I've honestly never thought of buying a scuba air compressor?
I don't mind dropping by the dive shop to get an air fill and talk to other divers. Not to mention the chance to do some browsing for new toys while waiting.
Although the idea of being able to get fills 24/7 no matter where I am does sound good.
As good as that sounds, scuba compressors aren't cheap and there is a lot to think about before buying one.
What do you need to know when shopping for a dive compressor?
A high pressure compressor is the only type of compressor you need to think about when it comes to scuba diving.
Scuba tanks are usually filled to 3000psi/207bar or higher so you need a compressor capable of filling a tank to these pressures.
A low pressure breathing air compressor is used in surface supplied diving to supply a diver with air through an umbilical.
Commercial - A Commercial scuba compressor usually fills a bank of cylinders from which scuba tanks are filled. This is called a cascade system.
These are very large and very expensive compressors that are usually out of the price range for the everyday person.
These systems take up a lot of room and are usually only used by Scuba Shops and other professional diving operations that can afford to buy them.
I can't imagine seeing the average Joe having one of these in their garage just to fill a couple of tanks for a weekend dive.
Personal - A personal breathing air compressor will be smaller, probably even portable.
It might even have wheels to make it easier to move around.
Besides price and size, one big difference between the two is flow rate.
Even though most large high pressure compressors are set up with a cascade system they are usually capable of filling a tank directly in under 10 minutes.
A smaller portable compressor can sometimes take up to 20 minutes.
If you're setting up your scuba air compressor up at home in your garage you could make your own cascade system and use the compressor to fill your cascade cylinders then fill your scuba tanks from that.
You can buy a high pressure compressor that runs on gas, diesel or even electric power.
There are quality models that use each so I wouldn't say any one is better than the other.
Oil lubricated or Oil Free
Filters are what make a compressor a breathing air compressor.
The first thing that needs to be removed is water. When you try and compress air you separate it from the water vapor that's in the air.
Air can be compressed, water can't.
It would suck to have your tank rust from the inside out, so you need to have a water trap to remove it before it gets in.
Other filters remove carbon monoxide, carbon dioxide, Oil particles and other contaminates.
One final note. If you are buying a large commercial breathing air system you will need to check your local standards for breathing air and follow and testing and record keeping required.
If you are buying a scuba air compressor for personal use I would strongly urge you to stay on top of maintenance and test to make sure the air you are filling your tanks, and lungs, with are within accepted breathing air standards.