The usual pick for a 4x4 or 5x5 grow tent with a carbon filter: plenty of airflow, high static pressure and quiet running.
Amazon $99The AC Infinity CLOUDLINE S6 is the better inline duct fan overall, rated 3.4 to 3.1. The AC Infinity CLOUDLINE S6 leads on airflow. The Hon&Guan PRO 6 in Inline Fan wins on value. The Hon&Guan PRO 6 in Inline Fan costs $22.01 less ($76.99 vs $99).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
A low-cost 6 in EC fan with strong rated airflow. Its power draw is not published, which keeps it below documented rivals.
Amazon $76.99Which should you buy?
- Choose the AC Infinity CLOUDLINE S6 for airflow (425 CFM through 6 in duct vs 405 CFM through 6 in duct).
- Choose the Hon&Guan PRO 6 in Inline Fan for value ($19.01 per 100 CFM ($76.99, 405 CFM) vs $23.29 per 100 CFM ($99, 425 CFM)).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 6 in inline duct fan; a clear win is highlighted. How we rank explains each one.
| Factor weight | AC Infinity CLOUDLINE S6 | Hon&Guan PRO 6 in Inline Fan |
|---|---|---|
| Overall rating | 3.4/5 | 3.1/5 |
| Value 25% | 55 $23.29 per 100 CFM ($99, 425 CFM) | 76 $19.01 per 100 CFM ($76.99, 405 CFM) |
| Efficiency 25% | 34 6.1 CFM per watt (425 CFM, 70 W) | 0 power draw not published, scored as the lowest |
| Airflow 15% | 88 425 CFM through 6 in duct | 78 405 CFM through 6 in duct |
| Noise 15% | 86 30 dBA at full speed | 80 32 dBA at full speed |
| Controls 10% | 40 speed controller included | 40 speed controller included |
| Warranty 10% | 25 2-year warranty | 0 warranty not published, scored as none |
Specifications
| AC Infinity CLOUDLINE S6 | Hon&Guan PRO 6 in Inline Fan | |
|---|---|---|
| Performance | ||
| Duct size | 6 in | 6 in |
| Rated airflow | 425 CFM | 405 CFM |
| Static pressure (not scored) | 503 Pa | - |
| Power at full speed | 70 W | - |
| Power figure | Max power draw | - |
| Average power (not scored) | 38 W | - |
| Airflow per watt | 6.1 CFM/W | - |
| Price per 100 CFM | $23.29 | $19.01 |
| Noise at full speed | 30 dBA | 32 dBA |
| Controls | ||
| Motor | EC | EC |
| Controller | 10-speed controller | Stepless speed controller |
| Speeds | 10 | Stepless |
| Temperature and humidity control | No | No |
| Phone app | No | No |
| Timer or cycle modes | No | No |
| Build | ||
| Housing | Plastic | Metal |
| Ingress rating | IP44 | IP42 |
| Voltage | 100-240 V | - |
| Warranty | 2 years | - |
