10 Best In Line Duct Fans 2025 in the United States

The AC Infinity CLOUDLINE PRO T4 is a versatile 4-inch in-line duct fan designed for various applications such as ventilating hydroponic grow rooms, transferring heating/cooling, cooling AV closets, and exhausting odors. A standout feature is its advanced control options, including a WiFi-integrated app, which allows for remote access and programming based on temperature and humidity.

The unit's airflow capacity of 205 CFM is suitable for small to medium spaces, and its noise level of 28 dBA ensures quiet operation. The fan is also energy efficient, thanks to its PWM-controlled EC motor and mixed flow design. The build quality is robust with dual ball bearings enhancing durability.

Users will appreciate the dynamic programming capabilities which include timers, grow cycles, and minimum speed settings, all accessible via a user-friendly app. The 4-inch duct size might limit its use in larger setups. Additionally, it is mainly designed for indoor use and may not be suitable for all environments. The price point may also be higher due to its advanced features. This in-line duct fan is ideal for users looking for an efficient, quiet, and highly controllable ventilation solution, particularly in the hydroponics and indoor gardening sectors.

The AC Infinity CLOUDLINE A6 is a 6-inch inline duct fan designed for various ventilation needs such as grow tents, cooling AV closets, and transferring heating or cooling to different rooms. This fan offers a solid airflow capacity of 352 CFM, making it suitable for medium to large spaces. Its EC motor and mixed flow design contribute to its quiet operation, with a noise level of just 34 dB, which is quieter than a typical conversation. This makes it ideal for use in noise-sensitive environments like living rooms or bedrooms.

Energy efficiency is another strong point, with the fan operating at a modest 35 watts, benefiting both the environment and your electricity bill. The build quality is robust, featuring dual ball bearings which ensure longevity and stable performance over time. The inclusion of a wired 10-speed fan controller allows for precise control over the airflow, and the fan is also compatible with smart controllers from the CLOUDLINE Series, providing flexibility in how you manage it.

The fan is corded electric, which might limit placement options depending on where your power sources are located. Additionally, while the fan performs well in typical use cases, it might be overkill for smaller spaces or minor ventilation tasks. The AC Infinity CLOUDLINE A6 is a reliable, quiet, and energy-efficient choice for anyone in need of a powerful inline duct fan, particularly in medium to large spaces, with the added benefit of smart control options.