Compressors Buying Guide
So what, exactly, is an air compressor?
Basically, it is a pump that powers pneumatic (air-powered) tools. Air-powered tools are used for a number of automotive and construction tasks such as tightening the lug nuts on your vehicle’s wheels or driving nails in home renovation. At one time, pneumatic tools were used mostly in industry. Today, they are gaining popularity with do-it-yourselfers coast-to-coast.
Popular air tools sold by Canadian Tire include an impact wrench, air ratchet, air chisel, roofing nailer, framing nailer, finish nailer and brad nailer.
Why would I use air tools?
Air-powered and pneumatic tools have lots to offer. First, their high power to weight ratio reduces operator fatigue so you can work longer. Second, because air-powered tools run cooler, they do not generate heat and are, therefore, more comfortable to hold. Air-powered tools also offer variable speed and torque control. Finally, you can operate more air-powered tools for less money compared to electric-powered tools.
How an air compressor works
An air compressor is made up of three major parts: motor, pump and tank. The motor drives the pump, which draws in air and compresses it to higher than atmospheric pressure. This compressed air is stored in the tank for later use. As you use up this air, the pump automatically comes on to refill the tank.
Which air compressor is right for me?
SCFM (pumping power) is the most important feature to consider. Not HP. Not PSI. SCFM (standardized cubic feet/minute) is a measure of airflow. The higher the SCFM, the greater the airflow, and the more powerful the pump.
How much power is enough? We recommend 1-1/2 times the SCFM rating of your most powerful air tool. For example, if your impact wrench requires 5.0 SCFM, choose a compressor that generates 7.5 SCFM. If you use several tools simultaneously, add all of their SCFM ratings together and multiply by 1.5.
What will I use the compressor for?
Need a compressor around the home to inflate tires, sports equipment or a pool? Perhaps you’d like to install some moulding or reupholster your furniture. You may be interested in airbrush painting. In any case, a lightweight, portable unit with a 2-gallon tank size would be ideal for all your home and car care projects.
If you tackle bigger jobs like fencing or decking, you’ll need a larger compressor (minimum 8-gallon tank) that produces more SCFM. These larger compressors typically have heavier motors and pumps. The good news is that they also run quieter.
How often will you use it?
- 4 times a year: Select a model that is oil-free, with a universal motor.
- Up to 4 times a month: Choose a model that is oil-lubricated and has a cast iron induction motor and direct drive.
- More than 4 times a month: Be sure to get one featuring a solid cast iron pump, induction motor and belt drive.
A quick study in compressor terminology
- Duty cycle: A rating that describes the amount of time the motor and the pump can both run without burning out. Eg. 50%. The compressor shouldn’t run more than ½ hour for every hour it is used.
- Motor (Induction): A type of compressor motor offering low RPM and long life.
- Motor (Universal): A type of compressor motor offering high RPM and low cost.
- PSI: Pounds per square inch. This is the measure of air flow generated by the compressor.
- PSI (max): The maximum amount of air in PSI stored in the tank.
- Pump (Aluminum): Aluminum pumps usually have a cast-iron sleeve to help extend the life.
- Pump (Cast iron): Typically solid cast-iron pumps last longer and are quieter than their aluminum counterparts.
- Pump (belt-drive): A belt drive lowers the RPM of the pump and reduces noise level of the compressor - great for working around your home.
- Pump (Oil free): A type of compressor that is maintenance-free.
- Pump (Oil lubricated): A type of compressor that lasts longer than an oil-free model but is usually higher priced.
- RPM: Revolutions per minute. A high RPM unit compresses air faster, but wears out more quickly. A low RPM unit runs quieter and will usually have a longer life.
- SCFM: Standardized cubic feet per minute. This is volume of compressed air delivered by the compressor.
- SCFM @40 PSI: The measure of air the compressor is producing while its outlet gauge is set at 40 psi. Spray guns are used at this pressure.
- SCFM @ 90 PSI: The measure of air the compressor is producing while its outlet gauge is set at 90 psi. Air tools and nailers are used at this pressure.
- Stage (single): A pump that compresses air once before sending it to the tank. The most common type of pump.
- Stage (double): A pump that compresses air twice before sending it to the tank. This produces a higher SCFM output and higher maximum working pressure (PSI), which is required if the compressor is being used by more than one worker at a time.
- Style (hot dog): A lightweight, easily portable air compressor for do-it-yourselfers wishing to power a brad nailer or finish nailer. Also handy for inflating tires and sports equipment.
- Style (pancake): A versatile air compressor (more powerful than a hot dog) designed to deliver high SCFM for short spurts. Suitable for 2-person roofing or flooring crews.
- Style (twin tank): A heavy-duty air compressor capable of running several finishing, framing or roofing guns at one time.
- Tank size: Measured in gallons. The larger the tank, the longer a job can be done at the air tool’s required pressure before pausing to rebuild pressure in the tank.
Air compressor tips:
- Extending your reach. It is better to avoid extension cords. Plug the compressor directly into an electrical outlet and use a longer air hose for trouble-free performance. If you must use an extension cord, check the compressor’s manual for the proper gauge, which will be based on the length of the extension cord you plan to use.
- Avoiding compressor burnout. Once you’ve used all the air in the storage tank, the pump will come on. This is a good time for a break. Otherwise, your gun may not drive nails in all the way if it is not getting enough air. And if you keep working, you may burn out the compressor’s motor. Wait for the tank to refill.
- Oil-lube compressors require a level surface. If you use one on an angled surface (10-degree pitch or more) the piston may not reach the oil when it dips into the reservoir. This could result in the pump seizing and the motor burning out.
Fittings and accessories
From air filters to hose repair kits to couplers, Canadian Tire carries the fittings and accessories you need to get the most from your air compressor.
Using a quick coupler, for instance, is a faster way to connect your air tool. And attaching an in-line air tool oiler enables you to lubricate your tool as you use it.