PEX Tubing for Air Compressor Lines in a Garage – Is It a Good Idea?

If you’ve been outfitting your garage with an air system and you’re not keen on spending a fortune on black iron pipe or wrestling with rigid copper, you’ve probably looked at PEX tubing and thought, “Can I use that for my air compressor lines?” The short answer? Maybe, but there are some important caveats. Digging in…

What Is PEX?

PEX (cross-linked polyethylene) is a flexible plastic tubing commonly used for residential water systems. It’s affordable, easy to install, and resistant to corrosion. PEX comes in three types—A, B, and C—with PEX-A being the most flexible and durable.

PEX is also available in different colors (red, blue, white), typically used to indicate hot and cold water lines, but all types function the same. It’s installed using barbed or expansion fittings and secured with crimp rings, cinch clamps, or compression fittings.

Can You Use PEX for Compressed Air?

This is where things get tricky. PEX is not technically rated for compressed air by most manufacturers. Here’s why:

• Pressure rating vs. burst risk – While PEX can handle high PSI (160 PSI at 73°F is common), it’s designed for water, not air. The danger isn’t necessarily the operating pressure, but the potential for sudden rupture due to UV degradation, impact damage, or heat exposure.
• Shrapnel hazard – If PEX fails under pressure, it can shatter, sending plastic fragments flying. This is very different from rubber hose or even metal pipe, which tends to split or dent rather than explode.
• Insurance and liability – Using materials outside their rated use may void insurance coverage if something goes wrong.

That said, many DIYers and home garage builders still use PEX for air lines—with precautions.

PEX-AL-PEX: A Better Alternative

If you’re set on using PEX-style tubing, PEX-AL-PEX is a much safer option. It’s a multi-layer pipe with an aluminum core sandwiched between two layers of PEX. This construction allows it to hold its shape, resist UV damage, and handle higher pressures with more stability.

Most importantly, some PEX-AL-PEX brands are rated for compressed air, especially in radiant heating or snow melt systems that use pressurized lines.

Check the specs: you want something with a PSI rating over 150 at room temperature and ideally certified for compressed air use. Do not confuse this with standard PEX.

Installation Tips

If you’re moving forward with a PEX-based air system, here’s what to keep in mind:

1. Use PEX-AL-PEX whenever possible.
2. Avoid direct sunlight – UV is PEX’s enemy and will cause it to become brittle over time.
3. Secure it properly – Use appropriate clamps or brackets every 2-3 feet. Don’t leave lines hanging.
4. Add protection at outlets – Use metal or reinforced hose near the tool connections to reduce flexing at the weakest point.
5. Install a regulator – Keep PSI under 125 for most garage setups. Your compressor probably has an upper limit around 135-150 PSI.
6. Consider a manifold system – Use a brass or aluminum manifold for your tool drops and keep the PEX runs as short as possible.

What did I do? PEX, here’s why.

My garage has a little side shed and I decided to place the air compressor in the shed to keep it out of the garage, mostly for the noise of the compressor. I didn’t intend to run lines all over the garage since I tend to use more cordless tools and a nice hose reel will allow me to reach anywhere.

The location of the compressor is just on the other side of the wall from where I was going to put the outlet and hose reel. The PEX allows for easy and inexpensive installation. I never run my compressor at more than 120psi so the PEX should handle the pressure and all of the line is out of any kind of sunlight. A single 10 foot section of PEX was plenty for my installation so the length of pipe is minimal.

A small moisture separator was installed along with mountable end fittings. The end fittings secure the line and prevent the line from moving around when connecting/disconnecting things. PEX Shark Bite type fittings still amaze me that they work but I’ve never had one fail. They are typically rated for 600psi.

I used 1/2″ PEX line with shark bite fittings. A 90 degree fitting that can be mounted is a great addition, this allows for a sturdy attachment point that doesn’t move avoiding stress on the PEX or the other fittings. I installed a tee to attach the Merlin hose reel and an open fitting for a second line.

The Merlin hose reel is 50 foot long so it easily reaches everywhere within the garage. The auto retract is a nice added feature. So far it has worked flawlessly for me. It’s available from Harbor Freight.

Final Verdict

In the end PEX isn’t perfect for air compressor systems, but PEX-AL-PEX can be a solid budget-friendly alternative if installed carefully and used within rated limits. For garages where DIY and budget reign supreme, PEX is a viable option, as long as you’re aware of the risks and make safety a priority. I may in the future replace the lines I’ve installed with PEX-AL-PEX. If you haven’t started an installation consider the PEX-AL-PEX if your budget allows.