Air compressors are useful tools to have for both home use and in professional or industrial settings. There are two main types of compressors – oil-lubricated and oil-free. Before you invest in one of these pieces of equipment, it would be helpful to understand the difference so you can choose the right one for your application.
Oil-lubricated air compressors are normally more expensive than oil-free units and costlier to maintain over time. However, some applications require oil-free to prevent contamination. Oiled compressors are more heavy duty while oil-free compressors are suitable for smaller jobs or non-commercial use.
What’s the Difference Between Oil-Free and Oil-Lubricated Air Compressors?
Air compressors are differentiated by whether or not they use an oil-lubricated pump. The compressors without an oil-lubricated pump are oil-free.
Unlike the oil-lubricated design, oil-free compressors either operate without mechanical contact and friction inside the compression chamber or use other self-lubricating materials besides oil. Some compressors use water or non-stick coatings to reduce friction and keep everything running smoothly.
Lubricated compressors use oil to reduce friction and prevent overheating. Oil coats the piston or rotary mechanism to ensure that the parts run smoothly during operation.
One big difference between the two types of compressors is the price. Oil-lubricated air compressors are typically more expensive than their oil-free counterparts.
|Air Compressor Type||Average Price|
|Oil-Lubricated||$2,000 – $50,000|
|Oil-Free||$200 – $2,000|
Still, there may be some circumstances where one type of compressor must be used because of the application. For example, food and beverage, medical applications, and pharmaceuticals typically use oil-free air compression systems because of the contamination risk.
On the other hand, heavy-duty industrial settings normally have oil-lubricated air compressors because they can hold up to more intensive use.
Another way to understand the difference between compressor types is to look at the three primary types of lubrication systems.
- Oil-free: these compressors contain no oil and rely on other materials to lubricate the piston and cylinder. Sometimes materials like teflon are used for their non-stick properties.
- Splash: This is an oil-lubrication system where an oil dipper is attached to the bottom of a rod that dips down into an oil reservoir. This is the most common lubrication system in standard compressors.
- Pressure: Pressure lubrication systems use an oil pump to pull oil from the crankcase. The oil then filters into the crankshaft and cylinder walls. This is a more expensive setup, but is typically better quality and is used primarily in industrial applications.
Which Compressor is Better? Oil or Oil-Free?
Oil-lubricated compressors are better for heavy-duty projects and industrial applications, especially where oil contamination is not a concern. Oil-free air compressors are better in settings where oil contamination could pose a risk.
Still, there are advantages and disadvantages to using either type of air compressor. To make the best decision, it’s a good idea to consider the differences between the two and how each one would meet your needs.
Advantages of Oil-Free Compressors
There are many advantages to using an oil-free air compressor, and in some cases it may be the only option depending on what you’re using the equipment for.
Here are some of the most common advantages of an oil-free design:
- User-Friendly: Oil-free compressors are typically simpler to operate, making them ideal for home or non-commercial use.
- Smaller Design: Oil-free compressors come in a variety of sizes, including some that are compact and portable. That makes them ideal for on-the-go use or for a home workshop.
- Less Expensive: You can easily find an oil-free compressor for under $1,000. Oil-lubricated units typically cost several thousand dollars.
- Maintenance: These units don’t require manual lubrication and you don’t have to worry about adding oil to keep the machine running properly.
- Cleaner: Since the compressor doesn’t use oil, the air is cleaner and drier. There’s also no risk of oil contamination like you have with oil-lubricated units.
- Quiet and Efficient: These smaller oilless units typically run quieter and operate more efficiently than a large oil-lubricated compressor.
Disadvantages of Oil-Free Compressors
Though there are plenty of pros to using an oil-free compressor, there are also some disadvantages to consider. Before you choose which one is best for you, it’s a good idea to understand both sides.
Here are some of the most common disadvantages of using an oil-free compressor:
- Noise: One of the biggest differences between the two types of compressors is the noise level. Oil-lubricated compressors operate much more quietly than oil-free compressors. Depending on your application and use, the noise level might be an important factor to consider.
- May Not be Ideal for Commercial Use: Whether you’re using the compressor for professional or industrial applications, oil-lubricated compressors are normally better suited for heavy-duty or commercial use.
