Air compressors, sometimes called pneumatic compressors, draw energy from pressurized air and use it to power air tools. Whether you lead a construction team or perform home repairs, compressors are a great power source. While air tools are generally safe, misusing subpar equipment can lead to injury or death. The best way to ensure your safety is by using the right size air compressor.
To find the best-sized compressor, check your air-powered tools with the highest air pressure and air delivery requirements and pick a model that exceeds these requirements. For example, if you own a compressed air drill requiring 5 CFM at 90 PSI, choose a pneumatic compressor that will provide 7.5 CFM at 90 PSI.
Reviewing the components behind a compressor’s performance will reveal the right size model for your team.
6 Factors That Affect Air Compressor Performance
Contrary to popular belief, a big air compressor isn’t necessarily more powerful than a small air compressor. Many factors affect their performance, including size, air pressure, air delivery and overall design. The points to consider include:
Power supply: 3 options
Air capacity and tank size: 4 common tank types
- Twin Stack
Compressor design and configuration: 5 options to consider
- Rotary screw
Air pressure: PSI (pounds per square inch)
- Use air compressors with about 20% more PSI than what’s needed.
Air delivery: CFM (cubic feet per minute)
- Most compressors have CFM ratings between 10 and 110 — confirm the tool’s requirements.
Duty Cycle: The amount of time a compressor can run before it needs to pressurize new air.
- For large teams and industrial-scale equipment, aim for 75% and above. Small crews and hobbyists can aim for a duty cycle of 50% or less.
See additional process details and considerations below.
How To Find the Right Air Compressor Size
To pick the right size air compressor, note your tools’ CFM requirements and pick a model that goes 10-20% above the required amount. Next, find a compressor with a large enough tank to power your tools for extended periods. Usually, 10-20 gallons 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 20-gallon 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.
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 about 20% more PSI than what their tools need; this will prevent frequent air pressure drops and get the best output.
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: When running more than one tool at once, make sure their total CFM doesn’t exceed your compressor’s air delivery rating.
2. Note Your CFM Requirements:
Air compressor tools require specific air delivery levels. The table below outlines the average CFM rating for some of the most common air-powered tools. Assuming all of the listed devices operate at 90 PSI, see the below CFM chart for standard air delivery ranges.
|Air Compressor CFM Chart|
|Brad Nailer||0.3 CFM|
|Cut-Off Tool||4-10 CFM|
|Dual Sander||11-13 CFM|
|Framing Nailer||2.5 CFM|
|Grease Gun||4 CFM|
|Paint Brush||4-11 CFM|
|Speed Saw||5 CFM|
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.
Gasoline-powered compressors are a popular alternative. Gas 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
While a compressor’s overall size isn’t too important, the dimensions of its tank affect air capacity and performance. A small compressed air tank requires frequent refills and can’t function for extended periods. As a result, a small, portable compressed air tank suits hobbyists.
Construction crews require a larger, higher-pressure air compressor. Tank sizes on bigger models range from 1 gallon to 80 gallons. In general, most teams should stay around 20 gallons since a big air compressor is more difficult to store.
5. Consider Compressor Design and Configuration
A pneumatic air compressor’s design and tank configuration affect how the compressor works and the kind of tasks it’s suited 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: A scroll compressor services power from two interleaving scrolls that push pockets of air to 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
Duty cycles refer to the ratio of time between air delivery and air refill. Because pressurizing and transporting air takes time, most compressors need to rest and recharge their reservoir after expelling air. Larger compressors tend to 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.
Benefits of Air Compressors
Compared to other energy sources like electricity, air tools offer unique benefits. Not only can compressors generate more power than other devices, but air equipment provides greater control. Some of the reasons teams choose air tools include:
- Energy efficiency: So long as compressors aren’t always left on or kept in disrepair, they waste almost none of the energy they generate.
- 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: Whether you run a construction company or like to make home repairs, you’ll 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.
Air Compressor Safety
Although air compressors are valuable tools, they come with their fair share of hazards. Unsafe usage can lead to injury and equipment damage on a job site. The main risks to look out for include:
Even mid-sized air compressors can cause severe hearing damage. Tools operating at 40 PSI or higher will rupture an eardrum if held less than half a foot away from an operator’s head. When using an air compressor, team members should wear sound-blocking gear and keep equipment away from their ears.
An overheated air compressor can explode when exposed to temperatures over 100 degrees. Only proper lubrication will keep a compressor stable in hot environments. Conversely, freezing temperatures will clog and crack essential components.
Tools that use pressurized air exert enough force to dislodge particles. When working on a hard surface, these materials can harm crew members. Teams should use face protection when operating air tools like drills and jackhammers.
Should You Buy or Rent a Compressor?
A small, 5 CFM air compressor costs around $150, while larger models cost upwards of $2,000. Although hobbyists with small tools can shop for air compressors, teams using larger equipment should rent. Because every job involves different tools with varying CFM ratings, renting affords the flexibility to pick the best model for each project.
With the right size air compressor, your team will enjoy the benefits of air tools. When you partner with BigRentz, you can rent air compressors of the perfect size for your next project.