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Compact 4 inch inline duct fan with sensor and controller, 4.72 by 3.86 inches

BFKK

BFKK 4 Inch Inline Duct Fan with Humidity Temperature Sensor 6-Speed Controller

SKU CH-9S4R-KP1Z4

Compact 4-inch inline duct fan with built-in humidity and temperature sensor for automatic on/off control, six-speed DC motor, and 1450-5000 RPM airflow

  • Six manual speeds plus automatic sensor control for tailored airflow
  • Compact 4.72 × 3.86 inch body fits tight installation spaces
  • Built-in humidity and temperature sensor triggers fan on or off automatically
  • Quiet DC centrifugal motor runs at 1450-5000 RPM with low noise
  • 100 % pure copper motor delivers 30 % better heat dissipation and 50 % lower energy use

Compact 4 Inch Inline Duct Fan

This compact 4 inch inline duct fan measures 4.72 by 3.86 inches and fits limited installation spaces. It serves as an inline fan, duct fan, and air duct fan for grow tents, bathrooms, basements, and fresh air intake systems. The unit is new and designed for reliable airflow in greenhouses and similar environments.

Check Power and Duct Compatibility

Verify that your setup can supply power to a DC motor unit with a 6-speed controller and remote. Ensure the 4 inch ducting matches your existing ventilation layout for proper fit. Confirm there is adequate clearance for the short-body design and sensor placement in the intended location.

Sensor Automation and Motor Efficiency

The built-in humidity and temperature sensor enables automatic on/off operation based on real-time conditions. A 100% pure copper DC motor runs at 1450 to 5000 RPM with less than 20K temperature rise. Compared to aluminum motors, it offers 30 percent better heat dissipation and 50 percent lower energy use for durable, heavy-duty performance.

Highlights

  • Six manual speeds plus automatic sensor control for tailored airflow
  • Compact 4.72 × 3.86 inch body fits tight installation spaces
  • Built-in humidity and temperature sensor triggers fan on or off automatically
  • Quiet DC centrifugal motor runs at 1450-5000 RPM with low noise
  • 100 % pure copper motor delivers 30 % better heat dissipation and 50 % lower energy use

Specifications

No published specifications for this item yet.

Questions about this item

Does the box include mounting hardware or duct tape, or do I need to buy those separately?

The package contains the 4.72 × 3.86 inch inline fan with built-in humidity and temperature sensor, the 6-speed controller and the remote with SPEED+/- buttons; mounting brackets, clamps and duct tape are not included.

I see only one 4-inch model listed — are there different airflow or motor versions to choose from?

The single version uses a 100% pure copper DC motor running 1450-5000 RPM with six selectable speeds, so you adjust airflow by changing gear rather than by picking a different model.

What does the 1450-5000 RPM range mean for actual air movement in a grow tent or bathroom?

At the lowest speed the fan moves a gentle volume of air for quiet background ventilation; at the highest speed it delivers maximum exhaust power for rapid heat and humidity removal, all while the motor stays below a 20 K temperature rise.

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