CLOUDLINE PRO S6 Quiet 6 Inline Duct Fan with Speed Controller

Our review of the CLOUDLINE PRO S6 finds it best suited for home growers, small grow tents, and AV racks where quiet, reliable ventilation matters most. The single biggest reason to buy is its combination of a PWM-controlled EC motor and a wired 10-speed controller, which together deliver high airflow with very low noise and energy use. In practice this fan moves up to 402 CFM while running around 32 dBA, so it stays unobtrusive in living spaces yet powerful enough to handle moderately restrictive duct runs.

Key Features

• PWM-controlled EC motor: Provides quiet, energy-efficient performance with minimal heat buildup, helping reduce electricity usage during continuous operation.
• Wired 10-speed fan controller: Lets you dial in ventilation precisely and is compatible with UIS controllers for more advanced programming if needed.
• Mixed flow design: Stator blades and hydrodynamic wind circles improve airflow delivery through high-resistance ducting and filters.
• High airflow at modest noise: Rated for 402 CFM at about 32 dBA, balancing strong air movement with low acoustic impact in occupied spaces.
• Dual ball bearings: Built for longevity and continuous-use applications such as grow tents, hydroponics, or AV cooling racks.

Who It's For

The CLOUDLINE PRO S6 is ideal for hobby and small commercial growers running 6 in ducting, users who need an inline fan that stays quiet in living spaces, and anyone wanting a controllable, energy-efficient ventilation solution for tents, rooms, or AV cabinets. Its programmable controller and compatibility with UIS systems make it suitable for setups that benefit from scheduled or sensor-driven operation.

Those who should look elsewhere include users who require larger duct sizes, fans rated for much higher than 402 CFM, or ultra-budget shoppers who cannot justify a performance-oriented EC motor and controller. For basic intermittent ventilation in open, low-resistance areas a simpler axial fan may be more economical.

Pros & Cons

Pros

• Very quiet operation that customers consistently praise for low noise in living areas.
• Strong build quality and dual ball bearings for reliable, long-term performance.
• Controllable speeds with the included 10-speed wired controller and UIS compatibility for advanced automation.
• Delivers substantial airflow through restrictive ducting thanks to the mixed flow design.

Cons

• At 402 CFM it is powerful for 6 in ducting but not suitable where much higher CFM is required.
• The wired controller adds capability but also requires space and wiring considerations that some users may find less convenient than plug-and-play fans.

Specifications

Brand	AC Infinity
Model	CLOUDLINE PRO S6
Duct size	6 in
Airflow	402 CFM
Noise	32 dBA
Dimensions	7.9 x 12.6 x 8.4 in
Bearings	Dual Ball

Our Verdict

The CLOUDLINE PRO S6 is a well-engineered inline duct fan that pairs quiet, efficient EC motor performance with a flexible 10-speed controller, making it a smart choice for growers and AV users who need reliable, low-noise ventilation. It represents good value for anyone who needs controllable, continuous airflow in 6 in ducting and prefers lower energy and acoustic impact over the cheapest option.

Frequently Asked Questions

Is this fan quiet enough for a home grow tent?
Yes, the fan is rated around 32 dBA and customers consistently report it runs very quietly in occupied spaces.

Can I use the wired controller for automated schedules?
The included wired 10-speed controller allows manual speed control and the fan is compatible with UIS controllers for intelligent programming and automation.

Will it move air effectively through filters and long duct runs?
Yes, the mixed flow design with stator blades and hydrodynamic wind circles is intended to maintain airflow in higher resistance conditions like filters and longer ducting.