The Castair RD247-55K is a large-capacity refrigerated compressed air dryer rated at 247 CFM. This is a commercial and industrial unit for high-demand operations — large auto body operations running multiple spray booths simultaneously, manufacturing facilities with high compressed air demand, fleet maintenance shops with multiple service bays running at full capacity, or any shop where a single 25–50 HP compressor (or multiple smaller units) is feeding a large distribution system. The RD247-55K sits above Castair's standard product table; call for current pricing and availability.
Castair refrigerated dryers maintain a 37°F pressure dew point — cold enough to condense and eliminate the moisture that causes air tool failures, spray finish defects, pneumatic cylinder corrosion, and piping rust. At the 247 CFM capacity of this unit, it handles the output of compressors that would overwhelm any of the smaller single-phase dryers in the Castair lineup.
How Castair Refrigerated Dryers Work
- Refrigeration cycle: Freon refrigerant (environmentally compliant R134a or R407c) chills the compressed air inside the stainless steel heat exchanger, dropping air temperature to 37°F and condensing water vapor into liquid droplets.
- Dual-function single-body heat exchanger: Outgoing cold dry air pre-cools incoming hot wet air, reducing refrigerant load and improving energy efficiency across the full operating cycle.
- Automatic demand drain: Ejects condensate only when liquid is present — does not bleed compressed air on a fixed timer schedule.
- No computer logic required: Simple mechanical design with a reliable dew point indicator — no PLC, no programming, no proprietary control board to source when it fails.
- Quick-connect refrigerant port: Field recharge without full disassembly.
Key Features
- Rated capacity: 247 CFM — for large compressor systems above the standard Castair product table
- Pressure dew point: 37°F — reduces downstream condensation to near zero under rated conditions
- Maximum inlet pressure: 232 PSIG
- Heat exchanger: Stainless steel for long service life in high-moisture industrial environments
- Drain: Automatic, demand-based — conserves compressed air
- Refrigerant: R134a or R407c (environmentally compliant, not R22)
- Certifications: UL listed
Note: Full dimensional specifications, electrical requirements (voltage, phase, amperage), and connection sizes for the RD247-55K are available by contacting us directly. This unit is above the standard Castair published product table. Call 866-217-0063 for current specs, pricing, and lead time.
What's in the Box
- Castair RD247-55K refrigerated air dryer unit
- Power cord and connection hardware per unit specifications
- Refrigerant pre-charged at the factory
A properly sized pre-filter is required for warranty coverage. Contact us for the correct filter specification for your installation.
Available Configurations / Upgrade Path
The RD247-55K is the largest unit in Castair's refrigerated dryer series available through this listing. The complete lineup for reference:
- RD25-6K — 25 CFM @ 37°F: 3/4" NPT, 115V/1-phase, 57 lbs. Single compressor, 5–7.5 HP.
- RD59-11K — 59 CFM @ 37°F: 3/4" NPT, 115V/1-phase, 73 lbs. 10–15 HP compressors.
- RD71-15K — 71 CFM @ 37°F: 1" NPT, 115V/1-phase, 110 lbs. 15–20 HP compressors.
- RD113-60K — 107 CFM @ 37°F: 1" NPT, 115V/1-phase, 119 lbs. 20–25 HP compressors.
- RD161-37K — 161 CFM @ 37°F: 1-1/2" NPT, 115V/1-phase, 137 lbs. High-demand single-compressor shops.
- RD247-55K — 247 CFM @ 37°F: This unit. Large commercial and industrial operations. Call for specs and pricing.
When Does a Shop Need This vs. a Smaller Unit
The RD247-55K is appropriate for:
- Shops running compressors that produce 162–247 CFM peak demand
- Large fleet maintenance facilities with multiple simultaneous tool operations
- Auto body operations running two or more full-size spray booths from a common air system
- Manufacturing and production lines where compressed air feeds multiple pneumatic stations continuously
- Situations where a smaller dryer would be undersized at peak demand and moisture would break through at the dew point
Capacity note: Like all Castair refrigerated dryers, rated capacity is based on 100°F inlet air temperature, 100°F ambient temperature, and 100 PSI operating pressure. At 150°F inlet air temperature, effective capacity drops to 55% of rated. At 247 CFM rated capacity, that means approximately 136 CFM effective capacity at 150°F inlet. An aftercooler before the dryer inlet is strongly recommended in high-temperature installations to maintain full rated capacity and extend dryer service life.
Technical Specifications
- Model: RD247-55K
- CFM @ 37°F dew point: 247
- Pressure Dew Point: 37°F
- Maximum Inlet Pressure: 232 PSIG
- Refrigerant: R134a / R407c
- Heat Exchanger: Stainless steel, dual-function single body
- Drain Type: Automatic, demand-based
- Certifications: UL Listed
- Electrical, connection size, weight, and dimensions: Contact us for full specifications — 866-217-0063
Why Buy From Air Compressor Factory Direct?
We have been selling and supporting Castair compressed air equipment since 2016. For a large-capacity unit like the RD247-55K, a phone call before ordering saves time — we can confirm current specs, electrical requirements, filter sizing, and lead time, and help you determine whether this dryer fits your compressor output and air demand. Free shipping on qualifying orders, free pre-sale technical support, and full Castair manufacturer warranty.
Call 866-217-0063 for quick answers and help!
