If you have a basic understanding of how air compressors work, then you no doubt know that there are two main kinds of air compressors; oil lubricated and oil-free versions.
While most everyone knows about these two main kinds of air compressors, what most don’t know about is what the pros and cons of each kind are. This article, as you can probably guess just based on the name, is intended to explain the difference between the two and to help you pick the right one.
Jump to: Comparison Chart
I’m going to go through the benefits and drawbacks to each kind of air compressor, as well as going over what situations each kind of compressor is best for. I don’t expect that you will be buying different kinds of compressors for different situations, but it might be helpful for determining what tool you need for your current situation.
What Are Oil Lubricated Compressors?
The first thing that I want to go over is what oil-lubricated air compressors are. Again, many of you probably already know this, but it doesn’t hurt to do a bit of review just to make sure everyone is crystal clear about how they work.
As the name indicates, oil lubed compressors use a special oil to help keep internal friction to a minimum. It may not look like it from the outside, but there are a surprising number of moving parts (and quite delicate ones at that) inside an air compressor. These moving parts can obviously generate heat due to friction and get worn out.
The most common kind of oil lubrication used in air compressors is what is called “splash lubrication.” Basically, how this works is a series of dippers inside the air compressor is constantly dipping into a reservoir of oil and splashing it upwards (hence the name). There are also oil-injected models. The oil coats the moving parts and prevents friction damage.
What is an Oil-Free Air Compressor?
The name alone is more than enough to tell you what oil-free compressors are. However, what it doesn’t tell you is how they work.
If the compressor isn’t using oil, then how are the internal parts of an oil-free air compressor lubricated? The answer is quite simple.
Oil-free compressors use very special components that are coated with pre-lubricating material that keeps them from wearing out due to friction. One of the most popular materials used for such coating is Teflon, which reduces the friction between moving parts without oil.
How long do oil free air compressors last?
For older models, the average equipment life used to be 200 to 400 hours. But with the advancement in technology, modern oilless compressors can last up to 2000 hours or more.
Comparison Oil vs. Oil-Free Compressor
Alright, so now that we are all on the same page regarding what the two types of air compressors are, it is time to go about comparing the two. Where does each kind of compressor shine and where does each kind fall short? Let’s find out.
|Layer of lubricating oil between parts reduces friction.||Pre-lubricated coating (Teflon) on moving parts.|
|Noise: Quiet operation.||Comparatively higher noise levels|
|Durability: Longer product life||Shorter life span|
|Maintenance: Higher||Lower maintenance cost|
|Size: Large and heavy units||Relatively smaller in size and more portable.|
|The use of lubricating oil can be messy and synthetic oils are not environment friendly.||Clean air and less pollution, although noise is an issue on older models.|
Top Rated Model
|Best suited for hot weather and heavy-duty applications.||Suitable for cold climates and DIY, Handyman, and contractor work.|
Oil Lubricated Compressor Pros and Cons
Here are the major advantages and disadvantages of lubricated units.
Advantages of Oil Lubricated
By far the two biggest pros of oil-lubricated air compressors are noise and durability.
Low Noise: As you might have expected, the presence of a constant source of lubricating oil helps to keep the grinding to a minimum, which in turn helps to keep the noise levels down significantly.
Performance: The same logic applies to the overall durability of the air compressor as well. The oil layer helps to prevent the internal components of the air compressor from grinding needlessly against each other. Not only is this a lot quieter, but it is also a lot better for the longevity of the parts.
Cons of Oil Lubricated
Oil-lubed machines aren’t perfect, of course. They do have some flaws; otherwise, there would be no need for oil-free models. So, what are some of the more common issues that people complain about with regard to oil lubed models?
Cost: The biggest issue is, without a doubt, their cost. Because oil lubrication is so effective at keeping air compressors running longer, it makes sense that they tend to cost more because you don’t have to replace them as often.
Size and Weight: The other issue is weight, oil lubed air compressors are definitely much heavier on average than their oil-less cousins.
Maintenance: You should fill the lubricating oil at regular intervals, and you may need to do periodic maintenance to ensure that the equipment is running smoothly.
Pros and Cons of Oil-Free Air Compressor
Pros of Oil-Free
Are oil free air compressors better? The pros of going oilless are basically the exact opposite of the cons of going with an oil-lubricated model (and vice versa).
Cost and Size: For example, oil-less air compressors tend to be both cheaper and a lot lighter.
Maintenance: They also compressors also require a lot less maintenance since you don’t have to spend time changing out oil filters or adding in more oil.
Clean & Dry Air: The compressed air from these units is less contaminated and free from lubricants.
Additionally, you have a clean workplace without the mess created by the lubricant, and these units are more environmentally friendly.
Cons of Oil-Free
Durability: While oil-free compressors are cheaper, they also tend to break a lot quicker due to the friction-resistant coating wearing off and the parts becoming vulnerable to friction-induced damage.
Noise: The rubbing together of parts inside the compressor creates some pretty loud and frankly annoying noises. However, modern oil-less models are relatively quiet. They achieve this by a combination of sound dampening and soundproofing techniques.
You can also utilize some DIY techniques to keep your compressor quiet.
When to Use Each Kind of Compressor
In general, we would say that those who are dedicated professionals should go for an oil-lubricated model as they last longer and generally provide better performance. Also, doing maintenance on them isn’t as big of a deal as it is for a professional as it is for, say, a DIYer.
Speaking of DIYers, are the ones who should go for the oilless model. Why? Well, they probably don’t have as many resources to invest in an industrial air compressor, so the cheaper price and lower maintenance needs of the oil-free air compressor work well for them.
Also, DIYers generally use their tools less than a professional would, and this definitely applies to air compressors. So, the fact that oilless air compressors generally break down a bit quicker than oil-lubricated models won’t matter quite as much.
Type of Powertools
Another important consideration is the type of pneumatic power tools that you want to connect. Are you looking for a compressor to powerup your nail gun or impact gun? Does it require clean, dry air? In these cases, an oil-less version works well.
On the other hand, a compressor for a painting shop or machine shop should run continuously for several hours. In such cases, a lubed version is a better choice.
- Oil Lubed: For industrial applications that require heavy-duty performance.
- Oil-Free: For home users, handyman, contractors, etc., where portability, lower cost, and maintenance is important.
Back to Contents
- What Are Oil Lubricated Compressors?
- What is an Oil-Free Air Compressor?
- Comparison Oil vs. Oil-Free Compressor
- Oil Lubricated Compressor Pros and Cons
- Pros and Cons of Oil-Free Air Compressor
- When to Use Each Kind of Compressor