The AC Infinity CLOUDLINE PRO S6 is a 150 mm (6″) inline duct fan built to move serious air quietly — 722 m³/h · 201 L/s (425 CFM) through filters, bends and long duct runs without the drone of a traditional AC-motor fan. It is the same fan body, impeller and EC motor as the T6; what you get here instead of the smart controller is a corded 10-speed dial, which is why it costs less. It's the size most people land on for a 1.2 × 1.2 m (4×4) tent, and it does the same job in a subfloor, attic, garage or AV cupboard.
Set-and-forget speed control
The included controller is a corded dial with ten speed levels and backup memory — cut the power and it returns to the setting you left it on. No menus, no app, no probe to position. In a stable space, or anywhere the fan's job is simply constant extraction through a carbon filter, that is all the control the job needs.
The dial sits on a 3.05 m lead so it can live outside the space the fan is in, and mounts with the supplied hardware. Speed is handled by the EC motor through PWM rather than by choking voltage, so the low settings stay smooth and quiet instead of humming — the reason a level 3 on this fan sounds like nothing and a level 3 on a cheap AC fan sounds like a transformer.
Quiet, energy-efficient performance
Most cheap duct fans use an AC motor — loud, one-note, and only crudely controllable. The S6 uses a PWM-controlled EC motor, which is why it can idle at genuinely low noise and why it draws so little power: 38 W average, 70 W maximum. That draw also falls away steeply as you dial the speed back, because fan power scales with roughly the cube of speed. An AC-motor fan pulls close to its full rated wattage the moment it's switched on, whatever speed you've set it to.
The mixed-flow design and 503 Pa static-pressure rating are what let it hold airflow once you add a carbon filter, a silencer and a few bends — the point where straight axial fans fall over. AC Infinity rate the dual ball bearings at 67,000 hours, the fan mounts horizontally or vertically, and the motor box detaches from the frame so you can pull it out and clean the impeller without dismantling your ducting.
What people use it for
Home ventilation
- Subfloor and underfloor moisture extraction
- Attics and roof spaces
- Garages, sheds and workshops
- Compliant ducted bathroom exhaust systems
- Room-to-room air transfer and AV equipment cooling
Hydroponic ventilation
- Grow tents up to 1.2 × 1.2 m (4×4)
- Indoor grow rooms
- Heat, humidity and odour extraction
- Fresh-air intake and circulation
- Constant-speed extraction through a carbon filter
Full specifications
| Manufacturer | AC Infinity Inc. |
| Product / model | CLOUDLINE PRO S6 / AI-CLS6 |
| UPC | 819137020306 |
| Duct diameter | 150 mm (6″) |
| Fan dimensions | 200 × 320 × 212 mm |
| Mounting-hole spacing | 80 × 60 mm |
| Screw-hole diameter | 6 mm |
| Cord to controller | 3.05 m |
| Power cord | 2.44 m |
| Controller | Corded 10-speed dial with backup memory |
| Maximum airflow | 722 m³/h · 201 L/s (425 CFM) |
| Maximum noise | 30 dBA |
| Static pressure | 503 Pa |
| Voltage / frequency | 100–240 V AC / 50–60 Hz |
| Maximum / average power | 70 W / 38 W |
| Current | 0.94 A |
| Power connection | Australian three-pin plug |
| Operating range | 0–60°C / 35–85% RH |
| Ingress protection | IP44 |
| Mounting | Horizontal or vertical |
| Bearings | Dual ball |
| Rated bearing life | 67,000 hours (manufacturer rating) |
| In the box | Fan unit, corded 10-speed speed controller, two duct clamps, mounting hardware, manual |
| Certifications | SAA · CE · ETL · RoHS · IC |
| Product manual | CLOUDLINE S & T series manual (PDF) |
FAQ
What's the difference between the CLOUDLINE S6 and the T6?
The fan itself is identical — same motor, same impeller, same 425 CFM. The difference is control. The S6 comes with a corded 10-speed dial. The T6 comes with the Controller 69 Pro, which adds temperature, humidity and VPD triggers, dynamic speed, timers, schedules and WiFi app control. If you just want a fan you set once and forget, the S6 saves you money. If you want the fan to respond to conditions on its own, you want the T6.
What size grow tent will an S6 handle?
For growing, the S6 suits tents up to 1.2 × 1.2 m (4×4). That is a grow-tent rating, not a room limit: it allows for a carbon filter, the heat from the lights and roughly one full air change every minute, which is far more work than ventilating a room in a house. In a 4×4 with a carbon filter fitted, most people sit around speed 5–6 and never need to go higher. If your tent is bigger than that, step up to an S8 rather than running an S6 flat out — a larger fan running slower is quieter, cooler and lasts longer than a smaller one at maximum. For a bathroom or other room in the home, see the questions below.
Is it actually quiet? Some reviews mention noise at high speeds.
Fair question, and worth answering straight. At the speeds most people run — up to about level 6 — it's quiet enough that you generally won't hear it outside the room. Above level 6 it does get audible, because it's moving more air than most competing 6″ fans do at the same setting. If you're regularly needing levels 8–10, that's the signal your space wants a larger fan, not that this one is underperforming. Adding a silencer and lined ducting makes a noticeable difference either way.
Can I add a smart controller later, or do I have to buy the T6?
You can add one later. The fan is UIS compatible, so a Controller 69 Pro or Controller AI+ plugs straight into it in place of the 10-speed dial. Buying the T6 up front is cheaper than buying the S6 and a controller separately, so make the call now if you already know you want automation — but you are not locked out of it.
Will it still pull properly with a carbon filter and ducting attached?
Yes — that's what the mixed-flow design and 503 Pa static-pressure rating are for. Every filter, bend and metre of flexible duct costs you airflow, and a straight axial fan loses far more of its rated CFM under that load than a mixed-flow fan does. Keep duct runs as short and straight as you reasonably can and you'll retain most of the rated output.
Can I use it for subfloor, attic or bathroom ventilation rather than growing, and which size suits a bathroom?
Yes, and a good portion of the S6s we ship go to exactly those jobs. It's IP44-rated and mounts horizontally or vertically. Worth noting for subfloor work: if you want the fan to run only when humidity is high rather than on a timer or constantly, that's the T6's job, not this one. For bathroom exhaust, read the installation requirements above — it must be part of a properly designed ducted system.
Most people use the 150 mm for a bathroom, or the 100 mm for smaller rooms such as ensuites and toilets. The larger the fan, the quieter it is for the same airflow, because it can run slower. What suits your job also depends on the space in the ceiling, the duct route and how much noise you can live with, so if you are unsure, send us the details and we will help.
How does the airflow compare with a ceiling or bathroom exhaust fan?
Installers rate exhaust fans in m³/h or L/s. The S6 moves up to 722 m³/h (201 L/s) at full speed. For comparison, the National Construction Code minimum for a bathroom or toilet is 25 L/s (90 m³/h), and 40 L/s (144 m³/h) for a kitchen or laundry, discharged outdoors rather than into the roof space. Real airflow drops with every metre of duct, bend and grille, which is where the 503 Pa static pressure rating matters. Check the requirements for your job with your installer.
Is this a genuine AC Infinity unit with Australian warranty?
Yes. Quick Bloom Lights is the official Australian importer and distributor for AC Infinity. Every unit ships with an Australian three-pin plug, SAA certification, and a two-year warranty handled here in Sydney — no shipping units overseas and no dealing with an offshore seller if something goes wrong.