- Better Suited for Cold than Heat: Since the compressor doesn’t use oil or other lubricants to dissipate heat from friction and use, you may add more wear and tear than normal with an oil-free design.
- Less Powerful: Oil-free compressors are great for smaller projects or home use, but they normally aren’t the best choice when you need a lot of power.
- Less Durable: Oil-free compressors don’t require a lot of ongoing maintenance, but they’re also typically less durable than their oil-lubricated counterparts. They’re lighter and more portable, but that also means they’re not as sturdy and heavy-duty.
Oil-Free Air Compressor Life Expectancy
When it comes to how long oilless air compressors last, oil-lubricated types have traditionally had the longer life expectancies of the two. Still, the technology has only improved over the years. Today’s oil-free compressors can last 2,000 hours or more.
However, the life expectancy of a compressor will ultimately depend on the use and maintenance.
Since oil-free compressors typically run at higher temperatures and are less durable than their oil-lubricated counterparts, they normally don’t have the same long-lasting endurance.
Plus, as the oil-free compressors start wearing out, they tend to become louder and operate more roughly because of the added friction. So, even if the oil-free type lasts longer, it may not work as well as it did when you first bought it.
Oil-Free Air Compressor Maintenance
One of the advantages of oil-free air compressors is that they require less maintenance than oil-lubricated compressors. Still, that doesn’t mean that oil-free units are also maintenance-free. Proper care and maintenance are essential to extend your compressor’s life, especially if it’s oil-free.
Here are some common steps to help care for your compressor:
1. Release the pressure and drain the water: As the unit compresses air, the receiver tank will collect the air’s moisture. The more moisture you have in the air, the more water will end up in the tank, so it’s necessary to drain your air compressor. So, if you live somewhere humid, you’ll have to pay even closer attention to this issue. Never leave water sitting inside your compressor’s tank.
2. Keep air vents clean: As the compressor pulls in air, the vents may become clogged with dust and other debris. Keeping the vents clean will ensure your compressor isn’t becoming overworked and will help extend its life.
3. Change air filters regularly: Just like your vents, the air filter will eventually become loaded with dust and debris from the air. When the unit can’t pull air through the filter properly, it adds strain to the machine and may shorten the lifespan. Keeping the filter clean and changing it every 6 months (or according to the instructions) will keep the unit in tip-top shape.
4. Perform routine equipment checks: Check the other high-stress areas on your machine and follow any of the manufacturer’s recommended maintenance instructions. For example, you may want to check your hoses and fasteners and clean any of the accessible parts or components.
Air Compressor Noise Levels
Noise is another major difference between an oil-less air compressor and an oiled one. As you would expect, the lubricated, oil air compressors are a lot quieter than the oil-free variety. So, if you plan on putting an air compressor in a relatively quiet environment, it would probably stand out a lot more and seem a lot louder if it is an oil-free air compressor.
The truth of the matter is, that there are many pros and cons when it comes to oil vs oil-free air compressors. As far as which one is best to get, that really comes down to your specific needs, budget, and use case.
The Bottom Line
Choosing the right type of air compressor for your needs depends on factors such as what kinds of jobs you’ll be using the equipment for and how much power will be needed. Oil-free compressors work great in situations where contamination is a concern, but they typically aren’t the best option for very heavy-duty use.
For home or light-duty projects, an oil-free compressor is a good choice because of the cost and efficiency. The units are normally smaller and more portable than an oil-lubricated compressor.
Still, for maximum durability and ongoing industrial or commercial use, many people choose standard oil-lubricated air compressors. These units normally have a longer lifespan and will hold up better over time.
The oil lubrication keeps the unit working properly and helps maintain the appropriate temperature on the internal components. Oil-free compressors often run hotter because of the increased friction, which adds to the strain on the components.
In either case, the technology for air compressors has only improved over the years and closed the gap between the two types of equipment. So for most people it really comes down to a personal preference and the kind of setting the compressor will be used in.
Other important factors to consider include cost, space, ongoing maintenance and care over time, keeping up with changing and adding oil, and keeping the unit clean and operational.