If you are planning to buy an air compressor, you would need to carefully consider several vital features. Whether you are a homeowner who needs to inflate tires, or provide power for air tools like a brad nailer or an impact wrench, or you are a small workshop owner who needs compressed air for professional applications, you will get several valuable tips from this air compressor buying guide.
Here’s a brief description of the important features of air compressors:
Every compressor has a horsepower (HP) rating. The horsepower rating is used to measure the power that the motor (or engine) produces. Most consumer grade compressors have motors that produce between 1.5 and 6.5 HP. For most homeowners, a motor that produces 3 HP is sufficient for most tasks as long as the airflow and pressure are enough to meet your requirements.
The air flow from a compressor is measured in cubic feet per minute (CFM). Common air tools like brad nailers, spray guns, and reversible drills usually need about 2 to 6 CFM. But larger sanders and shears will need between 10 to 16 CFM.
A good rule-of-thumb when selecting a compressor is to list out all the tools you need to operate. Then pick the tool that needs the highest CFM and add extra 50 per cent. For instance, if your spray gun requires 4 CFM, you should choose an air compressor that delivers at least 6 CFM. This will provide a good safety margin.
Most air tools have unique volume (air flow) and pressure requirements. The pressure that is produced by air compressors is measured in pressure per square inch (PSI). To determine the PSI for your compressor, you should follow the procedure given above for determining CFM.
For those who only need a compressor to inflate their tires or sports balls, a compressor that delivers 6 CFM at 90 PSI will be adequate. But if you need to power several tools you in your workshop, choose a compressor that will meet the pressure requirement of the most powerful tool you need to use.
How do you determine the ideal tank size for your air compressor? For auto technicians and those who own workshops, you will need a big air tank that can hold about 30 gallons. If you are not an auto mechanic and you just need to inflate your tires, you can get a smaller tank with a 2 – 6 gallon capacity.
If you will need to use your compressor to work on your roof or in your yard, you should seriously consider buying a portable compressor. Pick a compressor that is mounted on wheels with a very sturdy frame. This will make it easy for you to move it from its storage location in your garage to the exact location where you need to use it.
Electric air compressors are the most commonly used in homes and workshops. They can be plugged at any convenient location and they function very well where gas fumes are not permitted. Electric compressors are convenient for workshop use. However, a few household electrical systems may not be able to handle the high wattage demands of some 110v compressors. If you want to use a 220v model, you may need to get an electrician to create a special power outlet for your compressor
Gas powered compressors are ideal for those who need to work in the open where there’s no suitable electric power supply. However, gas compressors are more expensive and they require ventilation because of the gas fumes.
Basically, there are two kinds of air compressors – oil-lubricated and oil-free. The oil-free compressor is also referred to as a maintenance-free compressor. The bearings in an oil-free compressor are sealed. Hence, they don’t require lubrication. These compressors provide adequate power for most homeowners, especially those who don’t want to be bothered with changing oil and other technical details.
Oil-lubricated compressors will, however, require you to change the oil at regular intervals. These compressors are quieter and more durable. If you use high grade pump oil, you may not need to change the oil very often. Those who need compressors for commercial purposes usually have to purchase oil-lubricated compressors.
Vertical vs. Horizontal
If you have space constraints in your workshop, you may opt for a vertical compressor that occupies less floor space than a horizontal one. In most cases, vertical compressors are kept stationary, while horizontal compressors are used for portable applications.
That was a concise air compressor buying guide. It highlighted some of the vital features you need to consider when buying an air compressor such as the horsepower rating, air flow, tank size, power source, portability and maintenance.