Episode 49: Water: The Compressor Killer

Jason Reed

Alright, welcome back to The Big Dog Podcast. Today’s episode is a big one. We’re talking water—the absolute compressor killer. And I mean, it gets everywhere if you’re not paying attention.

Lisa Saunders

Yeah, you know, when folks think about compressor issues, they usually blame the component or maybe the oil, but I swear, water is that silent troublemaker nobody looks for until it’s too late. Let’s start with the big question—how does water actually get into the system in the first place?

Jason Reed

First off, you can’t really avoid ambient air. Unless you’ve got some laboratory-grade air purification and chilling right at the intake, your compressor’s pulling in humidity every time it cycles on. Humid day? Well, congratulations, that moisture comes in with the air, and once it’s compressed, all that vapor just turns into liquid water inside your compressor.

Lisa Saunders

I think a lot of people miss just how much water is in the air already. It’s not just a little mist in the morning—it’s always there, and compressors pull it in whether you’re running in Arizona or you’re drowning in Gulf Coast humidity.

Jason Reed

Speaking of Gulf Coast—here’s one for you. I worked with a facility down there that kept their rotary screw units basically just sitting out in the open. No roof, no shielding, nothing. Every time the weather shifted, you’d get water sneaking in. They had so much downtime chasing weird failures, but really it all traced back to moisture. Unprotected outdoor installs are a huge deal and honestly, so easy to avoid with a little planning.

Lisa Saunders

That’s brutal. And there are so many other easy-to-miss entry points. Like, people always forget about poor moisture separation between stages. If you’ve got a two-stage or a multi-stage centrifugal compressor and your drains aren’t working, you might just send all that water downstream. The coolers basically sweat out water at each stage—if you don’t get it out right then, it’s staying in the system.

Jason Reed

Yeah, and cracked heat exchangers are another sneaky one. One little crack, and suddenly you’ve got water mixing into not just the airflow but the oil circuit too—turning everything into a mess. These are the problems you don’t see until you get, well, catastrophic results down the line.

Lisa Saunders

So the main ways—ambient air brings in the humidity, outdoor installs leave you wide open, poor moisture separation sends water further into your compressor, and cracked coolers or heat exchangers are like an open door. Did I miss anything big?

Jason Reed

Nah, that pretty much covers the top culprits. I’ll just add—liquid-based cooling systems are meant to help, but they’re not magic. If those systems aren’t maintained or filtered, unwanted water can get picked up and circulated too, especially with open or semi-closed loop setups.

Lisa Saunders

Exactly. And all this just underscores how relentless water is—it doesn’t care if you planned perfectly. If you leave an opening, it’ll find its way in.

Lisa Saunders

Alright, so let’s say the water’s in. What happens next is where things get scary, right? I always think about that call—maintenance guy freaking out because the oil had literally turned into jelly. I’m talking sticky, grey mess clogging up the entire cooler bank. They almost lost the whole line for that shift. It’s wild just how fast water can wreck things.

Jason Reed

Yeah, it’s ugly. Water does not play around. First, you lose lubrication—water basically washes oil off the parts. That means way more wear and your efficiency tanks. Then you’ve got oil degradation. Once water mixes in, oil starts breaking down, losing its ability to, you know, protect your compressor.

Lisa Saunders

That ‘jelly’—the emulsification—man, that’s the one people never forget. Water and oil start blending and next thing you know, you’ve got this goop plugging up aftercoolers, coolant passages, scavenger lines. Your compressor loses capacity, everything backs up, and airflow gets gnarly. I mean, the stuff literally blocks oil and air passages. Wet air’s heavier, too, so pressure drop goes up, everything gets harder for the system.

Jason Reed

Don’t get me started on rust and corrosion. Internal carbon steel parts are kind of sitting ducks if water builds up, especially when the unit is shut down overnight and the oil’s not coating everything. You come back next shift and suddenly, nothing spins right, everything’s squeaking, chunks of rust floating around.

Lisa Saunders

Let’s not forget, once you’ve got rust, it throws off these flakes and those create clogs down the line. Now the coolers and passages are packed up—plus, if you’re running oil-free units, those protective coatings only last so long against constant moisture.

Jason Reed

And then bearings. Water in your oil means you’re risking bearing damage—or even a flat-out bearing failure. Centrifugals, especially, are spinning crazy fast and even a bit of water is enough to chip an impeller or toast a bearing way before its time. I might be ranting here, but I’ve seen more bearings go out from moisture than any other single cause.

Lisa Saunders

You’re not overselling it. I mean, yeah, glycol systems help. Using a glycol mix in closed-loop cooling can reduce corrosion and freezing, but there’s a tradeoff—glycol’s not as good at heat exchange as water. So you end up needing a bigger, more robust system to keep up with the same cooling jobs.

Jason Reed

It’s always about the tradeoffs, right? Nothing’s perfect, but like we said—water left unchecked can quickly take you from “running smooth” to “plant at a standstill” if you aren’t vigilant.

Lisa Saunders

And it’s not just the compressor. The water, rust, and oil junk can move downstream, cause product quality problems, and even damage your end equipment. So you’re fighting fires on a few fronts all from some water nobody noticed at the start.

Jason Reed

So, knowing all that, let’s talk defense. How do you actually catch and get rid of water before the wheels fall off?

Lisa Saunders

The single most important thing—oil sampling. Every 2,000 hours for standard, 1,000 for food-grade. Not every test checks for water directly, but rising acid levels or a bump in wear metals—especially iron—are screaming signs you’ve got moisture sneaking in.

Jason Reed

And you know, people love to skip this step or “do it later,” but that’s just an invitation for expensive surprises. Once those acid numbers go up or you see iron in the results, something’s breaking down inside. That’s your warning signal to dig deeper.

Lisa Saunders

Zero-loss drains are your best friend here. The second you let drains fail or they get clogged, all that water starts to pool. That’s why some units—like Kaishan’s KCOF centrifugals—have stainless steel coolers and epoxy coatings, plus zero-loss drains with alarms. Those alarms are priceless, honestly. Regular draining isn’t just nice to have, it’s 100% critical, rotary screw or centrifugal, both.

Jason Reed

I’d say, too, don’t try to tough it out alone. Your local compressed air pro or a factory-trained distributor—they deal with this stuff daily. They’re not just there to sell you something; these folks can spot the subtle signs, help you tune your drains, do thorough diagnostics, and keep you running. And they move quicker than the big guys, less red tape—if you’ve got water trouble, you want a real partner who knows your system, not a corporate helpline that puts you on hold.

Lisa Saunders

Absolutely. It’s like, you wouldn’t ignore an oil leak in your car, right? So don’t ignore oil sampling, drain alarms, or regular check-ins on your compressor. Do those things, lean on the people who know the systems, and water loses a lot of its bite.

Jason Reed

Could not have said it better. Water’s just waiting for you to slip up, so you’ve got to stay sharp. That’s the episode for today—let’s keep those compressors bone dry. Lisa, always good to have your take on this stuff.

Lisa Saunders

Right back at you, Jason. Thanks to everyone listening—keep those questions coming, and check in next time for even more ways to keep your air system running strong. Take care!

Jason Reed

See you next time, folks!