The Cast Air BGAC1 Belt Guard Aftercooler is a 35 CFM air-cooled heat exchanger that mounts directly to the compressor belt guard and cools compressed air before it enters your tank and distribution system. If you are running a 5 HP, 7 HP, or 10 HP reciprocating piston compressor and dealing with moisture in your lines, water in your tools, or corrosion in your downstream equipment, this is the component that solves the problem at the source. Air exiting a compressor pump head runs hot — often above 200°F — and that heat carries water vapor. When that vapor cools in your tank and lines, it condenses into liquid water that travels downstream. An aftercooler intercepts that heat immediately after the pump, cools the air to within 15°F of ambient temperature, and drops most of the moisture out before it ever enters the tank. The BGAC1 is sized and configured to do that job for the 5-10 HP compressor range without adding a separate cooling fan, an external mounting structure, or a major plumbing overhaul.
How the Belt Guard Mount Works
- Flywheel Fan Cooling: The BGAC1 mounts to the compressor belt guard and uses the existing flywheel fan airflow to cool the heat exchanger core — no separate fan motor, no electrical connection, no parasitic load on the system
- Clean Installation: Because the aftercooler integrates into the belt guard assembly, you avoid the separate mounting brackets and exposed plumbing runs that come with standalone aftercooler installations
- Passive Operation: Once installed, the BGAC1 operates automatically any time the compressor runs — there is nothing to switch on or maintain beyond periodic inspection
- Compatible Mounting Footprint: The 18" L x 10-1/2" W core dimensions fit within the belt guard mounting envelope of compatible Cast Air compressor models — verify fitment with your specific compressor model number before ordering
Moisture Reduction Performance
- Cools to Within 15°F of Ambient: Based on 250°F inlet air temperature, the BGAC1 brings discharge air temperature to within 15°F of the ambient air temperature at the installation site
- Reduces Water Content by Up to 65%: At rated conditions, the BGAC1 removes up to 65% of the water vapor from the compressed air stream before it reaches the tank
- 20°F = 50% Moisture Reduction: Every 20°F drop in air temperature reduces the water content of the air by approximately 50% — the more the aftercooler cools the air, the more moisture drops out
- Protects Downstream Equipment: Less moisture reaching your filters, dryers, regulators, and tools means longer service intervals, fewer regulator failures, and less internal corrosion in your lines and tanks
Technical Specifications
- SKU: BGAC1
- Type: Air-cooled aftercooler, belt guard mounted
- CFM Rating: 35 CFM
- Core Dimensions: 18" L x 10-1/2" W
- Inlet Connection: 3/4" NPT
- Outlet Connection: 3/4" NPT
- Weight: 8 lbs
- Maximum Operating Pressure: 250 PSIG
- Maximum Operating Temperature: 350°F
- Performance Basis: 250°F inlet air temperature
- Temperature Drop: Cools to within 15°F of ambient
- Moisture Reduction: Up to 65% at rated conditions
- Cooling Method: Air-cooled via compressor flywheel fan
- Compatible Compressor Size: 5 HP, 7 HP, 10 HP
- Price: $307.23
Available Configurations — BGAC Aftercooler Lineup
Cast Air makes belt guard aftercoolers across four size ranges. Choose based on your compressor output and HP rating:
- BGAC1 / BGAC1M — 35 CFM: 18" L x 10-1/2" W, 3/4" NPT connections, 8 lbs — fits 5 HP, 7 HP, and 10 HP compressors. BGAC1 is the standalone unit; BGAC1M is the mounted variant. $307.23 for the loose unit.
- BGAC2 / BGAC2M — 50 CFM: 18" L x 14-1/2" W, 1" NPT connections, 12 lbs — fits 15 HP compressors. Step up here if your compressor output exceeds 35 CFM at your operating pressure.
- BGAC3 / BGAC3M — 75 CFM: 24" L x 20-1/2" W, 1" NPT connections, 20 lbs — fits 20+ HP compressors. For shops running larger two-stage machines or high-demand applications.
- BGAC4 / BGAC4M — 100 CFM: 23" L x 26-1/2" W, 1" NPT connections, 25 lbs — for larger industrial systems where a 75 CFM unit is undersized.
If you are not sure which size fits your compressor, call 866-217-0063 with your compressor model number and HP rating and we will confirm the correct unit.
When Does a Shop Need the BGAC1 vs. Stepping Up or Down
- BGAC1 is the right call when: You are running a 5 HP, 7 HP, or 10 HP reciprocating piston compressor with moisture problems in your lines — water at the drains, rust in fittings, air tool failures related to moisture, paint defects from water contamination. The BGAC1 handles up to 35 CFM, which covers the output range of this compressor class at typical duty cycles.
- Step up to BGAC2 when: Your compressor output exceeds 35 CFM, or you are running a 15 HP machine. Undersizing an aftercooler reduces its effectiveness — the air moves through too fast to cool properly. Match the aftercooler CFM rating to your compressor output, not just the HP.
- The BGAC1K kit is better when: You are installing an aftercooler on a compressor that does not currently have one and you need the mounting hardware included. The BGAC1K bundles the aftercooler with the installation hardware in one order.
- The BGAC1x2M is what you need when: You are running a duplex (twin-compressor) setup and need to cool the combined output. The x2M configuration handles dual-compressor discharge in a single mounted unit.
Typical Applications
- Auto body shops and paint booths where moisture causes fish-eye defects and coating failures
- General auto repair shops with air-powered tools that are failing prematurely due to moisture in the air supply
- Fabrication and welding shops with plasma cutting equipment sensitive to water in the air line
- Any shop in a humid climate where tank draining alone is not keeping up with moisture in the system
- Facilities adding an inline desiccant dryer — an aftercooler upstream dramatically extends desiccant service life by removing the bulk of the moisture before it reaches the dryer
Why Buy From Air Compressor Factory Direct?
Air Compressor Factory Direct has been supplying compressor components and accessories to shops and industrial buyers since 2016. We stock the Cast Air BGAC1, BGAC1M, BGAC1K, BGAC1x2M, and the full BGAC lineup so you can get the right unit for your system without waiting on special orders. Free shipping on qualifying orders. If you need to confirm that the BGAC1 is compatible with your specific Cast Air compressor model, call us with the model number and we will verify fitment before you order. Full Cast Air manufacturer warranty. Our technical team is available directly at 866-217-0063 — not a call center, not a ticketing system.
Call 866-217-0063 for quick answers and help!
