Castair I518HC1-S: 5HP Single-Phase Industrial Air Compressor — 80 Gallon Horizontal with Aftercooler and Mounted Starter
The Castair I518HC1-S is a 5-horsepower, single-phase, 80-gallon horizontal industrial air compressor priced at ,356. The model number tells the story: I5 (5HP Industrial), 18 (80-gallon), HC (Horizontal, C1 pump), 1 (single-phase), -S (with aftercooler and mounted starter). This is the fully equipped version of the C1-based 5HP horizontal — you get the BGAC1M belt guard mounted aftercooler, the factory-mounted magnetic motor starter, and the ASME horizontal tank all in one package.
The aftercooler distinguishes this from the I513HC1-S (same pump and starter, no aftercooler). If you are running spray guns, sandblasting, paint booths, or any air-operated process where moisture in the compressed air line causes problems — fisheyes in paint, rust staining on surfaces, water damage to air tools — the aftercooler is the correct specification. It cools the compressed discharge air before it enters the tank, condensing moisture at the warmest point in the system where it can be drained rather than carried downstream.
The C1 pump runs at 767 RPM and delivers 22.0 CFM free air, 17.5 CFM at 175 PSI. Dimensions are 64 x 20 x 48 inches, weight 600 lbs — same as the no-aftercooler C1 models since the aftercooler mounts to the belt guard without changing the tank footprint.
Pump, Tank, and Control Specifications
C1 Pump
- Pump designation: C1 — Two-stage, Inline 2 cylinder
- Rated HP range: 4-7.5HP
- Pump RPM: 767
- Oil capacity: 2 quarts
- Construction: 100% cast iron — cylinders, heads, valve plates, crankcase
- Bearings: Tapered roller bearings at both crankshaft ends
- Connecting rods: Precision steel with automotive-type rod insert bearings
- Valves: Disc and spring — field-replaceable
- Pistons: 4-ring configuration
- Unloader: Centrifugal — loadless start-up
Aftercooler
- Part number: BGAC1M — belt guard mounted, 35 CFM rated (for 5, 7, 10HP models)
- Function: Cools compressed discharge air before it enters the tank, condensing and removing moisture
- Benefit: Drier air delivered to your tools, spray equipment, and downstream processes — reduced water contamination, reduced corrosion in air lines, better paint finish quality
- Mounting: Integrated onto the belt guard — no separate plumbing or mounting required
Motor and Starter
- Horsepower: 5HP
- Phase: Single-phase
- Motor speed: 1725 RPM industrial
- Service factor: 15% minimum
- Motor starter: Factory-mounted magnetic motor starter
- Max working pressure: 175 PSI
Tank
- Tank capacity: 80 gallons, horizontal
- Tank construction: Powder-coated ASME-rated steel, channel saddle frame
- Safety valve: ASME-rated, factory installed
Performance Specifications
- Motor output: 5 HP
- Electrical: Single-phase with factory-mounted starter
- Tank capacity: 80 gallons, horizontal
- Pump: C1 (Two-stage, Inline 2), 767 RPM
- Free air delivery (0 PSI): 22.0 CFM
- Delivery at 175 PSI: 17.5 CFM
- Max pressure: 175 PSI
- Dimensions (LxWxH): 64 x 20 x 48 inches
- Weight: 600 lbs
- Price: ,356
What's in the Box
- Castair I518HC1-S compressor — fully assembled
- BGAC1M belt guard mounted aftercooler (35 CFM)
- Factory-mounted magnetic motor starter
- ASME safety valve (factory installed)
- Pressure switch with unloader
- Totally enclosed metal belt guard
- Copper discharge and unloader tubing
- Owner's documentation
5HP Horizontal Lineup — Configuration Comparison
- I513HC1: C1 pump, 767 RPM, no starter, no aftercooler — base unit
- I513HC1-S: C1 pump, 767 RPM, mounted starter, no aftercooler
- I518HC1-S (this unit): C1 pump, 767 RPM, mounted starter + aftercooler — ,356
- I518HC2-S: C2 pump, 420 RPM, mounted starter + aftercooler — ,930 — quieter, heavier
When Does a Shop Need This vs. the No-Aftercooler Version?
If your work involves spray painting, powder coating, sandblasting, air-operated pneumatic tools that are sensitive to water, or any process where moisture contamination causes product defects or equipment damage — buy the aftercooler version. The BGAC1M pays for itself when you avoid a single repaint or a water-damaged air tool.
If your shop is running purely mechanical tools (impacts, ratchets, air chisels) in a dry environment, the no-aftercooler I513HC1-S at lower price is adequate. The aftercooler adds value where moisture control matters.
Why Buy From Air Compressor Factory Direct?
Since 2016, we have sold industrial air compressors to body shops, detail shops, spray booths, and general service operations. We understand which configuration fits which application — call us before you order and we will confirm this is the right unit for your specific setup.
- Free shipping to commercial addresses in the lower 48 states
- Free tech support at 866-217-0063
- Full Castair manufacturer warranty
- Honest buying guidance
- Authorized dealer with direct Castair factory support
Call 866-217-0063 for quick answers and help!
