
Thanks to improving technology, even small and medium-sized air compressors offer a relatively high CFM and PSI. Only the biggest industrial tools require more than a 75 Litre tank and an above-average CFM. You can break this process into the following steps:
- Know the Necessary Air Pressure and Delivery
- Note Your CFM Requirements
- Confirm Your Power Supply Needs
- Choose the Air Capacity and Tank Size
- Consider Compressor Design and Configuration
- Pick The Right Duty Cycle
1. Know the Necessary Air Pressure and Delivery
Air pressure, measured in PSI, and air delivery, measured in CFM, are some of the most important metrics to consider. CFM and PSI determine the number and size of tools your compressor can power.
Air Pressure
PSI, or pounds per square inch, describes the air pressure a compressor produces. While most compressors can power small and medium-sized tools, models with a larger PSI offer more air volume production.
- Tip: Teams should use air compressors with a PSI higher than what their tools need. This will prevent air pressure drops and ensure optimal performance. Aim for a 20% difference.
Air Delivery
Operators measure the quantity of air a compressor delivers in CFM, or cubic feet per minute. The majority of compressors offer CFM ratings between 10 and 110. A 10 CFM air compressor will work for tire inflation and small air tools. A CFM over 50 suits industrial devices like rock drills, impact wrenches and jackhammers.
- Tip: Don’t run more than one tool at the same time. Check the total CFM of the tools. Ensure that it is lower than the air delivery rating of your compressor.
2. Note Your CFM Requirements:
Air compressor tools need a certain amount of air to work effectively. This table provides the average CFM rating for several popular air-powered tools. This rating was recorded when the tools were running at 90 PSI. Refer to the chart for the average air delivery rate for each device.
3. Confirm Your Power Supply Needs
Electric air compressors are the most common. On these models, a small electric motor powers the device. Hobbyists and small teams favor electric compressors because of their ease of use and quiet operation.
Fuel-powered compressors are a popular alternative. Fuel air compressors are essential on job sites disconnected from a power grid. However, they are much louder than electric models. Their exhaust also requires ventilation for teams to operate around them safely.
Hydraulic air compressors are the least popular option. These models derive power from the hydraulics on a vehicle or piece of equipment. Teams with robust hydraulics systems in their equipment will benefit the most from these compressors.
4. Choose the Air Capacity and Tank Size
The size of a compressor is not significantly important. However, the size of the tank affects its air capacity and performance.
Tanks that are small need frequent refills. They are not suitable for long-term use. Consequently, they are a good choice for hobbyists who need portability.
Construction teams need a bigger, more powerful air compressor.
Tanks on these models vary in size. They can be as small as 4 Litres or as large as 300 Litres. Most teams should choose a model with a 75 Litre tank. Larger models may be difficult to store.
5. Consider Compressor Design and Configuration
The design and tank configuration of a pneumatic air compressor affect its functionality. This, in turn, determines the types of tasks the compressor is suitable for. There are five common air compressor designs:
- Piston-Powered Compressors: These compressors feature reciprocating pistons that compress air and send it into the reservoir. For this reason, they are sometimes called reciprocating compressors. Piston-powered air compressors are the most common.
- Rotary Screw Compressors: This model generates power by trapping air between meshed rotors and pressuring it. While they deliver more air per minute than reciprocating models, they come at a higher cost and require specialized maintenance.
- Scroll Compressors: This model uses two interleaving scrolls to generate power. These scrolls push pockets of air towards the center of the device. Instead of powering tools, these compressors help operate HVAC units.
- Axial Compressors: These compressors use rotating airfoils to produce and transport highly-pressurized gas. They are typically installed in airplanes and ships.
- Centrifugal Compressors: These models pressurize cooled air with a high-powered diffuser. Because of their massive size, they often help power chemical plants and manufacturing centers.
Air compressors also come in two air tank configurations: horizontal and vertical. While these positions don’t affect performance, they change how compressors fit into a space.
- Hobbyists often use vertical models because they easily fit into enclosed spaces.
- Construction teams typically use horizontal tanks on stationary air compressors because they don’t tip over as easily.
6. Pick the Right Duty Cycle
The duty cycle is the ratio of time air is delivered to the time a compressor takes to refill its reservoir. Since it takes time to pressurize and transport air, most compressors require a period of rest to recharge. Generally, larger compressors have shorter duty cycles.
Assuming a compressor takes one minute to refill its reservoir, common duty cycles include:
- 25%: Operators can expel pressurized air for 15 seconds after one minute of rest. This duty cycle suits small compressors for hobbyists.
- 50%: For every 30 seconds of operation, this duty cycle requires a full minute to cycle in new air. This duty cycle works for small teams who use air power intermittently.
- 75%: After one minute of recharge, these compressors can function for 45 seconds. This duty cycle works for medium-sized tools like pneumatic wrenches, saws and chisels.
- 100%: These compressors generate air as quickly as they expel it. Because they can operate for hours on end, their engines are equipped with a cooling feature. Large crews use them for large tools in manufacturing and construction.
What are the Benefits of Air Compressors?
Air tools are advantageous over other energy sources, such as electricity. They generate more power and provide a higher level of precision. Some of the reasons teams choose air tools include:
- Energy efficiency is key: Compressors should not be left running or neglected. Doing so wastes energy.
- Wide range of attachments and functions: Almost all repair and construction tools come in an air-powered variety. Air power can assist with everything from paint spraying to running industrial facilities.
- Easy to store and transport: Most air compressors comfortably fit in the back seat of a car or truck bed. Teams can transport larger models by towing them to the back of vehicles.
- Great for professionals and hobbyists alike: If you run a construction company, you will find it especially useful. Even if you just like to do home repairs, you can still benefit from an air compressor.
- Low cost: Small air compressors run for less than €200. Not only does this make them more accessible than other power sources, but air refills cost less than gasoline or electricity.
