The Castair FSAC75 is a free-standing air-cooled aftercooler rated for 75 CFM. It installs in the compressed air discharge line and cools hot compressed air — which can reach 350 degrees F at the pump outlet — back down to within 15 degrees of ambient temperature. That temperature drop forces suspended moisture to condense and drain at the aftercooler, reducing water in your air system by up to 65%. At 70 pounds and 27" x 15" x 36", the FSAC75 is a substantial unit built for high-flow commercial and industrial shop installations.
The Moisture Problem an Aftercooler Solves
Compression heats air significantly. At those temperatures, water is suspended as vapor and stays in the air stream. As the air cools in distribution piping, it drops below the dew point and condensation forms — inside your piping, inside your tools, and inside your spray equipment. An aftercooler captures that condensation at one point, at the compressor outlet, where it can be drained and controlled.
Castair's aftercooler data: a 20-degree temperature reduction removes 50% of suspended moisture. The FSAC75 cools to within 15 degrees of ambient, producing up to 65% moisture reduction over uncooled discharge air. This is the correct fix for shops experiencing rust in air lines, water in spray guns, corrosion in pneumatic tools, or condensate problems in refrigerated dryers.
Key Specifications
- Part Number: FSAC75
- Style: Free standing
- Rated Capacity: 75 CFM
- Inlet/Outlet Connection: 1" NPT
- Dimensions (L x W x H): 27" x 15" x 36"
- Weight: 70 lbs
- Maximum Operating Pressure: 250 PSIG
- Maximum Operating Temperature: 350 degrees F inlet
- Performance Basis: 250-degree F inlet air temperature
- Electrical: 115V, 1-phase, 60 Hz
- Mounting: Floor or suspended; horizontal or vertical airflow
Free Standing vs. Belt Guard Style at 75 CFM
Castair offers belt-guard-mounted aftercoolers up through the BGAC3 (75 CFM, 1" connections, 24" x 20.5", 20 lbs), which mounts directly on the compressor. The FSAC75 is the free-standing equivalent — it can be mounted independently in the air line, on the floor, or suspended from the ceiling, wherever the plumbing makes sense for your shop layout.
Free Standing Aftercooler Lineup
- FSAC35 — 35 CFM, 3/4" NPT, 21x12x27", 30 lbs
- FSAC50 — 50 CFM, 1" NPT, 21x12x31", 40 lbs
- FSAC75 — 75 CFM, 1" NPT, 27x15x36", 70 lbs (this model)
- FSAC100 — 100 CFM, 1-1/4" NPT, 26x16x42", 80 lbs
- AC120 — 120 CFM, 1-1/2" NPT, 43.5x14.75x46.5", 140 lbs
- AC150 — 150 CFM, 1-1/2" NPT, 43.5x14.75x46.5", 145 lbs
- AC240 — 240 CFM, 2" NPT, 200 lbs
- AC300 — 300 CFM, 2" NPT, 300 lbs
Sizing and Buying Guidance
- FSAC75 is correct for compressors delivering 50-75 CFM — common for 7.5-10 HP commercial rotary screw or large piston compressors
- Step down to FSAC50 only if your compressor delivers 35-50 CFM; the FSAC50 is meaningfully lighter at 40 lbs vs. 70 lbs
- Step up to FSAC100 if your compressor exceeds 75 CFM output — never undersize an aftercooler
- Both FSAC50 and FSAC75 use 1" NPT connections — if you are between 50 and 75 CFM, use the FSAC75
Optional Accessories
- Filter with auto drain — Available on all free-standing models; eliminates manual condensate draining
- Temperature control valve #86816 — Optional; prevents overcooling in cold-climate installations
Why Buy From OEM Diagnostic Tools?
OEM Diagnostic Tools has supplied professional shop equipment and components since 2016. We stock Castair aftercoolers and air treatment equipment so shops can address moisture problems at the source. Free shipping on qualifying orders, free tech support at 866-217-0063, and full manufacturer warranty. Call us if you need help sizing the correct aftercooler for your compressor's actual CFM output.
Call 866-217-0063 for quick answers and help!
