AC Infinity CLOUDLINE S6
#2 in 6 inFull review
The usual pick for a 4x4 or 5x5 grow tent with a carbon filter: plenty of airflow, high static pressure and quiet running.
Amazon $99$99
The AC Infinity CLOUDLINE S6 is the better inline duct fan overall, rated 3.4 to 3.2. The AC Infinity CLOUDLINE S6 leads on airflow and noise. The VIVOSUN R6 6 in Inline Fan wins on value. The VIVOSUN R6 6 in Inline Fan costs $35.01 less ($63.99 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.
VIVOSUN R6 6 in Inline Fan
#3 in 6 inFull review
A low-cost 6 in fan for bathroom, basement or tent exhaust when running cost and filter performance matter less than price.
Amazon $63.99$63.99
Which should you buy?
- Choose the AC Infinity CLOUDLINE S6 for airflow (425 CFM through 6 in duct vs 390 CFM through 6 in duct) and noise (30 dBA at full speed vs 34 dBA at full speed).
- Choose the VIVOSUN R6 6 in Inline Fan for value ($16.41 per 100 CFM ($63.99, 390 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 | VIVOSUN R6 6 in Inline Fan |
|---|---|---|
| Overall rating | 3.4/5 | 3.2/5 |
| Value 25% | 55 $23.29 per 100 CFM ($99, 425 CFM) | 91 $16.41 per 100 CFM ($63.99, 390 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 | 70 390 CFM through 6 in duct |
| Noise 15% | 86 30 dBA at full speed | 74 34 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 | VIVOSUN R6 6 in Inline Fan | |
|---|---|---|
| Performance | ||
| Duct size | 6 in | 6 in |
| Rated airflow | 425 CFM | 390 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 | $16.41 |
| Noise at full speed | 30 dBA | 34 dBA |
| Top speed | - | 2,450 RPM |
| Controls | ||
| Motor | 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 | Plastic |
| Ingress rating | IP44 | - |
| Voltage | 100-240 V | - |
| Warranty | 2 years | - |