What size air compressor do i need for my garage?
This common question is like asking what size engine you need in your car; it depends on what you use it for. By “size,” many buyers focus on the size of the tank, which is measured in gallons. So, we’ll start there, although that only gives you part of the picture. Since a compressor tank is used to store compressed air, the bigger it is, the longer you can work without the compressor having to pause and refill the tank. This is why a compressor with a one or two gallon tank will have to stop and fill much more than a compressor with a ten or more gallon tank. For jobs that do not require continuous pressure for long periods of time, a smaller tank is suitable. But a spray painter, for example, is best used with a larger tank so that the paint spray isn’t interrupted too often. For spray painting a car, which requires long periods of continuous application, experts recommend a large tank of 60 gallons or more.
What other specifications should I look for when purchasing?
In addition to tank size, other critical considerations are the PSI (pounds per square inch) and CFM (cubic feet per minute) ratings of a compressor. Think of PSI as the force of the air (good for, say, pressure washing or inflating a tire) and CFM as the volume of air that the compressor can continuously deliver (essential, say, for spray paint or use an orbital or disc sander). Both specifications affect the tools the compressor can power. Before purchasing, consult the manuals or datasheets of any tools you plan to use to see their PSI and CFM requirements and note which ones are higher. Then make sure you get a compressor that delivers a bit more than that, which will give you a reasonable margin of error.
How Much Power Does It Take to Operate Air Tools?
Most air tools require around 70 to 100 psi, which all of our recommended models can provide. To inflate the tires, you will need a compressor that can match the highest recommended psi for your tires. CFM requirements for tools vary more. According to Garage tools advisor, tools that do not need constant air, such as a nailer or stapler, require a flow rate of only 2 CFM or less. A drill, half-inch impact driver, ratchet, or air hammer may require about 3 to 4 CFM. An orbital sander may require 6 to 9. And a disc sander requires up to 20. Paint guns can range from around 4 to 14 CFM, depending on usage.
Is it worth buying a compressor with a lower noise level?
Yes. After tank size, CFM and PSI, we believe the sound volume of a compressor is the second most important consideration. Most of the compressors we reviewed ranged in volume from 60 to 80 dB. It doesn’t sound like much on paper, but remember that for every 10dB, the sound volume doubles. Thus, a compressor that emits 70 dB sounds twice as quiet as one that emits 80. And a compressor at 60 dB is four times lower than this model at 80 dB. In other words, 60 dB is roughly the level of a normal conversation, 70 dB is roughly the same volume as a vacuum cleaner or hair dryer, and 80 is roughly the level of a noisy restaurant or lawn mower. Volumes above approximately 85 dB are considered harmful to hearing. Thus, a lower noise level is not only more pleasant for your ears, it can also provide a more pleasant overall experience by allowing you, for example, to listen to music or easily chat with someone during that the compressor is running.
Should I buy an oil-free compressor?
Many portable compressors are now “oil-free” (or “oil-free”), which means they use interior parts with friction-reducing coatings instead of conventional oil lubrication. One of the main benefits is reduced maintenance because you don’t need to change the oil. Of the compressors we researched for garage use, all of the smaller models were oil-free, while this varied among the larger, more durable models. Thus, we would consider the low maintenance of an oil-free design to be a good tie-breaker if all other specifications are similar.
What else should I know about air compressors?
- If the compressor does not reach where you are working, add more hose, not more extension. Why: The voltage drops and the compressor does not deliver its full power.
- At the end of the day, drain the tank: turn off the compressor, bleed the air pressure in the tank, then open the drain valve at the bottom to release the water in the tank. Why: Water in the tank causes rust, and rust years later can cause the tank to rupture.
- Do not playfully spray the air from the hose on a person. Why: People get hurt. High pressure delivered up close, especially if it picks up metal particles, could damage the eyes. Children should never see this; don’t let them get into bad and dangerous habits.