AC Infinity CLOUDLINE S4 4-Inch Quiet Inline Duct Fan with Speed Controller (226 CFM, PWM EC Motor, UIS Smart Ecosystem Ready)

Whisper-Quiet, High-Static-Pressure Ventilation for Indoor Cultivation

Achieve commercial-grade airflow control, thermal regulation, and continuous fresh air exchange in your indoor garden with the AC Infinity CLOUDLINE S4 4-Inch Quiet Inline Duct Fan with Speed Controller (Model AI-CLS4). Engineered by industry leader AC Infinity specifically for hydroponic grow tents, propagation rooms, drying spaces, and enclosed AV racks, this 4-inch inline blower pushes up to 226 CFM of air while operating at an ultra-quiet 26 dBA. Whether exhausting heat from high-output LED grow lights or pulling fresh CO2-enriched air across your canopy, the CLOUDLINE S4 maintains steady, reliable airflow without disruptive mechanical noise.

PWM-Controlled EC Motor & Mixed-Flow Aerodynamics

Unlike conventional AC duct fans that rely on voltage suppression—creating loud electrical hum, excess motor heat, and wasted electricity—the CLOUDLINE S4 features an advanced Electronically Commutated (EC) motor driven by Pulse Width Modulation (PWM). Drawing just 28W maximum power (with an average draw of approximately 21W) at 2,800 RPM, this motor spins smoothly even at ultra-low speeds. Paired with a mixed-flow impeller, stator blade, and dual hydrodynamic wind circles, the S4 generates 223 Pa of static pressure, effortlessly pushing air through restrictive carbon filters, long duct runs, and intake silencers.

Wired 10-Speed Controller & UIS™ Smart Ecosystem Integration

Out of the box, the CLOUDLINE S4 includes a compact wired 10-speed controller featuring single-button speed selection, an integrated power switch, and built-in backup memory that automatically restores your last speed setting following a power interruption. Designed as a core component of the AC Infinity UIS™ (Universal Infinite System) platform, this fan connects via its 10-foot UIS cord to advanced AC Infinity smart controllers—including the flagship CLOUDCOM™ AI touchscreen system—unlocking dynamic VPD triggers, temperature and humidity automation, custom schedules, and multi-device synchronization.

IP44 Protection, Dual Ball Bearings & Detachable Motor Box

Built to thrive in demanding, high-humidity cultivation environments, the CLOUDLINE S4 carries an IP44 ingress protection rating against dust, debris, and liquid splashes. Its motor houses precision dual ball bearings rated for 67,000 hours of continuous service, allowing horizontal or vertical mounting in any orientation. For effortless upkeep between harvest cycles, the central motor box detaches quickly from the mounted frame via dual latches, letting you clean the impeller and blades without disconnecting your ducting.

Versatile Applications Beyond the Grow Tent

While optimized for 2×2, 2×4, and 3×3 indoor grow tents, the CLOUDLINE S4 excels at boosting HVAC heating and cooling transfer between rooms, exhausting excess humidity from attics and basements, and quietly cooling home theater cabinets, server closets, and electronics enclosures.

Technical Specifications

• Brand / Model: AC Infinity CLOUDLINE S4 (SKU: AI-CLS4 / UPC: 819137020290)
• Duct & Flange Size: 4 Inches (100 mm)
• Maximum Airflow Capacity: 226 CFM (205 CFM standard rating)
• Acoustic Noise Rating: 26 dBA (28 dBA max load)
• Static Pressure & Max Speed: 223 Pa; 2,800 RPM
• Motor Architecture: PWM-Controlled Brushless EC Motor
• Power Draw & Voltage: 28W Max (21W Avg.); 100–240V AC, 50/60 Hz
• Fan Unit Dimensions: 7.40″ × 11.93″ × 6.93″ (18.8 × 30.3 × 17.6 cm)
• Controller & Cord Length: Wired 10-Speed Controller (3.34″ × 2.95″ × 0.51″) with 10-ft UIS Cord
• Bearings & Mounting: Dual Ball Bearings (67,000-Hour L10 Lifespan); Horizontal or Vertical Mounting
• Environmental Rating: IP44 Dust & Splash Resistant; Operating Temp 32°F to 140°F
• Certifications: ETL, CE, RoHS, SAA Certified

What’s Included in the Box

• 1 × AC Infinity CLOUDLINE S4 4-Inch Inline Duct Fan Unit
• 1 × Wired 10-Speed Fan Controller with UIS Cord
• 1 × Corded AC Power Adapter (US NEMA 1-15 Type-A Plug)
• Complete Wall/Ceiling Mounting Hardware & Installation Manual