Many people often wonder what exactly the differences are between an oil-free compressor and an oil, or oil-lubricated, compressor. The answer is really quite simple, but in order to better understand it, we’ll first need to explain how a compressor, whether oil-free or otherwise, works.
Air compressors draw in and compress air with, depending on the model, one or two pistons which are not all that different from those used in cars. As the piston moves downward, air is drawn in through a valve, and when the piston moves upward, that air is compressed before being moved to a storage tank. The primary difference between an oil-free compressor and an oil compressor is the way in which this piston is lubricated.
As its name suggests, an oil-free compressor does not use any oil to keep its piston lubricated and functioning properly. Instead, this type of compressor has cylinder sleeves and piston rings which are coated in Teflon. The Teflon keeps friction between these parts to a minimum, thus eliminating the need for oil. On the other side of the coin, an oil compressor has cast iron cylinder sleeves and piston rings that require the use of oil to remain lubricated and functional.
As you might imagine, each type of compressor presents a number of advantages and disadvantages, ranging from their maintance and durability to the levels of noise they produce. Price, which for some may be the most important thing to consider, can also vary between an oil-free compressor and an oil compressor.
In general, an oil-free compressor is much easier to maintain, mostly because there’s no oil to change. This, of course, means that you will never have to deal with cleaning up any messy oil spills. However, the fact that no constant maintenance is performed on an oil-free compressor eventually leads to the Teflon wearing out and needing to be replaced. Although this can be done both easily and economically, many folks choose to go with an oil compressor because they don’t want to deal with replacing the parts.
An oil compressor, on the other hand, will last much longer without your needing to replace any of its parts. This is especially true if the compressor is being used frequently, as it would be in a commercial setting. That being said, if you only plan on using your compressor to fill sports balls and tires, an oil-free model is probably the way to go, as infrequent use will not lead to the Teflon coatings wearing out quickly.
Another big difference between these two types of compressors is the level of noise they produce. Oil-free compressors are, for one reason or another, much more noisy than oil compressors. So if you plan on using your compressor in a quiet environment, you might want to go with a model that uses oil. For instance, if you’ve got a small baby that always wakes up in the middle of nap time, having an oil-free compressor running out in the garage probably isn’t a very good idea.
Finally, when it comes to cost, oil-free compressors are definitely the better option. Oil-free compressors have fewer parts than oil compressors. The fact that they have fewer parts means they cost less. Another reason that oil-free compressors are less expensive is because their designs are usually much simpler than those of oil compressors.