How to Choose the Right Air Compressor

Air compressors come in a variety of shapes and sizes and they’re reliable tools that can make tough jobs easy. Understanding the different types and features of compressors is key to making an informed decision. Maybe you’re a new hobbyist adding one to your garage or in the market to upgrade from an older model or larger size. This guide will help address common questions to determine the best air compressor for your specific needs.

Air Compressor Basics

What is an air compressor and how do they work? Air compressors work by sucking in surrounding air (low pressure) and converting it into high pressurized air. Once the maximum air pressure, measured in pounds per square inch (PSI) is reached, the air compressor’s duty cycle is complete. The overall air volume a compressor can generate is measured in cubic feet per minute (CFM), also known as the flow rate. This is often the most important factor in choosing the right one to power all your tools. While horsepower (HP) is important, the CFM rating and max PSI will be most important to use in making your decision.

Key Factors & Considerations in Choosing the Right Air Compressor

To choose the best air compressor, it’s important to match it to the job(s) required. Determine what you’ll be using the air compressor for, where it will be used, how much pressure will be needed and the tools you want it to power.

Pneumatic or air tools are rated by the air flow rate they require (CFM) and the operating air pressure they can deliver (PSI). Start by determining which of the tools you’ll be using that requires the highest CFM at the highest PSI and multiply by 1.5 to calculate the minimum CFM rating for your needs. Then look for a compressor that meets those requirements.

Compressor tank size is measured in gallons. If your tool usage will be intermittently, a smaller sized tank should fit your needs. Smaller tanks from two to six gallons are useful for projects using quick bursts of air like nail guns, airbrushing or brad nailers. These usages drain the tank at a slower pace. If you need continuous use with tools requiring a high volume of air like an air ratchet, impact wrenches, air sander or tire inflator, you should consider a larger tank size with a higher CFM. This will allow the compressor to cool between cycles. These are suitable for tasks like remodeling projects and automotive work.

Types of Air Compressors: Portable & Stationary

Air compressors come in different shapes and air tank sizes and two popular specific types of air compressors are reciprocating and rotary screw compressors. However, all fall into two main categories that we’ll examine here: portable and stationary. Determining whether a portable or stationary air compressor is best for you will depend on how and where you need to use the air compressor.

Portable Air Compressors

Portable air compressors are typically equipped with wheels and handles to provide convenient transportation for moving locations or job sites. Some are light enough to carry while others are large but on wheels for mobility. Another decision with a portable compressor is choosing a “hot dog” style tank or a “pancake” air compressor. Pancake air compressors don’t include wheels, but the storage tank is mounted on the bottom, giving it stability and requiring less space than other sizes. This makes it a good option if you’re using a nailer on a roof or somewhere you don’t want it to roll away. Portable air compressors can be used at home for DIY projects like building a deck, re-siding your house or for use at jobsites.

Stationary Air Compressors

Stationary air compressors are often larger units that are better suited for long periods of continuous use and designed to be fixed to an area or stay put in a workshop or garage. If you know most of your projects could take place in the same spot, a stationary air compressor could be the best option. You’ll want to make sure you have the proper space in the location you plan to use it.

Types of Air Compressor Pumps

Air compressors are available in two pump types: single stage and two-stage. How you plan to use your unit will help determine how to choose between single and two-stage options.

• Single stage air compressors are typically used in smaller-scale applications and come in gas or electricity power sources. They are popular with hobbyists, woodworking, shop and garage use, air-driven nailers, sawing and drilling.
• Two-stage compressors have two cylinders and compress air twice for higher pressure and power than a single stage compressor. They are often powered by electricity and useful in larger applications requiring continuous tool operation or powering multiple tools at once. Two-stage designs will provide significant longer life. Most commercial applications will require a two-stage compressor.

As you shop pump types, you’ll notice that some are oil lubricated, and some are oil free.

• Oil lubricated air compressors use oil to lubricate the moving parts to reduce friction and wear and are typically quieter than their oil-free counterparts.
• Oil free compressors produce a cleaner air output without oil contamination and are environmentally friendly. These units tend to be lighter in weight, while producing as much air flow and pressure as oil lubed pumps.

Air Compressor Power Sources

Air compressors are available in either gas or electric powered models. Attributes of both types will help you determine if a gas powered, or electric powered air compressor is better suited for your needs.

Gas powered air compressors:

• Good for jobsites or areas where electricity is not available
• Heavier than electric
• Works best in well-ventilated spaces
•  Can be used outside or inside
• Typically has more horsepower and can generate greater CFM

Electric powered air compressors:

• Lighter than gas models, portability
• Provide quieter units
• Best for indoor operation
• Doesn’t emit fumes, so ideal with limited ventilation
• Many function on 120-volt household current although larger models may vary

Best Air Compressor Parts & Accessories

What air compressor parts and accessories you need for your air compressor will determine what you’re using it for, but these are considered basic parts and accessories for a well running air compressor.

• Start Up Kits – Lubricant, pads, & anchor bolts to equip the compressor for start up
• Air Hose – some units come with a hose, but a longer hose is often more beneficial based on your project. Make sure to select the proper hose size based on the CFM of the compressor. Lower CFM compressors require smaller diameter hoses and compressors with a higher CFM need a larger diameter.
• Hose Reel – using an air hose reel helps increase the life of the hose, saving it from wear and tear and allows convenient storage when not in use.
• Fittings & Couplers - these connect your air compressor hose to your tools. They create a seal between the air compressor parts so there is no loss in pressure, and they stay in place.
• Gauge – these allow for precise adjustments of pressure settings so you can match the requirements of each tool and application. They can also help you detect leaks or malfunctions within the system.
• Filter– these remove impurities from the air like dust, oil and other foreign particles that can cause premature wear to the control valves and compressor.

In short, when it comes to buying an air compressor, determine what you’ll be using it for, where you’ll be using it and the flow rate required to power the tools for your needs. Then, based on where and how you’ll use it, determine if a portable or stationary compressor work best and if a gas powered or electric powered air compressor is best for you. Once you determine your air compressor needs, let Tractor Supply help you get started with the right air compressor and air tools for your needs.