Used Air Dryers for Air Compressors

Air dryers for compressed air systems

An air dryer removes moisture from compressed air before it reaches your tools, valves, pneumatic actuators, or downstream process equipment. Without one, water vapor condenses inside lines as the air cools, leading to rust in piping, frozen control valves in cold weather, contaminated paint finishes, and premature failure of pneumatic components. Browse our inventory of air dryers for sale to pair with rotary screw and reciprocating compressors across construction, manufacturing, oil and gas, and fabrication operations.

You'll find compressed air dryers listed both as standalone units and as part of complete air compressor and treatment equipment packages — often bundled with filters, separators, and receiver tanks from previous fleet rollouts.

Refrigerated vs. desiccant air dryers

The two dominant technologies serve different pressure dew point requirements, and knowing which one fits your application is the single biggest factor in buying the right unit.

Refrigerated air dryers

A refrigerated air dryer chills the compressed air through a heat exchanger, condensing moisture out before it enters your distribution lines. Typical pressure dew point sits around 35–50°F, which is sufficient for most general industrial uses — sandblasting, pneumatic tools, paint booths, assembly lines. Brands like Ingersoll Rand, Atlas Copco, Sullair, Kaeser, and Hankison dominate this space. Cycling models save energy at partial loads; non-cycling models run continuously and tend to be simpler mechanically.

Desiccant air dryers

Desiccant (or regenerative) dryers use beds of activated alumina or molecular sieve to adsorb water vapor, achieving pressure dew points as low as -40°F or -100°F. These are the units you want for instrument air, outdoor pipelines in freezing climates, pharmaceutical air, or any application where liquid water in the line is unacceptable. Twin-tower designs alternate between drying and regeneration — heatless models purge with dry air, while heated and blower-purge models cut purge losses but add complexity.

Top brands you'll see in our listings

• Ingersoll Rand: The D-series refrigerated dryers (D42IN, D108IN, D255IN) and the HOC heatless desiccant line are common in mid-size shops and rental yards.
• Atlas Copco: FX and FD refrigerated models and the CD/BD desiccant series are built for industrial duty and frequently appear alongside GA-series rotary screw compressors.
• Sullair: SRD refrigerated dryers and SAR desiccant units pair naturally with Sullair compressor packages already in many fleets.
• Kaeser: Secotec TF/TG refrigerated dryers are known for thermal-mass design and stable dew points at fluctuating loads.
• Hankison, Pneumatech, Domnick Hunter (Parker), Gardner Denver: Strong second-tier options, often priced more aggressively at auction.

Matching the dryer to your compressor

Three numbers matter when you're sizing: rated CFM at your operating pressure, maximum inlet temperature, and ambient temperature. A dryer rated 200 CFM at 100 PSIG and 100°F inlet will lose significant capacity if your compressor discharges air at 110°F or if it sits in a 105°F equipment room. Always check the manufacturer's correction factors against your real-world conditions, not the nameplate alone. Undersized dryers run hot, fail to hit dew point, and shorten compressor life by sending wet air back through the system.

What to look for when buying a used air dryer

• Refrigeration circuit condition: On refrigerated units, check for oil staining around the compressor, condenser fins, and brazed joints — signs of refrigerant leaks. A dryer that won't hold charge is an expensive repair.
• Desiccant bed and valves: On desiccant dryers, ask about the age of the desiccant. Activated alumina typically needs replacement every 3–5 years. Listen for proper tower switching and inspect the purge mufflers — clogged mufflers are a common failure point.
• Heat exchanger fouling: Air-to-air and air-to-refrigerant exchangers collect oil carryover and scale over time. A dryer downstream of a poorly maintained compressor often shows reduced capacity from internal fouling.
• Drain functionality: Automatic condensate drains (timed, level-sensing, or zero-loss) clog with sludge and stick open or closed. Confirm the drain operates and isn't bypassed.
• Dew point sensor and controls: On premium units, verify the dew point sensor reads accurately and the controller display is functional. Replacement sensors aren't cheap.
• Operating hours and pressure rating: Match the max working pressure to your system. A 150 PSIG dryer won't survive long on a 175 PSIG line.

Buy used air dryers at Ritchie Bros.

Our inventory of air dryers for sale moves through unreserved auctions and Marketplace-E listings every week, with units coming from manufacturing plant liquidations, oilfield disposals, and fleet refresh cycles. You'll find refrigerated and desiccant models from Ingersoll Rand, Atlas Copco, Sullair, Kaeser, and Hankison in capacities from under 50 CFM to over 3,000 CFM. Each listing includes condition photos, nameplate data, and inspection notes so you can match the right dryer to your compressed air system before you bid.