Garage Basics – Air Compressors, Features, Benefits, How They Work

Wed, Jun 22, 2016 | Posted by:

Garage Life, Tech, Uncategorized

Compressed air is one of those features that can take your garage to the next level. Having a basic, standard-issue air compressor opens the door to advanced tasks well beyond detailing, increasing the completion speed, the amount of torque you can unleash, and the overall scope of projects you can complete in your home garage.

Know The Flow

You can’t run an air chisel from a portable 1/2-horsepower compressor; it’s all about SCFM, or Standard Cubic Feet per Minute, a measurement of how much air the compressor can move when running at full speed. Tools are rated in SCFM so choose a compressor that can keep pace. Most tools are rated at either 40 psi or 90 psi. For instance, average air consumption for a typical High Volume Low Pressure (HVLP) paint gun ranges from 6 cfm at 40 psi to 12 cfm at 40 psi while a typical orbital sander will check in between 6 and 9 cfm at 90 psi. These are wide ranging ratings so it is critical that your air compressor can move enough air to support the tools you intend to use.

Type Casting

Built to run quiet, our twin-tank Portable 4.2 Gallon Air Compressor features a 2.0 horsepower motor that puts out a mere 79 dBA. It provides up to 125 psi operating pressure [4.8 cfm at 40 psi / 4.2 cfm at 90 psi].

There are two distinct types of compressors: single-stage and dual-stage. Simply put, the big difference between a single-stage compressor and a dual-stage compressor is how many times that the air is compressed. A single-stage system compresses the air once while a dual-stage compresses the air twice.

Air in a single-stage compressor is compressed by a single pump. Typically the air is pressurized to approximately 125 to 150 psi. A dual-stage compressor does not direct its initial compression into a storage tank. The charge air is sent, sometimes via a finned intercooler tube or some sort of intercooler housing, to a second high-pressure pump where it is compressed a second time. As a result dual-stage compressors can store from 175 to 200 psi. You can spot the difference by the compressor pump. A single-stage has one pump usually mounted vertically while a dual-stage has two pumps mounted in a V formation. Price can also be a good indicator as the dual-stagers usually cost more. Further, the dual-stage pump may have intercooling apparatus somewhere in the mix. Click here and check out our Portable 4.2 Gallon Air Compressor.

Tank Size

Because of their superior capacity, twin-tank designs do not have to run as often as conventional single-tank setups, giving you more time to work in silent tranquility.

Attaining a higher pressure affords greater storage in the tank. Take an 80 gallon holding tank for example. It will hold 83 cubic feet at 100 psi but that jumps to 120 cubic feet at 150 psi. Still, air compressor tank size is important because it determines how long air tools can run before the compressor engine cycles back on. Tank sizes are rated in gallons and are typically offered from one gallon up to 80 gallons. Generally speaking if your plan calls for using air tools that require a high volume of air for continuous use, you should consider a larger tank. If you only intend to use the tool intermittently your can select a smaller tank size. Having a large enough tank with a compressor pump that exceeds the SCFM requirement of the tools will allow the compressor time to cool between cycles. Tools that require only quick bursts of air, like pneumatic brad and finish nailers, drain the air tank much more slowly. For these tasks, tank sizes between two and six gallons are sufficient. The portability of the unit can also be a factor in the tank size debate.

Compressor System Set-up

Going with an upright compressor saves space. Using a retractable hose reel is also a great way to free up space while making it easy to pull out and coil up the hose while also lengthening the reach of your system. Running quick-release couplers so you can swap tools fast is another great way to speed along projects. You will also want to consider a filtering/drying set-up, an add-on that removes moisture, a byproduct of compression, from the lines. This safeguards your tools’ internal workings and is especially critical if you’re going to run a paint gun.

The Payoff

Armed with the right accessories the home garage can be outfitted for serious projects. From blasting away debris with a simple blow-off nozzle to running our BOSS G10 AIR or 3-inch Pneumatic Random Orbitals, our blow gun, or a Tornador detailing gun, to operating cut-off wheels and saws for hacking off dead body panels, air power can open up a new slew of DIY projects. Better yet, air power can turbocharge your easy projects and allow you get more done during your invaluable garage therapy sessions.

Remember to consider your current and future SCFM needs before committing to air power… when in doubt overshoot. Getting a unit with too much capacity affords you the chance to run more powerful tools in the future. After determining flow rate also note the tank capacity of the unit you are considering.

Compressed air is the kind of garage update that after using it for a week or so makes you wonder how you ever got by without it.

The chart below illustrates the typical SCFM requirements of common air tools. It is a guide and the rating of your individual tools may vary. Note: most paint guns are High Volume Low Pressure (HVLP) and operate at SCFM of 40 psi.

Air Tool Description SCFM @ 90 PSI
Angle Disc Grinder – 7″ 5-8
Brad Nailer 0.3
Chisel/Hammer 3-11
Cut-Off Tool 4-10
Drill, Reversible or Straight-Line 3-6
Dual Sander 11-13
Framing Nailer 2.2
Grease Gun 4
Hydraulic Riveter 4
Impact Wrench – 3/8″ 2.5-3.5
Impact Wrench – 1/2″ 4-5
Impact Wrench – 1″ 10
Mini Die Grinder 4-6
Needle Scalar 8-16
Nibbler 4
Orbital Sander 6-9
Ratchet – 1/4″ 2.5-3.5
Ratchet – 3/8″ 4.5-5
Rotational Sander 8-12.5
Shears 8-16
Speed Saw 5


Have fun in your garage!


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